Why We Get Cancer: Let's Fight Cancer With Hope.
Dr Sarah Scott
All rights reserved. No part of this publication may be published, distributed, or transmitted in any form or by any means including photocopying, recording or or other electronic or mechanical methods, without prior written permission of the punisher, except in the case of brief questions embodied in critical reviews and certain other non commercial uses permitted by copyright law.
copyright ©Sarah Scott 2022.
Table of contents
Introduction
Chapter 1
Cancer
Chapter 2
Cancer Symptoms
Chapter 3
Causes Of Cancer
Chapter 4
Types of Cancer
Chapter 5
Diagnosis
Chapter 6
Cancer Treatment
Conclusion
“Cancer is only a chapter in our lives and not the full story.”
Introduction
In most people's perceptions, there is no worse diagnosis than that cancer. Cancer is frequently conceived of being an untreatable, terribly painful illness with no cure. However overall this perspective of cancer may be, it is overblown and over-generalized. Cancer is a severe and even life-threatening condition. For example, it is the top cause of death among Americans under the age of 84 and the second highest cause of death in older Americans. There will be 1.4 million new instances of cancer occurring in the United States next year, and over 560,000 deaths due to it not adding basal and squamous skin cancers which are not recorded but might add another two million cases each year (ABS, 2020). (ABS, 2020). However, it is a mistake to suppose that all kinds of cancer are untreatable and lethal. The fact of the problem is that there are various varieties of cancer, many of which can now be treated appropriately to eradicate, lessen or delay the effects of the illness on patients' lives. While a cancer diagnosis may still leave people feeling powerless and out of control, in many situations nowadays there are grounds for optimism rather than despair.
My purpose in this book is to educate you on the fundamentals of cancer, why we develop cancer, and the facts concerning cancer. Possessing this information will, we hope, assist you in better understanding what cancer is, how it arises, and how to make educated decisions regarding cancer treatment alternatives.
Chapter 1
Cancer
Our body is composed of many millions of tiny cells, each a self-contained living unit. Normally, each cell coordinates with the others that compose the tissues and organs of your body. One way that this coordination occurs is reflected in how your cells reproduce themselves. Normal cells in the body grow and divide for some time and then stop growing and dividing. Thereafter, they only reproduce themselves as necessary to replace defective or dying cells. Cancer occurs when this cellular reproduction process goes out of control. In other words, cancer is a disease characterized by uncontrolled, uncoordinated, and undesirable cell division. Unlike normal cells, cancer cells continue to grow and divide for their whole lives, replicating into more and more harmful cells.
The abnormal growth and division observed in cancer cells are caused by damage to these cells' DNA (genetic material inside cells that determines cellular characteristics and functioning). There are a variety of ways that cellular DNA can become damaged and defective. For example, environmental factors (such as exposure to tobacco smoke) can initiate a chain of events that results in cellular DNA defects that lead to cancer. Alternatively, defective DNA can be inherited from your parents.
As cancer cells divide and replicate themselves, they often form into a clump of cancer cells known as a tumor. Tumors cause many of the symptoms of cancer by pressuring, crushing, and destroying surrounding non-cancerous cells and tissues.
Tumors come in two forms; benign and malignant. Benign tumors are not cancerous, thus they do not grow and spread to the extent of cancerous tumors. Benign tumors are usually not life-threatening. Malignant tumors, on the other hand, grow and spread to other areas of the body. The process whereby cancer cells travel from the initial tumor site to other parts of the body is known as metastasis.
The Differences Between Cancer and Normal Cells
Cancer cells differ from normal cells in many ways. For instance, cancer cells:
grow in the absence of signals telling them to grow. Normal cells only grow when they receive such signals.
ignore signals that normally tell cells to stop dividing or to die (a process known as programmed cell death, or apoptosis).
invade into nearby areas and spread to other areas of the body. Normal cells stop growing when they encounter other cells, and most normal cells do not move around the body.
tell blood vessels to grow toward tumors. These blood vessels supply tumors with oxygen and nutrients and remove waste products from tumors.
hide from the immune system. The immune system normally eliminates damaged or abnormal cells.
trick the immune system into helping cancer cells stay alive and grow. For instance, some cancer cells convince immune cells to protect the tumor instead of attacking it.
accumulate multiple changes in their chromosomes, such as duplications and deletions of chromosome parts. Some cancer cells have double the normal number of chromosomes.
rely on different kinds of nutrients than normal cells. In addition, some cancer cells make energy from nutrients in a different way than most normal cells. This lets cancer cells grow more quickly.
Many times, cancer cells rely so heavily on these abnormal behaviors that they can't survive without them. Researchers have taken advantage of this fact, developing therapies that target the abnormal features of cancer cells. For example, some cancer therapies prevent blood vessels from growing toward tumors, essentially starving the tumor of needed nutrients.
How does cancer progress?
Cancer is a hereditary illness that is caused by alterations to genes that govern the way our cells behave, specifically how they grow and divide.
Genetic alterations that cause cancer can develop because of faults that occur while cells proliferate.
Damage to DNA is produced by toxic compounds in the environment, such as the toxins in cigarette smoke and UV radiation from the sun.
The body generally destroys cells with damaged DNA before they develop malignantly. But the body's ability to do so decreases reduced as we age. This is part of the reason why there is a higher risk of cancer later in life.
Each person's cancer has a unique combination of genetic changes. As cancer continues to grow, additional changes will occur. Even within the same tumor, different cells may have different genetic changes.
Types of Genes that Cause Cancer
The genetic changes that contribute to cancer tend to affect three main types of genes—proto-oncogenes, tumor suppressor genes, and DNA repair genes. These changes are sometimes called "drivers" of cancer.
Proto-oncogenes are involved in normal cell growth and division. However, when these genes are altered in certain ways or are more active than normal, they may become cancer-causing genes (or oncogenes), allowing cells to grow and survive when they should not.
Tumor suppressor genes are also involved in controlling cell growth and division. Cells with certain alterations in tumor suppressor genes may divide in an uncontrolled manner.
DNA repair genes are involved in fixing damaged DNA. Cells with mutations in these genes tend to develop additional mutations in other genes and changes in their chromosomes, such as duplications and deletions of chromosome parts. Together, these mutations may cause the cells to become cancerous.
As scientists have learned more about the molecular changes that lead to cancer, they have found that certain mutations commonly occur in many types of cancer. Now there are many cancer treatments available that target gene mutations found in cancer. A few of these treatments can be used by anyone with cancer that has the targeted mutation, no matter where cancer started growing.
When Cancer Spreads
Cancer that has spread from the place where it first formed to another place in the body is called metastatic cancer. The process by which cancer cells spread to other parts of the body is called metastasis.
Metastatic cancer has the same name and the same type of cancer cells as the original, or primary, cancer. For example, breast cancer that forms a metastatic tumor in the lung is metastatic, not lung cancer.
Under a microscope, metastatic cancer cells generally look the same as cells of original cancer. Moreover, metastatic cancer cells and cells of original cancer usually have some molecular features in common, such as the presence of specific chromosome changes.
In some cases, treatment may help prolong the lives of people with metastatic cancer. In other cases, the primary goal of treatment for metastatic cancer is to control the growth of cancer or to relieve the symptoms it is causing. Metastatic tumors can cause severe damage to how the body functions, and most people who die of cancer die of metastatic disease.
Tissue Changes that Are Not Cancer
Not every change in the body's tissues is cancer. Some tissue changes may develop into cancer if they are not treated, however. Here are some examples of tissue changes that are not cancer but, in some cases, are monitored because they could become cancer:
Hyperplasia occurs when cells within a tissue multiply faster than normal and extra cells build up. However, the cells and the way the tissue is organized still look normal under a microscope. Hyperplasia can be caused by several factors or conditions, including chronic irritation.
Dysplasia is a more advanced condition than hyperplasia. In dysplasia, there is also a buildup of extra cells. But the cells look abnormal and there are changes in how the tissue is organized. In general, the more abnormal the cells and tissue look, the greater the chance that cancer will form. Some types of dysplasia may need to be monitored or treated, but others do not. An example of dysplasia is an abnormal mole (called a dysplastic nevus) that forms on the skin. A dysplastic nevus can turn into melanoma, although most do not.
Carcinoma in situ is an even more advanced condition. Although it is sometimes called stage 0 cancer, it is not cancer because the abnormal cells do not invade nearby tissue the way that cancer cells do. But because some carcinomas in situ may become cancer, they are usually treated.
Chapter 2
Cancer Symptoms
Early cancer and certain types of cancer may not have any symptoms. However, some symptoms may be the result of cancer or a less serious illness.
Here are different symptoms of cancer:
BRAIN CANCERS
1. Brain Tumor: Brain tumors are masses of abnormal cells in or near the brain that multiply in an uncontrolled way. Tumors can start in the brain or from cancerous cells elsewhere in the body that spread (metastasize) to the brain. Spine tumors can also start inside or outside the spine and spinal cord.
The brain and spinal cord make up the central nervous system, which controls speech, hearing, vision, movement, thoughts, and many other functions. Therefore, a tumor in the brain or spinal cord can impact your ability to do everyday activities.
Symptoms of Brain Tumors
It's easy to mistake brain tumor symptoms for those of other conditions. Although each type of tumor can cause different symptoms, common brain tumor signs and symptoms include:
Behavior or personality changes
Difficulties with balance, hearing, speech, and vision
Headaches that become more frequent or severe
Increased confusion and inability to follow simple commands
Loss of feeling or movement in an arm or leg
Nausea or vomiting
Seizures
ENDOCRINE CANCERS
1. Adrenal cancer symptoms: Patients with adrenal cancer may have any or all of the following symptoms:
Pain in the abdomen or back
A lump in the abdomen
Unwanted or unexpected weight loss
Weakness and low potassium levels
Hirsutism (increased hairiness occurring mostly in women) or virilism (causes women to develop masculine features)
Difficulty controlling "labile" high blood pressure (blood pressure that goes up and down in an erratic manner)
New onset of diabetes that is hard to control
Cancer of the adrenal cortex can cause high blood pressure, weakening of the bones, and diabetes. People with this type of adrenal cancer may experience deepening of the voice, hair growth on the face, and swelling of the sex organs or breasts. These symptoms may happen if male or female hormones are produced by the tumor.
