雌激素受体是约75％的乳腺癌中的主要转录因子，是内分泌治疗的靶点，但药物抗性是一种常见的临床问题。在转移性肿瘤和来源于接受内分泌治疗的ER阳性乳腺癌患者的循环肿瘤DNA（ctDNA）中，通常会发现在配体结合域的ESR1点突变。虽然内分泌治疗和CDK4/6抑制剂治疗已经证明对乳腺癌有预临床和临床益处，但耐药性的发展仍然是一个重大挑战，而进一步揭示先进乳腺癌的详细机制和潜在治疗靶点仍然需要研究。由于肿瘤和肿瘤微环境（TME）之间的相互作用在肿瘤生长和转移中起着重要作用，这种效应可能在内分泌治疗的耐药性和乳腺癌细胞向转移的过渡中起关键调节作用。在本文中，我们回顾了最近在内分泌治疗方面的进展以及TME对ER阳性乳腺癌的贡献。版权所有©2023。Elsevier Inc.出版。

Estrogen Receptor is the driving transcription factor in about 75% of all breast cancers, which is the target of endocrine therapies, but drug resistance is a common clinical problem. ESR1 point mutations at the ligand binding domain are frequently identified in metastatic tumor and ctDNA (Circulating tumor DNA) derived from ER positive breast cancer patients with endocrine therapies. Although endocrine therapy and CDK4/6 inhibitor therapy have demonstrated preclinical and clinical benefits for breast cancer, the development of resistance remains a significant challenge and the detailed mechanisms, and potential therapeutic targets in advanced breast cancer yet to be revealed. Since a crosstalk between tumor and tumor microenvironment (TME) plays an important role to grow tumor and metastasis, this effect could serve as key regulators in the resistance of endocrine therapy and the transition of breast cancer cells to metastasis. In this article, we have reviewed recent progress in endocrine therapy and the contribution of TME to ER positive breast cancer.Copyright © 2023. Published by Elsevier Inc.