Colectomy with ileorectal anastomosis for familial adenomatous polyposis: the risk of rectal cancer.

One hundred thirty-three patients with familial adenomatous polyposis undergoing colectomy and ileorectal anastomosis have been reviewed for the occurrence of cancer in the rectal stump. Ten patients developed rectal cancer (Actuarial survivorship rate of 88% for those patients free of rectal cancer at 20 years). Potential risk factors for the development of rectal cancer, including age at colectomy, previous colon cancer, number of rectal polyps, and length of the rectal stump, were analyzed and no significant differences were found. A policy of total colectomy with ileorectal anastomosis at 12 to 15 cm with conscientious lifelong follow-up thereafter is advocated for persons affected by familial adenomatous polyposis.