Evaluation of a MOPP-type regimen in histiocytosis X--a Southwest Oncology Group study.

The overall 38% response rate in histiocytosis X for cyclophosphamide, vincristine (Oncovin), prednisone, and procarbazine was not superior to responses that can be achieved with the component single agents. This is in contrast to the higher response rates that can be achieved by the combination of these agents in Hodgkin's disease. This is the second study of combination chemotherapy with individually effective agents that has failed to improve the response rates in histiocytosis patients with poor prognostic indicators.