Targeting autophagy with tamoxifen in breast cancer: From molecular mechanisms to targeted therapy

Abstract Background Tamoxifen (TAM) is often recommended as a first‐line treatment for estrogen receptor‐positive breast cancer (BC). However, TAM resistance continues to be a medical challenge for BC with hormone receptor positivity. The function of macro‐autophagy and autophagy has recently been identified to be altered in BC, which suggests a potential mechanism for TAM resistance. Autophagy is a cellular stress‐induced response to preserve cellular homeostasis. Also, therapy‐induced autophagy, which is typically cytoprotective and activated in tumor cells, could sometimes be non‐protective, cytostatic, or cytotoxic depending on how it is regulated. Objective This review explored the literature on the connections between hormonal therapies and autophagy. We investigated how autophagy could develop drug resistance in BC cells. Methods Scopus, Science Direct, PubMed, and Google Scholar were used to search articles for this study. Results The results demonstrated that protein kinases such as pAMPK, BAX, and p‐p70S6K could be a sign of autophagy in developing TAM resistance. According to the study's findings, autophagy plays an important role in BC patients' TAM resistance. Conclusion Therefore, by overcoming endocrine resistance in estrogen receptor‐positive breast tumors, autophagy inhibition may improve the therapeutic efficacy of TAM.