Several series have reported on lung and liver metastases resection in oligometastatic breast cancer and most data are from small series of patients collected over many years. The largest dataset comes from the International Registry of Lung Metastases and presents results of lung metastasectomy in 467 breast cancer patients (9). Complete resection was possible in 84% of patients and led to a median survival of 37 months (5-year OS = 38%, 10-year OS = 22%). Identified prognostic factors for lung resection include disease-free interval and number of metastases (disease-free interval >36 months and solitary metastases being the most favorable), ER status, size of metastases, completeness of resection, and use of anatomical resection (as opposite to wedge resection) (9-19). Obviously, the reported data refer to a subset of patients who were selected for favorable prognostic factors, and any comparison with surgically untreated patients is threatened by serious biases.