BRCA and CDK4/6: allies or antagonists?—efficacy of CDK4/6 inhibitors in HR+/HER2− breast cancer with germline BRCA1/2 mutations: a narrative review

This review underscores the need for prospective studies to clarify the prognostic and predictive role of gBRCAm in CDK4/6i-treated HR⁺/HER2⁻ BC. Current evidence supports routine BRCA testing to inform therapeutic sequencing, with poly(ADP-ribose) polymerase inhibitors (PARPis) prioritized in high-risk early-stage and metastatic settings. Future research should focus on biomarker-driven strategies, including combinations to optimize outcomes. These insights may refine clinical guidelines, advocate for personalized treatment algorithms, and stimulate research into resistance mechanisms, ultimately improving care for BRCA-mutated BC patients.