RESUMO
BACKGROUND: Combining liver resection (LR) with radiofrequency ablation (RFA) is nowadays an accepted option for treating colorectal liver metastases (CRLMs), but the number of lesions ablated is regularly described as a recurrence risk factor. In this study, we report our experience and determine the impact of RFA on long-term outcomes. METHOD: This is a retrospective study including patients undergoing LR with or without RFA for CRLM. All variables influencing disease-free survival (DFS) and disease-specific survival (DSS) were examined through a Cox regression analysis before and after propensity-score matching (PSM). RESULTS: Among the 128 patients included, 71 (55.5%) underwent LR alone and 57 (44.5%) underwent LR+RFA. With univariate analysis, LR+RFA showed a significantly worse DFS than LR alone (p = 0.028), which was not confirmed after PSM (p = 0.064). Thermal ablation did not influence DSS before or after matching (p = 0.282 and p = 0.189). When analyzing the subgroups of patients according to number of RFAs performed, no difference in long-term outcomes was observed (after PSM: p = 0.192 for DFS and p = 0.624 for DSS). Analysis of site of recurrence revealed that neither performing an RFA (p = 0.893) nor the number of lesions ablated (p = 0.093, p = 0.550, and p = 0.087 for 1, 2, and ≥ 2 RFAs) were associated with an increased risk of liver-only relapse. DISCUSSION: In the setting of a parenchymal sparing strategy, combining RFA with LR is safe in terms of oncological outcomes. Tumor burden, rather than RFA performed, independently influences risk of recurrence and patient survival.