BACKGROUND The aim of this study was to evaluate the clinical treatment outcomes of recurrent breast cancer with a limited number of isolated lung metastases, and to evaluate the role of pulmonary metastasectomy.

METHODS The authors consecutively enrolled 140 recurrent breast cancer patients with isolated lung metastasis from 1997 to 2007 in Seoul National University Hospital and retrospectively analyzed 45 patients who had <4 metastatic lesions.

RESULTS Fifteen patients had pulmonary metastasectomy followed by systemic treatment (pulmonary metastasectomy group), and 30 received systemic treatment alone (nonpulmonary metastasectomy group). The 3-year progression-free survival (PFS) and 4-year overall survival (OS) was significantly longer in the pulmonary metastasectomy group than in the nonpulmonary metastasectomy group (3-year PFS, 55.0% vs 4.5%, P < .001; 4-year OS, 82.1% vs 31.6%, P = .001). In multivariate analysis, a disease-free interval (DFI) of <24 months (hazard ratio [HR], 4.53; 95% CI, 1.72-11.90), no pulmonary metastasectomy (HR, 9.52; 95% CI, 3.34-27.18) and biologic subtypes such as human epithelial growth factor receptor-2 positive (HR, 3.00; 95% CI, 1.04-8.64) and triple negative (HR, 3.92; 95% CI, 1.32-11.59) were independent prognostic factors for shorter PFS.

CONCLUSIONS The authors' results demonstrated that DFI and biologic subtypes of tumor are firm, independent, prognostic factors for survival, and pulmonary metastasectomy can be a reasonable treatment option in this population. Further prospective studies are warranted to evaluate the role of pulmonary metastasectomy.