EPID-08. TREATMENT OUTCOME FOR EPENDYMAL TUMORS IN THE UNITED STATES

Abstract

Ependymal tumors are rare CNS neuroectodermal neoplasm with a significant impact on patient mortality and quality of life. This study is to compare the effect of surgery and adjuvant radiation therapy (RT) on survival outcomes for ependymal tumors in the United States. 2091 patients aged >=18 with ependymal tumors were identified from the Surveillance, Epidemiology, and End Results registry (2000-2009). Surgical treatment was categorized into gross total resection (GTR) and no GTR. Log-rank test and multivariate Cox proportional hazard modeling were used to examine treatment effect on overall survival (OS). On univariate analysis, GTR was associated with improved OS for ependymoma (89% vs. 81%, p<0.01) and similar trend was observed for myxopapillary ependymoma (97% vs. 94%, p=0.13), subependymoma (93% vs. 89%, p=0.37), anaplastic ependymoma (50% vs. 26%, p=0.10). In multivariate analysis adjusting for age, sex, race, marital status, and year of diagnosis, GTR was associated with significantly improved OS for ependymoma (HR 0.711, 95% CI 0.527-0.953, p=0.02) but only a trend toward OS for anaplastic ependymoma (HR 0.703, 95% CI 0.426-1.145, p=0.16). Using multivariate analysis, adjuvant RT was found to associate with worse OS for ependymoma (HR 2.049, 95% CI 1.207-3.387, p=0.01), and no association was observed for the other histological groups. Among all prognostic factors, advanced age was determined to most significantly affect OS for all 4 histological groups: for age group 60-74 (compared to age group 18-44), myxopapillary ependymoma (HR 17.661, 95% CI 4.326-82.000, p<0.01), subependymoma (HR 4.932, 95% CI 1.522-19.044, p=0.01), ependymoma (HR 5.943, 95% CI 3.967-8.996, p<0.01), anaplastic ependymoma (HR 3.076, 95% CI 1.389-6.520, p=0.01). Ependymoma was the most common histological subtype among all ependymal tumors in the United States. Age at diagnosis was found to significantly contribute to patient long term survival. Surgery in the format of GTR provided survival benefit particularly in ependymoma.