Impact of Neoadjuvant Chemotherapy on the Postoperative Outcomes of Patients Undergoing Liver Resection for Colorectal Liver Metastases: A Population-Based Propensity-Matched Analysis

Background: The role of neoadjuvant chemotherapy in the management of colorectal liver metastases remains controversial. We sought to investigate whether neoadjuvant systemic chemotherapy contributes to clinically significant increases in postoperative morbidity and mortality using a population-based cohort. Study Design: The American College of Surgeons NSQIP Targeted Hepatectomy Participant Use Files were queried from 2014 to 2016 to identify patients with colorectal liver metastases who underwent liver resection. Patients were stratified by receipt of neoadjuvant chemotherapy using propensity score matching. Univariate and multivariable analyses were used to characterize the effect of neoadjuvant chemotherapy on perioperative morbidity and mortality. Results: After propensity score matching, 1,416 (50%) patients received neoadjuvant chemotherapy before hepatectomy and 1,416 (50%) underwent liver resection without neoadjuvant chemotherapy. There were no differences in age (60 vs 61 years), maximum tumor size (≤5 cm: 79% vs 80%, >5 cm: 21% vs 20%), resection type (partial hepatectomy: 69% vs 70%), simultaneous colectomy (9% vs 9%), or use of preoperative portal vein embolization (5% vs 5%) in those undergoing neoadjuvant chemotherapy compared with those who did not (all, p > 0.05). Overall 30-day postoperative morbidity (34% vs 33%), including rates of biliary fistula (6% vs 5%), post-hepatectomy liver failure (5% vs 5%), and mortality rates (0.8% vs 0.7%), were similar among patients who received neoadjuvant chemotherapy vs those who did not (all, p > 0.05). On multivariable analysis, receipt of neoadjuvant chemotherapy was not associated with increased morbidity (odds ratio 1.07; 95% CI 0.90 to 1.27; p = 0.43) or mortality (odds ratio 1.09; 95% CI 0.44 to 2.72; p = 0.85). Conclusions: In this propensity-matched population-based cohort study, the use of neoadjuvant systemic chemotherapy was not associated with higher rates of complications, biliary fistula, post-hepatectomy liver failure, or mortality among patients with colorectal liver metastases undergoing liver resection.