Local Ablative Therapy in Breast Cancer Liver Metastases: Survival Outcomes and Prognostic Factors-A Single-Center...

Background: Liver metastases from breast cancer (BCLM) are associated with poor prognosis and represent a significant clinical challenge in the era of modern systemic therapies. Local ablative therapies (LATs), including microwave ablation (MWA) and transarterial chemoembolization (TACE), have emerged as potentially beneficial locoregional approaches in selected patients. However, data on survival outcomes and prognostic determinants of LAT in BCLM remain limited. This study aimed to evaluate the survival outcomes and prognostic factors of LAT in patients with breast cancer liver metastases at a tertiary care center. Methods: Patients with de novo or metachronous breast cancer liver metastases who underwent LAT (MWA and/or TACE) between 2013 and October 2023 at a single tertiary center were retrospectively analyzed. Primary endpoints were overall survival (OS), defined as the time from LAT initiation to death from any cause, and progression-free survival (PFS), defined as the time from LAT initiation to the first radiographically confirmed progression. Treatment response was assessed per RECIST 1.1 criteria. Results: A total of 20 female patients were included. Median age at diagnosis was 42 years (IQR: 37-53). The majority had invasive ductal carcinoma (90%) and grade 3 disease (60%). Hormone receptor-positive, HER2-positive, and triple-negative subtypes comprised 45%, 25%, and 30% of the cohort, respectively. MWA was performed in 16 patients (80%), TACE was performed in 2 patients (10%), and both modalities were performed in 2 patients (10%). Complete response per RECIST 1.1 was achieved in 40% of patients. No grade 3-4 adverse events were recorded. Median OS was 20 months (95% CI: 14.9-25.1), and median PFS was 6 months (95% CI: 0-17.5). In univariate analysis, factors associated with improved OS included LM size < 18 mm (23 vs. 11 months, p < 0.001), unilateral lobar involvement (23 vs. 5 months, p = 0.025), and LAT application during first-line therapy (48 vs. 19 months, p = 0.021). Factors associated with improved PFS included LM size < 18 mm (19 vs. 5 months, p < 0.001) and achievement of complete ablative response per RECIST 1.1 (18 vs. 5 months, p = 0.005). Conclusions: LAT is a safe and feasible treatment modality in selected BCLM patients. In univariate analysis, smaller lesion size, unilateral hepatic involvement, and early-line LAT applications are associated with improved OS, while complete ablative response is associated with improved PFS. These findings warrant validation in prospective studies with larger cohorts. Multidisciplinary patient selection is essential to optimize outcomes.