Spotting the BAP1 Gene Mutation in Mesothelioma Patients

New guidelines may make it easier to tell which mesothelioma patients contracted the disease because of a BAP1 gene mutation. The knowledge could have an impact on mesothelioma treatment planning.

BAP1 stands for BRCA associated protein-1. People who have an inherited BAP1 gene mutation face a higher risk for several conditions, including malignant mesothelioma. 

Very few mesothelioma patients have the mutation and gene testing is not routine. So researchers at a top US cancer center have developed a set of screening criteria. The criteria may help predict which mesothelioma patients could benefit from genetic testing.

Testing for the Altered Gene

Mesothelioma is just one of the conditions associated with the inherited BAP1 gene mutation. People with this condition are also more prone to develop moles called atypical spitz nevi and a rare type of eye cancer. 

But not everyone with these conditions has an altered gene. Researchers at Memorial Sloan Kettering Cancer Center in New York wondered what the percentage was among mesothelioma patients. 

They collected blood samples, cancer histories, and asbestos exposure data from 183 patients. All of the patients had conditions that have been linked with BAP1 gene mutation.  

Predicting BAP1 Gene Mutation

Doctors cannot tell by looking which mesothelioma patients are likely to have a BAP1 gene mutation. But knowing if a mesothelioma case is linked to BAP1 loss may open up certain treatment possibilities. It may also help doctors determine mesothelioma prognosis.

In the new study, researchers extracted DNA from the blood samples. They used advanced gene sequencing to determine which patients had the altered gene.

Many patients with characteristics that made it seem like they might have a gene alteration did not actually have one. Only 4.4 percent of the mesothelioma patients had inherited a mutated BAP1 gene. 

The researchers used this data to develop and test a screening tool for predicting who is likely to have a BAP1 gene mutation.

“The proposed screening criteria successfully identified all patients with germline BAP1-mutant mesothelioma,” they report in the Journal of Thoracic Oncology. 

The hope is that the guidelines will help doctors decide which mesothelioma patients should be tested for BAP1 loss. 

The report concludes, “Future efforts should validate and refine these criteria and search for other germline [inherited] mutations associated with mesothelioma and related diseases.”

Source:

Zauderer, MG, et al, “Brief Report: Prevalence and Preliminary Validation of Screening Criteria to Identify Carriers of Germline BAP1 Mutations”, July 16, 2019, Journal of Thoracic Oncology, Epub ahead of print, https://www.jto.org/article/S1556-0864(19)30559-3/pdf