Treatment outcomes and prognostic factors of patients with supratentorial low-grade oligodendroglioma.

Abstract

Oligodendroglioma is a relatively rare central nervous system tumor. Currently, surgical intervention is the mainstay of treatment, and the role of postoperative radiotherapy (RT) remains a subject of controversy. The objective of this study was to investigate the prognostic factors, evaluate the treatment outcomes, and assess whether postoperative RT has a benefit on local control and overall survival rates. This was a retrospective review of 52 consecutive adult patients with supratentorial low-grade oligodendrogliomas diagnosed at our institution between September 1980 and September 1998. Thirty-two received postoperative RT. Data were analyzed retrospectively to survey the significant prognostic factors for local control and overall survival. The 5-year overall and progression-free survival rate was 80% and 67%, respectively. Twenty-five patients experienced local disease progression during the follow-up period. In multivariate analysis, postoperative RT and age at diagnosis showed independent prognostic significance for overall survival. For progression-free survival, postoperative RT was the only independent prognostic factor. On the basis of the results of this study, we recommend considering postoperative RT as one of the standard adjuvant treatment modalities for patients with supratentorial low-grade oligodendroglioma, regardless of the extent of surgical resection. The optimal treatment strategy to maximize the treatment outcome should still be explored.