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

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). 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. All consecutive patients with PC undergoing CRS+HIPEC using either ox-alone or ox-irino between 1998 and 2007 were evaluated. 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 48.5 months, the median overall survival (OS) was 41 months (95% CI, 32-60) and median relapse-free survival (RFS) was 15.7 months (95% CI, 12-18). The median RFS of ox-alone (16.8 months; 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. 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.