Localized HR-Positive Breast Cancer — Year in Review Series on Relevant New Datasets and Advances

Localized hormone receptor-positive breast cancer management requires integrating emerging clinical trial data with established treatment protocols. Recent findings from the Lidera study demonstrate the efficacy of oral selective estrogen receptor degraders (SERDs) in the adjuvant setting, while long-term follow-up from the Monarch-E trial confirms a durable overall survival benefit for adjuvant CDK4/6 inhibitors in high-risk patients. Clinical decision-making increasingly relies on genomic assays like the Breast Cancer Index and Oncotype DX to determine the necessity of chemotherapy and extended endocrine therapy. Experts emphasize that while ovarian function suppression with aromatase inhibitors remains critical for premenopausal patients, especially those with high-risk features, the role of chemotherapy in node-positive or high-genomic-risk cohorts continues to evolve. These discussions highlight the shift toward personalized, risk-stratified treatment strategies that balance therapeutic intensity with patient quality of life.