People with pheochromocytomas may develop high blood pressure, which can cause chest pain, sweating, headaches, pounding of the heart, heart palpitations, and anxiety.
It is important to remember that these symptoms can be caused by many other medical problems. If a person has any of these symptoms, they should see their doctor as soon as possible.
2. Parathyroid tumor symptoms: If the parathyroid tumor causes hyperparathyroidism, symptoms may include:
Aches and pains
Depression
Abdominal pain
Nausea
Vomiting
Fatigue
Excessive urination
Confusion
Muscle weakness
The symptoms of a parathyroid tumor may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.
3. Pituitary tumor symptoms: Many pituitary tumors do not cause symptoms. But larger tumors may pressure the brain or other structures and produce symptoms such as headaches or vision problems.
Pituitary tumors can also cause symptoms by producing (secreting) high levels of various hormones. Doctors call such tumors "functional," with 4 main types:
Nonfunctional adenomas (null cell adenomas) These tumors are the most common type.
Prolactin-producing tumors (prolactinomas) These benign tumors are also common.
ACTH-producing tumors.
Growth hormone-producing tumors.
4. Adrenocorticotropic tumors Symptoms
Adrenocorticotropic tumors stimulate adrenal glands to produce the hormone cortisol and may cause Cushing's syndrome.
Cushing's Disease: A condition that occurs from exposure to high cortisol levels for a long time.
Treatable by a medical professional
Requires a medical diagnosis
Lab tests or imaging always required
Chronic: can last for years or be lifelong
The most common cause is the use of steroid drugs, but it can also occur from overproduction of cortisol by the adrenal glands.
Symptoms of adrenocorticotropic tumors include:
Round face
Thin arms and legs
Severe fatigue
Muscle weakness
High blood pressure
High blood sugar
Purple or pink stretch marks on the skin, and
Weight gain, especially in the abdomen
5. Symptoms of prolactinomas
The pituitary gland secretes a hormone called prolactin that activates the production of breast milk in pregnant women. Tumors that secrete excess prolactin can cause a decrease in the production of sex hormones, leading to reduced estrogen in women and lower testosterone in men.
In women, symptoms may include:
Irregular menstrual periods or no menstrual periods
Milky discharge from the breasts when not pregnant or breastfeeding
Painful intercourse due to vaginal dryness
Acne and excessive body and facial hair growth
In men, symptoms may include:
Erectile dysfunction
Decreased body and facial hair
Smaller muscles
Enlarged breasts
In both females and males, prolactinoma can cause:
Infertility
Weak and brittle bones that break easily (osteoporosis)
Loss of interest in sexual activity
6. Thyroid tumor symptoms:
The thyroid gland is low and toward the front of the neck. It has two lobes that sit side-by-side. The thyroid gland is comprised of two primary classes of cells.
Follicular cells convert iodine that circulates naturally in the blood to produce thyroid hormone. The amount of thyroid hormone that is released is regulated by the pituitary gland that sits at the base of the brain.
C cells produce calcitonin, a hormone that regulates how the body uses calcium.
Other less common cells in the thyroid include lymphocytes which are part of the immune system and stromal cells which are part of connective tissue.
Cancer may develop from each type of cell. The differences affect prognosis and treatment.
Not all growths in the thyroid are cancerous, so a biopsy is usually performed to determine the diagnosis of tissue that appears suspicious appearing on imaging.
Lumps or bumps in the thyroid are called thyroid nodules. Most are noncancerous. People can develop nodules at any age, but they are more common in older adults. Benign thyroid nodules often can go without treatment. Others require some form of intervention.
FEMALE/GYNECOLOGIC CANCERS
1. Breast Cancer Symptoms: The breast is made up of a system of lobes and branching ducts that exit at the nipple. Breast cancer is cancer that developed in the tissues that make up the ductal or lobular system of the breast. It has many different forms, each with different behaviors and treatments.
In general, cancer develops after the genetic material in cells changes abnormally and the cells begin growing out of control. When there are enough of these abnormal cells, they can form a tumor that may be seen on a mammogram or felt as a lump during a breast exam.
Not all tumors in the breast are cancerous, so a biopsy is required to determine the diagnosis of a tumor that is suspicious on imaging.
How does breast cancer develop?
Many patients wonder why they developed breast cancer or if they are at high risk for the disease.
Most breast cancers occur in women who have no known inherited genetic risk factors. The vast majority of breast cancers are the result of random mistakes, or mutations, in genes accumulated over time. Because these mutations can increase in number over time, the older you get, the more at risk you are of developing cancer.
Only about 5-10% of breast cancers are linked to inherited genetic mutations such as BRCA1 and BRCA2. Patients who have an inherited mutation in one of these genes have trouble fixing the random mutations that occur over time, so they are at a much higher risk of developing breast cancer, often at a younger age than the average woman.
While most breast cancers are detected on screening mammography, self-detection plays an important role in early detection.
2. Cervical cancer symptoms: Cervical cancer is cancer from the cervix, which is the entryway going from the vagina into the uterus. Cancer cells grow abnormally rapidly, crowding out normal cells.
Cervical cancer is often detected from a screening test called the Pap smear. When it isn't detected that way, the first symptom may be abnormal bleeding from the vagina, especially after sexual activity.
Most cases of cervical cancer are linked to a virus called HPV (human papillomavirus).
Symptoms of Cervical Cancer
The first symptoms of cervical cancer are often unusual bleeding from the vagina that is not from menstruating. This includes bleeding after sexual activity, as well as pelvic cramps and pain after sexual activity.
Ovarian and fallopian cancer symptoms: Ovarian cancer is cancer starting in the ovaries or the fallopian tubes, which are located on either side of the uterus in a woman's pelvic area. Cancer cells grow abnormally rapidly, crowding out normal cells. Ovarian cancer can spread to other organs including the uterus, the pelvis, lymph nodes, and to the bowel, liver, and diaphragm.
Ovarian cancer often has vague symptoms that often feel like gastrointestinal problems
Uterine cancer symptoms: Endometrial cancer occurs in the lining of the uterus (the womb). The cancer cells grow abnormally, eventually crowding out normal cells.
How does endometrial cancer develop?
In general, cancer develops after genetic material in cells changes abnormally and the cells begin growing out of control. When there are enough of these abnormal cells, they can form a tumor.
Surgery is the most common treatment for endometrial cancer. When the cancer is caught early, surgery can often be a cure. In some cases, additional treatment can include radiation therapy and drug therapy.
3. Vaginal cancer symptoms: Vaginal cancer is rare cancer that occurs in your vagina — the muscular tube that connects your uterus with your outer genitals. Vaginal cancer most commonly occurs in the cells that line the surface of your vagina, which is sometimes called the birth canal.
While several types of cancer can spread to your vagina from other places in your body, cancer that begins in your vagina (primary vaginal cancer) is rare.
Early vaginal cancer may not cause any signs and symptoms. As it progresses, vaginal cancer may cause signs and symptoms such as:
Unusual vaginal bleeding, for example, after intercourse or after menopause
Watery vaginal discharge
A lump or mass in your vagina
Painful urination
Frequent urination
Constipation
Pelvic pain
4. Vulvar Cancer Symptoms: Vulvar cancer is a type of cancer that occurs on the outer surface area of the female genitalia. The vulva is the area of skin that surrounds the urethra and vagina, including the clitoris and labia.
Vulvar cancer commonly forms as a lump or sore on the vulva that often causes itching. Though it can occur at any age, vulvar cancer is most commonly diagnosed in older adults.
Signs and symptoms of vulvar cancer may include:
Itching that doesn't go away
Pain and tenderness
Bleeding that isn't from menstruation
Skin changes, such as color changes or thickening
A lump, wartlike bumps, or an open sore (ulcer)
GASTROINTESTINAL CANCERS
1. Anal cancer symptoms: The symptoms of anal cancer include bleeding from the anus, itching or discharge from the anus, a lump near the anus, and redness, swelling, or pain in the area of the anus.
2. Bile duct cancer symptoms: The following are the most common symptoms of cholangiocarcinoma. However, each individual may experience symptoms differently. Symptoms may include:
Jaundice (yellowing of the skin and eyes)
Abdominal pain
Poor appetite
Weight loss
Itching
Pale stools
Dark urine
Fever
The symptoms of cholangiocarcinoma may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
3. Colorectal cancer symptoms:
Colon cancer symptoms can be vague, including dull abdominal pain, fatigue, and anemia. Other colon cancer symptoms include rectal bleeding and changes in bowel habits.
If I don't have symptoms, why should I have a colonoscopy?
Early colon cancers and polyps that can develop into cancer often produce no symptoms. Early detection also means that cancer is less likely to have spread to nearby lymph nodes and other organs. Learn more about colonoscopies.
Most common symptoms of colorectal cancer
The following are the most common symptoms of colorectal cancer. However, each individual may experience symptoms differently.
People who have any of the following symptoms should check with their doctors, especially if they are over 50 years old or have a personal or family history of the disease:
A change in bowel habits such as diarrhea, constipation, or narrowing of the stool that lasts for more than a few days
Rectal bleeding, dark stools, or blood in the stool
Cramping or gnawing stomach pain
Decreased appetite
Vomiting
Weight loss
Weakness and fatigue
Jaundice—yellowing of the skin and eyes
The symptoms of colorectal cancer may resemble other conditions, such as infections, hemorrhoids, and inflammatory bowel disease.
4. Esophageal cancer symptoms: The esophagus is the organ that functions as a tube that allows food and liquids to travel from your mouth to your stomach in your abdomen. Esophagus cancer also called esophageal cancer, is the term used for cancers that form there.
Esophageal cancers account for about 1% of all cancers in the United States. Men are 4 times more likely to get the disease than women. Research shows that men's higher participation in risk factors such as tobacco use and excessive alcohol consumption may help explain this gender difference.
