Tolerance to single-dose dactinomycin in combination chemotherapy for solid tumors.

We have reviewed our experience using single-dose dactinomycin (Act D). Twenty-nine patients with Ewing's sarcoma or rhabdomyosarcoma received 114 courses of Act D (2 mg/m2) in combination with vincristine, cyclophosphamide, or DTIC with or without radiotherapy. Side effects included nausea and vomiting (100% of the courses), severe thrombocytopenia (16%), granulocytopenia (18%), and mucositis (25%). In addition, skin reactions were observed in 74% of the courses following concomitant radiotherapy. These results were compared with those following 152 courses of combination chemotherapy which contained doxorubicin in place of Act D and which were administered to these same patients. It is concluded that single-bolus Act D is no more toxic, is at least as effective, and is more conveniently administered than the traditional divided daily dose of Act D.