[Rhabdomyosarcoma].

Rhabdomyosarcoma (RMS) is the most common type of soft-tissue sarcoma in childhood. In Europe and the United States, survival rates of RMS patients, especially those with local or regional RMS, have dramatically improved from around 25% in 1970 to over 70% in 2001 as a result of the introduction of multimodality therapy and cooperative group trials. RMS patients require multimodal therapy including appropriate surgery at the primary site, histological diagnosis supported by molecular genetics, and a combination of chemotherapy and radiation therapy based on their risk group. In Japan, no nationwide studies on RMS have been performed so far. An analysis of registration data from the Japanese Society for Pediatric Surgery as well as our recent retrospective study indicates that the survival rates of each risk group are all lower than those in the US or Europe, even in the "low-risk" group. We have recently established the Japan Rhabdomyosarcoma Study Group (JRSG) and continued several studies in each risk group to improve the outcome and to establish a standard therapy in Japan.