Synovial sarcoma in children: surgical lessons from a single institution and review of the literature

BACKGROUND: Synovial sarcomas are malignant high-grade, soft-tissue neoplasms that account for 7% to 8% of all malignant soft-tissue tumors and are the most common nonrhabdomyosarcoma soft-tissue sarcomas in pediatric patients. STUDY DESIGN: A retrospective review of the records of children younger than 17 years with synovial sarcoma treated at the University of Texas MD Anderson Cancer Center from 1966 until 1999 was undertaken. Primary site, tumor size, tumor margins, surgical treatment, adjuvant therapy, local and distant recurrence, and survival were recorded for 42 patients. Overall survival (OS) and progression-free survival (PFS) rates were calculated by the Kaplan-Meier method. The PFS and OS comparisons were performed using the log-rank test. RESULTS: Forty-four patients were identified, but two patients were excluded because of incomplete records. The median followup duration for the 42 patients was 8.8 years (range 0.2 to 22.4 years). The 5-year progression-free survival and overall survival rates were 75.6% and 87.7%, respectively. Eleven patients were dead and four others had progressed but were alive without evidence of disease after further therapy. Intergroup Rhabdomyosarcoma Study (IRS) grouping and tumor invasiveness were found to be significant prognostic indicators (p < 0.01 and p = 0.02, respectively). Patients with initial gross total resection (IRS Groups I and II) and noninvasive tumors (T1) were most likely to have prolonged PFS and OS. Patients with small tumors (<5 cm) (p = 0.09) had better PFS and OS. Adjuvant radiation therapy appeared to be of benefit, and chemotherapy did not seem to impact PFS or OS. Tumors > or = 5 cm are associated with increased risk of local recurrence and distant metastases. CONCLUSIONS: Complete resection with clear, yet not necessarily large, margins remains the treatment of choice for synovial sarcoma in children. Adjuvant radiation therapy should possibly be considered in patients with clear margins (IRS Group I) and in patients with microscopic residual tumor (IRS Group II). Chemotherapy did not seem to impact PFS or OS. Lymph nodes should be evaluated for local regional disease.