Results of Two Bi-Institutional Prospective Studies Using Intraperitoneal Oxaliplatin With or Without Irinotecan During HIPEC After Cytoreductive Surgery for Colorectal Carcinomatosis

Objective: To assess the perioperative and long-term results of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) using oxaliplatin + irinotecan (ox-irino) versus oxaliplatin alone (ox-alone). Background: Treatment of peritoneal carcinomatosis (PC) of colorectal origin with CRS + HIPEC using mitomycin-C or oxaliplatin monotherapy has shown encouraging survival results. This bi-centric study evaluates an intensified intraperitoneal combination of ox-irino and compares it with ox-alone. Patients and Methods: All consecutive patients with PC undergoing CRS + HIPEC using either ox-alone or ox-irino between 1998 and 2007 were evaluated. Results: One hundred forty-six patients underwent CRS + HIPEC for PC, 103 received ox-irino and 43 received ox-alone. The median peritoneal carcinomatosis index (PCI) was 11 in both groups. 90.4% had complete cytoreduction. Overall mortality rate was 4.1%. The overall morbidity rate was 47.2% and was significantly lower with ox-alone (34.9% vs. 52.4%, P = 0.05). After a median follow-up of 48.5months, the median overall survival (OS) was 41months (95% CI, 32-60) and median relapse-free survival (RFS) was 15.7 months (95% CI, 12-18). The median RFS of ox-alone (16.8months; 95% CI, 11-25) was not significantly different from ox-irino (15.7 months; 95% CI, 11-18; P = 0.93). There was no significant difference between median OS of ox-alone (40.83 months; 95% CI, 29-61) and ox-irino (47 months; 95% CI, 32-61; P = 0.94). At 5 years, OS and RFS rates were 41.8% and 13.8% in ox-alone and 42.4% and 14.2% in ox-irino, respectively. Prognostic factors confirmed on multivariate analysis were lymph node metastasis and PCI. Conclusion: Our study showed no advantage of intensification of HIPEC by adding irinotecan, contrary to the results obtained with IV combination. Ox-alone HIPEC should continue as one of the standard HIPEC regimens for PC.