Cancer
Carcinoma; Malignant tumor
Cancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.
Causes
Cancer grows out of cells in the body. Normal cells multiply when the body needs them, and die when they are damaged or the body doesn't need them.
Cancer appears to occur when the genetic material of a cell becomes changed. This results in cells growing out of control. Cells divide too quickly and do not die in a normal way.
There are many kinds of cancer. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue.
There are many risk factors for cancer, including:
- Benzene and other chemicals
- Drinking too much alcohol
- Environmental toxins, such as certain poisonous mushrooms and a type of poison that can grow on peanut plants (aflatoxins)
- Genetic problems
- Obesity
- Radiation exposure
- Too much sunlight exposure
- Viruses
The cause of many cancers remains unknown.
The most common cause of cancer-related death is lung cancer.
In the U.S., skin cancer is the most commonly diagnosed cancer.
In U.S. men, other than skin cancer the three most common cancers are:
-
Prostate cancer
Prostate cancer
Prostate cancer is cancer that starts in the prostate gland. The prostate is a small, walnut-shaped structure that makes up part of a man's reproduc...
-
Lung cancer
Lung cancer
Small cell lung cancer (SCLC) is a fast-growing type of lung cancer. It spreads much more quickly than non-small cell lung cancer. There are two typ...
-
Colorectal cancer
Colorectal cancer
Colon, or colorectal cancer, is cancer that starts in the large intestine (colon) or the rectum (end of the colon). Other types of cancer can affect ...
In U.S. women, other than skin cancer the three most common cancers are:
-
Breast cancer
Breast cancer
Breast cancer is cancer that starts in the tissues of the breast. There are 2 main types of breast cancer:Ductal carcinoma starts in the tubes (duct...
- Lung cancer
- Colorectal cancer
Some cancers are more common in certain parts of the world. For example, in Japan, there are many cases of stomach cancer . But in the United States, this type of cancer is less common. Differences in diet or environmental factors may play a role.
Stomach cancer
Stomach cancer is cancer that starts in the stomach.
Some other types of cancer include:
-
Brain cancer
Brain cancer
A primary brain tumor is a group (mass) of abnormal cells that start in the brain.
-
Cervical cancer
Cervical cancer
Cervical cancer is cancer that starts in the cervix. The cervix is the lower part of the uterus (womb) that opens at the top of the vagina.
-
Hodgkin lymphoma
Hodgkin lymphoma
Hodgkin lymphoma is a cancer of lymph tissue. Lymph tissue is found in the lymph nodes, spleen, liver, bone marrow, and other sites.
-
Kidney cancer
Kidney cancer
Renal cell carcinoma is a type of kidney cancer that starts in the lining of very small tubes (tubules) in the kidney.
-
Leukemia
Leukemia
Leukemia is a type of blood cancer that begins in the bone marrow. Bone marrow is the soft tissue in the center of the bones, where blood cells are ...
-
Liver cancer
Liver cancer
Hepatocellular carcinoma is cancer that starts in the liver.
-
Non-Hodgkin lymphoma
Non-Hodgkin lymphoma
Non-Hodgkin lymphoma (NHL) is cancer of the lymph tissue. Lymph tissue is found in the lymph nodes, spleen, and other organs of the immune system. W...
-
Ovarian cancer
Ovarian cancer
Ovarian cancer is cancer that starts in the ovaries. The ovaries are the female reproductive organs that produce eggs.
-
Pancreatic cancer
Pancreatic cancer
Pancreatic cancer is cancer that starts in the pancreas.
-
Testicular cancer
Testicular cancer
Testicular cancer is cancer that starts in the testicles. The testicles are the male reproductive glands located in the scrotum.
-
Thyroid cancer
Thyroid cancer
Thyroid cancer is a cancer that starts in the thyroid gland. The thyroid gland is located inside the front of your lower neck.
-
Uterine cancer
Uterine cancer
Endometrial cancer is cancer that starts in the endometrium, the lining of the uterus (womb).
