A matched comparison of liver resection and laparoscopic radiofrequency ablation for colorectal liver metastases based on tumor burden and ASA status

Abstract

Objective: Studies comparing hepatectomy with radiofrequency ablation (RFA) for colorectal liver metastases (CRLM) have been hindered by differences in patient populations regarding tumor burden and comorbidities. The aim of this study is to compare the oncological outcomes of these modalities in matched cohorts. Methods: All patients who underwent hepatectomy or laparoscopic RFA for CRLM between 1999 and 2013 at a single institution were identified. Clinicopathologic characteristics and oncological outcomes were reviewed and propensity-score matched based on tumor number and size, and American Society of Anesthesiologists (ASA) status, to generate balanced cohorts. Overall (OS) and disease-free survival (DFS) were calculated and compared using Log-Rank and Cox proportional hazards tests. Results: 288 (50%) patients underwent liver resection and 292 (50%) underwent laparoscopic RFA. The median follow-up was 22 months. After propensity-score matching, 136 patients remained in each group for further analyses. Resection and RFA resulted in similar OS (p=0.183) and DFS (p=0.233) for patients with a solitary CRLM less than 3 cm. For patients with 4 or more CRLM, OS was similar (p=0.366), but DFS (p=0.011) better after resection compared to RFA. In patients with a solitary CRLM>3 cm, or 2-3 tumors, resection resulted in better OS and DFS compared to RFA. Conclusion: The liver tumor burden determines the relative difference in the expected oncologic outcomes between resection and RFA in the management of CRLM. In patients with little (solitary<3 cm) or significant (≥4 lesions) liver involvement, the results of the 2 modalities overlap. In the remaining patients, resection results in better oncologic outcomes.