Cohen L B
Department of geriatrics and adult development, Mount Sinai Medical Center, New York, USA.
Geriatrics. 1996 Dec;51(12):45-9; quiz 50.
The adenomatous polyp is the precursor of most--if not all--colorectal cancers. The average 10 to 12 years that it takes for a polyp to undergo malignant degeneration provides a window of opportunity to identify and remove benign neoplasms, before they become invasive cancers. The incidence of colorectal cancer rises significantly after age 50 and doubles with each successive decade. For screening asymptomatic patients age 50 and older, the fecal occult blood test and flexible sigmoidoscopy are the methods of choice. Recommendations for screening higher-risk individuals are based upon the relative risk of colon cancer in various subgroups, based on family and individual history.
腺瘤性息肉是大多数（即便不是所有）结直肠癌的癌前病变。息肉发生恶性变平均需要10至12年时间，这为在良性肿瘤发展为浸润性癌之前识别并切除它们提供了一个机会窗口。结直肠癌的发病率在50岁以后显著上升，并且每增长十岁就会翻倍。对于50岁及以上无症状患者的筛查，粪便潜血试验和乙状结肠镜检查是首选方法。基于家族史和个人史，针对高危个体筛查的建议是根据不同亚组患结肠癌的相对风险制定的。
