cyclophosphamide + doxorubicin + fluorouracil + goserelin

This is a combination regimen consisting of four drugs—cyclophosphamide, doxorubicin, fluorouracil, and goserelin—used primarily in the treatment of breast cancer. Cyclophosphamide is an alkylating agent that interferes with DNA replication and cell division. Doxorubicin is an anthracycline antibiotic that intercalates into DNA, inhibiting topoisomerase II and generating free radicals to induce cytotoxicity. Fluorouracil (5-FU) is an antimetabolite that inhibits thymidylate synthase, disrupting DNA synthesis and repair. Goserelin is a gonadotropin-releasing hormone (GnRH) agonist that suppresses ovarian function by downregulating pituitary GnRH receptors, leading to decreased estrogen production—a key driver in hormone-sensitive breast cancers. This combination leverages both cytotoxic chemotherapy (cyclophosphamide, doxorubicin, fluorouracil) for direct tumor cell kill and hormonal therapy (goserelin) for endocrine suppression in premenopausal women with hormone receptor-positive disease[1][3][8]. The regimen may be used sequentially or concurrently depending on protocol design.