5-fluorouracil + cyclophosphamide + diethylstilbestrol + methotrexate

This is a combination chemotherapy and hormonal therapy regimen consisting of four agents: - 5-fluorouracil (5-FU): an antimetabolite that inhibits thymidylate synthase, disrupting DNA synthesis. - Cyclophosphamide: an alkylating agent that crosslinks DNA, leading to cell death. - Methotrexate: a folate antagonist that inhibits dihydrofolate reductase, blocking DNA and RNA synthesis. - Diethylstilbestrol (DES): a synthetic nonsteroidal estrogen acting as a hormonal therapy. This combination has been explored in the treatment of various cancers, particularly breast cancer and prostate cancer. The rationale for combining these agents is to target cancer cells through multiple mechanisms—cytotoxic effects on rapidly dividing cells (chemotherapy) and modulation of hormone-responsive tumor growth (hormonal therapy). Each drug attacks the cancer via different pathways to maximize efficacy and potentially overcome resistance[1][2][4][8].