Adaptive Chemotherapy for the Treatment of Advanced Breast Cancer

Inclusion Criteria10

• Understands and voluntarily signs the informed consent form.
• ECOG PS of 0 or 1.
• Expected survival: \>3 months
• Histologically or cytologically confirmed advanced invasive breast cancer.
• Histological type: HR+/HER2- or HR-/HER2-. HR positivity is defined as ER and/or PR expression in ≥1% of tumor cells by IHC. HER2 negativity is defined according to the ASCO-CAP HER2 guidelines: IHC intensity of 0 or 1+, or IHC intensity of 2+ with negative in situ hybridization results.
• Previous failure of first-line treatment for metastatic disease. For HR+/HER2- patients: at least received endocrine therapy combined with CDK4/6 inhibitors. TNBC patients at least received chemotherapy combined with PD-1 inhibitors (if PD-L1 CPS ≥1), or PARP inhibitor treatment (if germline BRCA mutations), except for TNBC patients with known germline BRCA mutations whom the attending physician deems them unable or unsuitable for PARP inhibitor treatment.
• At least 1 measurable lesion as defined by Response Evaluation Criteria in Solid Tumors (RECIST) criteria.
• Adequate organ function including bone marrow, renal function, hepatic function, and cardiac reserve.
• Premenopausal women must use medically acceptable contraception during the study.
• Compliance with the study protocol.