Metastatic breast cancer continues to present difficulties despite the development of new treatments. Recently, a new term, oligometastases, a state in which the patient presents with distant relapse in only a limited number of regions, has been recognized. The standard therapy for lung metastases of breast cancer is systemic therapy. We assessed the efficacy of surgical resection for lung oligometastases of breast cancer. In addition, we compared the change in the subtypes of the primary tumor and the lung oligometastases.
We retrospectively analyzed 31 patients who previously underwent surgery for breast cancer and subsequently underwent video-assisted thoracic surgery (VATS) for lung oligometastases of breast cancer between 1995 and 2013 at our institute. The lung oligometastatic tumors were 1–2 in number and were completely resected in all cases.
The median age of the patients was 52 years. The primary tumor subtype was luminal A (LA) in 7 cases, luminal B (LB) in 7 cases, luminal-Her2 (LH) in 4 cases, triple negative (TN) in 10 cases, and undetermined in 3 cases. The median disease-free interval was 61 months (11–200) after excluding 2 cases with lung oligometastases at the time of first examination. The 5-year recurrence- free survival rate after resection of lung oligometastases was 55%, and the 5-year overall survival rate was 88%. The subtype did not change between the primary tumor and the oligometastases in 19 of 28 cases (68%). Among the 9 cases where the subtype changed (32%), the change was from LB to LA in 4 cases, which did not influence the subsequent treatment. However, in the remaining 5 cases, the subtype changed from LA, LB, or LH to TN in 4 cases and from TN to LA in 1 case, leading to a change in the subsequent treatment.
Resection of lung oligometastases of breast cancer may improve prognosis, although our data are limited and selective. Confirmation of the metastatic subtype may be useful in deciding the subsequent treatment following resection.
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All authors have declared no conflicts of interest.