Lung cancer risk and welding--preliminary results from an ongoing case-control study

Our plain-English summary of Lung cancer risk and welding--preliminary results from an ongoing case-control study, by K.H. Jöckel, W. Ahrens, U. Bolm-Audorff (American Journal of Industrial Medicine, 1994).

The study

• Authors: K.H. Jöckel, W. Ahrens, U. Bolm-Audorff
• Journal: American Journal of Industrial Medicine
• Published: 1994;25(6):805-12
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In a hospital-based case-control study, 391 male cases or primary lung cancer and the same number of controls--matched by sex, age, and region--were personally interviewed for their job and smoking histories. The data reported reflect the midpoint of a study aiming at a total of 1,000 cases. One objective of the study was to assess confounding by asbestos exposure in what was thought to be a welding-associated risk. While the odds ratios (OR) increased steeply with cumulative exposure to tobacco smoke and were raised also for lifelong asbestos exposure of over 4,100 working hours (OR = 1.91), the effect of welding exposure was reduced after adjustment for smoking and exposure to asbestos. Furthermore, no consistent dose-response relationship could be shown in relation to welding hours. Therefore the present study supports the hypothesis that some, if not all, of the excess risk of welders observed in the literature may be due to the exposure to asbestos. The finding that the subgroup of employees in the aircraft industry showed an increased odds ratio of 2.14 after adjustment for smoking and exposure to asbestos deserves further attention. This suggests the need for further research on the role of berryllium-containing alloys, which has been suggested by other authors.

In plain English

This was a midpoint report from a hospital-based case-control study in Germany. The authors interviewed 391 men with lung cancer from Bremen and Frankfurt hospitals (1988 to 1991) and 391 controls matched by sex, age and region about jobs and smoking. Asbestos exposure was estimated from job questionnaires; no fiber type was named. Men with more than 4,100 lifetime hours of asbestos exposure had an odds ratio of 1.88 (95% confidence limits 1.11 to 3.19) after adjustment for smoking. Men who had worked as welders or used oxyacetylene or manual metal arc welding regularly for at least half a year had a crude odds ratio of 1.35. After adjustment for smoking and asbestos it was 1.24 (0.83 to 1.86), and no consistent increase in risk with more welding hours was shown. Men who had worked in the aircraft industry had an odds ratio of 2.14 after adjustment for smoking and asbestos. The authors concluded that some, if not all, of the excess risk reported for welders may be due to asbestos, and suggested research on beryllium-containing alloys. They noted small numbers and an unfinished study.

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: Hospital-based case-control study; preliminary (midpoint) analysis of an ongoing study
• Who was studied: 391 men with newly diagnosed, histologically or cytologically confirmed lung cancer from one hospital in Bremen and two in Frankfurt, Germany (August 1988 to February 1991). They were compared with 391 population controls drawn from residents' registries and matched by sex, age and region. This was the midpoint of a study aiming at 1,000 cases.
• Exposure: Lifetime hours of welding (welding in general, oxyacetylene welding and manual metal arc [MMA] welding), and occupational asbestos exposure. Asbestos exposure was estimated retrospectively from supplementary job questionnaires and grouped as never, under 540, 540 to 4,100, and over 4,100 lifetime hours. No asbestos fiber type is specified.
• Main results:
  • Smoking: odds ratios rose from 4.14 (95% CL 1.79-9.59) for smokers of 0-20 packyears to 16.16 (95% CL 6.87-37.99) for smokers of more than 40 packyears.
  • Asbestos: men with more than 4,100 lifetime hours of exposure (56 cases, 32 controls) had an odds ratio of 1.91, and 1.88 (95% CL 1.11-3.19) after adjustment for smoking.
  • Men were classified as exposed to welding if they had ever worked as a welder and/or regularly used oxyacetylene or MMA welding for at least half a year. On this basis, 108 cases (28%) and 86 controls (22%) were exposed.
  • The crude odds ratio for men exposed to welding (as defined above) was 1.35.
  • The odds ratio for welding exposure rose to 1.48 after adjustment for smoking. It fell to 1.24 (95% CL 0.83 to 1.86) after further adjustment for asbestos.
  • No consistent dose-response relationship with cumulative welding hours was shown, for welding in general, oxyacetylene welding or MMA welding.
  • Employment in the aircraft industry had an odds ratio of 2.14 (p less than 5%) after adjustment for smoking and asbestos.
• The authors' conclusion: The authors concluded that the study supports the hypothesis that some, if not all, of the excess lung cancer risk of welders reported in the literature may be due to asbestos exposure. They added that the aircraft industry finding suggests a need for research on beryllium-containing alloys.
• Limitations the authors state:
  • The results are a midpoint evaluation of a study planned to include 1,000 cases.
  • Small numbers allowed no firm conclusions for other welding variables. They may also explain the borderline result for oxyacetylene and MMA welding.
  • The authors cautioned that a lower risk after adjusting for asbestos should not be read as meaning the workplace had no effect or a reduced effect.

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Case-Control Study, Confounding, Asbestos Exposure, Odds Ratio, Cumulative Exposure, Dose-response relationship.

Related studies

• Lung cancer risk and welding: results from a case-control study in Germany — K.H. Jöckel, W. Ahrens, et al. (1998)
• Heavy metals, welding fumes, and other occupational exposures, and the risk of kidney cancer: A population-based nested case-control study in three Nordic countries — I.M. Michalek, J.I. Martinsen, et al. (2019)
• Welding fumes and lung cancer: a meta-analysis of case-control and cohort studies — M.K. Honaryar, R.M. Lunn, et al. (2019)
• Occupational risk factors for lung cancer: a case-control study in West Germany — K.H. Jöckel, W. Ahrens, et al. (1998)
• Exposure to stainless steel welding fumes and lung cancer: a meta-analysis — B. Sjögren, K.S. Hansen, et al. (1994)
• Occupational lung cancer risk for men in Germany: results from a pooled case-control study — I. Brüske-Hohlfeld, M. Möhner, et al. (2000)

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