AMH Dynamic Changes to Predict Ovarian Reserve in Perimenopausal Breast Cancer

This study is a prospective observational cohort study aimed at developing a clinical model based on dynamic changes in anti-Müllerian hormone (AMH) to predict ovarian reserve in perimenopausal women with hormone receptor-positive breast cancer. The study will enroll approximately 300 women aged 45-55 years with perimenopausal status confirmed by menstrual history and hormone levels (FSH 10-40 IU/L, E2 \>20 pg/mL). Participants will be stratified by treatment regimen: (A) chemotherapy plus endocrine therapy, (B) chemotherapy plus targeted therapy plus endocrine therapy, and (C) endocrine therapy alone. Blood samples will be collected at seven time points to measure AMH, FSH, E2, and LH. Menstrual patterns and menopausal symptoms will be recorded prospectively. The primary outcome is the association between dynamic AMH changes and the occurrence of menopause. A predictive model will be constructed using LASSO regression and Cox proportional hazards models, with internal validation by bootstrap resampling. The goal is to develop a clinically applicable tool to guide endocrine therapy decisions-including the duration of ovarian function suppression (OFS), choice between tamoxifen and aromatase inhibitors (AIs), and selection of CDK4/6 inhibitors-as well as to provide individualized fertility preservation counseling for perimenopausal breast cancer patients.