An Occupational Legacy: Malignant Mesothelioma Incidence and Mortality in Wisconsin

Our plain-English summary of An Occupational Legacy: Malignant Mesothelioma Incidence and Mortality in Wisconsin, by C.D. Tomasallo, K.Y. Christensen, M. Raymond, et al (Journal of Occupational and Environmental Medicine, 2018).

The study

• Authors: C.D. Tomasallo, K.Y. Christensen, M. Raymond, P.D. Creswell, H.A. Anderson, J.G. Meiman
• Journal: Journal of Occupational and Environmental Medicine
• Published: 2018;60(12):1143-1149
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: The aim of the study was to describe mesothelioma occurrence in Wisconsin from 1997 to 2013 by usual industry and occupation (I&O), including occupations generally considered low risk.

Methods: Population-based rates and standardized incidence and mortality ratios were calculated. Two case-control analyses were designed to compare mesothelioma incidence and mortality in specific I&O groups with occurrence of (1) brain and central nervous system cancers and (2) other causes of death, using logistic regression.

Results: Mesothelioma incidence and mortality were elevated in Wisconsin (SIRadj = 1.20 [1.13 to 1.28]; SMRadj = 1.30 [1.22 to 1.38]). Certain industry (construction, manufacturing) and occupation (construction and extraction) groups were associated with increased odds of mesothelioma, with some evidence of increased risk among teachers.

Conclusions: Forty years after the Occupational and Safety Health Act, mesothelioma incidence and mortality remain elevated in Wisconsin, with increased risk continuing for certain I&O groups.

