Ribociclib in Combination With Adjuvant Endocrine Therapy for Patients With Early High-risk HR+HER2- Breast Cancer

The goal of this observational study is to learn about the effects of using ribociclib in combination with physician-selected endocrine therapy as adjuvant therapy for patients with early high-risk HR+HER2- breast cancer. The main question it aims to answer is: Whether it is effective and safe to use ribociclib in combination with physician-selected endocrine therapy as adjuvant therapy for patients with early high-risk HR+HER2- breast cancer? Participants will receive ribociclib (at a dose of 400mg per day for 3 weeks, followed by 1 week off, 4 weeks for 1 cycle) plus physician-selected endocrine therapy for three years. During the follow-up, their relevant clinical data will be recorded.