cyclophosphamide + epirubicin + nab-paclitaxel + trastuzumab

This is a four-drug combination regimen consisting of cyclophosphamide, epirubicin, nab-paclitaxel (nanoparticle albumin-bound paclitaxel), and trastuzumab. It is used primarily as neoadjuvant or adjuvant therapy for HER2-positive breast cancer. - **Cyclophosphamide** is an alkylating agent that crosslinks DNA, leading to cell death. - **Epirubicin** is an anthracycline antibiotic that intercalates into DNA and inhibits topoisomerase II, causing DNA damage and apoptosis. - **Nab-paclitaxel** is a taxane chemotherapeutic formulated as albumin-bound nanoparticles; it stabilizes microtubules and inhibits their disassembly, blocking cell division[1][7][9]. - **Trastuzumab** is a monoclonal antibody targeting the human epidermal growth factor receptor 2 (HER2), inhibiting proliferation of tumor cells that overexpress HER2[6][10]. This combination leverages cytotoxic chemotherapy with targeted anti-HER2 therapy to maximize pathologic complete response rates in early-stage or locally advanced HER2-positive breast cancer patients[7][9].