Clinical Efficacy of Percutaneous Image-Guided Ablation in Breast Cancer Metastases to the Liver

Objectives: This single-center retrospective study evaluates the clinical efficacy and safety of percutaneous ablation using microwave ablation (MWA) and irreversible electroporation (IRE) in patients with breast cancer liver metastases (BCLM). Methods: Between August 2018 and December 2023, 32 patients underwent 40 image-guided ablations for 57 BCLM. Mean age was 61.3 years (range: 32-85), and mean tumor size was 2.9 cm (range: 0.9-7.0 cm). Fifty lesions were treated with MWA and seven with IRE. Clinical efficacy was assessed by m-RECIST response at first follow-up imaging (after ≥1 month) and by monitoring local tumor progression (LTP), local tumor progression-free survival (LTPFS), and overall survival (OS). Safety was evaluated by adverse events according to CTCAE. Kaplan-Meier statistics were used for LTPFS and OS. Results: Median follow-up was 32.4 months (95% CI 16.6-48.0). Complete response was observed in 34 tumors (59.6%), partial response in 14 (24.6%), and progressive disease in 9 (15.8%). LTP occurred in 37 tumors (64.9%), with a median time to progression of 11.1 months (95% CI 1.4-20.8). One- and two-year LTPFS rates were 43.6% and 34.1%. Sixteen patients died during follow-up, with median OS of 27.8 months (95% CI 19.0-36.6) and 1- and 2-year OS rates of 90.1% and 55.9%. No major complications occurred. Complications included eight Grade 1 and two Grade 2 complications. Conclusions: Percutaneous ablation demonstrates clinical efficacy and a favorable safety profile in selected BCLM patients, achieving OS comparable to the current literature. Further studies should clarify its additive role within multimodality treatment.