Thermal ablation versus hepatic resection for colorectal cancer with synchronous liver metastases: a propensity score matching study

Objectives Several studies have compared the efficacy of hepatic resection (HR) and thermal ablation (TA) for unresectable tumors; however, results remain inconsistent. Most cohorts in previous studies were heterogeneous groups of synchronous colorectal liver metastases (CRLM) and extrahepatic metastases. This retrospective study aimed to compare the therapeutic efficacy between TA and HR in synchronous CRLM without extrahepatic metastases. Methods Cases with initially synchronous CRLM without extrahepatic metastases between January 2007 and December 2018 were enrolled. Of the 448 cases, 346 received HR and 102 TA. Propensity score matching with a 1:1 ratio was used to improve the comparability between the HR and TA groups. Technical success, complications, disease-free survival (DFS), and overall survival (OS) were compared before and after matching. Results All patients achieved technical success. Major complication rates in the HR and TA groups were, respectively, 36.7% and 8.8% ( p < 0.001). Before matching, the 5-year OS and DFS ( p = 0.004 and p = 0.020, respectively) were significantly higher in the HR group than in the TA group. After matching, no significant difference in the 5-year OS and DFS was found between the groups ( p = 0.770 and p = 0.939, respectively). Local tumor progression rate was significantly higher in the TA group both before ( p = 0.027) and after ( p = 0.029) matching. Conclusions For patients with CRC with synchronous CRLM, TA and HR provide comparable OS and DFS. TA is preferable if complete ablation is predicted. Key Points • Thermal ablation and hepatic resection provide comparable overall survival and disease-free survival. • Thermal ablation is a safe and effective treatment for patients with colorectal cancer with synchronous liver metastases and has a lower major complication rate and higher repeatability than hepatic resection. • Thermal ablation is preferable if complete ablation is predicted.