Prognostic factors in children with rhabdomyosarcoma.

The characteristics of 554 evaluated patients entered into a clinical trial conducted by the Pediatric Intergroup Rhabdomyosarcoma Committee between November 1972 and September 1978 were examined for their relationship to prognosis. Prognosis was defined as disease-free time and overall survival time in clinical groups I and II and time on study and survival time in clinical groups III and IV; all times were measured from the start of treatment. The percentage of patients surviving 2 years differed significantly among the clinical groups: I, 92; II, 78; III, 64; and IV, 35. The percentage of patients free of disease at 2 years was significantly higher in group I than in group II (83 vs. 72%, respectively); P = 0.02. The patient characteristics of group I most related to disease-free and overall survival were histologic cell type (alveolar, unfavorable), lymphocyte count (low count, unfavorable), and primary site (disease in extremities, unfavorable). In group II, sex (male, favorable) and lymphocyte count (low count, unfavorable) were significantly related to disease-free and overall survival times. Patients in the clinical subgroup with both microscopic residual disease and lymph node metastasis had poorer survival than patients in other subgroups. Primary site of disease was the only characteristic of group III related to length of time on study and to survival. Orbit and the genitourinary system were favorable primary sites, whereas the retroperitoneal area and extremities were unfavorable. In group IV, primary site (genitourinary, favorable) was related to length of time on study and survival. Sex (male, favorable) was related to survival experience.