Modest advances in survival for patients with colorectal-associated peritoneal carcinomatosis in the era of modern chemotherapy

Background The treatment of metastatic colorectal cancer (CRC) has evolved rapidly over the last decade, with combination chemotherapy and targeted biologic agents leading to significant improvements in survival. Despite these advances, little is known about their effectiveness in CRC-associated peritoneal carcinomatosis. The purpose of this study was to evaluate outcomes in patients with CRC-associated PC treated in the era of modern chemotherapy. Methods We retrospectively reviewed an institutional tumor database from 1996 to 2008. Survival data were evaluated for patients treated with PC before and after 2003. No patients before 2003 were treated with combination chemotherapy or biologic therapy. The modern chemotherapy group consisted of patients treated after 2003. Survival curves were estimated. Results Overall, 173 patients were identified. Median follow-up was 8.6 months. Median survival in the historic group (n = 91) was 8.9 months and 16.3 months in the modern chemotherapy group (n = 82) (P < 0.004). Age was the only significant covariate. The survival difference between the modern chemotherapy cohort and control cohort persisted after adjustment for age. In a subset of patients in the modern chemotherapy era group, for which treatment regimen could be definitively identified, survival was even greater - 23.8 months. Conclusions Patients with CRC-associated PC treated with modern combination chemotherapy and biologic therapy have a significantly longer median survival compared to our historical cohort. Despite these improvements, outcomes still remain poor. Therapeutic adjuncts such as surgical cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) in appropriately selected patients remain promising options to improve outcomes for patients with peritoneal-based disease.