The Upper Midwest Health Study: Industry and occupation of glioma cases and controls

Abstract

Background Understanding glioma etiology requires determining which environmental factors are associated with glioma. Upper Midwest Health Study case–control participant work histories collected 1995–1998 were evaluated for occupational associations with glioma. “Exposures of interest” from our study protocol comprise our a priori hypotheses. Materials and Methods Year-long or longer jobs for 1,973 participants were assigned Standard Occupational Classifications (SOC) and Standard Industrial Classifications (SIC). The analysis file includes 8,078 SIC- and SOC-coded jobs. For each individual, SAS 9.2 programs collated employment with identical SIC-SOC coding. Distributions of longest “total employment duration” (total years worked in jobs with identical industry and occupation codes, including multiple jobs, and non-consecutive jobs) were compared between cases and controls, using an industrial hygiene algorithm to group occupations. Results Longest employment duration was calculated for 780 cases and 1,156 controls. More case than control longest total employment duration was in the “engineer, architect” occupational group [16 cases, 10 controls, odds ratio (OR) 2.50, adjusted for age group, sex, age and education, 95% confidence interval (CI) 1.12–5.60]. Employment as a food processing worker [mostly butchers and meat cutters] was of borderline significance (27 cases, 21 controls, adjusted OR: 1.78, CI: 0.99–3.18). Conclusions Among our exposures of interest work as engineers or as butchers and meat cutters was associated with increased glioma risk. Significant associations could be due to chance, because of multiple comparisons, but similar findings have been reported for other glioma studies. Our results suggest some possible associations but by themselves could not provide conclusive evidence.

The epidemiology of glioma in adults: a "state of the science" review

“…141,142 However, in contrast to previous studies, 58,142 -144 there was no association between farming and glioma risk in the Upper Midwest Health Study (UMHS) conducted between 1995 and 1998. 145 The difference in findings might be explained by differences in the study populations: UMHS included nonurban controls with farming as their longest job, whereas De Roos's study 143 included only controls with at least 5 years of farm experience. In both the UMHS and a Canadian study, being an engineer, an architect, or a surveyor was associated with an increased risk of glioma.…”

Association between butchers and cancer mortality and incidence

“…[ 26 ] Their publication years ranged from 1989 to 2011. Among the studies, 6 were conducted in the USA, [ 9 , 20 , 25 , 27 , 28 , 31 ] 3 in Sweden, [ 10 , 12 , 24 ] 2 in New Zealand, [ 11 , 22 ] 2 in Uruguay, [ 29 , 30 ] and 1 in the Netherlands. [ 13 ] Moreover, 1 was conducted in 10 participating centers in the following locations: Denmark, Italy, the Netherlands, Norway, Spain, Sweden, UK, Germany, Greece, and France.…”

“…In addition, 11 studies were of high methodological quality, [ 9 , 10 , 13 , 20 , 22 , 23 , 26 – 28 , 30 , 31 ] 3 studies [ 11 , 24 , 29 ] were of moderate quality, and 3 studies [ 12 , 21 , 25 ] were of poor quality based on the modified NOS. The main deficiency was the selection bias related to the insufficient adjustment of confounding factors among the included studies.…”

Brain and Central Nervous System Tumors☆

“…In the Upper Midwest Health Study (UMHS), Ruder et al (2012) developed, a priori, a list of 21 exposures of interest identified from the literature as being potentially related to glioma risk. These studies are complicated by small numbers and the difficulties of segregating one of the many agents in the workplace, as well as other inherent problems in retrospective studies.…”