New Approaches to Endocrine Therapy for Breast Cancer.

The management of advanced hormone receptor-positive disease has evolved with the emergence of CDK4/6 inhibitors. Improvements in progression-free survival of approximately 10 months were noted in pivotal trials of palbociclib. Strong efficacy was also seen with ribociclib, which was recently approved by the FDA. In the adjuvant treatment setting of hormone receptor-positive disease, an important issue for consideration is the duration of endocrine therapy.