Both Pleural and Peritoneal Mesothelioma Connected to Asbestos

Italy has one of the highest rates of mesothelioma in the world and according to two new studies, mesothelioma rates are a “suitable indicator” of asbestos exposure for both peritoneal and pleural mesothelioma.

Asbestos has long been known to be the cause of mesothelioma.  Italian researchers have highlighted this association by analyzing Italian mesothelioma data from 1995-2002.  They discovered that the annual mortality rate was 1.9 per 100,000. Significant mesothelioma clusters were found in the industries often associated with asbestos exposure, including: asbestos-cement industries, shipyards, oil refineries and petrochemical industries.  The authors concluded that their study “confirms malignant pleural neoplasms mortality as a suitable indicator of asbestos exposure at geographic level.”

In a related study, Italian researchers examined the relationship between asbestos exposure and peritoneal mesothelioma. Some investigators had suggested that this association could be weaker than that observed for pleural mesothelioma.  The researchers examined mesothelioma rates in the Lombardy Region of Italy.  The regional mesothelioma registry was used and data was analyzed from all peritoneal mesothelioma cases diagnosed between 2000 and 2007 and all pleural mesothelioma cases that occurred between 2000 and 2001.  There were 110 cases of peritoneal mesothelioma during this 7 year period and 515 cases of pleural mesothelioma during the one year period.  Asbestos exposure data (occupational, environmental/familial, or both) were collected by using a questionnaire administered to each mesothelioma victim or the mesothelioma patient’s family.  CT scans were also used to determine the presence or absence of asbestosis or pleural plaques as indicators of asbestos exposure.

The scientists found that both pleural mesothelioma patients and peritoneal mesothelioma patients had similar proportions of occupational and environmental or familial asbestos exposure. Approximately 60% of all mesothelioma victims had occupational exposure and 7% had environmental or family exposure.  However, twice as many pleural mesothelioma patients had both occupational and environmental or family exposures.  In addition, asbestosis and pleural plaques were more frequent in peritoneal mesothelioma than pleural mesothelioma.  No difference was detected in duration of asbestos exposure in either group of mesothelioma patient.  The researchers concluded that, “high cumulative asbestos exposures are the main risk factors not only for pleural but also for peritoneal mesothelioma.”

Sources:

Mensi, C., et al., Differences among peritoneal and pleural mesothelioma: data from the Lombardy Region Mesothelioma Register (Italy). Med Lav. 2011 Sep-Oct;102(5):409-16.

Fazzo L, et al., Pleural mesothelioma mortality and asbestos exposure mapping in Italy. Am J Ind Med. 2011 Oct 24. doi: 10.1002/ajim.21015. [Epub ahead of print]