Adjuvant Abemaciclib for Locoregional Recurrence of HR-positive, HER2-negative Breast Cancer (JCOG2313, AURA)

Inclusion Criteria

• •1. The patient has been diagnosed with the first locoregional recurrence (LRR) after receiving definitive treatment for primary breast cancer. LRR includes one or more of the following:
• •(i) Ipsilateral breast tumor recurrence (ii) Ipsilateral chest wall recurrence (iii) Regional lymph node recurrence
• •2. At least one LRR lesion must be confirmed by a biopsy, surgical specimen, or cell block from cytology, and must meet all of the following:
• •(i) Pathologically confirmed as invasive breast cancer, or diagnosed as breast cancer in a cytology cell block (in cases where only a cell block is available, the initial primary breast cancer must have been invasive).
• •(ii) Hormone receptor (HR) expression is positive. (iii) HER2 expression is negative.
• •※ If multiple lesions are pathologically evaluated and any lesion is HR-negative or HER2-positive, the patient is ineligible.
• •3. No prior diagnosis of distant metastasis of breast cancer.
• •4. Imaging assessment before registration confirms:
• •No lymph nodes ≥10 mm in short axis No evidence of distant metastasis
• •5. Age ≥18 years at the time of registration.
• •6. ECOG Performance Status of 0 or 1.
• •7. Chemotherapy for LRR is allowed prior to enrollment.
• •8. The patient does not have bilateral breast cancer.
• •9. No prior history of treatment with CDK4/6 inhibitors.
• •10. Written informed consent has been obtained for participation in this clinical trial.