Multimodal Treatment of Children With Sacrococcygeal Yolk Sac Tumor: Retrospective Analysis of Clinicopathology Characteristics and Relapse-free Survival

The aim of the study was to explore the clinicopathologic characteristics of sacrococcygeal yolk sac tumor (SYST) associated with relapse and the role of sensitivity to neoadjuvant chemotherapy in predicting outcome. The authors investigated prognostic factors of age, stage, initial tumor size, pathologic response to neoadjuvant chemotherapy, and alfa fetoprotein. A total of 26 patients with SYST were enrolled. Neoadjuvant chemotherapy was administered to 20 cases. Six patients underwent resection as initial therapy. Recurrence occurred in 12 patients. Nine patients with specimens exhibiting no malignant component after chemotherapy did not experience recurrence. By contrast, relapses occurred in 7 of 11 patients with viable residual tumor after neoadjuvant chemotherapy. All relapsed patients still achieved partial remission or complete remission after salvage therapy. Five-year relapse-free survival and overall survival rates were 55.2% and 100%, respectively (median follow-up, 59.5 mo; range, 16 to 155). Patients with complete necrosis after neoadjuvant chemotherapy had a better outcome compared with children with viable residual tumor. Relapse-free survival of pediatric SYSTs in this cohort were still low and warrants the multidisciplinary effort.