Practice-changing interventions in the systemic management of breast cancer

Systemic treatment for metastatic breast cancer now incorporates many targeted agents and a plethora of combinations specific to the breast cancer subtype. New to the treatment paradigm are fam-trastuzumab deruxtecan-nxki, and tucatinib for HER2-positive disease; the PI3K inhibitor alpelisib in combination with fulvestrant for estrogen receptor–positive and PIK3CA-mutated tumors; PARP inhibitors for patients with germline BRCA1/2 mutations; and the anti–PD-L1 agent atezolizumab in combination with albumin-bound paclitaxel for triple-negative disease with PD-L1 mutations in tumors. In addition, for estrogen receptor–positive disease, the role of CDK4/6 inhibitors increased substantially during the past year, as overall survival results have emerged. These targeted agents are greatly improving patient outcomes, and thus have all been incorporated into the NCCN Guidelines for Breast Cancer.