# The effect of sex on vestibular schwannoma incidence varies across the lifespan and modifies associations with race/ethnicity

## TL;DR

This study finds that the risk of developing a vestibular schwannoma varies with age, sex, and race/ethnicity, with notable differences in how these factors interact.

## Contribution

The study reveals how age modifies the effects of sex and race/ethnicity on vestibular schwannoma risk using nationally representative data.

## Key findings

- Females had higher risk than males until age 59, after which males had higher risk.
- Non-Hispanic Black and Hispanic individuals had significantly lower VS risk compared to non-Hispanic White individuals.
- The protective effect of non-Hispanic Black race was stronger in males than in females.

## Abstract

Vestibular schwannoma (VS) is a benign tumor of the eighth cranial nerve with incidence that differs by age, sex, and race/ethnicity. Prior research has not characterized how the contributions of sex and race/ethnicity to VS risk may interact or vary by age. We sought to examine the joint contributions of age, sex, and race/ethnicity to VS risk using nationally-representative data.

Diagnoses of non-malignant, intracranial VS were extracted from the Central Brain Tumor Registry of the United States (CBTRUS, 2004–2020) and used to calculate average age-adjusted annual incidence rates (AAAIRs) and incidence rate ratios (IRRs). Poisson regression was used to evaluate associations of VS risk with sex, race/ethnicity, and their interaction (sex*race/ethnicity), both overall and in ten-year intervals of age.

Over an eighteen-year period, 78002 unique individuals received a new diagnosis of VS (52.9% female). Females were at elevated risk compared to males from ages 10–59, after which this trend inverted with males at increased risk. Compared to non-Hispanic White individuals, Hispanic and non-Hispanic Black individuals were at significantly reduced risk of VS throughout the lifespan. The protective effect of non-Hispanic Black race/ethnicity was apparent among both females (IRR=0.40; 95% CI: 0.38–0.42) and males (IRR=0.36; 95% CI: 0.34–0.38), but was significantly stronger among males (Pinteraction<0.001).

Age significantly modifies the relationship between sex and risk of VS, while sex significantly modifies the relationship between race/ethnicity and risk of VS. Findings underscore the importance of incorporating demographic data into studies of VS biology, diagnosis, and clinical management.