Preoperative pelvic radiation increases the risk for ileal pouch failure in patients with colitis-associated colorectal cancer.

Background And Aims: To evaluate the impact of preoperative radiation on pouch outcomes in patients with colitis-associated cancer (CAC).

Methods: CAC patients who underwent restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) from 1984 to 2009 were identified from our registry. The impact of preoperative pelvic radiation for CAC or other pelvic cancer on pouch related outcomes was evaluated.

Results: Sixty-three pouch patients with confirmed CAC were included (37 male, 58.7%). The mean age at pouch construction was 46.9±10.6 years. Seven patients were excluded due to the presence of persistent diverting ileostomy (n=2) or no follow-up (n=5). The remaining 56 patients were analyzed, including 9 who received pelvic radiation prior to IPAA creation for CRC or other cancers. Preoperative pelvic radiation was significantly associated with chronic pouchitis (P=0.024). There was, however, no correlation between pelvic radiation and pouch/anal transitional zone neoplasia, pouch stricture, pelvic abscess and pouch fistula/sinus. Pouch failure occurred in 13 patients after a median follow-up of 66.4 (range: 2.7-322.2) months. Although a simple statistical analysis based on the number of patients with pouch failure did not achieve significance (4/9 vs. 9/47, P=0.19), Kaplan-Meier analysis showed a strong association between preoperative pelvic radiation and the risk for pouch failure (P<0.001). A subgroup analysis of rectal cancer patients revealed that 3/7 patients (42.9%) with radiation and 3/17 (17.6%) without had pouch failure (P=0.31). Again, the association between pelvic radiation and pouch failure was confirmed using Kaplan-Meier analysis (P=0.02).

Conclusions: Pelvic radiation administered prior to IPAA creation appears to be associated with poor pouch outcomes. Oncological benefits and pouch functional outcomes should be carefully balanced before pelvic radiation is considered prior to restorative proctocolectomy.