Current treatment options for metastatic breast cancer: what now?

Approximately 30% of patients with breast cancer will develop metastatic breast disease. Metastatic breast cancer is considered an incurable disease, with complete remission rarely achieved after treatment. The goal of treatment for metastatic breast cancer patients is to increase overall survival time and delay disease progression while ameliorating symptoms and improving or maintaining quality of life. Single-agent therapeutic regimens are appropriate for most metastatic breast cancer patients. Patients with the luminal A subtype of breast cancer, which is more indolent in nature and tends to be more sensitive to treatment in general, often respond well to single-agent therapy. Several chemotherapy regimens are recommended for the treatment of metastatic breast cancer. Compared with single-agent regimens, these combination regimens often produce a greater improvement in the rate of objective response as well as a prolongation of progression-free survival. There is little evidence, however, of improvement in overall survival. Combination chemotherapy regimens are often associated with a greater degree of toxicity depending on schedules and doses used. The use of bevacizumab in metastatic breast cancer is currently a topic of controversy. It is hoped that forthcoming trial data will enable the identification of a group of patients, based on tumor biology, who could benefit from bevacizumab-based therapy.