Multimodality treatment of colorectal peritoneal metastasis with perioperative systemic chemotherapy, cytoreductive surgery (CRS), and HIPEC: First safety results of the COMBATAC trial.

Abstract

LBA382 Background: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) provide a promising therapeutic option as part of an interdisciplinary multimodal treatment regimen for selected patients with peritoneal metastasis arising from colorectal cancer. The COMBATAC trial evaluates the feasibility, safety, and efficacy of perioperative cetuximab-containing systemic polychemotherapy, CRS and bidirectional oxaliplatin-based HIPEC. Methods: The COMBATAC trial is a prospective, multicenter, open-label, single-arm, single-stage phase II trial recruiting patients with histologically proven wild-type KRAS colorectal or appendiceal adenocarcinoma and synchronous or metachronous peritoneal metastasis. The planned total number of patients to be recruited is 60. The primary endpoint is progression-free survival (PFS). Results: Preliminary data of the first 16 documented patients show a total number of 51 adverse events. According to CTCAE v4 the distribution of AE was 23 grade 1, 14 grade 2, 13 grade 3, and one grade 4, respectively. Of the 14 grade 3/4 adverse events three were chemotherapy-related, four surgery-related, and seven not directly treatment-related. Most common grade 3/4 complications were infection, thrombosis, and urinary tract obstruction. Conclusions: First data indicate that perioperative systemic polychemotherapy including cetuximab in combination with CRS and bidirectional HIPEC is feasible and might not lead to increased morbidity and toxicity rates. Nevertheless, the COMBATAC trial is still recruiting, and data regarding progression-free survival (PFS) and overall survival (OS) is not yet available. Clinical trial information: NCT01540344.