Lung cancer in asbestos cement workers in Denmark

Our plain-English summary of Lung cancer in asbestos cement workers in Denmark, by E. Raffn, E. Villadsen, G. Engholm, et al (Occupational and Environmental Medicine, 1996).

The study

• Authors: E. Raffn, E. Villadsen, G. Engholm, E. Lynge
• Journal: Occupational and Environmental Medicine
• Published: 1996;53(6):399-402
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objectives: To study the relative and absolute risks of main types of lung cancer in a cohort of asbestos cement workers from Denmark.

Method: A cohort of 7887 men and 576 women employed between 1928 and 1984 was compiled from the personnel files of Danish Eternit Production. The cohort was followed up for deaths, emigrations, and incident cancer cases during the period 1943-90. The observed number of lung cancer cases in the cohort was compared with the expected number based on incidences for the Danish population. Internal comparison was made with Poisson modelling.

Results: A total of 226 lung cancer cases were observed (223 men and three women). The standardised incidence ratio (SIR) for all lung cancer among men was 1.7 (observed number 223, expected number 129.7, 95% confidence interval (95% CI) 1.5-2.0). The SIRs were raised for all main types of lung cancer; adenocarcinoma 2.6, squamous cell carcinoma 1.7, and anaplastic carcinoma 1.5. The higher SIR for adenocarcinomas was found particularly with a latency period of 25 years or more. Among the 93 excess lung cancer cases, 36 were squamous cell carcinomas and 32 were adenocarcinomas.

Conclusion: Asbestos cement work is associated with an increased risk of lung cancer of all main types. During the first 25 years after the start of employment this excess risk is shared almost equally between the different histological types of lung cancer, but the risk of adenocarcinomas is clearly higher after this point.

In plain English

This cohort study followed 7887 men and 576 women employed 1928 to 1984 at Danish Eternit Production, an asbestos cement factory, for cancer from 1943 to 1990. Chrysotile was 90% of the asbestos used; amosite was added from 1946, and small amounts of crocidolite used 1952 to 1968. Only three lung cancers occurred in women, so results covered men only. Men had 1.7 times the lung cancers expected from Danish population rates (95% confidence interval 1.5 to 2.0). Ratios were 2.6 (1.9 to 3.4) for adenocarcinoma, 1.7 (1.4 to 2.2) for squamous cell carcinoma and 1.5 (1.1 to 2.0) for anaplastic carcinoma. Of 93 extra cases, 36 were squamous cell carcinomas, 32 adenocarcinomas and 17 anaplastic carcinomas. The adenocarcinoma excess was particularly high 25 or more years after first employment. No pattern was seen by year of first employment or length of employment. The authors concluded asbestos cement work is associated with increased risk of all main lung cancer types. Workers' smoking was never studied; a 1973 Alborg survey the authors cited found it similar to local men's.

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: Cohort study built from company personnel records. It compared observed lung cancers with numbers expected from Danish population rates (standardized incidence ratios) and added internal Poisson regression modelling.
• Who was studied: 7887 men and 576 women employed 1928-1984 at Danish Eternit Production, Denmark, followed for deaths, emigrations and incident cancer 1943-1990
• Exposure: Work in asbestos cement manufacturing. Chrysotile made up 90% of the asbestos used in total. Amosite was introduced in 1946, and small amounts of crocidolite were used 1952-1968.
• Main results:
  • Only three lung cancer cases occurred among the women, so results were reported for men only
  • Men, whole observation period: standardized incidence ratio (SIR) for all lung cancer 1.7 (95% CI 1.5-2.0)
  • Men: SIR for adenocarcinomas 2.6 (95% CI 1.9-3.4)
  • Men: SIR for squamous cell carcinomas 1.7 (95% CI 1.4-2.2)
  • Men: SIR for anaplastic carcinomas 1.5 (95% CI 1.1-2.0)
  • Men: 223 observed versus 130 expected, a difference of 93 cases, of which 36 were squamous cell carcinomas, 32 adenocarcinomas and 17 anaplastic carcinomas
  • Men: the SIRs changed only marginally when the analysis was restricted to 15 or more years after start of employment
  • Men: the higher SIR for adenocarcinomas was found particularly with a latency of 25 years or more
  • Poisson modelling (men): no pattern by year of first employment
  • Poisson modelling (men): no pattern by duration of employment
  • Poisson modelling (men): increased risks at the borderline of significance were found only for unspecified lung cancers and for adenocarcinomas 25-34 years since first employment
• The authors' conclusion: The authors concluded that asbestos cement work is associated with an increased risk of all main types of lung cancer. In the first 25 years after start of employment, the excess was shared almost equally between types. After that, the risk of adenocarcinomas was clearly higher.
• Limitations the authors state:
  • The authors questioned whether all Danish men are a reasonable comparison group
  • The smoking habits of the cohort's workers were never studied. The authors cited a 1973 cross-sectional study in Alborg that found asbestos cement workers had smoking habits similar to those of men in Alborg in general.
  • Duration of employment is a poor stand-in for accumulated asbestos dose
  • Job titles were available only for the small group employed in 1928-41

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, Asbestos-Cement, Eternit, Standardized Incidence Ratio (SIR), confidence interval, Adenocarcinoma, Squamous Cell Carcinoma, Carcinoma.

Related studies

• Incidence of lung cancer by histological type among asbestos cement workers in Denmark — E. Raffn, E. Lynge, et al. (1993)
• Colorectal cancer in asbestos cement workers in Denmark — E. Raffn, E. Villadsen, et al. (1996)
• Incidence of cancer and mortality among employees in the asbestos cement industry in Denmark — E. Raffn, E. Lynge, et al. (1989)
• Diagnostic accuracy and safety of semirigid thoracoscopy in exudative pleural effusions in Denmark — F. Willendrup, U. Bodtger, et al. (2014)
• Incidence, mortality and survival in malignant pleural mesothelioma before and after asbestos in Denmark, Finland, Norway and Sweden — K. Hemminki, A. Försti, et al. (2021)
• Cancer in ex-asbestos cement workers in Israel, 1953-1992 — T.H. Tulchinsky, G.M. Ginsberg, et al. (1999)

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