Early Postoperative Chemotherapy After Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Isolated Peritoneal Carcinomatosis of Colon Cancer: A Multicenter Study.

Abstract

The prognosis of peritoneal carcinomatosis (PC) from colorectal cancer has been improved with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). However, benefits of postoperative chemotherapy (CT) are unclear. This retrospective, multicenter study included 231 patients treated by CRS and HIPEC for isolated PC of colon cancer in four expert's centers. Overall survival (OS), progression-free survival (PFS), and peritoneal recurrence-free survival (PRFS) were compared between patients with adjuvant CT (started within 3 months after surgery) and patients with surveillance only. After exclusion of 10 patients for early postoperative death (4%), 221 patients were included (CT group: n = 151; surveillance group: n = 70). Main postoperative CT regimens (median of 6 cycles) were Folfox (28%), Folfiri bevacizumab (24.5%), Folfiri (16%), and Folfiri cetuximab (12.5%). The median OS after surgery was 43.3 months with no difference between CT and surveillance groups. In multivariate analysis, a low peritoneal cancer index (p < 0.0001) and a long delay between diagnosis of CP and HIPEC (p = 0.001) were associated with increased OS. The median PFS and PRFS were 12.4 and 17 months, respectively. At 1 year, more patients were without progression (p = 0.001) or PC recurrence (0.0004) in the CT group, but with prolonged follow-up this difference was no longer significant. Early postoperative CT does not improve OS after CRS and HIPEC for colon carcinomatosis. However, a transient effect on PFS and PRFS was observed. A subgroup of patients who may benefit more from CT remain to be defined.