Efficacy and Safety of CDK4/6 Inhibitors Combined With Endocrine Therapy in HR+/HER2- Neoadjuvant Therapy for Early Breast Cancer

Inclusion Criteria

• •1\. Age ≥18 years old.
• •2\. Premenopausal and postmenopausal women or men with stage II-III disease (multifocal and/or multifocal early invasive breast cancer) if all tumors on histopathological examination meet the pathological criteria for ER and/or PR \> 10% and HER2- (HER2 expression of 0 or 1+ or 2+ and negative FISH test).
• •3.Patients had to have histologically confirmed ER and (or PR\>10%, HER2 -, early-stage invasive disease.
• •4.Intolerance or insensitivity to neoadjuvant chemotherapy: 2 cycles of neoadjuvant chemotherapy, PD/SD according to tumor evaluation, old age, and basic diseases can not tolerate chemotherapy.
• •5\. ECOG PS score 0-2.
• •6\. Patients must be able and willing to swallow and retain oral medications.
• •7\. In premenopausal women, a serum or urine pregnancy test had to be negative within 14 days of enrollment or in women who had been amenorrhea for less than 12 months at enrollment.
• •9\. Absolute neutrophil count ≥1500/µL, platelet ≥100000/mm3, hemoglobin ≥10g/dL