Efficacy of Adjuvant Chemotherapy after Resection of Liver Metastases from Colorectal Cancer: Propensity Score Matching Analysis

Abstract

Background:We undertook this retrospective study to evaluate the efficacy of adjuvant chemotherapy after resection of liver metastases from colorectal cancer (colorectal liver metastases) using propensity score matching analysis.Methods: A total of 100 patients with colorectal liver metastases who had undergone hepatectomy between 2006 and 2019 were included in this study.The clinicopathological factors and long-term outcomes were compared between the patient group that had received adjuvant chemotherapy (Adj(+) group: n = 72) and the patient group that had not received adjuvant chemotherapy (non-adjuvant chemotherapy group; Adj(-) group: n = 28) following resection of the colorectal liver metastases. Propensity score matching was performed for clinicopathological factors, and 20 patients from each group selected.Results: Analyses prior to the matching revealed that the 3-year relapse-free survival rate was significantly higher in the Adj(+) group than in the Adj(-) group (43％ vs. 20％ ( p = 0.003)), while there was no significant difference in the 5-year cancer-specific survival rate between the two groups (67％ vs. 50 ％ ( p = 0.122)). Analysis after propensity score matching revealed that the 3-year relapse-free sur-