Epidemiology of mesothelioma of the pericardium and tunica vaginalis testis

Our plain-English summary of Epidemiology of mesothelioma of the pericardium and tunica vaginalis testis, by G. Mezei, E.T. Chang, F.S. Mowat, et al (Annals of Epidemiology, 2017).

The study

• Authors: G. Mezei, E.T. Chang, F.S. Mowat, S.H. Moolgavkar
• Journal: Annals of Epidemiology
• Published: 2017;27(5):348-359.e11
• Type of article: Systematic review
• Cited by: 60 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Purpose: Malignant mesothelioma most commonly arises in the pleura and peritoneum but also occurs rarely at other anatomical sites with mesothelial tissue, namely, the pericardium and tunica vaginalis testis (TVT). This review provides a better understanding of the epidemiology of mesothelioma of these extrapleural sites.

Methods: We conducted a systematic review of the epidemiologic and clinical literature on pericardial mesothelioma and mesothelioma of the TVT. We also analyzed U.S. Surveillance, Epidemiology, and End Results cancer registry data to describe incidence patterns of these malignancies.

Results: An etiologic role of asbestos exposure has been hypothesized for pericardial and TVT mesotheliomas, but no analytical case-control epidemiologic studies exist to test this relationship. A substantial proportion of cases with these malignancies report no known asbestos exposure. In large occupational cohorts with heavy asbestos exposures, no cases of pericardial or TVT mesothelioma have been reported. Trends in the incidence of these malignancies do not match those of pleural mesothelioma, which correspond to historical trends of commercial asbestos use. A male preponderance of pericardial mesothelioma is not evident.

Conclusions: In the absence of analytic epidemiologic studies, the etiologic role of environmental risk factors for mesothelioma of the pericardium and TVT remains elusive.

Copyright © 2017 Elsevier Inc. All rights reserved.

In plain English

This was a review of published case reports, case series and registries on malignant mesothelioma of the pericardium (around the heart) and tunica vaginalis testis (around the testes). The authors also analyzed U.S. SEER registry data through 2013. They found no case-control or cohort studies of risk factors for either cancer. In the SEER 9 registries (1973–2013), pericardial mesothelioma made up 35 (0.4%) of 9,138 malignant mesotheliomas. Its rate fell over time and did not differ appreciably by sex. Tunica vaginalis mesothelioma, which the authors counted as all male genital mesotheliomas, made up 52 (0.7%) of 7,101 in males, with a statistically nonsignificant rise over time. Both cancers increased with age. Asbestos exposure was considered in 109 of 251 pericardial case reports. Of these, 33 had potential, suspected or confirmed exposure, with few details. Among 89 tunica vaginalis case reports not in earlier reviews, exposure was considered for 50, and confirmed or assumed for 15 of them. The authors concluded these patterns argue against a role for inhaled asbestos. They noted the lack of analytic studies and small case numbers.

