[Oligometastatic breast cancer : therapeutic implications of a new paradigm].

INTRODUCTION: Oligometastatic breast cancer incidence is recently increasing thanks to screening and imaging improvements. Unlike patients with metastatic disease, a small number of oligometastatic patients may expect a definitive remission, in case of aggressive management performed with intent to cure. We report the atypical evolution of an oligometastatic breast cancer patient, who lately relapsed with a different Her2 status.

RESULTS: A 46 year old women was treated for an infiltrating duct breast carcinoma, initially diagnosed with oligometastases and an Her2- negative status. Treatments were performed in intent to cure but the patient relapsed 5 years later with a solitary Her2-positive liver metastasis. The aggressive local and systemic (using an anti- Her2 targeted therapy) management induced a still complete remission at last follow-up.

CONCLUSION: Prognosis of breast oligometastatic cancer is unpredictable, but an aggressive with intent-to-cure management may bring benefits to patients. However very rare, the switch of Her2 status between initial diagnosis and relapse highlights tumor heterogeneity, and the fact that a cell population featuring targetable characteristics may appear due to anticancer drug induced-cell selection.