Cytoreductive surgery and HIPEC offers similar outcomes in patients with rectal peritoneal metastases compared to colon cancer patients: a matched case control study.

Background & Objectives: The effect of cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with rectal peritoneal metastases (PM) is unclear. This case-control study aims to assess the results of cytoreduction and HIPEC in patients with rectal PM compared to colon PM patients.

Methods: Colorectal PM patients treated with complete macroscopic cytoreduction and HIPEC were included. Two colon cancer patients were case-matched for each rectal cancer patient, based on prognostic factors (T stage, N stage, histology type, and extent of PM). Short- and long-term outcomes were compared between both groups.

Results: From 317 patients treated with complete macroscopic cytoreduction and HIPEC, 29 patients (9.1%) had rectal PM. Fifty-eight colon cases were selected as control patients. Baseline characteristics were similar between groups. Major morbidity was 27.6% and 34.5% in the rectal and colon group, respectively (P = 0.516). Median disease-free survival was 13.5 months in the rectal group and 13.6 months in the colon group (P = 0.621). Two- and five-year overall survival rates were 54%/32% in rectal cancer patients, and 61%/24% in colon cancer patients (P = 0.987).

Conclusions: Cytoreduction and HIPEC in selected patients with rectal PM is feasible and provides similar outcomes as in colon cancer patients. Rectal PM should not be regarded a contra-indication for cytoreduction and HIPEC in selected patients. J. Surg. Oncol. 2016;113:548-553. © 2016 Wiley Periodicals, Inc.