Mesothelioma in blood related subjects: report of 11 clusters among 1954 Italy cases and review of the literature

Our plain-English summary of Mesothelioma in blood related subjects: report of 11 clusters among 1954 Italy cases and review of the literature, by V. Ascoli, D. Cavone, E. Merler, et al (American Journal of Industrial Medicine, 2007).

The study

• Authors: V. Ascoli, D. Cavone, E. Merler, P.G. Barbieri, L. Romeo, F. Nardi, M. Musti
• Journal: American Journal of Industrial Medicine
• Published: 2007;50(5):357-69
• Cited by: 38 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Malignant mesothelioma is a sporadic tumor related to asbestos. Its occurrence in blood relatives raises the question of potential contribution of predisposing factors.

Methods: The study analyses the features of mesothelioma in blood relatives that might explain the disease clustering. Data sources of familial clusters were three population-based Mesothelioma Registries in Italy (Veneto and Apulia Regions, Brescia province; 1978-2005) and Medline, Toxline, and Oshline/Hseline databases for a review of the literature (1968-2006).

Results: Eleven clusters (22 cases) were identified among 1954 Italy mesothelioma cases, and 51 clusters (120 cases) were extracted from 33 studies. The proportion of Italy familial cases was 1.4 per 100 mesothelioma cases; the ratio between the number of familial clusters and the number of non-familial mesothelioma cases was 1:148. The mesothelioma profile in consanguineous is the same as in non-consanguineous subjects (male prevalence; pleural site; age at diagnosis >50 years; asbestos exposure). Most clusters occurred in asbestos workers (shipyard, asbestos-cement production/processing, and insulation) and household-exposed blood relatives. Others were related to asbestos-cement factory pollution, asbestos-in-place, and handling asbestos-contaminated textiles. Two clusters were without any known exposure. Cancer family history revealed lung cancer cases in eight clusters.

Conclusions: Available data support asbestos exposure as the main risk factor in mesothelioma cases among blood relatives. Our finding of a low proportion of familial cases would not suggest the influence of a large genetic component for mesothelioma in blood relatives.

In plain English

This article combined a study of three Italian population-based mesothelioma registries with a review of published reports of mesothelioma among blood relatives. Among 1954 malignant mesothelioma cases in the registries, the authors identified 11 new family clusters of 2 cases each (22 patients: 19 men and 3 women). All 22 patients had a history of asbestos exposure. Seven clusters were linked to occupational exposure, one to domestic exposure, and three to combined occupational and household exposure. Counting two clusters described earlier, familial cases made up 1.38 per 100 mesothelioma cases, and the ratio of familial clusters to non-familial cases was 1:148. The literature review found 33 publications reporting 51 clusters and 120 cases. Exposure was unknown in two of these clusters. The authors concluded that clustering mainly reflected asbestos exposure. They wrote that the low familial proportion hardly supported a large genetic component, though they considered genetic susceptibility plausible. They noted that the published data were heterogeneous and that data on cancer in relatives were too limited for confident comment.

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: Retrospective population-based multicentre registry study of familial clusters, combined with a review of the published literature
• Who was studied: 1954 malignant mesothelioma cases from three Italian registries: Apulia Region (502 cases, 1980–2005), Brescia Province (373 cases, 1978–2005) and Veneto Region (1079 cases, 1987–2005). The literature review covered 33 publications reporting 51 clusters and 120 cases among blood relatives.
• Exposure: Asbestos exposure, assessed by interview and classified as occupational, household, environmental, hobbies, unlikely or unknown. In the new Italian clusters, exposures included asbestos cement production (3 clusters) and railroad, foundry-furnace, paper mill and cotton mill work (1 cluster each). One Veneto cluster involved railroad maintenance with crocidolite.
• Main results:
  • The authors identified 11 new clusters of 2 cases each among the 1954 Italian registry cases. Of the 22 patients, 19 were men and 3 were women.
  • In the new Italian clusters, the ratio of pleural to peritoneal cases was 21:1.
  • All patients in the new Italian clusters had a history of asbestos exposure: 7 clusters occupational, 1 domestic, and 3 combined occupational/household.
  • In the new Italian clusters, latency was 43.1 years in men and 49.9 years in women.
  • Across the 1954 Italian cases, the proportion occurring in blood relatives (27 cases, including two previously described Apulia clusters) was 1.38 per 100 mesothelioma cases.
  • Across the 1954 Italian cases, the ratio of familial clusters (13) to non-familial mesothelioma cases was 1:148.
  • The literature review found 33 publications reporting 51 clusters and 120 cases.
  • In the literature clusters, exposure was unknown in two clusters. Occupational exposure occurred in 68.1% of cases.
  • In the literature, eight studies documented cancers of the respiratory tract in the family tree.
  • Genetic analysis of tumor samples was available for only three published clusters. The chromosome changes found were similar to those reported in sporadic mesothelioma.
• The authors' conclusion: The authors concluded that the Italian data and the literature did not distinguish mesothelioma in blood relatives from the sporadic form, and that clustering mainly reflected asbestos exposure. They wrote that the low proportion of familial cases hardly supported a large genetic component. They also wrote that genetic susceptibility was plausible and that hereditary factors and asbestos exposure are not alternative explanations.
• Limitations the authors state:
  • The literature reports spanned four decades of changes in diagnostics and asbestos use, making the data heterogeneous.
  • Data on second primary cancers in patients and on cancer in relatives were too limited for confident comment.
  • Genetic analysis of tumor samples was available for only three clusters.

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, Asbestos Exposure, Asbestos-Cement, Lung Cancer.

Related studies

• A one-generation cluster of malignant mesothelioma within a family reveals exposure to asbestos-contaminated jute bags in Naples, Italy — V. Ascoli, C. Carnovale-Scalzo, et al. (2003)
• Epidemiological patterns of asbestos exposure and spatial clusters of incident cases of malignant mesothelioma from the Italian national registry — M. Corfiati, A. Scarselli, et al. (2015)
• Asbestos related diseases in Italy: an integrated approach to identify unexpected professional or environmental exposure risks at municipal level — A. Marinaccio, A. Scarselli, et al. (2008)
• Analysis of latency time and its determinants in asbestos related malignant mesothelioma cases of the Italian register — A. Marinaccio, A. Binazzi, et al. (2007)
• Is Mesothelioma Unrelated to the Lung Asbestos Burden? Comment on Visonà et al. Inorganic Fiber Lung Burden in Subjects with Occupational and/or Anthropogenic Environmental Asbestos Exposure in Broni (Pavia, Northern Italy): An SEM-EDS Study on Autoptic Samples. Int. J. Environ. Res. Public Health 2021, 18, 2053 — D. Mirabelli, A. Angelini, et al. (2021)
• The relationship between malignant mesothelioma and an asbestos cement plant environmental risk: a spatial case-control study in the city of Bari (Italy) — M. Musti, A. Pollice, et al. (2009)

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