Targeting Apoptosis: A New Paradigm for the Treatment of Estrogen Receptor-Positive Breast Cancer.

Standard treatment for estrogen receptor-positive metastatic breast cancer involves antiestrogen therapy used alone or in combination with inhibitors of CDK4/6 or mTOR; this approach works mechanistically by eliciting and reinforcing cell-cycle arrest. In this issue, Lok and colleagues diverge from this paradigm by combining the BCL2 inhibitor venetoclax with tamoxifen in a phase Ib clinical trial, building on preclinical work to demonstrate that targeting apoptosis could represent a promising new strategy in the treatment of breast cancer.See related article by Lok et al., p. 354. ©2019 American Association for Cancer Research.