Pulmonary metastasectomy for pulmonary metastasis of breast cancer has a limited prognostic impact: A multi-institutional retrospective analysis

Background: Pulmonary metastasectomy (PM) for breast cancer-derived pulmonary metastasis is controversial. This study aimed to assess the prognostic factors and implication of PM for metastatic breast cancer using a multi-institutional database. Methods: Clinical data of 253 females with pulmonary metastasis of breast cancer who underwent PM between 1982 and 2017 were analyzed retrospectively. Results: The median patient age was 56 years. The median follow-up period was 5.4 years, and the median disease-free interval (DFI) was 4.8 years. The 5- and 10-year survival rates after PM were 64.9% and 50.4%, respectively, and the median overall survival was 10.1 years. Univariate analysis revealed that the period of PM before 2000, a DFI <36 months, lobectomy/pneumonectomy, large tumor size, and lymph node metastasis were predictive of a worse overall survival. In the multivariate analysis, a DFI <36 months, large tumor size, and lymph node metastasis remained significantly related to overall survival. The 5- and 10-year cancer-specific survival rates after PM were 66.9% and 54.7%, respectively, and the median cancer-specific survival was 13.1 years. Univariate analyses revealed that the period of PM before 2000, DFI <36 months, lobectomy/pneumonectomy, large tumor size, lymph node metastasis, and incomplete resection were predictive of a worse cancer-specific survival. Multivariate analysis confirmed that a DFI <36 months, large tumor size and incomplete resection were significantly related to cancer-specific survival. Conclusions: As PM has limited efficacy in breast cancer, it should be considered an optional treatment for pulmonary metastasis of breast cancer.