Symptoms
Symptoms of cancer depend on the type and location of the cancer. For example, lung cancer can cause coughing , shortness of breath , or chest pain . Colon cancer often causes diarrhea , constipation , and blood in the stool .
Coughing
Coughing is an important way to keep your throat and airways clear. But too much coughing may mean you have a disease or disorder. Some coughs are d...
Shortness of breath
Breathing difficulty may involve:Difficult breathingUncomfortable breathingFeeling like you are not getting enough air
Chest pain
Chest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.
Constipation
Constipation in infants and children occurs when they have hard stools or have problems passing stools. A child may have pain while passing stools o...
Blood in the stool
Bloody stools often are a sign of a problem in the digestive tract. Blood in the stool may come from anywhere along your digestive tract from your m...
Some cancers may not have any symptoms. In certain cancers, such as pancreatic cancer, symptoms often do not start until the disease has reached an advanced stage.
The following symptoms may occur with cancer:
-
Chills
Chills
Chills refers to feeling cold after being in a cold environment. The word can also refer to an episode of shivering along with paleness and feeling ...
-
Fatigue
Fatigue
Fatigue is a feeling of weariness, tiredness, or lack of energy.
-
Fever
Fever
Fever is the temporary increase in the body's temperature in response to a disease or illness. A child has a fever when the temperature is at or abov...
-
Loss of appetite
Loss of appetite
A decreased appetite is when your desire to eat is reduced. The medical term for a loss of appetite is anorexia.
-
Malaise
Malaise
Malaise is a general feeling of discomfort, illness, or lack of well-being.
- Night sweats
-
Weight loss
Weight loss
Unexplained weight loss is a decrease in body weight, when you did not try to lose the weight on your own. Many people gain and lose weight. Uninten...
Exams and Tests
Like symptoms, the signs of cancer vary based on the type and location of the tumor. Common tests include the following:
-
Biopsy
of the tumor
Biopsy
A biopsy is the removal of a small piece of tissue for laboratory examination.
- Blood tests (which look for chemicals such as tumor markers)
-
Bone marrow biopsy
(for lymphoma or leukemia)
Bone marrow biopsy
A bone marrow biopsy is the removal of marrow from inside bone. Bone marrow is the soft tissue inside bones that helps form blood cells. It is foun...
-
Chest x-ray
Chest x-ray
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.
-
Complete blood count
(CBC)
Complete blood count
A complete blood count (CBC) test measures the following:The number of red blood cells (RBC count)The number of white blood cells (WBC count)The tota...
-
CT scan
CT scan
A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body. Related tests include:Abdomin...
-
Liver function tests
Liver function tests
Liver function tests are common tests that are used to see how well the liver is working. Tests include:AlbuminAlpha-1 antitrypsin Alkaline phosph...
-
MRI scan
MRI scan
A magnetic resonance imaging (MRI) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not us...
-
PET scan
PET scan
A positron emission tomography scan is a type of imaging test. It uses a radioactive substance called a tracer to look for disease in the body. A po...
Most cancers are diagnosed by biopsy. Depending on the location of the tumor, the biopsy may be a simple procedure or a serious operation. Most patients with cancer have CT scans to determine the exact location and size of the tumor or tumors.
A cancer diagnosis is often difficult to cope with. It is important that you discuss the type, size, and location of the cancer with your health care provider when you are diagnosed. You also will want to ask about treatment options, along with their benefits and risks.
It's a good idea to have someone with you at the provider's office to help you get through the diagnosis. If you have trouble asking questions after hearing about your diagnosis, the person you bring with you can ask them for you.
Treatment
Treatment varies based on the type of cancer and its stage. The stage of a cancer refers to how much it has grown and whether the tumor has spread from its original location.
-
If the cancer is in one location and has not spread, the most common treatment approach is surgery to cure the cancer. This is often the case with
skin cancers
, as well as cancers of the lung, breast, and colon.
Skin cancers
Basal cell cancer is the most common form of cancer in the United States. Most skin cancers are basal cell cancer. Basal cell cancer is almost alway...
