激素受体（HR）阳性和人表皮生长因子受体2（HER2）阴性乳腺癌是由雌激素受体和/或孕激素受体存在，以及缺乏HER2基因扩增所定义的。HR阳性/HER2阴性乳腺癌占所有乳腺癌的65%-70%，发病率随年龄增加而增加。治疗根据阶段而异，内分泌治疗是早期和晚期疾病的主要治疗方法。联合周期蛋白依赖性激酶4/6抑制剂可减少早期阶段远处复发并改善转移性情况的总体生存率。在早期阶段和内分泌耐药的晚期疾病中，根据阶段和肿瘤生物学使用化疗。包括新型内分泌药物和抗体-药物联合物在内的新疗法正在改变治疗格局。有了新的治疗选择，重要的是定义最佳的治疗顺序，在最大化临床效益的同时最小化毒性。在本综述中，作者首先讨论HR阳性/HER2阴性乳腺癌的病理和分子特征以及内分泌耐药的机制。然后，他们讨论早期阶段和转移性HR阳性/HER2阴性乳腺癌的当前和新兴疗法，包括基于当前数据的治疗算法。 ©2023 The Authors。由Wiley Periodicals LLC代表美国癌症协会出版的《CA：一个临床癌症杂志》。

Hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer is defined by the presence of the estrogen receptor and/or the progesterone receptor and the absence of HER2 gene amplification. HR-positive/HER2-negative breast cancer accounts for 65%-70% of all breast cancers, and incidence increases with increasing age. Treatment varies by stage, and endocrine therapy is the mainstay of treatment in both early stage and late-stage disease. Combinations with cyclin-dependent kinase 4/6 inhibitors have reduced distant recurrence in the early stage setting and improved overall survival in the metastatic setting. Chemotherapy is used based on stage and tumor biology in the early stage setting and after endocrine resistance for advanced disease. New therapies, including novel endocrine agents and antibody-drug conjugates, are now changing the treatment landscape. With the availability of new treatment options, it is important to define the optimal sequence of treatment to maximize clinical benefit while minimizing toxicity. In this review, the authors first discuss the pathologic and molecular features of HR-positive/HER2-negative breast cancer and mechanisms of endocrine resistance. Then, they discuss current and emerging therapies for both early stage and metastatic HR-positive/HER2-negative breast cancer, including treatment algorithms based on current data.© 2023 The Authors. CA: A Cancer Journal for Clinicians published by Wiley Periodicals LLC on behalf of American Cancer Society.