The Value Of A Cancer Register In The Study Of Asbestos Tumours

Our plain-English summary of The Value Of A Cancer Register In The Study Of Asbestos Tumours, by M. Greenberg (1973).

The study

• Author: M. Greenberg
• Published: Biological Effects Of Asbestos (J.C. Wagner, Editor), Lyon: Iarc Scientific Publications, Volume 8, Pp. 273-276 (1973)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 002390. The article is still under copyright, so we describe it here rather than post it.

In plain English

This report described a British register of mesothelioma, a cancer of the chest lining (pleura) or abdominal lining (peritoneum). Because of limited resources, cases in England, Wales and Scotland were investigated as fully as possible only for 1967 and 1968. Work histories came from interviewing patients or, failing that, relatives, employers and workmates. Of 246 people with definite tumours, 167 (68%) had an ascertained history of asbestos exposure at work. Among the 79 others (undecided, insufficient material, or definitely not mesothelioma), 38% had such a history. The author called this difference statistically significant but said diagnostic bias could invalidate it. Merseyside and Clydeside had both asbestos-using shipbuilding and doctors especially alert to the disease. In Greater London only half the cases had work exposure histories. Among people with definite work exposure, no significant difference in asbestos type could be determined between diagnostic groups; the author said such a register could not settle the relative hazards of asbestos types. The author concluded that the register posed more problems than it could solve and that a carefully controlled study was needed.

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 report on a national mesothelioma register, with cases for 1967 and 1968 investigated as fully as possible (questionnaire and interviews); partial comparison with death-certificate controls matched for sex and age but not area
• Who was studied: Cases in England, Wales and Scotland in 1967 and 1968 in which a diagnosis of malignant mesothelioma had been considered during life or after death: 246 with definite tumours and 79 others (undecided, insufficient material, or definitely not mesothelioma)
• Exposure: Occupational asbestos exposure history, obtained by interview with patients or, otherwise, with family, employers and workmates; the type of asbestos was also examined
• Main results:
  • Among the 246 subjects with definite tumours, 167 (68%) had an ascertained occupational asbestos exposure history
  • Among the remaining 79 subjects (undecided, insufficient material, definitely not mesothelioma), 38% had an ascertained occupational asbestos exposure history
  • The difference between the two groups was statistically significant, but the author stated it would be invalidated if there were diagnostic bias
  • Merseyside, Clydeside and Greater London had a frequency of mesothelioma diagnosis approximately four and five times the national experience
  • In the London area, only half the cases diagnosed had occupational asbestos exposure histories
  • Among subjects with definite occupational asbestos exposure whose diagnosis was definite mesothelioma, undecided, or definitely not mesothelioma, no significant difference could be determined in the type of asbestos to which they had been exposed. The author stated that such a register cannot resolve the relative hazards of asbestos types.
  • In cases that were definitely not mesothelioma and had no definite occupational exposure, corroborative evidence of asbestos exposure was never found. In definite mesothelioma cases without an occupational history, such evidence was found. The author considered the significance of this difference open to doubt.
  • Mesothelioma subjects were more often referred to the coroner than controls, which gave more precise job descriptions on their death certificates
• The authors' conclusion: The author concluded that a register of 'asbestos tumours' poses more problems than it can solve, though it brings cases to light. Until a carefully controlled study is made, neither the incidence of mesothelioma nor the role of asbestos in causing it can be confidently determined.
• Limitations the authors state:
  • Bias could not be eliminated in this register
  • Retrospective registers cannot resolve the hazard of asbestos or the relative hazards of asbestos types
  • Workers are rarely exposed to only one type of asbestos, and recall of exposure is unreliable
  • Controls were matched for sex and age but not for area of residence

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Pleura, Peritoneum, Asbestos Exposure.

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