Pediatric and adolescent synovial sarcoma: multivariate analysis of prognostic factors and survival outcomes.

PURPOSE: Treatment of synovial sarcoma (SS) is challenging because of its unpredictable clinical behavior. We reviewed our institutional experience with pediatric SS to identify prognostic indicators and survival outcomes. METHODS: We retrospectively reviewed all pediatric/adolescent patients (age<22 years) with confirmed SS treated from 1970 to 2010. Patient and clinical characteristics were evaluated for prognostic significance and survival outcomes. RESULTS: We identified 111 patients. The median age was 15.4 years. Sixty-seven tumors (60%) were monophasic, 42 (38%) were biphasic, and 2 (2%) were of unknown histology. Median follow-up was 5.3 years (range 0.8-36.8 years), 5-year overall survival (OS) was 73%, and 10-year OS was 65%. Greater tumor size (stratified as ≤5 cm, >5 cm, or ≥10 cm) (P=0.001) and depth (P=0.03) correlated with decreased OS. Primary tumor location in the upper extremity correlated with increased OS when compared with lower-extremity and central lesions (P=0.05). Bone and/or neurovascular invasion negatively impacted survival (P=0.02). Multivariate analysis revealed that tumor size (trichotomized) was the dominant and sole factor in discriminating survival risk. Neither radiotherapy nor chemotherapy correlated with improved 5-year survival. CONCLUSIONS: Tumor size, depth, invasion, and primary location affect survival in pediatric SS. The role of radiotherapy and chemotherapy for SS warrants future study.