Familial risk of pleural mesothelioma increased drastically in certain occupations: A nationwide prospective cohort study

Our plain-English summary of Familial risk of pleural mesothelioma increased drastically in certain occupations: A nationwide prospective cohort study, by E. Kharazmi, T. Chen, M. Fallah, et al (European Journal of Cancer, 2018).

The study

• Authors: E. Kharazmi, T. Chen, M. Fallah, K. Sundquist, J. Sundquist, M. Albin, E. Weiderpass, K. Hemminki
• Journal: European Journal of Cancer
• Published: 2018;103:1-6
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: We aimed to explore the effect of occupation on familial risk of pleural mesothelioma in a nationwide cohort study design.

Method: The nationwide Swedish Family-Cancer Database includes all Swedes born after 1931 and their biological parents, totalling 16.1 million individuals with about 2.3 million cancer patients. Hazards ratios (HRs) were calculated adjusting for age, sex and region of residence.

Results: Having asbestos-related occupation in the absence of family history of mesothelioma increased risk of mesothelioma more than threefold (adjusted HR = 3.2, 95% confidence interval [CI]: 3.0-3.5). In those who had a history of mesothelioma in their first-degree relatives and an asbestos-related occupation, risk of mesothelioma dramatically increased compared with individuals without such occupations and family history (without chronic obstructive pulmonary disease [COPD] HR = 24, 95% CI: 15-39; with COPD 45, 95% CI: 15-141). In those who had a family history of mesothelioma and no history of an asbestos-related occupation, risk of mesothelioma did not show significant increase compared with those who had no family history of mesothelioma and no asbestos-related occupation (HR = 1.6; 95% CI: 0.7-3.8).

Conclusion: First-degree relatives of patients with pleural mesothelioma had a drastic risk of developing this malignancy in case of certain occupations, which shows a gene-environment interaction is probable in risk of mesothelioma.

Copyright © 2018 Elsevier Ltd. All rights reserved.

In plain English

This Swedish study looked at whether occupation changed the risk of pleural mesothelioma among people whose parents, siblings or children had the disease. It used national family, cancer, census and hospital registers for 6,866,574 people with known occupations, followed up to 2015. Jobs were sorted as asbestos-related or not. All groups were compared with people who had no asbestos-related job, no family history and no hospitalisation for COPD, a chronic lung disease. Among people never hospitalised for COPD, those with an asbestos-related job but no family history had an adjusted hazard ratio of 3.2 (95% confidence interval 3.0 to 3.5). Those with a family history but no such job had a ratio of 1.6 (0.7 to 3.8), which was not statistically significant. Those with both had a ratio of 24 (15 to 39; 17 cases). People with both who had also been hospitalised for COPD had a ratio of 45 (15 to 141; 3 cases). The authors concluded that a gene-environment interaction is probable. They noted they had no information on how long or how heavily people were exposed.

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: Nationwide register-based cohort study (described as prospective), using Cox proportional hazard models
• Who was studied: 6,866,574 people in the Swedish Family-Cancer Database (Swedes born after 1931 and their parents) who had at least one first-degree relative on record and information on their occupation. Follow-up ran from 1961 at the earliest to 31 December 2015 (mean 46 years).
• Exposure: Occupation, classed from register and census records as asbestos-related or not. Jobs counted as asbestos-related included plumbers, welders, mechanics, chemical workers, insulators, seamen, smelter workers, engine operators, textile, shoe and leather, wood, construction and electrical workers. The study also looked at family history of pleural mesothelioma in first-degree relatives and at hospitalisation for COPD. No fiber types or doses were recorded.
• Main results:
  • People with an asbestos-related occupation, no family history of mesothelioma and no COPD: 1,183 developed mesothelioma. Adjusted HR 3.2 (95% CI 3.0 to 3.5 in the table and abstract; the results text gives 3.0 to 3.4). The comparison group had no asbestos-related job, no family history and no COPD.
  • People with an asbestos-related occupation, no family history and a history of hospitalisation for COPD: 94 developed mesothelioma. Adjusted HR 2.5 (95% CI 2.1 to 3.1).
  • People with a family history of mesothelioma, no asbestos-related occupation and no COPD: 5 developed mesothelioma. HR 1.6 (95% CI 0.7 to 3.8 in the table and abstract; 0.6 to 3.8 in the results text). The increase was not statistically significant.
  • People with both a family history and an asbestos-related occupation, without COPD: 17 with mesothelioma and 1,166 without. Adjusted HR 24 (95% CI 15 to 39).
  • People with both a family history and an asbestos-related occupation who had also been hospitalised for COPD: 3 with mesothelioma and 106 without. Adjusted HR 45 (95% CI 15 to 141).
  • The authors reported a positive interaction between family history and asbestos-related occupation on pleural mesothelioma risk (p less than 0.001).
  • Among pleural mesothelioma patients, most of those with a family history had worked in an asbestos-related job. 15% of familial patients had been hospitalised for COPD, compared with 8% of non-familial patients.
• The authors' conclusion: The authors concluded that first-degree relatives of pleural mesothelioma patients had a drastically higher risk in certain occupations, and that this shows a gene-environment interaction is probable.
• Limitations the authors state:
  • The authors had no information on the exact duration or dose of asbestos exposure.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Cohort Study, Mesothelioma, confidence interval, COPD.

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