Survival rate of patients who develop cancer in rectal stump after colectomy and ira in FAP patients

Purpose Patients with familial adenomatous polyposis (FAP) undergoing Total Colectomy with ileum-rectum anastomosis (IRA) could develop cancer in the rectal stump. The purpose of this study was to evaluate the survival rate after developing cancer in rectal stump in patients with FAP. Methodology The database of Hereditary Digestive Tumor Registry at Fondazione IRCCS Istituto Tumori of Milan was reviewed. Patients underwent Total Colectomy/IRA between 1935 and 2014 were included in the study, and patients who developed cancer in rectal stump were identified. The survival rate of the patients who developed a cancer in rectal stump was assessed using Kaplan-Meier method. Results From a total of 697 patients undergone total colectomy with IRA, 49 patients (7%) developed a cancer in the rectal stump. The median (range) age at diagnosis of cancer in the rectal stump, for the 49 patients, was 42 years (21-67), the APC mutation was pathogenetic in 43 (88%) patients and in 12 patients (24%) the mutation location was identified between codon 1061 and 1309. Median (range) interval from Total Colectomy/IRA and developing cancer in rectal stump was 157 months (12-486). The stage of cancer in rectal stump was A/B in 38 pts (77.5%) while stage C/D in 11 pts (22.5%). With a median (range) follow-up of 88.3 months (12-368) after developing cancer in rectal stump the survival rate at 10 years was 72%. Conclusion Within the present series the cancer in rectal stump is a quite long term risk, and may support the conservative approach at first surgery in FAP pts.