An Open-label Prospective Study to Evaluate the Efficacy and Safety of Pegfilgrastim in Triple-Negative Breast Cancer Patients Receiving AC Regimen Following Paclitaxel and Carboplatin as Neoadjuvant Therapy

Inclusion criteria

• 1. Women diagnosed with triple-negative breast cancer by pathology or cytology. 2. Age ≥19 and ≤70 years. 3. ECOG performance status 0-1. 4. Stage II-III breast cancer confirmed pathologically or clinically. 5. Planned to receive AC chemotherapy following paclitaxel/carboplatin as neoadjuvant therapy.

• Adequate organ function:
• Absolute neutrophil count (ANC) ≥1,000 cells/mm³
• Platelet count ≥75,000 cells/mm³
• Creatinine clearance ≥50 mL/min or serum creatinine <1.5× ULN
• Total bilirubin ≤1.5× ULN
• AST ≤2.5× ULN
• ALT ≤2.5× ULN 7. Ability to provide written informed consent and willingness to comply with study procedures.

Exclusion criteria

• 1. Prior treatment with cytotoxic chemotherapy. 2. Prior treatment with G-CSF or pegylated G-CSF. 3. History of conditions that may affect bone marrow function (e.g., severe liver or kidney disease).

• Receipt of radiotherapy within 4 weeks prior to study initiation. 5. Active uncontrolled infection or inflammatory disease that may affect study outcomes.

• Receipt of blood transfusion within 60 days prior to study initiation. 7. Pregnant, breastfeeding, or unwilling to use appropriate contraception. 8. Any condition judged by the investigator to make the patient unsuitable for participation.