Abstract: Endocrine therapy is the most important systemic therapy for hormone receptor positive breast cancer. However, intrinsic or acquired resistance to endocrine therapy is a challenge currently. Crosstalk between estrogen receptor pathway and other pathway is considered to be one of the underlying mechanisms. Progress has been made in reversing resistance by blocking signaling through pathways such as the phosphoinositide 3-kinases-protein kinase B-mammalian target of rapamycin and epidermal growth factor receptor pathway.

Key words: Breast neoplasms, Receptors, estrogen, Endocrine therapy