The most common symptom of esophageal cancer occurs when a tumor grows big enough to make it hard for food to pass through. Patients notice that it feels like food gets stuck low in their chest, and the symptoms can often get worse with time and cause people to begin to lose weight. Liquids tend to be easier to swallow than solid food, and patients sometimes feel like they have to regurgitate because the food will not pass.
How does esophageal cancer develop?
In general, cancer develops after the genetic material in cells changes abnormally and the cells begin growing out of control. When there are enough of these abnormal cells, they can form a tumor.
Esophageal cancer often is a result of chronic irritation of the esophagus. This may be triggered by chronic gastroesophageal reflux disease (GERD), a precancerous condition known as Barrett's esophagus, by drinking alcohol, smoking, or by prior radiation treatment to the chest or upper abdomen. Patients with esophageal cancer associated with reflux disease often will not have a history of significant heartburn symptoms.
How does esophageal cancer spread?
Esophageal cancer generally starts in the layer that is the inner lining of the esophagus (also called the mucosa), and then spreads outward, from the mucosa to the other 3 layers of the esophagus wall. Starting from the inside, those other layers are:
Submucosa: Connective tissue located next to the mucosa that contains nerves, blood vessels, and glands that produce mucous
Muscularis propria: A muscle layer that pushes food down the esophagus.
Adventitia: Connective tissue that makes up the outer layer of the esophagus
When the cancer is traveling through the layers in the wall of the esophagus, tumor cells can spread to lymph nodes that live in the area close to the esophagus. Cancer cells can also spread through both the bloodstream and the lymphatic system to travel to other organs in the body, most commonly the liver, lung, and bone.
5. Gallbladder cancer symptoms: The symptoms of gallbladder cancer usually do not appear until cancer has reached an advanced stage. Many symptoms are like those due to gallstones or gallbladder inflammation.
The following are typical symptoms of gallbladder cancer:
Pain or discomfort in the right side of the upper abdomen
A sense of fullness after eating even small amounts
Heartburn
Nausea and vomiting
Poor appetite
Loss of weight without trying
Fever
Yellowing of the skin (jaundice) or the white area of the eyes (scleral icterus)
Severe itching
6. Gastrointestinal stromal tumors (GIST) symptoms: People with early-stage GIST often do not have any symptoms of the disease. Most GISTs are diagnosed after a person develops symptoms. These may include:
Abdominal discomfort or pain
Vomiting
Blood in stools or vomit
Fatigue due to anemia (low blood counts)
Feeling full after eating only a small amount (early satiety)
Loss of appetite
These symptoms may be the result of GIST or other less serious causes. A person with these symptoms should discuss them with their doctor.
7. Liver cancer symptoms: Signs and symptoms of liver cancer often do not show up until the later stages of the disease, but sometimes they may show up sooner. If you go to your doctor when you first notice symptoms, your cancer might be diagnosed earlier, when treatment is most likely to be helpful. Some of the most common symptoms of liver cancer are:
Weight loss (without trying)
Loss of appetite
Feeling very full after a small meal
Nausea or vomiting
An enlarged liver felt fullness under the ribs on the right side
An enlarged spleen felt fullness under the ribs on the left side
Pain in the abdomen (belly) or near the right shoulder blade
Swelling or fluid build-up in the abdomen (belly)
Itching
Yellowing of the skin and eyes (jaundice)
Other symptoms can include fever, enlarged veins on the belly that can be seen through the skin, and abnormal bruising or bleeding.
People who have chronic hepatitis or cirrhosis might feel worse than usual or might just have changes in lab test results, such as liver function tests or alpha-fetoprotein (AFP) levels.
Some liver tumors make hormones that act on organs other than the liver. These hormones may cause:
High blood calcium levels (hypercalcemia), can cause nausea, confusion, constipation, weakness, or muscle problems
Low blood sugar levels (hypoglycemia), which can cause fatigue or fainting
Breast enlargement (gynecomastia) and/or shrinkage of the testicles in men
High counts of red blood cells (erythrocytosis) can cause someone to look red and flushed
High cholesterol levels
8. Pancreatic cancer symptoms: Pancreatic cancer usually doesn't cause symptoms at first. It's silent and painless. Symptoms usually don't begin until cancer has spread. They may include:
Pain in the upper belly or back.
Jaundice. This yellowing of the skin and whites of the eyes can happen when the growing tumor presses the bile duct closed.
Unexpected weight loss.
Loss of appetite.
Extreme tiredness.
9. Stomach cancer symptoms: The symptoms of stomach cancer are in two distinct stages:
Early-stage stomach cancer symptoms
Advanced stomach cancer symptoms
Early Stage Stomach Cancer Symptoms
It is common for people with early-stage early-stage stomach cancer to experience no symptoms. However, as stomach cancer grows and spreads, it exhibits some telltale signs and symptoms, even while still in the early stages.
Symptoms may include:
Unexplained weight loss
Abdominal pain or vague pain just above the belly button area
Indigestion, heartburn, or vomiting
Loss of or decrease in appetite
Weakness or fatigue
Blood in vomit or stool
A feeling of fullness after small meals
Many symptoms of early-stage stomach cancer are also the symptoms of less serious stomach issues. If you are experiencing any of these signs and symptoms, it is important to see your doctor. The earlier we diagnose cancer, the more successfully we can treat it.
Advanced Stomach Cancer Symptoms
Symptoms of advanced stomach cancer are more serious than symptoms of early-stage stomach cancer. Because advanced-stage stomach cancer has grown and spread, it can also affect nearby organs including:
The liver
The large intestine (also known as the colon)
If stomach cancer has grown to create a blockage within the stomach or the large intestine, you may experience:
Loss of appetite
Significant weight loss
Uncontrolled vomiting
Signs that stomach cancer has spread to the liver include:
Jaundice (yellowing of skin or eyes)
Ascites (enlargement of the stomach from fluid)
GENETIC CANCER SYNDROMES
1. Peutz-Jeghers syndrome: The features associated with Peutz-Jeghers syndrome may include the following:
Melanocytic macules (dark blue or brown moles)
These moles may be located around and/or in the mouth (including the lips), and around the eyes, nostrils, and anus. Dark moles may also appear on the fingers. These lesions may fade by adulthood.
Multiple polyps in the gastrointestinal tract
Increased risk of benign (noncancerous) tumors of the ovaries and testes
Increased risk of stomach, esophageal, breast, colon, pancreatic, and ovarian cancers
2. Von Hippel-Lindau syndrome symptoms: Von Hippel-Lindau syndrome (VHL) is characterized by an increased risk of developing the tumors listed below:
Hemangioblastomas (benign, or noncancerous, tumors made up of nests of blood vessels) of the brain and spine
Hemangioblastomas of the retina
Pheochromocytomas (a tumor of the chromaffin cells, which are present in the adrenal gland; usually benign, or noncancerous) within or outside of the adrenal gland
Renal cell carcinoma (cancerous tumor of the kidney)
Less commonly, some individuals develop endolymphatic sac tumors (ear tumors that can cause deafness if undetected), pancreatic tumors, and cystadenomas of the epididymis or broad ligament. Other manifestations include cysts (pockets of fluid) of the kidney and pancreas.
HEAD AND NECK CANCERS
1. Hypopharyngeal cancer symptoms: These and other symptoms may be caused by hypopharyngeal cancer. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:
A sore throat that does not go away
Ear pain
A lump in the neck
Painful or difficult swallowing
A change in voice
Noisy breathing or difficulty breathing
2. Laryngeal cancer symptoms: These and other symptoms may be caused by laryngeal cancer or by other conditions. A doctor should be consulted if any of the following problems occur:
Hoarseness
A sore throat or cough that does not go away
Coughing up of blood or bloody sputum
Trouble or pain when swallowing
Ear pain
A lump in the neck or throat
3. Nasopharyngeal cancer symptoms: Some symptoms of NPC may include nasal congestion, nose bleeds, changes in hearing, or changes in vision because structures critical to functions of the eyes, nose, and ears are adjacent to the nasopharynx. Another common symptom may be painless swelling of lymph nodes in the neck, especially neck nodes below the ear (rather than below the chin or jaw). It is relatively uncommon but not rare for patients to show evidence of NPC spreading beyond the head and neck regions.
These and other symptoms may be caused by nasopharyngeal cancer. Other conditions may cause the same symptoms.
A doctor should be consulted if any of the following problems occur:
A lump in the nose or neck
A sore throat
Trouble breathing or speaking
Nosebleeds
Trouble hearing
Pain or ringing in the ear
Headaches
4. Oral cancer symptoms: Symptoms of oral cancer include sores or lumps on the lips or in your mouth. Talk with your doctor if you have any of these signs:
A sore on your lip or in your mouth that bleeds easily and doesn't heal
A lump or thickening on your lips, gums, cheek, or in your mouth
A white or red patch on your gums, your tongue, tonsils, or the lining of your mouth
A sore throat or a feeling that something is caught in your throat
Unexplained difficulty chewing, swallowing, speaking, or moving your jaw or tongue
Numbness or pain in your tongue or other areas of your lips or mouth
Swelling in your jaw that makes your teeth lose or your dentures fit poorly
Changes in your voice
Dry mouth
5. Oropharyngeal cancer symptoms: Signs and symptoms of oropharyngeal cancer include a lump in the neck and a sore throat.
A sore throat that does not go away.
Trouble swallowing.
Trouble opening the mouth fully.
Trouble moving the tongue.
Weight loss for no known reason.
Ear pain.
A lump in the back of the mouth, throat, or neck
6. Paranasal sinus and nasal cavity cancer symptoms: A doctor should be seen for any of the following problems:
Blocked sinuses that do not clear
A sinus infection
Nosebleeds
A lump or sore that doesn't heal inside the nose
Frequent headaches or sinus pain
Swelling or other trouble with the eyes
Pain in the upper teeth
Dentures that no longer fit well
7. Parathyroid cancer symptoms: If the parathyroid tumor causes hyperparathyroidism, symptoms may include:
Aches and pains
Depression
Abdominal pain
Nausea
Vomiting
Fatigue
Excessive urination
Confusion
Muscle weakness
The symptoms of a parathyroid tumor may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.
