Systemic chemotherapy plus cetuximab after complete surgery in the treatment of isolated colorectal peritoneal carcinoma: COCHISE phase II clinical trial.

Objective: The primary objective of this non-randomised phase II study was to evaluate the combination of systemic chemotherapy plus cetuximab after complete cytoreductive surgery (CCS) for treatment of isolated colorectal peritoneal carcinoma (CRPC). This multicentre, prospective phase II clinical trial was conducted in seven national cancer referral centres, however research published during study recruitment indicated cetuximab treatment as ineffective in patients with mutated KRAS genes, leading to an additional exclusion criterion to the current protocol, excluding patients with mutated KRAS genes. This significantly impacted recruitment and the study did not achieve the necessary recruitment of 46 patients.

Results: Fourteen patients underwent CCS and were included in the study, however one did not provide informed consent and another received only one cycle of chemotherapy leading to 12 patients in the per protocol population for analysis. Adjuvant Folfox Cetuximab was administered when CCS was achieved for patients > 18 years with histologically proven CRPC and no other metastatic disease (liver, lungs, lymphadenopathy, etc.). CRPC median index was 5.00 (range: 1-17). Median PFS was 12.3 months [95% CI (3.7-28.2)] with 8.3% [95% CI (0.5-31.1)] and 0% PFS at 3 and 5 years respectively. Median OS was 43.4 months [95% CI (16.8-60)]. Trial registration Clinical Trials NCT00766142, October 3, 2008. Retrospectively registered.