Although metastatic breast cancer is unlikely to be cured, meaningful improvements in survival have been seen, coincident with the introduction of newer systemic therapies [1-3]. Median overall survival approaches two years, with a range from a few months to many years .
The selection of a therapeutic strategy depends upon both tumor biology and clinical factors, with the goal being a tailored approach. Although a subset of patients with oligometastatic disease may benefit from an intensified locoregional approach, most patients with metastatic breast cancer receive systemic medical therapy, consisting of chemotherapy, endocrine therapy, and/or biologic therapies, and supportive care measures [5,6].
Principles in selecting a chemotherapy regimen are presented here. Active single agent and combination chemotherapy regimens, including biologic therapies, are discussed separately, as are endocrine therapy and supportive care.
The selection of chemotherapy for metastatic breast cancer must be individualized and balance disease-related factors, such as disease sites, apparent progression rate, and hormone receptor and human epidermal growth factor receptor 2 (HER2) status, with patient factors, such as comorbidities and general health. Response and resistance to prior chemotherapy, as well as prior therapy-related toxicities, should also be taken into account.