Synovial sarcoma of childhood and adolescence. Report of the German CWS-81 study

BACKGROUND: Synovial sarcoma is the third most common pediatric soft tissue tumor. It requires an aggressive approach to achieve a cure. However, optimal treatment modalities adapted to disease extension and histologic variants have not been determined because there is little information about prospectively treated patients. METHODS: A multicenter trial for soft tissue sarcomas (Protocol CWS 81) was conducted in West Germany between 1981-1985, and 31 patients with synovial sarcoma were registered. Treatment included multiagent chemotherapy and irradiation after initial tumor excision or biopsy. The male-female ratio in this group was 1:1.6 with a median age of 14 years (range, 1-19 years). The median follow-up time after diagnosis was 101 months (range, 77-131 months). RESULTS: The overall event-free survival (EFS) for patients with synovial sarcoma was 74.2% at 5 years. Group I-II tumors had a significantly better prognosis than those in Group III-IV (EFS at 5 years 84.4% and 58.3%, respectively; P = 0.024). Small tumors (< 5 cm) responded better than larger tumors (> or = 5 cm; EFS, 93% versus 58%; P = 0.029). Synovial sarcoma involved the extremities in 28 patients who had a better outcome compared with those with extremity rhabdomyosarcoma in this study (EFS for Group I-IV was 82% versus 24%, P = 0.001). CONCLUSIONS: The results appeared superior to previous experience using radical surgery alone and suggested that after initial, nonmutilating surgery, adjuvant chemotherapy, and irradiation contributed to the improved long-term survival.