Rhabdomyosarcoma.

In children and young adults, rhabdomyosarcoma occurs with a frequency that is equal to or greater than that of all the other forms of soft-tissue sarcoma combined. Although the responsiveness of rhabdomyosarcoma to chemotherapy varies greatly among tumors with different primary sites and with different histologic features, the overall results of chemotherapy have been more impressive in rhabdomyosarcoma than in any other form of soft-tissue sarcoma. Rhabdomyosarcomas occur in almost all sites and age groups. Those that occur in trunk and extremity sites have an unusually high instance of alveolar or undifferentiated histologic features and are more common in older children and young adults. Although they constitute only one third of all patients with rhabdomyosarcoma, tumors that are primary in trunk and extremity sites present some of the most difficult therapeutic problems in the management of all patients with this tumor. The ability to accomplish an initial complete local tumor excision still represents a major factor in survival. Early reexcision in the case of incompletely excised tumors with small volumes of residual tumor is effective when feasible. Local control of rhabdomyosarcoma can be achieved by high-dose irradiation and frequently by lower-dose irradiation when given in conjunction with chemotherapy. Second-look surgery is an accurate predictor of outcome, and late excision of residual tumor after chemotherapy-radiation therapy regimens may influence outcome. A regimen of vincristine, actinomycin-D, and cyclophosphamide given as a "pulse", with or without Adriamycin (doxorubicin), is the standard chemotherapy with cisplatin, etoposide, melphalan, and other agents now under study in trials of the Intergroup Rhabdomyosarcoma Study.