A mutation on the BAP1 tumor suppressor gene can influence the development of malignant mesothelioma but may have little bearing on survival.
That conclusion comes from a new Chinese study of more than 2,400 people with cancers directly linked to the BAP1 genetic mutation, including pleural mesothelioma.
BAP1 and Mesothelioma
BRCA1-associated protein 1 (BAP1) is a tumor suppressing protein encoded by the BAP1 gene. Multiple studies have confirmed that people with a mutation on the BAP1 tumor suppressor gene are more likely to develop certain kinds of cancer, including malignant mesothelioma.
The BAP1 gene helps explain why some people develop mesothelioma after exposure to asbestos exposure while others do not.
In addition to mesothelioma, other cancers associated with BAP1 mutation include uveal melanoma, clear cell renal cell carcinoma, and possibly cholangiocarcinoma (a cancer of the bile ducts). People with the syndrome are also more likely to develop benign melanocytic skin tumors when they are young.
Mesothelioma Survival and BAP1 Mutation
In the new study, researchers with China’s Fudan University analyzed 21 different BAP1 studies including 2,457 cancer patients. The study contains some good new for mesothelioma patients who have the BAP1 mutation.
“Although the pooled results demonstrated that BAP1 mutation was a negative indicator of overall survival and disease-free survival, this prognostic value was only applicable to uveal melanoma and clear cell renal cell carcinoma, but not to malignant pleural mesothelioma or cholangiocarcinoma,” reports XY Wang, a surgeon whose name appears first on the paper.
According to Dr. Wang and colleagues, BAP1 mutation only influenced how the cancer looked under the microscope (clinicopathological features) in uveal melanoma and clear cell renal cell carcinoma. Mesothelioma cells from people with the BAP1 mutation looked the same as any other mesothelioma cells.
In fact, there is evidence that BAP1 mutation may actually have a positive impact on mesothelioma survival. A 2015 study of mesothelioma patients with BAP1 mutations suggested that these patients may live longer than mesothelioma patients without the mutation because they tend to be younger and healthier at diagnosis.
Wang, XY, et al, “Tissue-specific significance of BAP1 gene mutation in prognostic prediction and molecular taxonomy among different types of cancer”, June 2017, Tumour Biology