Real-world evidence: Adjuvant chemotherapy in colorectal cancer with liver metastases.

Abstract

e16008 Background: Systematic chemotherapy with biologics improves survival in metastatic colorectal cancer (mCRC). Oxaliplatin-based adjuvant chemotherapy is suggested in stage III and high-risk stage II CRC. However, whether adjuvant oxaliplatin-based chemotherapy remains standard treatment in CRC with liver metastases after hepatectomy is not elucidated. Methods: Medical records were searched in Chang-Gung Research Database from 2004 to 2017. Patients with CRC and liver metastases who received systematic therapies and salvage hepatectomy were included. The Kaplan-Meier method was used to estimate survival, and multivariate Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Total 454 patients received upfront hepatectomy (cohort 1) and 232 patients received neoadjuvant chemotherapy +/- biologics and salvage hepatectomy (cohort 2) were included in this study. In cohort 1 or cohort 2, the baseline characteristics of those received either postoperative oxaliplatin-containing regimen or other systematic regimens were not statistically different in gender, age, primary site, and biologic drugs. In cohort 1, overall survival (OS) in those received postoperative oxaliplatin-containing chemotherapy was significantly better than that of those received non-oxaliplatin-containing chemotherapy (median OS: 6.6 vs. 4.5 years, Log-rank p = 0.032; 5-year survival rate: 57.5 vs. 47.0%). In cohort 2, OS in those received postoperative oxaliplatin-containing chemotherapy was similar with that of those received irinotecan or biologics-containing chemotherapy (median OS: 3.1 vs. 3.5 vs. 3.8 years, Log-rank p = 0.472; 5-year survival rate: 30.9 vs. 33.3 vs. 37.0%). Conclusions: Oxaliplatin-containing chemotherapy provides better OS and remains standard adjuvant treatment in CRC with liver metastases after upfront hepatectomy. However, adjuvant chemotherapy in those received neoadjuvant chemotherapy +/- biologics and salvage hepatectomy should be individualized. Further prospective studies are warranted to validate these findings.