Clinical Outcome of Combinations of Endocrine Therapy with Targeted Therapy in Women with HR +/ HER2 - Postmenopausal Advanced Breast Cancer: A Systematic Review and Meta-analysis

Background and aim: Breast cancer is one of the most common and worrying health problems of women in the world. The efficacy and safety of first-line and second-line/next-line treatments in women with HR + / HER2 − postmenopausal advanced breast cancer is unclear. Therefore, the present study aimed to determine progression-free survival and overall survival of endocrine therapy combinations with targeted therapy in this population.Material and methods: To obtain documentation and scientific evidence related to the first and second line/further line in the treatment of postmenopausal women with HR +/ HER2 - advanced breast cancer, articles published in international databases such as PubMed, Web of Science, Scopus, Sites Direct, Elsevier, Wiley, and Google Scholar search engine were used. Data were analyzed using STATA software, Version 17. the odds ratio, hazard ratio, and risk ratio with 95% confidence interval (CI), fixed effect model, and inverse–variance method were used.Results: Twenty-four studies were reviewed. Abemaciclib/Letrozole showed the best PFS in first-line therapies (HR:0.51 95% CI -2.26, 3.28). Dalpiciclib/Fulvestrant showed the best PFS in second/further-line therapies(HR:0.43 95% CI 0.09, 0.77). Ribociclib/Fulvestrant improved overall survival by 0.67 (HR:0.67 95% CI -0.31, 1.65) for first-line treatments, and Abemaciclib/Fulvestrant improved overall survival for second/further-line treatments65 (HR:0.65 95% CI 0.10, 1.20).Conclusions: Based on the findings of the present study, superior efficiency can be seen in first-line treatment with combinations of endocrine therapy with targeted therapy.