Over-treatment in metastatic breast cancer

Metastatic breast cancer is an incurable disease and the main goals of treatment are prolongation of survival and preservation/improvement of quality of life. Thus the main philosophy of treatment should be to use the least toxic methods, as long as they provide sufficient disease control. In ER-positive tumours this can be in many cases achieved by endocrine therapy; in HER2-positive cancers efficacy of backbone therapy can be enhanced by an anti-HER2 agent. In patients requiring chemotherapy, consecutive single agent regimen provide disease control of a duration at least comparable to multidrug regimen, at a cost of significantly lower toxicity and are a preferred strategy in the majority of cases. Available data demonstrate, however, that aggressive chemotherapy is still overused in many metastatic breast cancer patients. The objective of this manuscript is to critically review available data on treatment choices and sequence in metastatic breast cancer across all breast cancer subtypes in relation to possible overtreatment, including therapies which are not recommended by current guidelines or not even approved. Our aim is to provide guidance on applying these data to clinical practice, but also to describe various, often non-scientific factors influencing therapeutic decisions in an aim to identify areas requiring educational and possibly political actions.