Analysis of prognostic factors of pediatric-type sarcomas in adult patients

Objective: Pediatric-type sarcomas such as Ewing's sarcoma (EWS)/primitive neuroectodermal tumor family and rhabdomyosarcoma are relatively uncommon in adult patients. Optimal treatment strategies for this population and prognosis in adult patients compared with pediatric patients remain controversial. Methods: We retrospectively reviewed pediatric-type sarcoma patients older than 15 years at a single institution. Results: A total of 84 consecutive patients between 1995 and 2009 were identified at the Samsung Medical Center, Seoul, Korea. Median age was 30 years with a range of 15-74 years. Forty-seven patients (56.0%) were diagnosed with Ewing's sarcoma/primitive neuroectodermal tumor family, 34 (40.5%) with rhabdomyosarcoma and 3 (3.6%) with desmoplastic round-cell tumor. Median follow-up duration was 5.9 years. Median overall survival for all patients was 33.1 months (95% CI 13.5-52.7) and median event-free survival for all patients was 14.4 months (95% CI 5.9-22.9 months). Multivariate analysis revealed that localized disease was a significant independent prognostic factor for longer overall survival (hazard ratio 0.30, 95% CI 0.14-0.66, p = 0.003), and favorable primary tumor sites were associated with longer event-free survival (hazard ratio 0.33, 95% CI 0.11-0.98, p = 0.045). Conclusion: We identified the prognostic variables which may facilitate risk-adapted therapies for this rare adult sarcoma group, which should be further investigated.