- If the tumor has spread to local lymph nodes only, sometimes these can be removed.
-
If surgery cannot remove all of the cancer, the options for treatment may include
radiation
,
chemotherapy
, targeted cancer therapies, or other types of treatment. Some cancers require a combination of treatments. Lymphoma, or cancer of the lymph glands, is rarely treated with surgery. Chemotherapy, radiation therapy, and other nonsurgical therapies are often used.
Radiation
Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells.
Chemotherapy
The term chemotherapy is used to describe cancer-killing drugs. Chemotherapy may be used to:Cure the cancerShrink the cancerPrevent the cancer from ...
Although treatment for cancer can be difficult, there are many ways to keep up your strength.
If you have radiation treatment:
- Treatment is usually scheduled every weekday.
- You should allow 30 minutes for each treatment session, although the treatment itself usually takes only a few minutes.
- You should get plenty of rest and eat a well-balanced diet during the course of your radiation therapy.
- Skin in the treated area may become sensitive and easily irritated.
- Some side effects of radiation treatment are temporary. They vary depending on the area of the body that is being treated.
If you have chemotherapy:
- Eat right.
- Get plenty of rest, and don't feel like you have to accomplish tasks all at once.
- Avoid people with colds or the flu. Chemotherapy can cause your immune system to weaken.
Talk with family, friends, or a support group about your feelings. Work with your health care providers throughout your treatment. Helping yourself can make you feel more in control.
Support Groups
The diagnosis and treatment of cancer often causes a lot of anxiety and can affect a person's entire life. There are many resources for cancer patients.
Resources
The following organizations are good resources for information on cancer:American Cancer Society -- www. cancer. orgCancerCare -- www. cancercare. or...
Outlook (Prognosis)
The outlook depends on the type of cancer and the stage of the cancer when diagnosed.
Some cancers can be cured. Other cancers that are not curable can still be treated effectively. Some patients can live for many years with cancer. Other tumors are quickly life threatening.
Possible Complications
Complications depend on the type and stage of cancer. The cancer may spread.
When to Contact a Medical Professional
Contact your health care provider if you develop symptoms of cancer.
Prevention
You can reduce the risk of getting a cancerous (malignant) tumor by:
- Eating healthy foods
- Exercising regularly
- Limiting alcohol
- Maintaining a healthy weight
- Minimizing your exposure to radiation and toxic chemicals
- Not smoking or chewing tobacco
- Reducing sun exposure, especially if you burn easily
Cancer screenings, such as mammography and breast examination for breast cancer and colonoscopy for colon cancer, may help catch these cancers at their early stages when they are most treatable. Some people at high risk for developing certain cancers can take medication to reduce their risk.
Mammography
A mammogram is an x-ray picture of the breasts. It is used to find breast tumors and cancer.
Colonoscopy
A colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope. The colonoscope has a sm...
References
National Cancer Institute. Chemotherapy and you: support for people who have cancer. Available at: http://www.cancer.gov/cancertopics/coping/chemotherapy-and-you. Accessed January 8, 2015.
National Cancer Institute. Radiation therapy and you: support for people who have cancer. Available at: http://www.cancer.gov/cancertopics/coping/radiation-therapy-and-you. Accessed January 8, 2015.
Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff's Clinical Oncology . 5th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014.
Perry MC. Approach to the patient with cancer. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 182.
Siegel RL, Miller KD, Jemal A. Cancer statistics, 2015. CA Cancer J Clin . 2015;65:5-29.
-
Colon and rectal cancers
(In-Depth)
-
Melanoma and other skin cancers
(In-Depth)
-
Ovarian cancer
(In-Depth)
-
Non-small cell lung cancer
(In-Depth)
-
Prostate cancer
(In-Depth)
-
Skin cancer
(Alt. Medicine)
-
Prostate cancer
(Alt. Medicine)
-
Lung cancer
(Alt. Medicine)
-
Bone cancer
(Alt. Medicine)
-
Breast cancer
(Alt. Medicine)
Review Date: 1/18/2015
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.