Advances in endocrine and targeted therapy for hormone-receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer

• Main Authors: Le-Sang Shen, Xiao-Yan Jin, Xu-Meng Wang, Lai-Zhen Tou, Jian Huang, Qiang Shi
• Format: Article
• Language: English
• Published: Wolters Kluwer 2020-05-01
• Series: Chinese Medical Journal
• Online Access: http://journals.lww.com/10.1097/CM9.0000000000000745

Abstract. Nearly 70% of breast cancer (BC) is hormone-receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, and endocrine therapy is the mainstay of treatment for this subtype. However, intrinsic or acquired endocrine resistance can occur during the endocrine treatment. Based on insights of endocrine resistance mechanisms, a number of targeted therapies have been and continue to be developed. With regard to HR-positive, HER2-negative advanced BC, aromatase inhibitor (AI) is superior to tamoxifen, and fulvestrant is a better option for patients previously exposed to endocrine therapy. Targeted drugs, such as cyclin-dependent kinases (CDK) 4/6 inhibitors, mammalian target of rapamycin (mTOR) inhibitors, phosphoinositide-3-kinase (PI3K) inhibitors, and histone deacetylase (HDAC) inhibitors, play a significant role in the present and show a promising future. With the application of CDK4/6 inhibitors becoming common, mechanisms of acquired resistance to them should also be taken into consideration.