8. Parotid gland/salivary glands cancer symptoms: A doctor should be seen if there is a swelling under the chin or around the jawbone, the face becomes numb, muscles in the face cannot move, or there is pain that does not go away in the face, chin, or neck.
9. Thyroid cancer symptoms:
The thyroid gland is low and toward the front of the neck. It has two lobes that sit side-by-side. The thyroid gland is comprised of two primary classes of cells.
Follicular cells convert iodine that circulates naturally in the blood to produce thyroid hormone. The amount of thyroid hormone that is released is regulated by the pituitary gland that sits at the base of the brain.
C cells produce calcitonin, a hormone that regulates how the body uses calcium.
Other less common cells in the thyroid include lymphocytes which are part of the immune system and stromal cells which are part of connective tissue.
Cancer may develop from each type of cell. The differences affect prognosis and treatment.
Not all growths in the thyroid are cancerous, so a biopsy is usually performed to determine the diagnosis of tissue that appears suspicious appearing on imaging.
Lumps or bumps in the thyroid are called thyroid nodules. Most are noncancerous. People can develop nodules at any age, but they are more common in older adults. Benign thyroid nodules often can go without treatment. Others require some form of intervention.
How does thyroid cancer develop?
In general, cancer develops after the genetic material in cells changes abnormally and the cells begin growing out of control. When there are enough of these abnormal cells, they can form a tumor that may be seen on an ultrasound or felt as a lump during a clinical exam.
Symptoms
Thyroid gland showing larynx and trachea
Thyroid glandOpen pop-up dialog box
Most thyroid cancers don't cause any signs or symptoms early in the disease. As thyroid cancer grows, it may cause:
A lump (nodule) that can be felt through the skin on your neck
A feeling that close-fitting shirt collars are becoming too tight
Changes to your voice, including increasing hoarseness
Difficulty swallowing
Swollen lymph nodes in your neck
Pain in your neck and throat
HEMATOLOGIC CANCERS/LEUKEMIA
1. Acute lymphocytic leukemia symptoms: Leukemia is a cancer of the blood. In leukemia, normal blood cells are transformed in ways that lead to high counts of white blood cells called lymphocytes.
Lymphocytes are made by the bone marrow and by organs of the lymph system. The term "acute" means that the disease progresses rapidly.
Acute lymphoblastic leukemia (ALL) is a fast-growing, aggressive cancer. Sometimes ALL also spreads beyond the blood and affects internal organs or other areas of the body.
Symptoms of ALL can develop quickly—within days to a few weeks—after the onset of the disease. The most common symptoms include:
Feeling tired
Feeling weak
Feeling dizzy or lightheaded
Shortness of breath
Pale skin
Infections that don't go away or keep coming back
Bruises (or small red or purple spots) on the skin
Bleeding, such as frequent or severe nosebleeds, bleeding gums, or heavy menstrual bleeding in women
General symptoms
Patients with ALL also often have several non-specific symptoms. These can include:
Weight loss
Fever
Night sweats
Loss of appetite
2. Acute myelogenous leukemia symptoms: Myeloid leukemia develops from cells that give rise to white blood cells called granulocytes and monocytes. The main function of granulocytes is to destroy bacteria.
In acute leukemias, which develop quickly, the cancerous cells (called blasts) are immature and incapable of performing their immune system functions. That can leave people vulnerable to infections.
Acute myeloid leukemia (AML) is also known as acute myelogenous leukemia. It is a fast-growing, aggressive condition. It is the most common kind of acute leukemia in adults.
Symptoms of AML can develop quickly—within days to a few weeks—after the onset of the disease. The most common symptoms include:
Weight loss
Fatigue
Fever
Night sweats
Loss of appetite
3. Chronic lymphocytic leukemia symptoms: Leukemia is a cancer of the blood. In leukemia, normal blood cells are transformed in ways that lead to high counts of white blood cells.
The term "chronic" means that the disease progresses slowly over a while.
In chronic lymphocytic leukemia, there may be no noticeable symptoms early in the disease. Many cases are diagnosed from routine blood tests.
Some people notice swollen lymph nodes. The following are some common symptoms others may experience:
Enlarged, but painless, lymph nodes
Fatigue
Fever
Pain in the upper left portion of the abdomen, which may be caused by an enlarged spleen
Night sweats
Weight loss
Frequent infections
4. Chronic myelogenous leukemia symptoms: Myeloid leukemia develops from cells that give rise to white blood cells called granulocytes and monocytes. The main function of granulocytes is to destroy bacteria.
The term "chronic" means that the disease progresses slowly over some time, unlike acute leukemias which develop quickly. Chronic myeloid leukemia (CML) is considered a pre-leukemic condition. CML cells have genetic abnormalities that lead to excessive growth of blood cells. But it does not cause the same complications seen in other related fast-growing leukemias like acute myeloid leukemia.
Many people may not notice symptoms in the early phase of chronic myeloid leukemia (CML).
Many cases are detected from routine blood tests.
Some people may lose weight and feel weak. The following are some common symptoms others may experience:
Bone pain
Easy bleeding
Feeling full after eating a small amount of food
Feeling run-down or tired
Fever
Weight loss without trying
Loss of appetite
Pain or fullness below the ribs on the left side
Excessive sweating during sleep (night sweats)
5. Leukemia symptoms:
Leukemia is a cancer of the body's blood-forming tissues, including the bone marrow and the lymphatic system.
Many types of leukemia exist. Some forms of leukemia are more common in children. Other forms of leukemia occur mostly in adults.
Leukemia usually involves white blood cells. Your white blood cells are potent infection fighters — they normally grow and divide in an orderly way, as your body needs them. But in people with leukemia, the bone marrow produces an excessive amount of abnormal white blood cells, which don't function properly.
Leukemia symptoms vary, depending on the type of leukemia. Common leukemia signs and symptoms include:
Fever or chills
Persistent fatigue, weakness
Frequent or severe infections
Losing weight without trying
Swollen lymph nodes, enlarged liver or spleen
Easy bleeding or bruising
Recurrent nosebleeds
Tiny red spots on your skin (petechiae)
Excessive sweating, especially at night
Bone pain or tenderness
6. Myelodysplastic syndrome symptoms:
People with myelodysplastic syndromes might not experience signs and symptoms at first.
In time, myelodysplastic syndromes might cause:
Fatigue
Shortness of breath
Unusual paleness (pallor), which occurs due to a low red blood cell count (anemia)
Easy or unusual bruising or bleeding, which occurs due to a low blood platelet count (thrombocytopenia)
Pinpoint-sized red spots just beneath the skin that are caused by bleeding (petechiae)
Frequent infections, occur due to a low white blood cell count (leukopenia)
7. Myelofibrosis (AMM) symptoms:
Myelofibrosis symptoms are somewhat similar to chronic myelogenous leukemia (CML), but patients lack the genetic defect known to cause CML.
Patients tend to be over 60 years old and experience an enlarged spleen and anemia as the bone marrow stops making blood and other organs like the liver and spleen attempt to take over blood production.
Other symptoms may include:
Fatigue
A general feeling of discomfort
Difficulty breathing
Weight loss
Fever and night sweats
Anemia
Abnormal bleeding
Patients with myelofibrosis have an increased risk of bleeding. They are more susceptible to developing infections compared to healthy individuals. In addition, patients have an increased risk of developing an enlarged spleen. In extreme cases, the spleen may rupture.
LYMPHOMAS
1. Cutaneous lymphoma symptoms:
Symptoms of cutaneous lymphoma can include:
Dry, red, scaly patches or bumps on the skin
Rashes on the skin
Lesions on the skin
Tumors on the skin
Enlarged lymph nodes
The symptoms of cutaneous lymphoma may resemble other dermatological conditions.
2. Hodgkin's lymphoma symptoms:
Hodgkin lymphoma is cancer. Like other cancers, it starts when cells grow out of control, multiplying and crowding other normal cells.
Hodgkin's lymphoma starts in the lymph system, which contains the lymph nodes. The lymph system is part of the body's immune system that protects it from infections and diseases.
Lymph nodes contain the lymph fluid that carries white blood cells through a network of thin tubes spreading through the body.
Hodgkin's significantly differs from other lymphomas: Hodgkin cancer cells only make up a small part of the cells in a lymph node. The rest of the cells are normal cells. (In other lymphomas, cancer cells make up most of the cells in a lymph node.)
Hodgkin lymphoma can usually be cured if it is found early and treated soon.
Signs and symptoms of Hodgkin's lymphoma may include:
Painless swelling of lymph nodes in your neck, armpits, or groin
Persistent fatigue
Fever
Night sweats
Losing weight without trying
Severe itching
Pain in your lymph nodes after drinking alcohol
Picture of swollen lymph nodes...........
3. Non-Hodgkin's lymphoma symptoms: Non-Hodgkin lymphoma starts in the lymph system, which contains the lymph nodes, spleen, and bone marrow. The lymph system is part of the body's immune system that protects it from infections and diseases.
Lymph nodes contain the lymph fluid that carries white blood cells through a network of thin tubes spreading through the body.
Some common signs and symptoms include:
Enlarged lymph nodes
Chills
Weight loss
Fatigue (feeling very tired)
Swollen abdomen (belly)
Feeling full after only a small amount of food
Chest pain or pressure
Shortness of breath or cough
Severe or frequent infections
Easy bruising or bleeding
LUNG CANCERS
1. Lung cancer symptoms:
Lung cancer is not a single disease but rather a group of cancers that develop in the lung. Cancer occurs when cells mutate (change abnormally) and begin growing out of control. These cells form tumors that can often be seen on a chest X-ray.
Some tumors that form in the lung are benign (noncancerous), meaning they do not grow into surrounding areas or spread in the body. Malignant (cancerous) tumors grow into nearby tissues or spread to other parts of the body (metastasize).
A biopsy is required to determine the diagnosis of a tumor that appears suspicious on imaging.
How does lung cancer develop?
Many patients wonder why they developed lung cancer or if they are at high risk for the disease.
