Malignant mesothelioma, a rare cancer of the thin protective layer of tissue covering most internal organs, usually occurs in the pleura, the tissue surrounding the lungs, and in the peritoneum, the internal lining of the abdominal cavity. Very rarely, mesothelioma affects the pericardium, the tissue surrounding the heart, or the tunica vaginalis testis (TVT), the tissue surrounding the testicles; these tumors account for < 1% of all mesotheliomas. In light of their rarity, little is known about the distribution and determinants of mesothelioma at these sites. Therefore, scientists in Exponent’s Center for Health Sciences conducted a systematic review of the epidemiologic and clinical literature on malignant mesothelioma of the pericardium and TVT, and analyzed U.S. cancer registry data to understand demographic patterns and time trends in the occurrence of these cancers. This review is now in press for publication in Annals of Epidemiology as an article entitled, “Epidemiology of mesothelioma of the pericardium and tunica vaginalis testis."
Exponent’s findings showed that a substantial proportion of cases with malignant mesothelioma of the pericardium and TVT have no documented exposure to asbestos. Large occupational cohorts with heavy asbestos exposure have also reported no cases of pericardial or TVT mesothelioma. Incidence patterns showing no male preponderance of pericardial mesothelioma and time trends discordant with historical patterns of commercial asbestos use also argue against a major role of asbestos exposure in the development of these cancers. Analytic epidemiologic studies, which are currently lacking, are needed to identify environmental risk factors for malignant mesothelioma of the pericardium and TVT.
Read more about Exponent’s review of the epidemiology of pericardial and TVT mesothelioma here.