腺瘤的恶变风险已被证实。较大的腺瘤(大于1cm)5年、10年和20年的累积恶变风险分别为2.5%、8%和24%。[61]Stryker SJ, Wolff BG, Culp CE, et al. Natural history of untreated colonic polyps. Gastroenterology. 1987;93:1009-1013.http://www.ncbi.nlm.nih.gov/pubmed/3653628?tool=bestpractice.com在进行结肠镜监测人群中结肠癌发生率比预期低70%至90%。[19]Winawer SJ, Zauber AG, Ho MN, et al. Prevention of colorectal cancer by colonoscopic polypectomy. N Engl J Med. 1993;329:1977-1981.http://content.nejm.org/cgi/content/full/329/27/1977http://www.ncbi.nlm.nih.gov/pubmed/8247072?tool=bestpractice.com在息肉切除术后结肠镜随访中腺瘤发生率约30%-50%。[3]Atkin WS, Saunders BP. Surveillance guidelines after removal of colorectal adenomatous polyps. Gut. 2002;51;v6-v9.http://gut.bmj.com/cgi/content/full/51/suppl_5/v6http://www.ncbi.nlm.nih.gov/pubmed/12221031?tool=bestpractice.com结肠镜监测的价值在于在高风险腺瘤癌变前发现和切除(仅仅活检是不够的),同时根据患者的结直肠癌风险安排合适的监测方案。EPAGE II报道缺乏证据支持或反对在根治性结直肠癌切除术后进行结肠镜随访,但是大多指南推荐在切除后1年进行结肠镜监测。[62]Arditi C, Gonvers JJ, Burnand B, et al. Appropriateness of colonoscopy in Europe (EPAGE II). Surveillance after polypectomy and after resection of colorectal cancer. Endoscopy. 2009;41:209-217.http://www.ncbi.nlm.nih.gov/pubmed/19280532?tool=bestpractice.com