Cancers that begin in the large bowel (colon).


What is colon cancer?
Cancers that begin in the lower bowel (intestine) are called colon cancers. The colon is the last 4-6 feet of your intestine, which is the organ that helps get rid of solid waste from your body. The last 6 inches of the colon is called the rectum, and cancers that start here are called rectal cancers. Colon and rectal cancers will cause about 50,000 deaths in the United States this year. Only lung cancer will kill more Americans.  Seventy-five percent of colon and rectal cancers occur in people with no family history of colon cancer.

What causes colon cancer?
Colon cancer is a disease caused by genes and certain lifestyle factors (smoking, diet, etc). All cancers begin when the genes that control how cells grow stop working normally.  There are many factors that may increase the risk of developing colon cancer: age over 45, having a previous adenomatous (pre-cancerous) polyp or colon cancer, a personal history of inflammatory bowel disease, a family history of colon or rectal cancer, or an African-American, Native American or Ashkenazi Jewish ethnicity.  Other lifestyle factors linked to colon cancer include eating a lot of red meats, being overweight, not exercising, smoking cigarettes, using chewing tobacco, drinking too much alcohol, and type 2 diabetes.  Men and women have the same chance of developing colon cancer.

What are the symptoms of colon cancer?
Many people with colon cancer have no symptoms at the beginning of the disease.  When symptoms appear, they can be different depending on the cancer's size and location in your large intestine.  Symptoms of colorectal cancer may cause diarrhea, constipation, blood in your stool, abdominal pain that does not go away, a feeling that your bowel movement is not complete, fatigue, or losing weight without trying.

How is colon cancer diagnosed?
If your symptoms suggest that you could have colon cancer, your doctor may suggest blood tests, colonoscopy, barium enema x-ray, or computerized tomography (CT) scan to help make a diagnosis.  Colonoscopy is a procedure that allows doctors to view the lining of the colon to check for growths in the colon.  Biopsies, or samples of the colon lining, can be taken during the colonoscopy. A physician trained to identify cancer in cells then views these biopsies under a microscope. If you are diagnosed with colon cancer, your doctor will order tests to determine the stage of your cancer. Staging helps your doctor choose the best treatment for you.

How is colon cancer treated?
Depending on the stage of colon cancer, treatment may include surgery, radiation, and/or chemotherapy.

When to seek medical advice:
Talk with your doctor right away if you have a change in bowel habits (diarrhea or constipation), blood in or on your stool, or constant stomach pain.

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