In plain English

The authors analyzed Wisconsin's 1083 mesothelioma deaths and 1246 new cases from 1997 to 2013. From 2000 to 2013, Wisconsin had more mesothelioma deaths (age-adjusted ratio 1.30, 95% CI 1.22 to 1.38) and new cases (1.20, 95% CI 1.13 to 1.28) than expected from national rates. Case-control analyses compared the usual industry and job of mesothelioma patients against brain or nervous system cancer patients and a random sample of other deaths. Construction and manufacturing industries, and construction and extraction jobs, were linked to higher odds. Among deaths, paper manufacturing (odds ratio 2.38, 95% CI 1.22 to 4.73, versus public administration) and primary, secondary and special education teachers (2.10, 95% CI 1.05 to 4.26, versus other management occupations) had higher odds. Elementary and middle school teachers had higher odds of death versus professional and related occupations (3.50, 95% CI 1.46 to 8.38) and all other occupations (2.53, 95% CI 1.26 to 5.09); remaining teacher comparisons were not statistically significant. The authors concluded rates remain elevated compared with national data, and noted records gave only the usual or longest-held job.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Population-based surveillance study (standardized incidence and mortality ratios compared with the United States) plus two case-control analyses using logistic regression. One analysis used controls with brain and central nervous system cancers. The other used a random sample of all deaths, excluding asbestosis or mesothelioma deaths. Controls were frequency matched on age, race and sex.
• Who was studied: Wisconsin residents with mesothelioma, 1997 to 2013, identified through the Wisconsin Cancer Registry System and Wisconsin death certificates. There were 1083 mesothelioma deaths (1021 with mesothelioma as the underlying cause) and 1246 incident cases.
• Exposure: Usual (longest-held) industry and occupation, taken from death certificates and cancer registry records. No asbestos fiber types or exposure doses were measured.
• Main results:
  • Mesothelioma deaths in Wisconsin, 2000 to 2013: 957 observed versus 736.51 expected. Age-adjusted SMR 1.30 (95% CI 1.22 to 1.38); age-sex-race-adjusted SMR 1.22 (95% CI 1.14 to 1.30), compared with the United States.
  • Incident mesothelioma cases in Wisconsin, 2000 to 2013: 1054 observed versus 875.94 expected. Age-adjusted SIR 1.20 (95% CI 1.13 to 1.28); age-sex-race-adjusted SIR 1.16 (95% CI 1.09 to 1.23).
  • Average incidence in Wisconsin over 2000 to 2013 was 27.5 cases per million in men and 7.3 cases per million in women.
  • Among incident cases, 82.7% were pleural mesothelioma, 9.5% peritoneal and 7.8% other mesothelioma.
  • Industry groups with elevated odds of mesothelioma (reference: wholesale and retail trade) were construction (OR 3.02, 95% CI 2.01 to 4.55, for death; OR 2.51, 95% CI 1.67 to 3.77, for incidence) and manufacturing (OR 1.71, 95% CI 1.22 to 2.41, for death; OR 1.48, 95% CI 1.04 to 2.09, for incidence).
  • Among broad occupation groups (reference: transportation and material moving), only construction and extraction was associated with elevated odds (OR 2.83, 95% CI 1.86 to 4.31, for death; OR 3.06, 95% CI 1.99 to 4.72, for incidence).
  • In the broad-group analysis, there was no significant difference in odds of mesothelioma death or incidence for the educational services industry or for the professional and related occupation group, which includes teachers.
  • In the detailed analysis of deaths, paper manufacturing had an OR of 2.38 (95% CI 1.22 to 4.73), with 37 cases among 59 people, compared with public administration. Chemical manufacturing had an OR of 3.92 (95% CI 1.36 to 13.07), with 15 cases among 20 people.
  • In the detailed analysis of deaths, primary, secondary and special education school teachers had an OR of 2.10 (95% CI 1.05 to 4.26), with 28 cases among 49 people, compared with other management occupations.
  • Compared with the rest of the professional and related occupations group, primary, secondary and special education teachers had nonsignificant increases: mortality OR 1.91 (95% CI 0.89 to 4.11) and incidence OR 1.48 (95% CI 0.77 to 2.85). Compared with all other occupations, they also had nonsignificant increases: mortality OR 1.79 (95% CI 0.97 to 3.32) and incidence OR 1.14 (95% CI 0.66 to 1.98).
  • Elementary and middle school teachers had significantly increased mesothelioma mortality, both compared with the professional and related occupations group (OR 3.50, 95% CI 1.46 to 8.38) and compared with all other occupations (OR 2.53, 95% CI 1.26 to 5.09). Their increased incidence was not significant (OR 1.64, 95% CI 0.74 to 3.65, and OR 1.20, 95% CI 0.62 to 2.33, respectively).
• The authors' conclusion: The authors concluded that mesothelioma rates remain elevated in Wisconsin compared with national data. They found increased risk in certain groups, including construction and extraction and paper manufacturing, and evidence of increased risk among those employed in the educational field. They proposed further investigation of groups with borderline statistical significance, using more detailed work and personal histories.
• Limitations the authors state:
  • Only the usual or longest-held job was available, so asbestos exposure in other work periods could not be determined.
  • There was no information on non-work asbestos exposure, such as during home renovations, which could lead to exposure misclassification.
  • Possible miscoding of ICD-9 codes and underreporting of mesothelioma may have reduced the ability to assess the true burden.
  • The brain and nervous system cancer control group could include more people in jobs with exposure to other cancer-causing substances, which would bias findings toward no effect.
  • Usual industry and occupation were missing from about half of cancer registry records.
  • The sample was too small to analyze risk factors separately for pleural and peritoneal mesothelioma.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Mesothelioma.

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• Patterns in the incidence, mortality and survival of malignant pleural and peritoneal mesothelioma, New South Wales, 1972-2009 — M.J. Soeberg, N. Creighton, et al. (2016)
• Incidence and survival trends for malignant pleural and peritoneal mesothelioma, Australia, 1982-2009 — M.J. Soeberg, J. Leigh, et al. (2016)
• Incidence and survival of peritoneal malignant mesothelioma between 1989 and 2015: A population-based study — N. Le Stang, V. Bouvier, et al. (2019)
• Occupational and environmental cancer incidence and mortality in China — P. Li, S.S. Deng, et al. (2012)

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