RARE-31. OUTCOME AND PROGNOSTIC FEATURES FOR PEDIATRIC PINEAL GLAND TUMORS

Abstract

Pineal gland tumor is a rare type of brain neoplasm, which typically occurs in children and young adults. However, systematic study of pineal gland tumor has been difficult given its low incidence. Using NCI Surveillance, Epidemiology, and End Results registry (1973-2012), we identified 593 patients of age 18 or younger with the diagnosis of malignant tumor located in pineal gland. The impact of radiotherapy (RT) and surgery on overall survival (OS) was determined using Log-rank test and multivariate Cox proportional hazard modeling. The major histological categories were germ cell tumor (GCT, 64.9%) and pineal parenchymal tumor (PPT, 28.3%). RT was delivered to 71.3% of patients. 11.5% of patients underwent sub-total resection (STR), while 20.2% underwent gross total resection (GTR). OS for all patients at 10 years was 69.3%. Pediatric patients with GCT were predominantly male (93.0%), and that for PPT was only 48.8% (p<0.01). The mean age for GCT is 13.1 years while that for PPT was 7.7 years (p<0.01). OS at 10 years was better for GCT (79.4%) than for PPT (47.5%). Using multivariate analysis, the delivery of RT was associated with improved OS among all 593 pineal gland tumor patients (HR 0.505, 95% CI 0.360-0.719, p<0.01). Specifically, RT was found to prolong OS in patient subgroups with germinoma (HR 0.286, 95% CI 0.137-0.624, p<0.01) or PPT (HR 0.387, 95% CI 0.233-0.646, p<0.01), but no survival benefit was seen for RT among patients with nongerminomatous GCT (HR 0.668, 95% CI 0.313-1.398, p=0.32). Histology is an important prognostic factor for pediatric patients with pineal gland tumor, with male predominance, older age at diagnosis, and improved OS for GCT compared to PPT. Our study also suggests beneficial effect of RT to prolong OS among all patients and those within subgroups of GCT or PPT.