The incidence of malignant mesothelioma in Australia 1982-1988

Our plain-English summary of The incidence of malignant mesothelioma in Australia 1982-1988, by J. Leigh, C.F. Corvalán, A. Grimwood, et al (American Journal of Industrial Medicine, 1991).

The study

• Authors: J. Leigh, C.F. Corvalán, A. Grimwood, G. Berry, D.A. Ferguson, R. Thompson
• Journal: American Journal of Industrial Medicine
• Published: 1991;20(5):643-55
• Cited by: 29 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004913).

Abstract

From 1980 to 1985, the Australian Mesothelioma Surveillance Program, and since 1986, the Australian Mesothelioma Register, have been collecting data on all cases of malignant mesothelioma that could be ascertained in Australia. Incidence rates were calculated on 854 Program and 696 Register cases (total 1271) diagnosed in Australia between January 1, 1982 and December 31, 1988. Australia has one of the highest national rates of mesothelioma in the world (15.8 cases per million of population aged 20 years and older), and the rate is rising. The rate is far higher in males (28.3) than females (3.3). The Western Australian rate (28.9) is the highest among the states, as may be expected because of the crocidolite mine at Wittenoom; however, the largest numbers of cases occur in the more populous and industrial New South Wales. The high incidence rate, its expected continuing increase, and absence of a history of exposure to asbestos in approximately 28% of cases, demand consideration of potential environmental factors other than asbestos in the causation of this tumor, as well as continued surveillance.

In plain English

This study measured how often malignant mesothelioma was diagnosed in Australia, 1982 to 1988. Cases came from the Australian Mesothelioma Surveillance Program (1980 to 1985) and the Australian Mesothelioma Register (from 1986). The crude national rate per million people aged 20 and over rose from 12.8 in 1982 to 19.6 in 1988. The age-standardized rate for the whole period was 15.8 overall, 28.3 for males and 3.3 for females. Western Australia, home of the Wittenoom crocidolite mine, had the highest state rate (28.9); New South Wales had the most cases. Of 1,346 cases with this information, 91 (6.8%) were exposed at Wittenoom. About 28% of Program cases gave no history of asbestos exposure. Where tumor site was known, most tumors were pleural; peritoneal tumors made up 5% of men's and 17% of women's cases. The authors said it was unclear whether the rise was real or reflected fuller reporting, but noted that a continuous rise since 1947, found in earlier research, supported a real effect. They concluded that potential environmental factors other than asbestos should be considered, along with continued surveillance.

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: National incidence study based on a mesothelioma surveillance program and register
• Who was studied: Cases of malignant mesothelioma diagnosed in Australia from 1982 to 1988 and notified to the Program (854 cases) or the Register (696 cases). Rates were calculated nationally and by state and territory for people aged 20 and over.
• Exposure: Asbestos exposure histories (occupational and environmental) collected for Program cases. These included exposure at the Wittenoom crocidolite mining town in Western Australia.
• Main results:
  • The national crude incidence rate per million people aged 20 and over rose from 12.8 in 1982 to 19.6 in 1988.
  • Over 1982 to 1988, the standardized rate was 15.8 per million people aged 20 and over for the whole population, 28.3 for males and 3.3 for females.
  • The male crude rate ranged from 22.7 to 35.9 over the period, about seven times the female crude rate (3.1 to 3.6).
  • Western Australia had the highest state rate (28.9). The authors linked this to the Wittenoom crocidolite mine.
  • 91 of 1,346 cases (6.8%) had direct occupational or environmental exposure at Wittenoom.
  • About 28% of Program cases gave no history of asbestos exposure.
  • Among 723 men with known tumor site, 676 (93%) had pleural mesothelioma, 38 (5%) had peritoneal mesothelioma and 9 had tumors in other sites.
  • Among 101 women with known tumor site, 84 (83%) had pleural mesothelioma and 17 (17%) had peritoneal mesothelioma.
  • 24% of women had some form of asbestos exposure, compared with 75% of men.
  • In both sexes the rate rose with age up to 79 years and then declined.
  • Of 777 Program cases reviewed by the Pathology Panel, 746 were confirmed as mesothelioma. A correction factor of 0.96 was therefore applied to Register cases, which were not reviewed.
  • The Australian national rate (15.8) was the highest among the countries the authors compared.
  • The authors noted that the continuous rise since 1947, reported in earlier research, supported a real increase rather than only better reporting.
• The authors' conclusion: The authors concluded that the high and rising rate, together with the roughly 28% of cases with no asbestos exposure history, call for consideration of potential environmental factors other than asbestos and for continued surveillance.
• Limitations the authors state:
  • It was unclear whether the high and rising rates reflect a genuine increase or more complete reporting due to greater awareness.
  • Comparisons of incidence rates between countries are of doubtful validity because of differences in time periods, age groups and case collection.
  • Register cases had no pathology review. The correction factor assumes the same share would have been rejected as among Program cases.
  • The 1988 rates were expected to rise slightly because some cases had not yet been notified.
  • The dip in 1987 was attributed to a drop in notifications during the changeover from the Program to the Register.
  • Peritoneal mesothelioma is thought to be underreported in Australia, as in some other countries.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Incidence, Crocidolite, Wittenoom, Causation.

Related studies

• Incidence and survival trends for malignant pleural and peritoneal mesothelioma, Australia, 1982-2009 — M.J. Soeberg, J. Leigh, et al. (2016)
• The incidence of malignant mesothelioma in Australia, 1947-1980 — A.W. Musk, P.J. Dolin, et al. (1989)
• Malignant mesothelioma in Australia 2015: Current incidence and asbestos exposure trends — M.J. Soeberg, J. Leigh, et al. (2016)
• Retinol supplementation and mesothelioma incidence in workers earlier exposed to blue asbestos (Crocidolite) at Wittenoom, Western Australia — H.S. Alfonso, A. Reid, et al. (2010)
• Epidemiology of malignant mesothelioma in Western Australia — B.K. Armstrong, A.W. Musk, et al. (1984)
• Mortality and cancer incidence of Australian participants in the British nuclear tests in Australia — R.T. Gun, J. Parsons, et al. (2008)

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