Socioeconomic status and glioblastoma risk: a population-based analysis

Socioeconomic status (SES) is associated with risk of various cancer types because of correlation between SES and causal factors or increased case ascertainment, or both. Studies evaluating the association between glioblastoma and occupational or SES factors have yielded inconsistent results. We evaluated the association between SES and glioblastoma risk using a large, population-based cancer registry dataset. Data of the Surveillance, Epidemiology, and End Results Program were used to evaluate the impact of SES on glioblastoma risk. SES was divided into quintiles on the basis of census tract of residence. Census tracts are small, geographically defined areas with relatively homogeneous population characteristics. Higher SES was strongly associated with increased risk of glioblastoma (p < .001). Relative to persons living in census tracts of the lowest SES quintile, the highest SES quintile had a rate ratio of 1.45 (95 % CI 1.39-1.51) (p < .001). Similar associations were seen in population subgroups defined by age, sex, and race. The strong association between higher SES and greater glioblastoma risk is unlikely to represent an ascertainment effect because glioblastoma is rapidly progressive and ultimately fatal. A number of previously proposed glioma risk factors may be correlated with SES, including atopy and allergy rates, cellular telephone use, and body morphometric measures. Further research is needed to define the mechanism of this association.