The risk for colon cancer among the general population is about 6%. (Colon cancer is a common type of cancer.) The risk of developing colon cancer if one first degree (parent, child or sibling) relative has colon cancer at an older age is approximately twice the general population or 12%. The recommendations regarding screening for colon cancer at this risk level are not absolute, but many experts recommend intensified screening.
Routine screening for colon cancer would include standard screening with fecal occult blood testing yearly and sigmoidoscopy every 3 to 5 years beginning at age 40. Many experts also would recommend colonoscopy at age 40-50 with recommendations regarding further colonoscopies based on the findings at this first colonoscopy. (For example, if no polyps or cancers are found, colonoscopy might not be repeated.)
There are a few uncommon cancer syndromes in which cancers of several different organs are associated in families; however, cancer of the stomach and colon are not associated in such syndromes.
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Last Editorial Review: 8/17/2001