Cytoreductive surgery and intraperitoneal chemotherapy versus systemic chemotherapy for colorectal peritoneal metastases: A randomised trial

Background First-line treatment of isolated resectable colorectal peritoneal metastases remains unclear. This study (the Swedish peritoneal study) compares cytoreductive surgery and intraperitoneal chemotherapy (surgery arm) with systemic chemotherapy (chemotherapy arm). Methods Patients deemed resectable preoperatively were randomised to surgery and intraperitoneal 5-fluorouracil 550 mg/m2/d for 6 d with repeated courses every month or to systemic oxaliplatin and 5-fluorouracil regimen every second week. Both treatments continued for 6 months. Primary end-point was overall survival (OS) and secondary end-points were progression-free survival (PFS), and morbidity. Results The study terminated prematurely when 48 eligible patients (24/arm) were included due to recruitment difficulties. Two-year OS was 54% in the surgery arm and 38% in the chemotherapy arm (p = 0.04). After 5 years, 8 versus 1 patient were alive, respectively (p = 0.02). Median OS was 25 months versus 18 months, respectively, hazard ratio 0.51 (95% confidence interval: 0.27–0.96, p = 0.04). PFS in the surgery arm was 12 months versus 11 months in the chemotherapy arm (p = 0.16) with 17% versus 0% 5-year PFS. Grade III–IV morbidity was seen in 42% and 50% of the patients, respectively. No mortalities. Conclusions Cytoreductive surgery with intraperitoneal chemotherapy may be superior to systemic oxaliplatin-based treatment of colorectal cancer with resectable isolated peritoneal metastases.(ClinicalTrials.gov nr:NCT01524094).