Occupational lung cancer

Our plain-English summary of Occupational lung cancer, by P.L. Whitesell, C.W. Drage (Mayo Clinic Proceedings, 1993).

The study

• Authors: P.L. Whitesell, C.W. Drage
• Journal: Mayo Clinic Proceedings
• Published: 1993;68(2):183-8
• Type of article: Review
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Exposure to certain industrial agents has been thought to have carcinogenic potential, both for employees who work closely with such agents and for the general population that comes in contact with them. Although case reports, laboratory studies, and epidemiologic analyses help to determine the carcinogenicity of implicated agents, each of these types of investigation has limitations and deficiencies in distinguishing causal from noncausal associations. Asbestos has been linked with bronchogenic carcinoma, but several controversial factors--the degree of risk relative to exposure dose, the synergistic effect of cocarcinogens, and the question of existence of a threshold dose--complicate the understanding of the magnitude of the risk for exposed persons. Several other physical and chemical agents (such as chromium, nickel, and radon) have also been associated with an increased incidence of lung cancer in epidemiologic and animal studies. As with asbestos, the specific type of the agent and exposure conditions are important in determining the degree of carcinogenicity. In studies of exposure to man-made mineral fibers, formaldehyde, and silica, the findings have been inconsistent. Because the degree of health hazard attributable to asbestos and other known and suspected lung carcinogens is controversial, a wide range of opinions exists about the importance of occupational exposures to the overall incidence of lung cancers. Nevertheless, attempting to prevent lung cancers by minimizing or eliminating exposure to carcinogens is preferable to treating existent cases.

In plain English

This article was a review. The authors discussed how the cancer-causing potential of workplace agents is judged and summarized published data on agents and occupations linked to lung cancer. It reported no new study of its own. On asbestos, the authors cited a 1955 report by Doll in which lung cancers among 113 male workers with more than 20 years of asbestos exposure were 10 times the expected number. They noted four further points from other studies. The dose-response slope varied by as much as 50-fold across studies. Tremolite miners had a severalfold greater relative risk than chrysotile miners at the same cumulative exposure. Several studies indicated that smoking and asbestos multiply rather than add risk. Whether a threshold dose exists is debated. Findings for man-made mineral fibers, formaldehyde and silica were described as inconsistent. Published estimates of the share of lung cancers due to occupation ranged from 1 to 50%. The authors concluded that preventing exposure to carcinogens is preferable to treating existing cases.

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: Narrative review (symposium article) of published literature on occupational lung cancer; no new data collected
• Who was studied: No study population of its own; the review drew on published case reports, laboratory, animal and epidemiologic studies
• Exposure: Asbestos (including comparison of tremolite and chrysotile miners), plus other agents such as chromium, nickel, radon, arsenic, man-made mineral fibers, formaldehyde and silica
• Main results:
  • From a 1955 report by Doll cited in the review: lung (bronchogenic) cancers among 113 male workers with more than 20 years of asbestos exposure were 10 times the expected number
  • Across the studies reviewed, the slope of the relationship between asbestos dose and lung cancer frequency varied by as much as 50-fold
  • From a cited study: for the same cumulative exposure, tremolite miners had a severalfold greater relative risk than chrysotile miners
  • Several cited studies indicated a multiplicative rather than additive interaction between smoking and asbestos in lung cancer risk
  • Whether a threshold dose for asbestos exists was described as debated; some investigators argue that the lack of effect at low doses reflects small numbers
  • The authors' table gave standard mortality ratios for asbestos compiled from the literature ranging from 104 to 1,400, with the International Agency for Research on Cancer category listed as Sufficient
  • Findings for man-made mineral fibers, formaldehyde and silica were described as inconsistent
  • Reported estimates of the proportion of lung cancers due to occupational exposures ranged from 1 to 50%
  • The authors summarized that asbestos is well established as a lung carcinogen, but that understanding of the overall size of the problem and of the factors determining risk remains incomplete
• The authors' conclusion: The authors concluded that preventing lung cancers by minimizing or eliminating exposure to carcinogens is preferable to treating existing cases
• Limitations the authors state:
  • The authors stated that the standard mortality ratios in their table are only an approximation, drawn from a wide range of studies that differ in exposure history and in the quality and selection of control populations

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Carcinogenic, Bronchogenic Carcinoma, Synergistic Effect, Mineral Fiber, Occupational Exposure.

Related studies

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• Occupational exposures and risk of oesophageal cancer by histological type: a case-control study in eastern Spain — M. Santibañez, J. Vioque, et al. (2008)
• Finnish Institute of Occupational Health Asbestos Program 1987-1992 — M.S. Huuskonen, K. Koskinen, et al. (1995)
• Occupational exposure to rock wool and glass wool and risk of cancers of the lung and the head and neck: a systematic review and meta-analysis — L. Lipworth, C. La Vecchia, et al. (2009)
• Asbestos-related occupational cancers compensated under the Industrial Accident Compensation Insurance in Korea — Y.S. Ahn, S.K. Kang (2009)

Browse more research in Mayo Clinic Proceedings, or return to medical research.