In general, cancer develops after the genetic material in cells changes abnormally and the cells begin growing out of control. When there are enough of these abnormal cells, they can form a tumor.
Lung cancer often is a result of chronic exposure to tobacco smoke, either from smoking or from being around secondhand smoke. It also is linked to exposure to certain substances like radon gas or asbestos, or from prior radiation treatment to or over the lungs.
People who have had lung cancer before are at higher risk of recurrence. People who have a close relative who has had lung cancer are at a slightly higher risk of developing the disease.
The most common symptoms of lung cancer are:
A cough that does not go away or gets worse
Coughing up blood or rust-colored sputum (spit or phlegm)
Chest pain that is often worse with deep breathing, coughing, or laughing
Hoarseness
Loss of appetite
Unexplained weight loss
Shortness of breath
Feeling tired or weak
Infections such as bronchitis and pneumonia that don't go away or keep coming back
New onset of wheezing
If lung cancer spreads to other parts of the body, it may cause:
Bone pain (like pain in the back or hips)
Nervous system changes (such as headache, weakness or numbness of an arm or leg, dizziness, balance problems, or seizures), from cancer, spread to the brain
Yellowing of the skin and eyes (jaundice), from cancer spreading to the liver
Swelling of lymph nodes (collection of immune system cells) such as those in the neck or above the collarbone
Thymoma and thymic cancer symptoms: Consult your doctor if you have shortness of breath or other symptoms of thymoma or thymic cancer.
Most thymic tumors are discovered after a person starts to have symptoms. These may be related to the tumor itself, or they may be part of a condition related to cancer, but not caused directly by the tumor mass.
The thymus is in the middle of the chest, near the airways and certain blood vessels. Tumors in the thymus can press on nearby structures, causing symptoms such as:
Shortness of breath
Cough (which may be bloody)
Chest pain
Trouble swallowing
Loss of appetite
Weight loss
The thymus is near the superior vena cava, the main blood vessel bringing blood from your head and upper body to your heart. Larger tumors that press on this vessel can cause symptoms of superior vena cava syndrome, which can include:
Swelling in the face, neck, and upper chest, sometimes with a bluish color
Swelling of the visible veins in this part of the body
Headaches
Feeling dizzy or light-headed
Paraneoplastic syndromes
Thymomas are often associated with symptoms that are not directly caused by the tumor mass itself pushing on surrounding structures. For example, about 30% to 50% of people with thymomas also have myasthenia gravis (MG), a disease in which the immune system forms antibodies that block the chemical signals that stimulate the muscles to move. This may cause varying degrees of muscle weakness, double vision (from eye muscle involvement), or swallowing problems.
Other common paraneoplastic syndromes related to thymoma include red cell aplasia (causing low blood cell count), and hypogammaglobulinemia (low antibody levels).
MALE / UROLOGIC CANCERS
1. Adrenal cancer symptoms: Patients with adrenal cancer may have any or all of the following symptoms:
Pain in the abdomen or back
A lump in the abdomen
Unwanted or unexpected weight loss
Weakness and low potassium levels
Hirsutism (increased hairiness occurring mostly in women) or virilism (causes women to develop masculine features)
Difficulty controlling "labile" high blood pressure (blood pressure that goes up and down in an erratic manner)
New onset of diabetes that is hard to control
Cancer of the adrenal cortex can cause high blood pressure, weakening of the bones, and diabetes. People with this type of adrenal cancer may experience deepening of the voice, hair growth on the face, and swelling of the sex organs or breasts. These symptoms may happen if male or female hormones are produced by the tumor.
People with pheochromocytomas may develop high blood pressure, which can cause chest pain, sweating, headaches, pounding of the heart, heart palpitations, and anxiety.
It is important to remember that these symptoms can be caused by many other medical problems. If a person has any of these symptoms, they should see their doctor as soon as possible.
2. Bladder cancer symptoms: In its early stages, the only symptom of bladder cancer may be the appearance of blood in the urine. If patients act on this symptom and go to the doctor, it is often possible to catch bladder cancer at its earliest, most treatable stage.
Pain in the bladder or pelvic region is rare and usually occurs only in advanced cancers. Many other noncancerous conditions also cause pain and other urinary symptoms, so it is important to see a doctor.
3. Kidney cancer symptoms: Frequently early kidney cancers and renal cell carcinomas do not cause any signs or symptoms. The following are the most common symptoms of renal cell cancer. However, each individual may experience symptoms differently.
Symptoms may include:
Blood in the urine
Rapid, unexplained weight loss
Low back pain (not caused by an injury)
Loss of appetite
Swelling of ankles and legs
Mass or lump in the belly
Fatigue
Recurrent fever (not caused by a cold or the flu)
High blood pressure (less frequently)
Anemia (less frequently)
Unrelieved pain in the side
The symptoms of renal cell cancer may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
4. Penile cancer symptoms: Although many men with penile cancer have early symptoms, you may have no symptoms until the cancer is in its later stages. You may notice symptoms but think they are due to something other than cancer. Tell your doctor about any changes in the skin of your penis, the color of the skin, or any unusual discharge, such as bleeding or foul odor. In many cases, the first sign of penile cancer is an ulcer, sore, or growth on the penis. The growth is usually painless and shows up on the glans or the foreskin, but can also show up on the shaft of the penis. These are some other symptoms:
Changes in skin color, thickening of the skin, tissue growth
A red, velvet-like rash
Bleeding
Small and crusty bumps
Flat growths with a bluish brown color
A discharge under the foreskin, with or without an odor
Swelling at the tip of the penis, especially if the foreskin is tight
Swelling in the groin
These symptoms may or may not mean penile cancer. If you have any of them, you should see your doctor right away.
5. Prostate cancer symptoms: Prostate cancer is cancer that occurs in the prostate. The prostate is a small walnut-shaped gland in males that produces the seminal fluid that nourishes and transports sperm.
Prostate cancer is one of the most common types of cancer. Many prostate cancers grow slowly and are confined to the prostate gland, where they may not cause serious harm. However, while some types of prostate cancer grow slowly and may need minimal or even no treatment, other types are aggressive and can spread quickly.
Prostate cancer may cause no signs or symptoms in its early stages.
More advanced prostate cancer may cause signs and symptoms such as:
Trouble urinating
Decreased force in the stream of urine
Blood in the urine
Blood in the semen
Bone pain
Losing weight without trying
Erectile dysfunction
6. Testicular cancer symptoms: Common symptoms of testicular cancer include:
Swelling and/or lump in one or both of the testes. You may or may not have pain in the testes or scrotum.
A heavy feeling in the scrotum.
Dull pain or feeling of pressure in the lower belly or groin.
Sometimes these symptoms can be caused by other problems, such as a hydrocele or epididymitis.
Symptoms of advanced testicular cancer
Testicular cancer that has spread (metastasized) beyond the testicles and regional lymph nodes to other organs may cause other symptoms depending on the area of the body affected. Symptoms of late-stage testicular cancer may include:
Dull pain in the lower back and belly.
Lack of energy, sweating for no clear reason, fever, or a general feeling of illness.
Shortness of breath, coughing, or chest pain.
Headache or confusion.
SARCOMA / BONE CANCERS
1. Chondrosarcoma symptoms: Chondrosarcoma is a rare type of cancer that usually begins in the bones, but can sometimes occur in the soft tissue near bones. Chondrosarcoma happens most often in the pelvis, hip, and shoulder. More rarely, it can happen in the bones of the spine.
Most chondrosarcomas grow slowly and may not cause many signs and symptoms at first. Some rare types grow rapidly and have a high risk of spreading to other areas of the body, which can make these cancers difficult to treat.
Chondrosarcoma tends to grow slowly, so it might not cause signs and symptoms at first. When they occur, signs and symptoms of chondrosarcoma may include:
Increasing pain
A growing lump or area of swelling
Weakness or bowel and bladder control problems, if cancer presses on the spinal cord
2. Ewing's sarcoma symptoms:
The following are the most common symptoms of Ewing's sarcoma. However, each individual may experience symptoms differently. Symptoms may include:
Pain around the site of the tumor
Swelling and/or redness around the site of the tumor
Fever
Weight loss decreased appetite
Fatigue
Paralysis and/or incontinence (if the tumor is in the spinal region)
Symptoms related to nerve compression from tumor (e.g., numbness, tingling, paralysis, etc.)
The symptoms of Ewing's sarcoma may resemble other medical conditions or problems.
3. Osteosarcoma symptoms: The following are the most common symptoms of osteosarcoma. However, each individual may experience symptoms differently. Symptoms may include:
Pain in the affected bone
Swelling around the affected site
Increased pain with activity or lifting
Limping
Decreased movement of the affected limb
The symptoms of osteosarcoma may resemble other medical conditions, such as Ewing's sarcoma.
4. Soft tissue sarcoma symptoms: People with early-stage soft tissue sarcoma usually do not notice any symptoms. Symptoms of soft tissue sarcoma may not appear until the cancer has grown for some time. The following are common symptoms of soft tissue sarcoma.
A lump on the body, which is usually painless
Stomach pain and vomiting
A full feeling after not eating very much
Blood in the stool (a red or tar-like black stool)
Lack of appetite or weight loss
These symptoms may be the result of soft tissue sarcoma. They may also be symptoms of less serious illnesses.
SKIN CANCERS
1. Basal cell carcinoma symptoms: Basal cell cancer usually appears as a scaly red patch or a small, shiny bump or nodule on the skin, and mainly on the areas exposed to the sun, such as the head, neck, arms, hands, and face. Basal cell carcinoma can also occur on the trunk as well as the arms and legs. Although these cancers are rarely painful, the most common sign is a sore or lesion that bleeds easily and does not heal.
2. Melanoma symptoms: Melanoma is the least common of the 3 main types of skin cancer. Other types are called non-melanoma skin cancers and usually include basal cell and squamous cell carcinomas.
Melanoma occurs when pigment cells in the skin (called melanocytes) mutate and begin growing out of control. This is often related to excessive sun exposure, either from natural sunlight or artificial sources, such as indoor tanning beds. The abnormal cells form a spot or lesion that can be seen on top of the skin. The spot can be entirely new, or less commonly involve a prior mole on the skin.
