Prognostic significance of staging factors of the UICC staging system in childhood rhabdomyosarcoma: a report from the Intergroup Rhabdomyosarcoma Study (IRS-II).

Abstract
The need for a pretreatment staging system to accurately assess programs of therapy for the various sites and stages of childhood rhabdomyosarcoma has become apparent as detailed analyses of many factors affecting prognosis and treatment choices have been accomplished through the national cooperative trial, the Intergroup Rhabdomyosarcoma Study (IRS). Initiated in 1972, the IRS has thus far used a clinicopathologic grouping system that is based heavily on therapeutic decisions, particularly on whether or not excision is accomplished and the extent of such an operation. The major problem with this and several other staging classifications now in use is that they depend on pathologic data obtained after surgical treatment has been initiated or rejected. In addition, they do not consider histologic variations of this neoplasm which may be important in estimating prognosis. The large body of clinical data now accumulated in the IRS has provided an excellent opportunity for developing a database for evaluating...