An attempt to use a common staging system in rhabdomyosarcoma: a report of an international workshop initiated by the International Society of Pediatric Oncology (SIOP).

One hundred medical records of children with rhabdomyosarcoma were reviewed independently by ten European and American specialists primarily concerned with pediatric cancer patients. Each specialist assessed the stage of disease using a pre-treatment staging system (International Society of Pediatric Oncology-Union Internationale Contre le Cancer TNM [SIOP-UICC TNM] and a post-surgical staging system (Inter-group Rhabdomyosarcoma [IRS] grouping system). These two prognostic systems are based on different criteria, and there is no simple correspondence between them. The reliability of the two systems, based on patients' characteristics extracted from medical records, was similar and satisfactory (Kappa index: 0.78 and 0.82 with the TNM system and with the IRS system, respectively). Nevertheless, the IRS grouping system, which considers a primary method of treatment: Surgery, is dependent upon the surgeon, the institution, and the current concept of treatment. We believe that the TNM system provides the best description of extent of disease and should be used for determining therapeutic options and comparing therapeutic results.