Primary Brain Tumors Second Among Common Cancers in Adolescents, Young Adults

The epidemiology of primary brain tumors among adolescents and young adults aged 15 to 39 in the United States between the years 2016 and 2020 is comprehensively described in the Central Brain Tumor Registry of the United States (CBTRUS) Statistical Report, which was recently published in Neuro-Oncology. 

The CBTRUS was developed in partnership with the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute (NCI) of the US National Institutes of Health (NIH). To update its previously published statistical report on the epidemiology of primary brain and other central nervous system (CNS) tumors diagnosed in the US between 2012 and 2016, CBTRUS collected incidence, survival, and mortality data and classified tumors by site, histopathology, behavior, and brain molecular markers.

Between 2016 and 2020, the annual average age-specific incidence rate of primary malignant and nonmalignant brain tumors in patients aged 15 to 39 was 12.00 per 100,000. The incidence for malignant tumors only and nonmalignant tumors only was 3.21 and 8.79 per 100,000, respectively.

Combined, primary malignant and nonmalignant brain tumors in patients aged 15 to 39 were more prevalent among women vs men (14.67 vs 9.38 per 100,000, respectively). Primary malignant brain tumors alone, however, were more prevalent in men vs women (3.66 vs 2.75 per 100,000, respectively). 

Incidence of brain tumors was slightly higher in patients aged 15 to 39 who were non-Hispanic American Indian/Alaska Native (12.75 per 100,000) vs those who were non-Hispanic White (12.71 per 100,000), non-Hispanic Black (11.50 per 100,000), non-Hispanic Asian or Pacific Islander (6.55 per 100,000), or Hispanic of all races (10.44 per 100,000).

The incidence of brain tumors was also higher among young adults aged 35 to 39 (18.05 per 100,000) vs all other age groups. 

Approximately 13,350 new cases of primary malignant or nonmalignant brain tumors are expected to be diagnosed among patients aged 15 to 39 in 2024.

Between 2016 and 2020, a total of 5090 primary malignant brain tumor-related deaths were reported in patients aged 15 to 39, representing an annual average age-specific mortality rate of 0.96 per 100,000 and an average of 1018 deaths per year caused by primary malignant brain tumors.

Despite overall mortality attributable to primary brain tumors decreased by 1.6% (95% CI, -2.2% to -1.0%) between 1969 and 1981 and by 1.8% (95% CI, -2.4% to -1.3%) between 1991 and 2007, mortality related to these tumors has not significantly changed since. 

After the diagnosis of a primary malignant or nonmalignant brain tumor, the 5-year relative survival rate was 91.1%. Following diagnosis, survival was highest among patients aged 15 to 19 (92.0%) and lowest among patients aged 35 to 39 (89.9%). Regarding malignant tumors among patients aged 15 to 39, the 5-year relative survival rate was 72.7%.

By 2024, approximately 208,620 patients aged 15 to 39 will be living with primary brain tumor.

The most prevalent histopathologic group is predicted to be tumors of the sellar region, with an approximate 57,850 cases expected in 2024.

“Accordingly, an accurate statistical assessment of primary BT [brain tumors] in the AYA [adolescent and young adult] population is vital for better understanding the impact of these tumors on the US population and to serve as a reference for afflicted individuals, for researchers investigating new therapies, and for clinicians treating these patients,” the scientific team concluded.