COMMENTARY

Metastatic breast cancer (MBC) is a heterogeneous disease that has a variety of different clinical scenarios, ranging from solitary met-astatic lesions to diffuse and multiple organ involvement. Overall, survival of patients with MBC is slowly but steadily improving (1)—the risk of death is decreasing by 1%–2 % each year (2). The greatest improvement is most probably related to the development and widespread availability of modern systemic therapies (3). In addition, modern diagnostic tools allow the detection of early met-astatic disease, which may be more responsive to treatment than late metastatic disease (4,5). However, earlier diagnosis of meta-static disease may also result in a lead time bias, falsely increasing the survival times of these patients (2). A distinctive subset of MBC patients who are most likely to gain substantial benefit from an intensified multidisciplinary ther-apeutic approach is represented by “oligometastatic ” disease, which is characterized by solitary or few detectable metastatic le-sions that are usually limited to a single organ. This population of “potentially curable ” stage IV disease is estimated to be 1%–10% of newly diagnosed MBC patients (6). The existing guideline