Objective: To evaluate prognostic factors associated with local control and disease-free-survival (DFS) of oligometastatic breast cancer patients treated by percutaneous thermal ablation (PTA).
Materials and methods: Seventy-nine consecutive patients (54.5 ± 11.2 years old) with 114 breast cancer metastases (28.9 ± 16.1 mm in diameter), involving the lungs, the liver, and/or the bone, were treated using PTA with a curative intent. The goal was to achieve a complete remission in association with systemic chemotherapy and hormonal therapy. We retrospectively evaluated the prognostic factors associated with 1- and 2-year local control and the 1- and 2-year DFS rates.
Results: The 1- and 2-year local control rates were 83.0 and 76.1 %, respectively. Tumor burden was associated with a poorer outcome for local control after PTA (HR 1.027 by additional millimeter, p = 0.026; >4 cm HR 3.90). The 1- and 2-year DFS rates were 54.2 and 30.4 %, respectively. In multivariate analysis, triple-negative histological subtype and increased size of treated metastases were associated with a poorer DFS (HR 2.22; 95 % CI [1.13-4.36]; p = 0.02 and HR 2.43; 95 % CI [1.22-4.82]; p = 0.011, respectively).
Conclusion: PTA is effective for local control of breast cancer oligometastases. Tumor burden >4 cm and triple-negative histological subtype are associated with a poorer outcome.
Keywords: Breast neoplasms; Cryotherapy; Metastases; Microwave ablation; Radiofrequency ablation.