Incidence of oligodendroglial tumors is 0.28 per 100,000 for ages 15–39 years and 0.31 for ages 40 + 1).
Comprise only ≈ 1% of primary brain tumors. Ratio of male:female = 1.3:1 2).
Location: > 50% occur in the frontal lobes, followed by temporal lobe, parietal lobe & occipital lobes.
They constitute together with mixed oligoastrocytoma 5–20% of all gliomas 3).
Data were analyzed from the Central Brain Tumor Registry of the United States (CBTRUS) from 2000 to 2013. Age-adjusted incidence rates per 100,000 person-years with 95% confidence intervals (CI) and annual percent changes (APCs) with 95% CI were calculated for oligodendroglioma (OD) and anaplastic oligodendroglioma (AOD) by age, sex and race. Survival rates were calculated for age, sex and race using a subset of the CBTRUS data. OD and AOD incidence peaked at 36-40 and 56-60 years, respectively. AOD:OD ratio increased up to age 75. Overall, OD and AOD incidence decreased [OD: APC -3.2 (2000-2013), AOD: -6.5 (2000-2007)]. OD incidence was highest in Whites but decreased significantly (2000-2013: APC -3.1) while incidence in Black populations did not significantly decrease (2000-2013: APC -1.6). Survival rates decreased with advancing age for OD, while persons aged 0-24 had the lowest survival for AOD. The current study reports a decrease in overall OD and AOD incidence from 2000 to 2013. Furthermore, AOD makes up an increasing proportion of oligodendroglial tumors up to age 75. Lower AOD survival in 0-24 years old may indicate molecular differences in pediatric cases. Thus, surveillance of tumor-specific trends by age, race and sex can reveal clinically relevant variations 4).