Trends in Combinatorial Endocrine Therapy for Breast Cancer Across Six Cities in China(2016-2021)

Chen Wang, Bo Chen, Qin Chen, Jie Chen, Liucheng Li Department of Pharmacy, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, People’s Republic of ChinaCorrespondence: Liucheng Li, Email [email protected]: This study aims to assess the prescribing patterns and combinations of endocrine therapy medications for breast cancer across six cities in China over a six-year period.Methods: Data on outpatient prescriptions were sourced from the China Hospital Prescription Analysis Cooperative Project database. The study analyzed trends in endocrine therapy medications, focusing on the number of prescriptions, total costs, defined daily doses (DDDs), and defined daily costs (DDC). The study also examined the use of two-drug combinations separately for premenopausal and postmenopausal women.Results: The number of prescriptions increased by 49.6% from 55,339 in 2016 to 82,791 in 2021. During the same period, annual costs ranged from 47.71 million to 88.37 million Chinese Yuan (CNY), marking an 85.2% increase. Tamoxifen, which led in DDDs in 2016, fell to sixth place, while exemestane rose from fifth to first place. Anastrozole’s rank dropped from first to fourth, with letrozole consistently holding the second position in DDDs. Fulvestrant and goserelin consistently ranked among the top two in DDC. Conversely, toremifene and tamoxifen consistently occupied the lowest two positions in DDC. The combination of aromatase inhibitors (AI) and ovarian function suppression (OFS) represented the largest proportion among drug combinations, with its usage significantly increasing over the years (P = 0.015).Conclusion: The use of endocrine therapy drugs has increased, with AI being the most frequently used. Additionally, the combination of AI and OFS has become the most prevalent treatment approach.Keywords: breast cancer, endocrine therapy drugs, aromatase inhibitor, ovarian function suppression, combinatorial drug therapy