Incidence of methacronous cancer after total colectomy with ileorectal anastomosis or total proctocolectomy in classical FAP patients.

646 Background: Total proctocolectomy (TPC) with ileal pouch is considered the procedure of choice in classic familial adenomatous polyposis (FAP), but total colectomy (TC) with rectal sparing can be performed in selected cases. The objective of this study is to determine and compare the incidence of methacronous cancer in the remanescent rectum in patients submitted to TPC or TC. Methods: We performed a retrospective analysis of 55 patients operated beteween 1992 and 2011. Patients were identified from 34 FAP families, registered at the AC Camargo Hereditary Colorectal Cancer Registry. Patients with attenuated FAP were excluded. The main endpoint was the occurence of cancer at the remanescent rectum. Results: Thirty seven patients were submitted to TPC and 18 to TC with ileo-rectal anastomosis. Among patients submitted to TPC, just one (2.7%) had methacronous adenocarcinoma just above the dentate line. Among patients submitted to TC with rectal sparing, 4 (22.2%) have another cancer at the remanescente r...