Trend and distribution of mesothelioma in Denmark

Our plain-English summary of Trend and distribution of mesothelioma in Denmark, by M. Andersson, J.H. Olsen (British Journal of Cancer, 1985).

The study

• Authors: M. Andersson, J.H. Olsen
• Journal: British Journal of Cancer
• Published: 1985;51(5):699-705
• Cited by: 40 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M nos. 001225, 004758).

Abstract

The time trend and the distribution of malignant mesothelioma in Denmark are described on the basis of all notifications of cancer cases to the Danish Cancer Registry during the period 1943-1980. The age and sex adjusted incidence rates of pleural as well as peritoneal mesothelioma are increasing with time and reached in the latest 3-year registration period 1978-1980 a remarkably high total incidence of 14.7 cases per million men and 7.0 cases per million women. Towards the end of the observation period, however, the rate of increase was stagnating and for the younger age-groups even a fall in incidence of this malignancy was noted, perhaps reflecting the introduction of compulsory hygienic precautions in the handling of asbestos in Denmark. The incidence and time trend of peritoneal mesothelioma was similar among males and females while pleural mesothelioma was three times more common among males compared with females and showed an increase in incidence 15 years previous to females. For pleural mesothelioma in men notified through the 10-year period 1968, 1977, a significant excess was associated with residence in areas with high degrees of urbanization and in ship building towns.

In plain English

This study described malignant mesothelioma notified to the Danish Cancer Registry from 1943 to 1980: 685 male and 338 female cases. Age-adjusted rates of pleural and peritoneal mesothelioma rose, with the total reaching 14.7 cases per million men and 7.0 per million women in 1978-1980. Pleural rates were 3 times higher in men than women and began rising 10-15 years earlier in men; peritoneal rates were similar in both sexes. The rise slowed in the 1970s, and the rate fell among people aged 45-59. For pleural mesothelioma in 1968-1977, the relative risk for men compared with all of Denmark was 1.76 (95% confidence limits 1.49-2.08) in Copenhagen and suburbs, 0.44 (0.33-0.63) in rural areas, and 1.78 (1.41-2.26) in provincial towns with major shipyards. The authors wrote that women showed the same pattern without statistical significance, though their table gives women in Copenhagen and suburbs 1.34 (1.01-1.75), an interval excluding 1. The authors concluded that Danish 1970s rates were among the highest ever recorded nationally, and that the slowing increase may reflect hygienic measures in asbestos handling.

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: Descriptive national cancer registry study of incidence trends, with a comparison of pleural mesothelioma rates by area of residence (standardised incidence ratios)
• Who was studied: All malignant mesothelioma cases notified to the Danish Cancer Registry from 1943 to 1980: 685 males and 338 females. Pericardial cases (1%) were excluded. The area analysis covered pleural mesothelioma diagnosed 1968-1977: 296 men and 116 women.
• Exposure: No individual asbestos exposure was measured. The study compared place of residence at diagnosis: capital and suburbs, provincial towns, and rural areas; towns with and without major shipbuilding industries; and coastal versus inland areas. Areas were chosen by the presence or absence of known asbestos-consuming industries.
• Main results:
  • In 1978-1980 the total age- and sex-adjusted incidence was 14.7 cases per million men and 7.0 cases per million women.
  • Peritoneal mesothelioma incidence was similar in men and women. Pleural mesothelioma rates were 3 times higher in males than in females.
  • The increase in pleural mesothelioma occurred 10-15 years earlier among males than among females.
  • The rate of increase in pleural mesothelioma declined throughout the 1970s.
  • Among people aged 45-59, mesothelioma incidence actually fell.
  • Pleural mesothelioma 1968-1977, men in the capital and suburbs: 137 cases observed, relative risk 1.76 (95% confidence limits 1.49-2.08) compared with all of Denmark.
  • Pleural mesothelioma 1968-1977, men in rural areas: 50 cases observed, relative risk 0.44 (95% confidence limits 0.33-0.63).
  • Pleural mesothelioma 1968-1977, men in provincial towns with shipyard industry: 68 cases observed, relative risk 1.78 (95% confidence limits 1.41-2.26).
  • Pleural mesothelioma 1968-1977, men in provincial towns without shipyard industry: 41 cases observed, relative risk 0.63 (95% confidence limits 0.46-0.84).
  • Pleural mesothelioma 1968-1977, women in the capital and suburbs: 51 cases observed, relative risk 1.34 (95% confidence limits 1.01-1.75) compared with all of Denmark.
  • Among females, the authors stated that the same geographic pattern was seen but that the deviations were not statistically significant.
  • No significant deviation was seen when towns and rural districts were divided into coastal and inland areas.
• The authors' conclusion: The authors concluded that Danish mesothelioma incidence in the 1970s was among the highest ever recorded nationally, with signs that the increase was stagnating. They suggested this may reflect hygienic measures introduced in the handling of asbestos in Denmark.
• Limitations the authors state:
  • Making the correct diagnosis of mesothelioma is known to be difficult.
  • The high Danish rates may partly be caused by a high autopsy frequency and a high proportion of diagnosed cases being reported to the registry.
  • The clustering of cases in shipbuilding towns could partly be explained by a higher degree of urbanization in those areas.
  • The authors found the uneven geographic distribution among men surprising, given a 5% annual migration rate between municipalities and the very long latency between exposure and diagnosis.
  • No dust-level measurements exist for asbestos-consuming plants in the 1930s and 1940s. The authors' explanation that working conditions improved is therefore a presumption.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Malignant Mesothelioma, Cancer Registry, Incidence, Peritoneal Mesothelioma, Pleural Mesothelioma.

Related studies

• Incidence of lung cancer by histological type among asbestos cement workers in Denmark — E. Raffn, E. Lynge, et al. (1993)
• 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)
• Distribution and trends in mesothelioma mortality in Italy from 1974 to 2006 — M.P. Gatto, D. Tanna (2013)
• Incidence of cancer and mortality among employees in the asbestos cement industry in Denmark — E. Raffn, E. Lynge, et al. (1989)
• Lung cancer in asbestos cement workers in Denmark — E. Raffn, E. Villadsen, et al. (1996)
• Colorectal cancer in asbestos cement workers in Denmark — E. Raffn, E. Villadsen, et al. (1996)

Browse more research in British Journal of Cancer, or return to medical research.