Safety of hepatic resection for colorectal metastases in the era of neo-adjuvant chemotherapy

The relationship between neo-adjuvant chemotherapy prior to hepatectomy in patients with resectable colorectal liver metastases and post-operative morbidity still has to be clarified. Data from 242 patients undergoing hepatectomy for colorectal liver metastases, judged resectable at first observation, were reviewed and their clinical outcome was related to neo-adjuvant chemotherapy (125 patients). Selection biases were outlined and properly handled by means of propensity score analysis. Post-operative death was 1.2% and morbidity 40.9%. Pre-operative chemotherapy was only apparently related to higher morbidity (P = 0.021): multivariate analysis identified extension of hepatectomy and intra-operative blood loss as independent prognostic variables (P < 0.05). Patients receiving and not receiving neo-adjuvant chemotherapy were significantly different for several covariates, including extension of hepatectomy (P = 0.049). After propensity score adjustment, 94 patients were identified as having similar covariate distribution (standardized differences <|0.1|) except for neo-adjuvant treatment (47 patients for each group). In this matched sample, mortality was similar and post-operative complications were only slightly higher (hazard ratio = 1.38) in treated patients. A significantly higher need for fluid replacement was only observed in patients receiving neo-adjuvant chemotherapy (P = 0.038). Neo-adjuvant chemotherapy showed a limited role in determining post-operative morbidity after hepatic resection and did not modify mortality.