Cancer Health Channel

Feature Article

Cancer

Definition

Cancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.

Alternative Names

Carcinoma; Malignant tumor

Causes, incidence, and risk factors

Cells are the building blocks of living things. Cancer grows out of normal cells in the body. Normal cells multiply when the body needs them, and die when the body doesn't need them. Cancer appears to occur when the growth of cells in the body is out of control and cells divide too quickly. It can also occur when cells “forget” how to die.

There are many different kinds of cancers. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue.

There are many causes of cancers, including:

  • Benzene and other chemicals
  • Certain poisonous mushrooms and a type of poison that can grow on peanut plants (aflatoxins)
  • Certain viruses
  • Radiation
  • Sunlight
  • Tobacco

However, the cause of many cancers remains unknown.

The most common cause of cancer-related death is lung cancer.

The three most common cancers in men in the United States are:

In women in the U.S., the three most common cancers are:

Some cancers are more common in certain parts of the world. For example, in Japan, there are many cases of gastric cancer, but in the U.S. this type of cancer is pretty rare. Differences in diet may play a role.

Some other types of cancers include:

Symptoms

Symptoms of cancer depend on the type and location of the tumor.

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Breast cancer (8 images) Average Rating: (Doctor-Reviewed information)
Breast cancer is a cancer that starts in the tissues of the breast. There are two main types of breast cancer: Ductal carcinoma starts in the tubes (ducts) that move milk from the breast to the nipple. Most breast cancers are of this type; Lobular carcinoma starts in parts of the breast, called lobules, that produce milk. In rare cases, breast cancer can start in other areas of the breast. Many breast cancers are sensitive to the hormone estrogen. This means that estrogen causes the breast cancer tumor to grow. Such cancer is called estrogen receptor positive cancer or ER positive cancer. Some women have what's called HER2-positive breast cancer. HER2 refers to a gene that helps cells grow, divide, and repair themselves. When cells have too many copies of this gene, cells - including cancer cells - grow faster. Experts think that women with HER2-positive breast cancer have a more aggressive disease and a higher risk of recurrence than those who do not have this type. Reviewer: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California.Date: 12/01/2008

Leukemia (9 images) (Doctor-Reviewed information)
Leukemia is a group of bone marrow diseases involving an uncontrolled increase in white blood cells (leukocytes. For information about a specific type of leukemia, see the following: Acute lymphocytic leukemia (ALL; Acute myelogenous leukemia (AML; Chronic lymphocytic leukemia (CLL; Chronic myelogenous leukemia (CML; Hairy cell leukemia. See also: Leukemia resources Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. Date: 03/02/2009

Lung cancer - small cell (18 images) (Doctor-Reviewed information)
Small cell lung cancer (SCLC) is a fast-growing type of lung cancer. It tends to spread much more quickly than non-small cell lung cancer. There are three different types of small cell lung cancer: Small cell carcinoma (oat cell cancer; Mixed small cell/large cell carcinoma; Combined small cell carcinoma. Most small cell lung cancers are the oat cell type. Reviewer: Sean O. Stitham, MD, private practice in Internal Medicine, Seattle, Washington; and James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/04/2008

Skin cancer (15 images) (Doctor-Reviewed information)
Skin cancer is the uncontrolled growth of abnormal skin cells. If left unchecked, these cancer cells can spread from the skin into other tissues and organs. There are different types of skin cancer. Basal cell carcinoma is the most common. Melanoma is less common, but more dangerous. Reviewer: Kevin Berman, MD, PhD, Associate, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 02/05/2008

Prostate cancer (5 images) Average Rating: (Doctor-Reviewed information)
Prostate cancer is cancer that grows in prostate gland. The prostate is a small, walnut-sized structure that makes up part of a man's reproductive system. It wraps around the urethra, the tube that carries urine out of the body. Reviewer: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California (6/10/2008).Date: 08/07/2008

Cervical cancer (5 images) (Doctor-Reviewed information)
Cervical cancer is cancer that starts in the cervix, the lower part of the uterus (womb) that opens at the top of the vagina. Reviewer: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Previously reviewed by James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California; and David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. (6/10/2008)Date: 12/24/2008

Endometrial cancer (7 images) (Doctor-Reviewed information)
Endometrial cancer is cancer that starts in the endometrium, the lining of the uterus (womb. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Susan Storck, MD, FACOG, Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine; Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. Date: 05/02/2008

Colon cancer (11 images) (Doctor-Reviewed information)
Colon cancer is cancer that starts in the large intestine (colon) or the rectum (end of the colon. Such cancer is sometimes referred to as "colorectal cancer." Other types of colon cancer such as lymphoma, carcinoid tumors, melanoma, and sarcomas are rare. In this article, use of the term "colon cancer" refers to colon carcinoma and not these rare types of colon cancer. Reviewer: Stephen Gund, MD, PhD, Chief of Hematology/Oncology and Director of the George Bray Cancer Center at New Britain General Hospital, New Britain, CT. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 03/24/2008