Many melanomas are diagnosed before they grow into surrounding areas or spread in the body. Others may grow into nearby tissues (mainly regional lymph nodes) or spread to other parts of the body (metastasize).
Melanoma is less common than non-melanoma skin cancer. In general, these skin cancers are highly treatable if they are detected and treated early.
Symptoms of Melanoma
Many people first notice melanoma when it forms a spot or lesion on the top of the skin. The spot may appear different from your moles or freckles, especially if it has an uneven border, unusual color, or change in growth. Regularly looking at your skin for an outlier skin lesion, or "ugly duckling" spot can help to detect melanoma earlier when it is more curable.
Some types of melanoma form a bump and begin to bleed, but others do not. Any change in an existing mole or new spot on your skin that does not go away or continues to grow should be evaluated by your health provider. If melanoma is not detected early, it can spread to other parts of the body such as nearby lymph nodes. Eventually, it can spread to more distant body areas.
3. Merkel cell carcinoma symptoms: Merkel cell carcinoma usually appears as firm, painless, shiny lumps of skin. These lumps or tumors can be red, pink, or blue and vary in size from less than a quarter of an inch to more than two inches. Merkel cell carcinoma is usually found on the sun-exposed areas of the head, neck, arms, and legs. This type of cancer occurs mostly in Caucasians between 60 and 80 years of age, but it can occur in people of other races and ages as well.
4. Squamous skin cancer Symptoms: Signs of squamous cell carcinoma include:
Any firm, red bump on sun-exposed skin, and the bump does not go away.
Any patch of skin that feels scaly, bleeds or develops a crust. The patch may get bigger over months and form a sore.
Any skin growth that looks like a wart.
Any sore that does not heal.
Any area of thickened skin on the lower lip.
This is more likely if you smoke or use chewing tobacco, or your lips are often exposed to the sun and wind.
Chapter 3
Causes Of Cancer
There is no single cause for cancer. Scientists believe that it is the interaction of many factors together that produces cancer. The factors involved may be genetic, environmental, or constitutional characteristics of the individual.
Diagnosis, treatment, and prognosis for childhood cancers are different than for adult cancers. The main differences are the survival rate and the cause of cancer. The overall five-year survival rate for childhood cancer is about 80%, while in adult cancers the survival rate is 68%. This difference is thought to be because childhood cancer is more responsive to therapy and a child can tolerate more aggressive therapy.
Childhood cancers often occur or begin in the stem cells, which are simple cells capable of producing other types of specialized cells that the body needs. A sporadic (occurs by chance) cell change or mutation is usually what causes childhood cancer. In adults, the type of cell that becomes cancerous is usually an epithelial cell. Epithelial cells line the body cavity and cover the body surface. Cancer occurs from environmental exposures to these cells over time. Adult cancers are sometimes referred to as acquired for this reason.
Cancer Risk Factors
As mentioned, some cancers, particularly in adults, have been associated with repetitive exposures or risk factors. A risk factor is anything that may increase a person's chance of developing a disease. A risk factor does not necessarily cause the disease, but it may make the body less resistant to it. The following risk factors and mechanisms have been proposed as contributing to cancer:
Lifestyle factors: Smoking, a high-fat diet, and working with toxic chemicals are examples of lifestyle choices that may be risk factors for some adult cancers. Most children with cancer, however, are too young to have been exposed to these lifestyle factors for an extended time.
Family history, inheritance, and genetics may play an important role in some childhood cancers: Cancer of varying forms can be present more than once in a family. It is unknown in these circumstances if the disease is caused by a genetic mutation, exposure to chemicals near a family's residence, a combination of these factors, or simply coincidence.
Some genetic disorders: For example, Wiskott-Aldrich and Beckwith-Wiedemann syndrome are known to alter the immune system. The immune system is a complex system that functions to protect our bodies from infection and disease. The bone marrow produces cells that later mature and function as part of the immune system. One theory suggests that the cells in the bone marrow, the stem cells, become damaged or defective, so when they reproduce to make more cells, they make abnormal cells or cancer cells. The cause of the defect in the stem cells could be related to an inherited genetic defect or exposure to a virus or toxin.
Exposures to certain viruses: Epstein-Barr virus and HIV, the virus that causes AIDS, have been linked to an increased risk of developing certain childhood cancers, such as Hodgkin's and non-Hodgkin lymphoma. Possibly, the virus alters a cell in some way. That cell then reproduces an altered cell and, eventually, these alterations become a cancer cell that reproduces more cancer cells.
Environmental exposures: Pesticides, fertilizers, and power lines have been researched for a direct link to childhood cancers. There has been evidence of cancer occurring among nonrelated children in certain neighborhoods and/or cities. Whether prenatal or infant exposure to these agents causes cancer, or whether it is a coincidence, is unknown.
Some forms of high-dose chemotherapy and radiation: In some cases, children who have been exposed to these agents may develop a second malignancy later in life. These strong anticancer agents can alter cells and/or the immune system. A second malignancy is a cancer that appears as a result of treatment of different cancer.
Cancer Genes
How do genes affect cancer growth?
The discovery of certain types of genes that contribute to cancer has been an extremely important development for cancer research. Over 90% of cancers are observed to have some type of genetic alteration. Some of these alterations are inherited, while others are sporadic, which means they occur by chance or occur from environmental exposures (usually over many years).
Types of cancer genes
Three main types of genes can affect cell growth and are altered (mutated) in certain types of cancers, including the following:
Oncogenes: These genes regulate the normal growth of cells. Scientists commonly describe oncogenes as similar to cancer "switch" that most people have in their bodies. What "flips the switch" to make these oncogenes suddenly become unable to control the normal growth of cells and allow abnormal cancer cells to begin to grow, is unknown.
Tumor suppressor genes: These genes can recognize abnormal growth and reproduction of damaged cells or cancer cells, and can interrupt their reproduction until the defect is corrected. If the tumor suppressor genes are mutated, however, and they do not function properly, tumor growth may occur.
Mismatch-repair genes: These genes help recognize errors when DNA is copied to make a new cell. If the DNA does not "match" perfectly, these genes repair the mismatch and correct the error. If these genes are not working properly, however, errors in DNA can be transmitted to new cells, causing them to be damaged.
Usually, the number of cells in any of our body tissues is tightly controlled so that new cells are made for normal growth and development, as well as to replace dying cells. Ultimately, cancer is a loss of this balance due to genetic alterations that "tip the balance" in favor of excessive cell growth.
Chapter 4
Types of Cancer
How Is Each Cancer Type Named?
Cancer is named after the part of the body where it originated. When cancer spreads, it keeps this same name. For example, if kidney cancer spreads to the lungs, it is still kidney cancer, not lung cancer. Lung cancer would be an example of a secondary tumor.
Staging is the process of determining whether cancer has spread and, if so, how far. There is more than one system used for staging cancer.
What Are the Different Types of Cancer?
Cancer is not just one disease but rather a group of diseases, all of which cause cells in the body to change and grow out of control. Cancers are classified either according to the kind of fluid or tissue from which they originate or according to the location in the body where they first developed. In addition, some cancers are of mixed types.
The following five broad categories indicate the tissue and blood classifications of cancer:
Carcinoma
Carcinoma is cancer found in body tissue known as epithelial tissue that covers or lines surfaces of organs, glands, or body structures. For example, a cancer of the lining of the stomach is called a carcinoma. Many carcinomas affect organs or glands that are involved with secretion, such as breasts that produce milk. Carcinomas account for 80-90% of all cancer cases.
Types of carcinoma include:
Melanoma
Basal cell carcinoma
Squamous cell skin cancer
Merkel cell carcinoma
Sarcoma
A sarcoma is a malignant tumor growing from connective tissues, such as cartilage, fat, muscle, tendons, and bones. The most common sarcoma, a tumor on the bone, usually occurs in young adults. Examples of sarcoma include osteosarcoma (bone) and chondrosarcoma (cartilage).
Types of sarcoma include:
Soft tissue sarcoma
Osteosarcoma
Ewing's sarcoma
Chondrosarcoma
Lymphoma
Lymphoma refers to cancer that originates in the nodes or glands of the lymphatic system, whose job it is to produce white blood cells and clean body fluids, or in organs such as the brain and breast. Lymphomas are classified into two categories: Hodgkin's lymphoma and non-Hodgkin's lymphoma.
Types of lymphoma include:
Hodgkin's lymphoma
Non-Hodgkin's lymphoma
Cutaneous lymphoma
Leukemia
Leukemia, also known as blood cancer, is a cancer of the bone marrow that keeps the marrow from producing normal red and white blood cells and platelets. White blood cells are needed to resist infection. Red blood cells are needed to prevent anemia. Platelets keep the body from easily bruising and bleeding.
Examples of leukemia include acute myelogenous leukemia, chronic myelogenous leukemia, acute lymphocytic leukemia, and chronic lymphocytic leukemia. The terms myelogenous and lymphocytic indicate the type of cells that are involved.
Types of leukemia include:
Acute lymphocytic leukemia
Acute myeloid leukemia
Agnogenic myeloid leukemia
Chronic lymphocytic leukemia
Chronic myeloid leukemia
Essential thrombocythemia (ET)
Hairy cell leukemia
Myelodysplastic syndromes (MDS)
Myeloma
Myeloma grows in the plasma cells of bone marrow. In some cases, the myeloma cells collect in one bone and form a single tumor, called a plasmacytoma. However, in other cases, the myeloma cells collect in many bones, forming many bone tumors. This is called multiple myeloma.
Chapter 5
Diagnosis
There is no single test that can accurately diagnose cancer. The complete evaluation of a patient usually requires a thorough history and physical examination along with diagnostic testing. Many tests are needed to determine whether a person has cancer, or if another condition (such as an infection) is mimicking the symptoms of cancer.
Effective diagnostic testing is used to confirm or eliminate the presence of disease, monitor the disease process, and plan for and evaluate the effectiveness of treatment. In some cases, it is necessary to repeat testing when a person's condition has changed, if a sample collected was not of good quality, or if an abnormal test result needs to be confirmed.
