Oligodendrogliomas in pediatric and adult patients: an outcome-based study from the Surveillance, Epidemiology, and End Result database.

INTRODUCTION: Oligodendrogliomas (OGs) account for <20% of all intracranial tumors and 25% of gliomas. Despite improvements in imaging techniques allowing for earlier diagnosis, OG is rare among the pediatric population. This study examines a large cohort of OG patients in an effort to define the demographic, clinical, and pathologic factors associated with clinical and survival outcomes.

METHODS: Data on 7,001 OG patients were abstracted from the Surveillance, Epidemiology, and End Result (SEER) database (1973-2013). Pediatric patients were defined as ≤19 years old, and adult patients were defined as age ≥20 years.

RESULTS: Among 7,001 OG patients, 6.5% were pediatric (mean age 12 ± 6 years), and 93.5% were adult (mean age 46 ± 15 years). Overall, OGs were more common among males, with a male-to-female ratio of 1.28:1. Overall, OGs were more common among Caucasians (76.9%) and also among the African American (10.8% pediatric vs. 4.0% adult) and Hispanic (12.8% pediatric vs. 11.8% adult). OGs occurred most commonly in the temporal lobe of pediatric patients and the frontal lobes of adults. Surgical resection was the primary treatment modality for both pediatric and adult populations (70.6% and 40.5%), followed by combined surgery and radiation (19.7% and 41.2%). Surgical resection was associated with significantly improved survival in both groups. Pediatric patients had a lower overall mortality (19.8% vs. 48.5%) and lower cancer-specific mortality (17.6% vs. 36.8%).

CONCLUSION: OGs most often present in Caucasian males in their fifth decade of life with tumors >4 cm in size. Children typically present with tumors in the temporal lobe, while adults present with tumors in the frontal lobe. Surgical resection confers a survival advantage among all patients, especially pediatric patients. Overall survival (OS) and cancer-specific survival are higher in the pediatric population. Further studies on novel treatment techniques, including bevacizumab and immunotherapy approaches, are required.