Bladder cancer (3 images) (Doctor-Reviewed information)
Bladder cancer is a cancerous tumor in the bladder - the organ that holds urine. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 02/12/2009

Ovarian cancer (8 images) (Doctor-Reviewed information)
Ovarian cancer is cancer that starts in the ovaries. The ovaries are the female reproductive organs that produce eggs. Reviewer: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Previously reviewed by James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California; and David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. (6/10/2008)Date: 12/24/2008

Esophageal cancer (2 images) (Doctor-Reviewed information)
Esophageal cancer is a malignant (cancerous) tumor of the esophagus, the muscular tube that moves food from the mouth to the stomach. See also: Barrett's esophagus Reviewer: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Mark Levin, MD, Hematologist and Oncologist, Newark, NJ. Review provided by VeriMed Healthcare Network (4/8/2008).Date: 07/22/2008

Oral cancer (2 images) (Doctor-Reviewed information)
Oral cancer is cancer of the mouth. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 02/12/2009

Pancreatic carcinoma (4 images) (Doctor-Reviewed information)
Pancreatic carcinoma is cancer of the pancreas. Reviewer: Sean O. Stitham, MD, private practice in Internal Medicine, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 08/17/2008

Thyroid cancer (4 images) (Doctor-Reviewed information)
Thyroid cancer is a cancerous growth of the thyroid gland. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 02/12/2009

Testicular cancer (2 images) (Doctor-Reviewed information)
Testicular cancer is cancer that starts in the testicles, the male reproductive glands located in the scrotum. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 04/05/2009

Gastric cancer (3 images) (Doctor-Reviewed information)
Gastric cancer is cancer that starts in the stomach. Reviewer: Sean O. Stitham, MD, private practice in Internal Medicine, Seattle, Washington; and James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. Date: 09/04/2008

Non-Hodgkin's lymphoma (2 images) (Doctor-Reviewed information)
Non-Hodgkin's lymphoma is cancer of the lymphoid tissue, which includes the lymph nodes, spleen, and other organs of the immune system. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 02/12/2009

Hepatocellular carcinoma (3 images) (Doctor-Reviewed information)
Hepatocellular carcinoma is cancer of the liver. Reviewer: Sean O. Stitham, MD, private practice in Internal Medicine, Seattle, Washington; and James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/04/2008

Cancer - penis (2 images) (Doctor-Reviewed information)
Cancer of the penis is cancer that starts in the penis, an organ that makes up part of the male reproductive system. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 11/10/2008

Vaginal tumors (3 images) (Doctor-Reviewed information)
A vaginal tumor is an abnormal growth of tissue in the vagina, a female reproductive organ. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed byDavid Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 06/10/2008

Diet - cancer treatment (Doctor-Reviewed information)
People with cancer need special nutritional planning and management. Reviewer: Patrika Tsai, M.D., M.P.H., Assistant Clinical Professor, Pediatric Gastroenterology, Hepatology and Nutrition, University of California, San Francisco, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 07/22/2008

Cancer - resources (Doctor-Reviewed information)
The following organizations are good resources for information on cancer: American Cancer Society - www.cancer.org; Cancer Care - www.cancercare.org; National Cancer Institute - www.cancer.gov. Reviewer: Jennifer K. Mannheim, CPNP, private practice, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 10/18/2008

Cancer treatment information (Doctor-Reviewed information)
The goals of cancer treatment are to: Kill or remove cancer cells; Prevent or delay the cancer from coming back; Treat cancer symptoms (if the cancer can not be cured. The types of treatment depend on the specific type of cancer, but may include: Chemotherapy; Radiation; Surgery. You may receive more than one type of treatment. This is called combined therapy. Cancer warning signs include: A change in bowel or bladder habits; A sore that does not heal; Unusual bleeding or drainage; Thickening or lump in the breast or elsewhere; Indigestion or swallowing difficulty; A change in a wart or mole; Persistent cough or hoarseness. It is important to note that these symptoms may also be due to conditions other than cancer. The following articles offer more detailed information: Breast cancer; Brain cancer - adults; Brain cancer - children; Cancer - general overview; Cervical cancer; Colon cancer; Esophageal cancer; Kidney cancer; Leukemia; Liver cancer; Lung cancer; Lymphoma; Oral cancer (includes mouth cancer; Ovarian cancer; Pancreatic cancer; Penis cancer; Prostate cancer; Skin cancer; Stomach cancer; Testicular cancer; Thyroid cancer; Uterine cancer (endometrial cancer; Vaginal cancer; Vulvar cancer. For information on cancer-related organizations, please see Cancer - support groups. Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 10/18/2008

Cell phones - do they cause cancer? (Doctor-Reviewed information)
Cancer and cell phones Reviewer: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 09/23/2008

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