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: Systematic review of published literature (mainly case reports, case series and registry reports) plus a descriptive analysis of U.S. SEER cancer registry incidence data
• Who was studied: Published reports found through PubMed up to September 18, 2015: 237 articles on malignant pericardial mesothelioma and 101 on mesothelioma of the tunica vaginalis testis (mTVT). Also cases of these cancers in the U.S. SEER 9 registries (1973–2013) and SEER 18 registries (2000–2013). In SEER, all malignant mesotheliomas of the male genital organs were treated as mTVT.
• Exposure: Asbestos exposure as reported or considered in published cases. Also other proposed risk factors such as prior radiation therapy, chemotherapy, heart disease and prior testicular-area conditions. The cohorts discussed involved chrysotile or amphibole asbestos, or both.
• Main results:
  • No analytic epidemiologic studies (case-control or cohort studies) of risk factors for pericardial mesothelioma were identified, and none were identified for mTVT.
  • SEER 9, 1973–2013: pericardial mesothelioma was 35 (0.4%) of 9,138 malignant mesothelioma patients. This was 16 (0.2%) of 7,101 cases among males and 19 (0.9%) of 2,037 cases among females.
  • SEER 9: the age-adjusted incidence rate of pericardial mesothelioma decreased from 0.78 per 10,000,000 person-years in 1973–1982 to 0.19 per 10,000,000 person-years in 2003–2013.
  • Pericardial mesothelioma rates in males and females were statistically indistinguishable overall and in three of the four decades examined.
  • SEER 18, 2000–2013: the pericardial mesothelioma rate was higher at ages 50 and over than at ages 0–49 (IRR 3.1, 95% CI 1.2 to 8.6).
  • Pericardial mesothelioma case reports: of 251 cases, the original authors considered potential asbestos exposure for 109. Of these 109, 33 had some potential, suspected, or confirmed exposure, and few details were provided.
  • SEER 9, 1973–2013: mTVT was 52 (0.7%) of 7,101 malignant mesotheliomas diagnosed among males.
  • SEER 9: the mTVT rate rose from 0.35 per 10,000,000 in 1973–1982 to 0.66 per 10,000,000 in 2003–2013 (IRR 1.9, 95% CI 0.8 to 4.9). The authors described this rise as statistically nonsignificant.
  • SEER 18, 2000–2013: mTVT incidence rose with age compared with ages 0–49. IRRs were 4.9 (2.2 to 10.7) for ages 50–59, 6.0 (2.5 to 13.7) for 60–69, 16.7 (8.1 to 34.7) for 70–79, and 18.6 (8.4 to 40.9) for 80 and over.
  • Among 89 mTVT case reports the authors identified as not previously included in literature reviews, asbestos exposure was considered for 50 (56%). Of those 50, exposure was confirmed or assumed for 15 (30%).
  • In the large occupational cohorts the authors reviewed, with heavy exposure to chrysotile or amphibole asbestos or both, no cases of pericardial mesothelioma or mTVT had been reported.
• The authors' conclusion: The authors concluded that three findings argue against a role for inhaled asbestos in these cancers: incidence trends did not match historical asbestos use, pericardial mesothelioma showed no male-female difference, and no cases were reported in heavily exposed cohorts. They also concluded that evidence on other risk factors remains elusive.
• Limitations the authors state:
  • No analytic epidemiologic studies were available to support a causal assessment.
  • Data were sparse and case numbers in the SEER registries were small.
  • Statistical power to detect differences by sex, ethnicity, year or region was limited.
  • Tumor misclassification, including miscoding of anatomic site, may have affected the mTVT patterns.

Topics

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

Medical terms in this study, explained in our Lexicon: Epidemiology, Mesothelioma, Pericardium, Tunica Vaginalis, Pleura, Peritoneum, Systematic Review, Pericardial Mesothelioma.

Related studies

• Comments on a recent case-control study of malignant mesothelioma of the pericardium and the tunica vaginalis testis — G. Mezei, E.T. Chang, et al. (2021)
• Mesothelioma of the tunica vaginalis testis — K.J. Butnor, E.N. Pavlisko, et al. (2019)
• Mesothelioma of the tunica vaginalis testis: report of 2 cases with asbestos occupational exposure — G. Gorini, M. Pinelli, et al. (2005)
• Malignant Mesothelioma of the Tunica Vaginalis Testis-A Malignancy Associated With Asbestos Exposure and Trauma: A Case Report and Literature Review — A.A. Baqui, N.A. Boire, et al. (2019)
• Association between asbestos exposure and pericardial and tunica vaginalis testis malignant mesothelioma: a case-control study and epidemiological remarks — A. Marinaccio, D. Consonni, et al. (2020)
• Authors' response: Mezei et al's "Comments on a recent case-control study of malignant mesothelioma of the pericardium and the tunica vaginalis testis" — A. Marinaccio, D. Consonni, et al. (2021)

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