Oligometastatic Disease: When Stage IV Breast Cancer Could Be “Cured”

SIMPLE SUMMARY: Breast cancers diagnosed at an advanced stage are often incurable, and systemic strategies such as chemotherapy, hormonotherapy, immunotherapy, and/or targeted therapy are the basis of treatment. Imaging tests are always required to determine the extent of the disease, and in selected cases with few metastatic lesions and organs involved (oligometastatic disease), radical treatment with surgery or radiotherapy may be considered to improve prognosis. In that situation, although it is basically impossible to know whether it is a curable disease or not, more and more patients achieve the status of no long-term evidence of disease. More prospective studies are needed to assess which patients may benefit. ABSTRACT: Although metastatic breast cancer remains an incurable disease, there are patients with a limited number of metastatic lesions that, in addition to systemic therapy, can be treated with “radical therapy” and sometimes reach the status of no long-term evidence of disease. Whether or not these patients can be considered cured is still a matter of debate. Unfortunately, the definition of the oligometastatic disease remains unclear, and it can occur with multiple different presentations. The absence of remarkable biomarkers, the difficulty in designing the appropriate clinical trials, and the failure to offer this group of patients radical approaches in advanced-stage clinical trials are just some of the current problems that we face in treating patients with oligometastatic breast cancer. Although most of the data come from retrospective studies and do not use the same definition of “oligometastatic disease,” here we review the main studies exploring the role of surgery or radiotherapy in patients with the oligometastatic disease and the different results. Some, but not all, studies have shown an increase in survival when surgery and/or radiotherapy were performed for oligometastatic disease. However, better clinical trial designs are needed to confirm the role of “aggressive” approaches for patients with breast cancer and oligometastatic disease.