The investigators combined postoperative radiotherapy with CDK4/6 inhibitors ± endocrine adjuvant therapy to explore the tolerability and safety of this treatment regimen in HR+/HER2- postoperative high-risk breast cancer patients. During the study, investigators also utilized PRO scales (FACT-B, FACT-ES, FACT-F) to evaluate patients' multidimensional experiences, such as physical function, emotional state, and treatment-related symptoms, thereby obtaining more authentic and reliable data for symptom assessment and patient benefit.
Age is 18-75 years old, gender is female
ER positivity and/or PR positivity is defined as: all positively stained tumor cells The proportion of tumor cells is ≥10%;
HER2 negativity is defined as: 0/1+ by standard immunohistochemistry (IHC) test; ISH test was negative.
The time from radical surgery or breast-conserving surgery to randomization shall not exceed 6 months;
Pathological examination diagnosed as HER2-positive breast cancer (HER2-positive definition: standard immune Histochemistry (IHC) test is 3+ or ISH test is positive).
Local or regional recurrence of breast malignant tumors.
The clinical stage of the tumor is stage IV (metastatic) breast cancer.
Bilateral breast cancer (including contralateral carcinoma in situ).