Diagnostic procedures for cancer may include imaging, laboratory tests (including tests for tumor markers), tumor biopsy, endoscopic examination, surgery, or genetic testing.
Cancer diagnosis methods:
Lab tests
Diagnostic imaging
Endoscopic exams
Genetic tests
Tumor biopsies
What are the different types of lab tests used to diagnose cancer?
Clinical chemistry uses chemical processes to measure levels of chemical components in body fluids and tissues. The most common specimens used in clinical chemistry are blood and urine.
Many different tests exist to detect and measure almost any type of chemical component in blood or urine. Components may include blood glucose, electrolytes, enzymes, hormones, lipids (fats), other metabolic substances, and proteins.
The following are some of the more common laboratory tests:
Blood tests
Complete blood count (CBC)
Urinalysis
Tumor markers
Learn more about laboratory tests.
Diagnostic imaging
What are the different types of diagnostic imaging?
Imaging is the process of producing valuable pictures of body structures and organs. It is used to detect tumors and other abnormalities, determine the extent of disease and evaluate the effectiveness of treatment. Imaging may also be used when performing biopsies and other surgical procedures. There are three types of imaging used for diagnosing cancer: transmission imaging, reflection imaging, and emission imaging. Each uses a different process.
Transmission imaging
X-ray computed tomography scans (CT scans), and fluoroscopy is radiological examinations whose images are produced by transmission. In transmission imaging, a beam of high-energy photons is produced and passed through the body structure being examined. The beam passes very quickly through less dense types of tissue such as watery secretions, blood, and fat, leaving a darkened area on the X-ray film. Muscle and connective tissues (ligaments, tendons, and cartilage) appear gray. Bones will appear white.
X-ray
Computed tomography scan (also called a CT scan or computed axial tomography or CAT scan)
Bone scan
Lymphangiogram (LAG)
Mammogram
Reflection imaging
Reflection imaging refers to the type of imaging produced by sending high-frequency sounds to the body part or organ being studied. These sound waves "bounce" off of the various types of body tissues and structures at varying speeds, depending on the density of the tissues present. The bounced sound waves are sent to a computer that analyzes the sound waves and produces a visual image of the body part or structure.
Ultrasound
Emission imaging
Emission imaging occurs when tiny nuclear particles or magnetic energy are detected by a scanner and analyzed by a computer to produce an image of the body structure or organ being examined. Nuclear medicine uses the emission of nuclear particles from nuclear substances introduced into the body specifically for examination. Magnetic resonance imaging (MRI) uses radio waves with a machine that creates a strong magnetic field that in turn causes cells to emit their radio frequencies.
Magnetic resonance imaging (MRI)
What are the different types of endoscopic examinations used to diagnose cancer?
Types of endoscopies include:
Cystoscopy (also called cystourethroscopy)
Colonoscopy
Endoscopic retrograde cholangiopancreatography (ERCP)
Esophagogastroduodenoscopy (also called EGD or upper endoscopy)
Sigmoidoscopy
What are the different types of genetic testing used to diagnose cancer?
Testing for mutations in genes that give an increased risk for cancer is complicated. The concepts are important to understand when considering cancer susceptibility gene testing.
What are the different types of tumor biopsies used to diagnose cancer?
A biopsy is a procedure performed to remove tissue or cells from the body for examination under a microscope. Some biopsies can be performed in a physician's office, while others need to be done in a hospital setting. In addition, some biopsies require the use of an anesthetic to numb the area, while others do not require any sedation.
Biopsies are usually performed to determine whether a tumor is malignant (cancerous) or to determine the cause of an unexplained infection or inflammation.
The following are the most common types of biopsies:
Endoscopic biopsy
Bone marrow biopsy
Excisional or incisional biopsy
Fine needle aspiration biopsy
Punch biopsy
Shave biopsy
Skin biopsy
Chapter 6
Cancer Treatment
Cancer is treated in several ways, depending on each person's medical condition and type of cancer. Common treatments involve chemotherapy and radiation therapy. Other treatments include surgery and biological therapies.
For many people with cancer, treatment is a process that is designed to meet their needs. Doctors plan treatments based on several key factors, such as the type and stage of cancer, as well as the person's age, health, and lifestyle.
If you have been diagnosed with cancer, you need to know that you play an important role in the treatment process. Offering input, asking questions, and expressing your concerns about treatment can help make treatment a better experience.
Cancer treatment terms you should know
Combined modality therapy: A term used to describe when doctors choose more than one therapy in treating a patient, such as a combination of radiation therapy and chemotherapy.
Adjuvant therapy: A term used to describe when doctors choose more than one therapy in treating a patient. However, the term adjuvant therapy is more specifically used to describe treatment given after the primary cancer treatment is completed to improve the chance of a cure. For example, if the doctor wants to treat cancer cells that may be present, he/she may prescribe one or more additional treatments.
Neoadjuvant therapy: A term used to describe when doctors choose to use more than one therapy in treating a patient. However, the term neoadjuvant therapy is more specifically used to describe cancer treatment given before the primary therapy—both to kill any cancer cells and contribute to the effectiveness of the primary therapy.
Preparing a patient for treatment
How can patients prepare for treatment?
As a patient, you play an important role in preparing for your cancer treatment. The following are some of the most important things to consider before treatment begins:
Find an oncologist and treatment center.
This step is important to everyone with cancer. Ask your general or primary care doctor for a referral to an oncologist. You can also contact government and professional medical organizations, such as your state's health department, the National Cancer Institute (NCI), or the American Medical Association (AMA) for information on cancer specialists and treatment centers in your area.
Get a second opinion.
It is common for people diagnosed with cancer to ask another cancer specialist for their opinion. A second opinion can help you to be sure your diagnosis and treatment plans are most appropriate for your individual medical history and profile. Asking for a second opinion also provides more information to consider when making choices about your treatment. Often, your oncologist can help you locate another cancer specialist for a second opinion.
Find out about your cancer treatment.
Your cancer care team will help you understand your treatment and answer questions. It also helps to learn about the type of cancer you have, as well as your treatment options. Ask your doctor where you can find more cancer information. The Stanford Cancer Center contains information on many cancer topics. Also, the National Cancer Institute (NCI), the American Cancer Society (ACS), and other cancer- and health-related organizations provide helpful information.
Find support when you need it.
Cancer treatment can be a long and tiring experience. Many people with cancer need help throughout the process. Finding help from others can make your experience more successful. Support groups for people with cancer are available in many communities. Managing your emotional health, your diet, and your finances are all things patients can do to reduce the stress involved in the treatment process. Oncology nurses and social workers are excellent resources for locating appropriate support groups.
Cancer treatment methods
Cancer is treated in several ways, depending on each person's medical condition and type of cancer. Common treatments involve chemotherapy and radiation therapy. Other treatments include surgery and biological therapies.
For many people with cancer, treatment is a process that is designed to meet their needs. Doctors plan treatments based on several key factors, such as the type and stage of cancer, as well as the person's age, health, and lifestyle. If you have been diagnosed with cancer, you need to know that you play an important role in the treatment process. Offering input, asking questions, and expressing your concerns about treatment can help make treatment a better experience.
There is a great deal of information to learn about the cancer treatment process, including various cancer treatment options—their goals, and side effects.
1. Radiation therapy
The use of high-energy radiation to kill or shrink cancer cells, tumors, and non-cancerous diseases.
2. Chemotherapy
The use of anticancer drugs to shrink or kill cancerous cells and reduce cancer spreading to other parts of the body.
3. Hormone therapy
Use of supplemental hormones to prevent or stop the growth or spread of tumors. The type of hormone therapy you receive depends upon many factors, such as the type and size of the tumor, your age, the presence of hormone receptors on the tumor, and other factors.
4. Blood and bone marrow transplant
A specialized therapy to transfer healthy bone marrow cells into a patient after their unhealthy bone marrow has been eliminated.
5. Biologic therapy
Treatment with substances that are made naturally in the body or that can block the growth of cancer cells.
6. Immunotherapy
Immunotherapy (also called biological therapy, biological response modifier therapy, or biotherapy) is designed to boost the body's immune system to fight cancer. The cells, antibodies, and organs of the immune system work to protect and defend the body against foreign invaders, such as bacteria or viruses. Doctors and researchers have found that the immune system might also be able to determine the difference between healthy cells and cancer cells in the body and eliminate the cancer cells.
7. Angiogenesis inhibitors
A substance that may prevent the formation of blood vessels. In anticancer therapy, an angiogenesis inhibitor may prevent the growth of new blood vessels where tumors need to grow.
Cancer and Diet:
Does it Matter?
Living a healthy life can be challenging when there are seemingly endless fad diets, do's and don'ts, celebrity tips, and kitchen hacks. It can all seem a little overwhelming. The truth is that being healthy is not as difficult or restrictive as people are led to believe. These excessively restrictive diets cause many people to find healthy eating 'too hard or not worth it. This is a particularly dangerous notion as diet is directly linked to cancer. Aside from quitting smoking, eating a healthy diet is the most effective way to reduce one's risk of cancer. But what does it mean to eat healthily?
How can a healthy diet prevent cancer?
Research suggests that simple lifestyle changes, such as following a healthy diet, could prevent 30-50% of all cancers. A healthy diet offers cancer-fighting nutrients but also reduces the likelihood of obesity which greatly increases one's risk of cancer.
Obese people often have chronic low-level inflammation, which can cause DNA damage that leads to cancer. Additionally, fat tissue produces excess amounts of estrogen and hormones that stimulate or inhibit cell growth. Naturally, hormones that interfere with cell growth can support the spread of cancer. High levels of estrogen are associated with increased risks of several cancers, including breast, ovarian, and endometrial cancers.
What foods are linked to cancer?
Eating too much of certain foods is linked to an increased risk of cancer. Such foods include:
Sugar and refined carbs – Researchers have found that a diet that causes blood glucose levels to spike is associated with an increased risk of several cancers, including stomach, breast, and colorectal cancers.
