Prognostic factors for recurrent breast cancer patients with an isolated, limited number of lung metastases and implications for pulmonary metastasectomy

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.