cyclophosphamide + docetaxel + doxorubicin + epirubicin

This is a combination chemotherapy regimen consisting of four cytotoxic agents—cyclophosphamide, docetaxel, doxorubicin, and epirubicin. All four are small molecule antineoplastic drugs commonly used in the treatment of breast cancer. Cyclophosphamide is an alkylating agent that crosslinks DNA, leading to cell death. Docetaxel is a taxane that stabilizes microtubules and inhibits their depolymerization, disrupting mitosis. Doxorubicin and epirubicin are anthracyclines that intercalate into DNA and inhibit topoisomerase II, resulting in DNA damage and apoptosis. While combinations such as TAC (docetaxel + doxorubicin + cyclophosphamide) or TEC (docetaxel + epirubicin + cyclophosphamide) are established regimens for breast cancer[1][2], the simultaneous use of all four agents together (cyclophosphamide + docetaxel + doxorubicin + epirubicin) is not standard or widely reported in clinical practice or literature.