Gestational choriocarcinoma, treatment

Dactinomycin is used in curative combined treatment of Wilms tumor, Ewing s sarcoma, rhabdomyosarcoma, and gestational choriocarcinoma. It is active in testicular tumors, lymphomas, melanomas, and sarcomas, although its use in most of these malignancies has been supplanted by other agents. 

The antibiotics that bind to DNA are nonspecific to the cell-cycle phase. Dactinomycin (actinomycin D and Cosmegen) binds to double-stranded DNA and prevents RNA synthesis by inhibiting DNA-dependent RNA polymerase. It is administered intravenously in the treatment of pediatric solid tumors such as Wilms tumor and rhabdomyosarcoma and for gestational choriocarcinoma. Dactinomycin causes skin reactions, gastrointestinal injury, and delayed bone marrow depression. 

Therapeutic applications Dactinomycin is used in combination with surgery and vincristine (see p. 390) for the treatment of Wilm s tumor. With methotrexate (see p. 378) it is effective in the treatment of gestational choriocarcinoma. Some soft-tissue sarcomas also respond. 

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