Rectal Cancer (cont.)

Rectal cancer usually develops over several years, first growing as a precancerous growth called a polyp. Some polyps have the ability to turn into cancer and begin to grow and penetrate the wall of the rectum.

The actual cause of rectal cancer is unclear.However, the following are risk factors for developing rectal cancer:

• Increasing age
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• Smoking
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• Family history of colon or rectal cancer
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• High-fat diet and/or a diet mostly from animal sources
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• Personal or family history of polyps or colorectal cancer

Family history is a factor in determining the risk of rectal cancer. If a family history of colorectal cancer is present in a first-degree relative (a parent or a sibling), then endoscopy of the colon and rectum should begin 10 years before the age of the relative's diagnosis or atage 50 years, whichever comes first.

An often forgotten risk factor, but perhaps the most important, is the lack of screening for rectal cancer.Routine cancer screening of the colon and rectum is the best way to prevent rectal cancer.