Oxaliplatin-based hyperthermic intraperitoneal chemotherapy with single drug versus multiple drug treatment for colorectal cancer with peritoneal metastases: an observational cohort study.

Abstract

Long-term survival for selected patients with peritoneal metastases (PM) from colorectal cancer (CRC) is possible when treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The objective of this study was to compare three different oxaliplatin-based (OX)-HIPEC regimens. Primary end-point was disease-free survival (DFS), and secondary endpoints, morbidity and overall survival (OS). This is a retrospective study of all patients with colorectal PM treated with CRS and HIPEC between 2004 and 2015 from the prospectively maintained Uppsala HIPEC database. One hundred and thirty-three patients were identified. Three HIPEC regimens were included: OX-HIPEC, OX-HIPEC + post-operative intraperitoneal chemotherapy (EPIC) with 5-fluorouracil (5-FU), and oxaliplatin-irinotecan-based (OXIRI)-HIPEC. Multivariable Cox regression for DFS was performed. Sixty-one patients received OX-HIPEC, 24 patients received OX-HIPEC + 5-FU EPIC, and 48 patients received OXIRI-HIPEC. The DFS for the OX-HIPEC group was 10.5 months, OX-HIPEC + EPIC 11.9 months, and OXIRI-HIPEC 13.4 months (OX-HIPEC vs. OXIRI HIPEC, P=0.049). The morbidity and OS did not differ between the groups. In the multivariable analysis, low peritoneal cancer index (PCI), absence of liver metastases, low completeness of cytoreduction (CC) score, and multiple drug (EPIC or OXIRI) HIPEC regimen were independent prognostic factors for DFS. This study showed improved DFS with an intensification of HIPEC by adding irinotecan or EPIC compared to oxaliplatin alone without an increase in morbidity or mortality.