Processed meats and red meats – Processed meats, or meats that have been treated to preserve flavor by undergoing salting, curing, or smoking, and red meats have been found to increase the risk of colorectal cancer.
Overcooked foods – Cooking certain foods at high temperatures, such as grilling, frying, or broiling, can produce harmful compounds that contribute to inflammation. Most studies have identified the most harmful overcooked foods to be those high in fat and protein as well as highly processed foods.
What foods prevent cancer?
A holistic dietary approach is the best way to live a healthy life and prevent cancer. Fruits and vegetables are high in cancer-fighting nutrients. However, it is also suggested that flaxseeds, spices, beans, legumes, and nuts can aid in a cancer-free lifestyle. Keeping diets as natural and unprocessed as possible will ensure that the body receives a higher amount of nutrients and antioxidants and a smaller percentage of salt and complex carbohydrates.
Is there a diet that is best for living a cancer-free lifestyle?
It is important to remember that while there is likely a link between many foods and the risk of developing cancer, there is not a guaranteed diet that can prevent cancer in full. With that in mind, a great way to increase the amount of cancer-fighting nutrients in one's diet is to emphasize fruits and vegetables in meals. It is best to eat these foods raw, as this will ensure that all nutrients are consumed. However, even boiled and steamed vegetables offer excellent health benefits.
In addition to fruits and vegetables, eating calcium-rich foods and lean meat can support a cancer-fighting diet. Instead of frying or breading meat, opt for grilling or baking to make meals healthier. Of course, this doesn't mean that secret family recipe books need to be tossed. A healthy diet is all about balance, so a starchy or calorie-dense meal now and then is certainly acceptable. Monitoring serving size and pairing it with exercise means that comfort foods can be enjoyed without guilt or worry.
What tips and tricks are there to support a healthy lifestyle?
A great way to dive into a healthy lifestyle is to enlist a nutritionist. Nutritionists are experts in food and nutrition who help patients choose meal plans and offer advice on the health effects of different foods. Of course, seeing a nutritionist is not always a simple solution. For those who are unable to see a nutritionist, the US Department of Agriculture offers a great alternative – MyPlate. MyPlate shows the user's food group targets. It monitors what to eat and how much to eat within the calorie allowance based on the user's age, sex, height, weight, and physical activity. It can also be immensely helpful to track one's diet using a food diary. This increases accountability and allows reflection on diet choices.
What is physical activity?
Physical activity is defined as any movement that uses skeletal muscles and requires more energy than resting. Physical activity can include walking, running, dancing, biking, swimming, performing household chores, exercising, and engaging in sports activities.
A measure called the metabolic equivalent of task, or MET, is used to characterize the intensity of physical activity. One MET is the rate of energy expended by a person sitting at rest. Light-intensity activities expend less than 3 METs, moderate-intensity activities expend 3 to 6 METs, and vigorous activities expend 6 or more METs.
Sedentary behavior is any waking behavior characterized by an energy expenditure of 1.5 or fewer METs while sitting, reclining, or lying down. Examples of sedentary behaviors include most office work, driving a vehicle, and sitting while watching television.
A person can be physically active and yet spend a substantial amount of time being sedentary.
What is known about the relationship between physical activity and cancer risk?
Evidence linking higher physical activity to lower cancer risk comes mainly from observational studies, in which individuals report their physical activity and are followed for years for diagnoses of cancer. Although observational studies cannot prove a causal relationship, when studies in different populations have similar results and when a possible mechanism for a causal relationship exists, this provides evidence of a causal connection.
There is strong evidence that higher levels of physical activity are linked to a lower risk of several types of cancer.
Bladder cancer: In a 2014 meta-analysis of 11 cohort studies and 4 case-control studies, the risk of bladder cancer was 15% lower for individuals with the highest level of recreational or occupational physical activity than in those with the lowest level. A pooled analysis of over 1 million individuals found that leisure-time physical activity was linked to a 13% reduced risk of bladder cancer.
Breast cancer: Many studies have shown that physically active women have a lower risk of breast cancer than inactive women. In a 2016 meta-analysis that included 38 cohort studies, the most physically active women had a 12–21% lower risk of breast cancer than those who were least physically active. Physical activity has been associated with similar reductions in the risk of breast cancer among both premenopausal and postmenopausal women. Women who increase their physical activity after menopause may also have a lower risk of breast cancer than women who do not.
Colon cancer: In a 2016 meta-analysis of 126 studies, individuals who engaged in the highest level of physical activity had a 19% lower risk of colon cancer than those who were the least physically active.
Endometrial cancer: Several meta-analyses and cohort studies have examined the relationship between physical activity and the risk of endometrial cancer (cancer of the lining of the uterus). In a meta-analysis of 33 studies, highly physically active women had a 20% lower risk of endometrial cancer than women with low levels of physical activity. There is some evidence that the association is indirect, in that physical activity would have to reduce obesity for the benefits to be observed. Obesity is a strong risk factor for endometrial cancer.
Esophageal cancer: A 2014 meta-analysis of nine cohorts and 15 case-control studies found that the individuals who were most physically active had a 21% lower risk of esophageal adenocarcinoma than those who were least physically active.
Kidney (renal cell) cancer: In a 2013 meta-analysis of 11 cohort studies and 8 case-control studies, individuals who were the most physically active had a 12% lower risk of renal cancer than those who were the least active. A pooled analysis of over 1 million individuals found that leisure-time physical activity was linked to a 23% reduced risk of kidney cancer.
Stomach (gastric) cancer: A 2016 meta-analysis of 10 cohort studies and 12 case-control studies reported that individuals who were the most physically active had a 19% lower risk of stomach cancer than those who were least active.
There is some evidence that physical activity is associated with a reduced risk of lung cancer. However, it is possible that differences in smoking, rather than in physical activity, are what explain the association of physical activity with reduced risk of lung cancer. In a 2016 meta-analysis of 25 observational studies, physical activity was associated with reduced risk of lung cancer among former and current smokers but was not associated with risk of lung cancer among never smokers.
For several other cancers, there is more limited evidence of an association. These include certain cancers of the blood, as well as cancers of the pancreas, prostate, ovaries, thyroid, liver, and rectum.
How might physical activity be linked to reduced risks of cancer?
Exercise has many biological effects on the body, some of which have been proposed to explain associations with specific cancers. These include:
Lowering the levels of sex hormones, such as estrogen, and growth factors that have been associated with cancer development and progression Prevents high blood levels of insulin, which has been linked to cancer development and progression
Reducing inflammation
Improving immune system function
Altering the metabolism of bile acids, decreasing the exposure of the gastrointestinal tract to these suspected carcinogens.
Reducing the time it takes for food to travel through the digestive system, decreases gastrointestinal tract exposure to possible carcinogens
Helping to prevent obesity, which is a risk factor for many cancers
How much physical activity is recommended?
The U.S. Department of Health and Human Services Physical Activity Guidelines for Americans, 2nd edition, released in 2018, recommends that for substantial health benefits and to reduce the risk of chronic diseases, including cancer, adults engage in
150 to 300 minutes of moderate-intensity aerobic activity, 75 to 100 minutes of vigorous aerobic activity, or an equivalent combination of each intensity each week. This physical activity can be done in episodes of any length.
muscle-strengthening activities at least 2 days a week
balance training, in addition to aerobic and muscle-strengthening activity
Is physical activity beneficial for cancer survivors?
Yes. A report of the 2018 American College of Sports Medicine International Multidisciplinary Roundtable on Physical Activity and Cancer Prevention and Control concluded that exercise training and testing are generally safe for cancer survivors and that every survivor should maintain some level of physical activity.
strong evidence that moderate-intensity aerobic training and/or resistance exercise during and after cancer treatment can reduce anxiety, depressive symptoms, and fatigue and improve health-related quality of life and physical function
strong evidence that exercise training is safe in persons who have or might develop breast-cancer-related lymphedema
some evidence that exercise is beneficial for bone health and sleep quality
insufficient evidence that physical activity can help prevent cardiotoxicity or chemotherapy-induced peripheral neuropathy or improve cognitive function falls, nausea, pain, sexual function, or treatment tolerance
In addition, research findings have raised the possibility that physical activity may have beneficial effects on survival for patients with breast, colorectal, and prostate cancers.
Breast cancer: In a 2019 systematic review and meta-analysis of observational studies, breast cancer survivors who were the most physically active had a 42% lower risk of death from any cause and a 40% lower risk of death from breast cancer than those who were the least physically active.
Colorectal cancer: Evidence from multiple epidemiologic studies suggests that physical activity after a colorectal cancer diagnosis is associated with a 30% lower risk of death from colorectal cancer and a 38% lower risk of death from any cause.
Prostate cancer: Limited evidence from a few epidemiologic studies suggests that physical activity after a prostate cancer diagnosis is associated with a 33% lower risk of death from prostate cancer and a 45% lower risk of death from any cause.
There is very limited evidence for the beneficial effects of physical activity on survival for other cancers, including non-Hodgkin lymphoma, stomach cancer, and malignant glioma.
Conclusion
Cancer is a disease characterized by uncontrolled, uncoordinated, and undesirable cell division. Unlike normal cells, cancer cells continue to grow and divide for their whole lives, replicating into more and more harmful cells.
The abnormal growth and division observed in cancer cells are caused by damage to these cells' DNA (genetic material inside cells that determines cellular characteristics and functioning).
Early cancer and certain types of cancer may not have any symptoms. However, some symptoms may be the result of cancer or a less serious illness.
There is no single cause for cancer. Scientists believe that it is the interaction of many factors together that produces cancer. The factors involved may be genetic, environmental, or constitutional characteristics of the individual.
There is no single test that can accurately diagnose cancer. The complete evaluation of a patient usually requires a thorough history and physical examination along with diagnostic testing. Many tests are needed to determine whether a person has cancer, or if another condition (such as an infection) is mimicking the symptoms of cancer.
Cancer is treated in several ways, depending on each person's medical condition and type of cancer. Common treatments involve chemotherapy and radiation therapy. Other treatments include surgery and biological therapies.
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