Sociodemographic factors and vestibular schwannoma: a Danish nationwide cohort study

Abstract

Vestibular schwannoma (VS) (or acoustic neuroma) accounts for about 5%-6% of all intracranial tumors; little is known about the etiology. We investigated the association between various sociodemographic indicators and VS in a cohort of 3.26 million Danish residents, with 1087 cases identified in 35 308 974 person-years under risk, with data accrued from 1993 to 2006. Complete ascertainment of cases was ensured by using population-based and clinical cancer registries. Information on sociodemographic indicators was obtained on an annually updated individual level from Statistics Denmark. Log-linear Poisson regression models were used to estimate incidence rate ratios (IRRs). Linear regression models were used to examine the association between sociodemographic indicators and tumor size. We found that IRRs decreased gradually with decreasing level of education, with values of 0.62 (95% CI: 0.49-0.78) for men and 0.62 (95% CI: 0.50-0.77) for women with a basic education compared with a higher education. Similar results were found for disposable income. Marital status was associated with a higher incidence of VS in men but not women; nonmarried men with a basic education had an IRR of 0.34 (95% CI: 0.23-0.50) compared with married men with a higher education. Lower incidence rates were also observed among unemployed or early-retirement pensioners, whereas there were no differences in incidence rates across the broad groups of occupations and across the types of districts. Sociodemographic indicators were not associated with the tumor size. The magnitude of the differences in incidence rates across the groups of different socioeconomic indicators suggests a high potential for earlier diagnosis of VS by improving the awareness of early symptoms.