antineoplastic antibiotic, a chemical substance derived from a microorganism or a synthetic analog of the substance, used in cancer chemotherapy. Dactinomycin, used in the treatment of Wilms’ tumor, testicular carcinoma, choriocarcinoma, rhabdomyosarcoma, and some other sarcomas, exerts its antineoplastic effect by interfering with ribonucleic acid (RNA) synthesis. Plicamycin, with a similar mechanism of action, is also administered for testicular cancer and for trophoblastic cancer. DOXOrubicin HCl, a broad-spectrum agent that is especially useful in treating breast carcinoma, lymphomas, sarcomas, and acute leukemia, and closely related daunomycin, which is also effective in acute leukemias, block the biosynthesis of RNA. Mitomycin C, prescribed for gastric, breast, cervical, and head and neck carcinomas, cross-links strands of deoxyribonucleic acid (DNA). Bleomycin sulfate, used in the treatment of squamous cell carcinomas of the head and neck, testicular carcinoma, and lymphomas, damages DNA and prevents its repair. Antineoplastic antibiotics cause bone marrow depression and usually cause nausea and vomiting; several cause alopecia.
