Geographic distribution of incidence of pericardial and paratesticular mesotheliomas in the USA.

Abstract

Exposure to asbestos is thought to cause the large majority of pleural mesotheliomas in the USA. It is unknown whether asbestos exposure plays a role in the etiology of rarer forms of mesothelioma, e.g., those located in the pericardium or in the tunica vaginalis of the testis. In order to address this question, we sought to determine whether geographic patterns of incidence of these mesotheliomas have paralleled those of pleural mesotheliomas. We used age-adjusted incidence data from the nine populations served by the National Cancer Institute's Surveillance, Epidemiology, and End Results program during 1973-2011. Among men ages ≥50years, we compared the incidence of pericardial and paratesticular mesotheliomas, respectively, with the incidence of pleural mesothelioma across the nine populations. The rate of pleural mesothelioma was approximately twice as high in the San Francisco-Oakland (SFO) and Seattle-Puget Sound (SPS) areas compared to the other regions. In contrast, rates of paratesticular and pericardial mesotheliomas were not elevated in SFO (n=3 paratesticular, 1 pericardial) or SPS (n=4 paratesticular, 1 pericardial) relative to other regions. The results of this ecologic study do not support a role for asbestos exposure in the etiologies of either pericardial or paratesticular mesotheliomas; however, this study was limited by small numbers and was unable to directly ascertain asbestos exposure.