High failure rate in spinal ependymomas with long-term follow-up

Abstract

1528 Background: Data on spinal ependymomas are sparse, and the prognostic value of many clinical variables remains controversial. The purpose of this study is to review a historical cohort of patients with spinal cord ependymomas treated with post-operative radiotherapy and assess the impact of extent of resection and radiation dose on progression-free survival (PFS) and overall survival (OS). We hoped the large patient number and long follow-up would lead to significant and relevant conclusions about a relatively rare and indolent disease. Methods: Thirty-seven patients with primary spinal cord ependymomas received postoperative radiation therapy from 1955–2001. The influence of radiation dose (range 45–59.4 Gy), extent of resection, KPS, tumor location, multifocality, and tumor grade was analyzed using the Cox proportional hazards model. Results: With a median follow-up of 157 months (range 8–492), 5-, 10-, and 15-year PFS rates are 75% ± 7.4%, 50% ± 9.1%, and 46% ± 9.3%, respectively, while OS rates are 83% ± 6.2, 74% ± 7.5%, and 61% ± 8.5%, respectively. The median time to recurrence is 68 months, with 57% of failures occurring after 5 years. Of the prognostic factors examined, only greater extent of resection significantly correlated with longer PFS (P=0.001). High-grade histology was associated with worse PFS in multivariate analysis (P=0.027). Conclusions: Large patient numbers and long follow-up demonstrate that local relapse rates for spinal ependymomas are higher than previously cited, with a large proportion of failures occurring more than 5 years after diagnosis. Aggressive surgical resection correlates with improved outcome and we thus recommend excision aimed at maximal resection while avoiding surgical morbidity. Regardless of the extent of resection, we recommend postoperative radiation to doses of 50–54 Gy and extended, close follow-up. No significant financial relationships to disclose.