But researchers at the Clinic of Oncology at the University Hospital of Zurich and University Hospitals in Leuven, Belgium say they have evidence to show that BAP1 mutations account for only a tiny percentage of sporadic mesothelioma cases.
Mesothelioma is normally associated with exposure to asbestos dust and previous studies have found that people with the BAP1 mutation are more susceptible to cancer-causing effects of asbestos. Twenty-three percent of mesothelioma tumor specimens have been found to have a mutated BAP1 gene.
But some cases of mesothelioma appear to arise “sporadically”, with no history of asbestos exposure. Researchers around the world have long been trying to pinpoint the reasons these sporadic mesothelioma cases develop in an effort to prevent and/or treat them.
The Swiss and Belgian researchers extracted DNA from the blood of 78 malignant pleural mesothelioma patients to screen for BAP1 mutations. In an article on the research in the journal Lung Cancer, lead author Andreas Rusch concludes, “Taking into account previous similar screenings, the prevalence of germline BAP1 mutations in sporadic malignant pleural mesothelioma patients can be estimated around 1-2%, suggesting a minor role of germline BAP1 mutation in the pathogenesis of sporadic MPM.”
Earlier this year, a team of researchers in Novara, Italy, an area with a high percentage of mesothelioma cases, reached the same conclusion. Writing in Genes, Chromosomes, and Cancer, the Italian team concluded, “Our data show that BAP1 mutations are very rare in patients with sporadic malignant mesothelioma.”
Asbestos remains the number one trigger for malignant mesothelioma worldwide. The disease impacts an estimated 2,500 people in the U.S. each year, most of whom worked in an industry that utilized asbestos-containing products.
Rusch, A et al, “Prevalence of BRCA-1 associated protein 1 germline mutation in sporadic malignant pleural mesothelioma cases”, November 6, 2014, Lung cancer, Epub ahead of print.
Betti, M, “Inference on germline BAP1 mutations and asbestos exposure from the analysis of familial and sporadic mesothelioma in a high-risk area”, Sept. 18, 2014, Gene, Chromosomes & Cancer, Epub ahead of print.