Definition of Colon cancer:

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.

Causes, incidence, and risk factors:

According to the American Cancer Society, colorectal cancer is one of the leading causes of cancer-related deaths in the United States. (However, early diagnosis often leads to a complete cure.)

There is no single cause for colon cancer. Nearly all colon cancers begin as non-cancerous (benign) polyps, which slowly develop into cancer.

You have a higher risk for colon cancer if you have:

• Cancer elsewhere in the body
• Colorectal polyps
• Crohn's disease
• Family history of colon cancer
• Personal history of breast cancer
• Ulcerative colitis

Certain genetic syndromes also increase the risk of developing colon cancer.

What you eat may play a role in your risk of colon cancer. Colon cancer may be associated with a high-fat, low-fiber diet and red meat. However, some studies found that the risk does not drop if you switch to a high-fiber diet, so the cause of the link is not yet clear.

Smoking cigarettes is another risk factor for colorectal cancer.