What is colon cancer?

Cancers that begin in the lower bowel are called colon cancers. The colon is the last 4-6 feet of your intestine, an organ that helps eliminate 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 over 50,000 deaths in the United States this year; only lung cancer will kill more Americans. 75% of colon and rectal cancers occur in persons without a family history of colon cancer.

What causes colon cancer?

Colon cancer is a disease caused by an interaction of genes and certain lifestyle factors (smoking, diet, etc). Cancers of all types, including those of the colon, begin when genes that regulate how cells grow stop working normally. There are many factors that may increase the risk of developing colon cancer. To list a few: age over 50, 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; African-American, Native American or Ashkenazi Jewish ethnicity. Other lifestyle related factors associated with colon cancer include a diet that is high in red meats, obesity, physical inactivity, tobacco use, smoking, heavy alcohol use and type 2 diabetes. Men and women are at equal risk for developing colon cancer.

What are the symptoms of colon cancer?

Many people with colon cancer experience no symptoms in the early stages of the disease. When symptoms appear, they'll likely vary, depending on the cancer's size and location in your large intestine. Symptoms of colorectal cancer may include a change in your bowel habits, including diarrhea or constipation, rectal bleeding or blood in your stool, persistent abdominal discomfort, such as cramps, gas or pain, a feeling that your bowel doesn't empty completely, weakness or fatigue or unexplained weight loss.

How is colon cancer diagnosed?

If your symptoms indicate that you could have colon cancer, your doctor may recommend blood tests, colonoscopy, barium enema x-ray, or computerized tomography (CT) scan to help make a diagnosis. Colonoscopy is a diagnostic procedure that allows direct viewing of the lining of the colon to check for colon growths. Biopsies, or samples, of the lining can be obtained at the time of the colonoscopy to be assessed under the microscope. If you are diagnosed with colon cancer, your doctor will then order tests to determine the extent, or stage, of your cancer. Staging helps determine what treatments are most appropriate 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 notice a change in bowel habits, rectal bleeding, blood in or on the stool, cramping or steady stomach pain.

Additional Resources

American Cancer Society

American Gastroenterological Association