Adjuvant Hepatic Artery Infusion Chemotherapy is Associated With Improved Survival Regardless of KRAS Mutation Status in Patients With Resected Colorectal Liver Metastases: A Retrospective Analysis of 674 Patients.

Abstract

To investigate the impact of adjuvant hepatic artery infusion (HAI) in relation to KRAS mutational status in patients with resected colorectal cancer liver metastases (CRLM). Patients with KRAS-mutated CRLM have worse outcomes after resection. Adjuvant HAI chemotherapy improves overall survival after liver resection. Patients with resected CRLM treated at MSKCC with and without adjuvant HAI who had available KRAS status (wild-type, WT; mutated, MUT) were reviewed from a prospectively maintained institutional database. Correlations between KRAS status, adjuvant HAI, clinical factors, and outcomes were analyzed. Cox proportional hazard model was used to adjust for confounders. Between 1993 and 2012, 674 patients (418 KRAS-WT, 256 MUT) with a median follow up of 6.5 years after resection were evaluated. Fifty-four percent received adjuvant HAI. Tumor characteristics (synchronous disease, number of lesions, clinical-risk score, 2-stage hepatectomy) were significantly worse in the HAI group; however, there were more patients with resected extrahepatic metastases in the no-HAI group. In KRAS-WT tumors, 5-year survival was 78% for patients treated with HAI versus 57% for patients without HAI [hazard ratio (HR) 0.51, P < 0.001]. In KRAS-MUT tumors, 5-year survival was 59% for patients treated with HAI versus 40% for patients without HAI (HR 0.56, P < 0.001). On multivariate analysis, HAI remained associated with improved OS (HR 0.53, P < 0.002) independent of KRAS status and other clinicopathologic factors. Adjuvant HAI after resection of CRLM is independently associated with improved outcomes regardless of KRAS mutational status. Adjuvant HAI may mitigate the worse outcomes seen in patients with resectable KRAS-MUT CRLM.