Racial/ethnic and sex differences in young adult malignant brain tumor incidence by histologic type.

BACKGROUND

Brain tumors are among the top four cancers in young adults. We assessed important windows of tumor development and examined the interplay of race/ethnicity, age, and sex in young adult brain tumor incidence.

METHODS

Using SEER 18 data (2000-2017), incidence rates were estimated by Poisson regression in individuals aged 20-39 years at diagnosis. Incidence rate ratios (IRR) and 95% confidence intervals (95% CI) were estimated by race/ethnicity, sex and age for 12 malignant histologies.

RESULTS

White incidence for all histologies was higher (White vs. Black IRR: 2.09, 95% CI: 1.94, 2.24; White vs Asian Pacific Islander IRR: 1.88, 95% CI: 1.75, 2.03; White vs Hispanic IRR: 1.70, 95% CI: 1.62, 1.78; White vs American Indian IRR: 1.40, 95% CI: 1.14, 1.73). Minority groups had higher lymphoma incidence (White vs Black IRR: 0.32, 95% CI: 0.25, 0.40, White vs Hispanic HR: 0.55, 95% CI: 0.44, 0.68). Males had higher incidence than females for all histologies (IRR: 1.36, 95% CI: 1.31, 1.41). Male rates were highest for lymphoma (male-to-female [MF] IRR: 2.00, 95% CI: 1.65, 2.42) and glioblastoma (MF IRR: 1.61, 95% CI: 1.48, 1.75). The male excess in incidence was similar by race/ethnicity and increased with age (20-24-year-old IRR: 1.18, 95% CI: 1.07, 1.29; 35-39-year-old IRR: 1.44, 95% CI: 1.35, 1.54).

CONCLUSIONS

A White race and male incidence excess was observed among brain tumors.

IMPACT

The male excess was similar by race/ethnicity and increased with age suggesting male sex may be an intrinsic risk factor for brain tumor development.