Diffuse peritoneal mesothelioma: A case series of 62 patients including paraoccupational exposures to chrysotile asbestos

Our plain-English summary of Diffuse peritoneal mesothelioma: A case series of 62 patients including paraoccupational exposures to chrysotile asbestos, by R.L. Kradin, G. Eng, D.C. Christiani (American Journal of Industrial Medicine, 2017).

The study

• Authors: R.L. Kradin, G. Eng, D.C. Christiani
• Journal: American Journal of Industrial Medicine
• Published: 2017;60(11):963-967
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Diffuse peritoneal malignant mesothelioma (DPM) is caused by exposure to asbestos. The medical literature has linked DPM primarily to high levels of asbestos exposure, in particular amosite. Controversy persists as to whether chrysotile is capable of causing DPM, especially when exposures are paraoccupational.

Methods: Sixty-two subjects (51 men, 11 women) with DPM were reviewed in medical-legal consultation with deposition and product identification evidence.

Results: All had pathologically confirmed DPM. Most were exposed to both amphibole and chrysotile, but chrysotile alone was documented in 14/62 (26%) cases. A total of 7/14 (50%) cases of the paraoccupational exposures were to chrysotile alone. Women were younger than men as were those with paraoccupational versus those with occupational exposure. The mean duration of exposure for all cases was 17.9 ± 10 years and latency from time of first exposure was 45.9 + 11.6 years.

Conclusions: DPM occurs with both occupational and paraoccupational exposures to asbestos and may be seen in paraoccupational exposures to chrysotile asbestos.

© 2017 Wiley Periodicals, Inc.

In plain English

This was an uncontrolled retrospective case series of 62 people (51 men, 11 women) with diffuse peritoneal mesothelioma (DPM). Plaintiffs' attorneys referred the cases to one of the authors for medico-legal consultation. Exposure was judged from deposition testimony and the products people described. No exposure levels were reconstructed and no tissue fiber counts were done. Of the 62, 48 (77%) had been exposed at work and 14 (23%) only through household (para-occupational) exposure. In 14 of 62 cases (23%), the only products described were classified as chrysotile-containing, such as brakes, clutches, gaskets, packing or joint compounds. This included 7 of the 14 household-exposed cases. The household-exposed group was younger (mean 49.4 versus 65.4 years). Mean latency from first exposure was 45.9 years overall. There were no differences between groups in exposure duration or latency. The authors concluded that people with household exposure to chrysotile alone can develop DPM. They noted that the legal referral source biases the series, and that tremolite contamination of the chrysotile could not be excluded.

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: Uncontrolled retrospective case series of cases seen in medico-legal consultation
• Who was studied: 62 people with pathologically confirmed diffuse peritoneal mesothelioma (51 men, 11 women), referred by plaintiffs' attorneys for medico-legal consultation. Location and years are not stated.
• Exposure: Occupational or para-occupational (household) asbestos exposure, determined from deposition testimony and product identification. Thermal insulation work, U.S. Navy service or shipyard work before 1980 counted as likely amphibole exposure. Friction materials, gaskets, packing and joint compounds counted as likely chrysotile exposure. People exposed only to cosmetic talcum powder were excluded.
• Main results:
  • Of all 62 cases, 48 (77%) had occupational exposure and 14 (23%) had only para-occupational household exposure
  • Of all 62 cases, 14 (23%) described only products classified as chrysotile-containing; the rest described mixed amphibole and chrysotile exposures
  • Of the 14 para-occupationally exposed cases, 7 were listed in Table 1 as exposed to chrysotile only
  • The para-occupational group was younger than the occupationally exposed group (49.4 ± 14.5 vs 65.4 ± 13.5 years, P = 0.002)
  • Men were older than women (63.6 vs 53.6 years, P = 0.043)
  • Of the 14 para-occupationally exposed cases, 10 were women
  • Mean duration of exposure was 17.9 ± 10 years for all cases, 19.4 ± 11.8 for the para-occupational group, and 18.8 ± 10 years for the chrysotile-only group
  • Mean latency from first exposure was 45.9 ± 11.6 years overall, 46.1 ± 11.3 years in the para-occupational group, and 42.2 ± 7.8 years in the chrysotile-only group
  • There were no differences between groups in exposure duration or latency
  • For the five cases first exposed after 1980 to chrysotile-containing products, mean exposure duration was 12.6 ± 5.2 years and mean latency was 34 ± 5.7 years
  • Of the 62 cases, 59 had epithelioid mesothelioma and 3 had biphasic mesothelioma; no pure sarcomatoid cases were found
  • On CT scans, 23% had pleural plaques and 5% had changes judged consistent with pulmonary asbestosis
• The authors' conclusion: The authors concluded that people with para-occupational household exposure to chrysotile asbestos alone can develop DPM, and that as a group they develop the disease at a younger age.
• Limitations the authors state:
  • Because all cases came through medico-legal consultation, the series is biased: it excludes people who could not recall any asbestos exposure.
  • The findings cannot be generalized to all DPM cases in the population.
  • Exposure levels were not reconstructed, and no fiber burden analyses of lung or peritoneal tissue were done.
  • The purity of the chrysotile was not determined, so tremolite contamination cannot be excluded.
  • Lung tissue was not available, so the true proportion with asbestosis could not be confirmed under the microscope.
  • Genetic abnormalities such as BAP-1 mutations were not examined.

Topics

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

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Chrysotile, Malignant Mesothelioma, Asbestos Exposure, Amosite, Deposition, Product Identification, Amphibole Group.

Related studies

• Two-Stage Cytoreductive Surgery and Intraperitoneal Chemotherapy for Diffuse Malignant Peritoneal Mesothelioma: Predictors of Overall Survival in an Intention-to-Treat Series — J.C. Leinwand, R.N. Taub, et al. (2020)
• Unusually favorable outcome of 6 consecutive patients with diffuse malignant peritoneal mesothelioma treated with repeated doses of intraperitoneal paclitaxel. A case series — P.H. Sugarbaker, O.A. Stuart (2020)
• Malignant peritoneal mesothelioma in a 17-year-old boy with evidence of previous exposure to chrysotile and tremolite asbestos — A. Andrion, S. Bosia, et al. (1994)
• An elaboration of "proof" of peritoneal mesothelioma from tremolite free chrysotile — D. Egilman (2011)
• Malignant peritoneal mesothelioma: a series of 19 cases — T. van Gelder, H.C. Hoogsteden, et al. (1989)
• Malignant peritoneal mesothelioma: prognostic significance of clinical and pathologic parameters and validation of a nuclear-grading system in a multi-institutional series of 225 cases — D.B. Chapel, J.J. Schulte, et al. (2021)

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