Switch maintenance endocrine therapy after induction chemotherapy for advanced ER-positive, HER2-negative breast cancer

Cytotoxic chemotherapy regimens typically cause unpleasant side-effects. The multicenter randomized phase 2 BOOSTER trial in Japan evaluated the benefit of switch maintenance endocrine therapy plus bevacizumab after fixed cycles of first-line induction chemotherapy with weekly paclitaxel plus bevacizumab in patients with ER-positive, HER2-negative advanced or metastatic breast cancer who had responded to induction therapy. Switch to maintenance endocrine therapy plus bevacizumab with the possibility of weekly paclitaxel reinduction if needed was an efficacious alternative, with a better safety profile, to continuing weekly paclitaxel plus bevacizumab.