Mesothelioma is a rare cancer, usually in the lungs and almost always caused by exposure to asbestos. Recently, a wide-ranging sample of 216 malignant pleural mesothelioma (MPM) tumors identified genetic mutations previously unknown. A number of these mutations may be available for diagnosis and treatment immediately. Investigators from the International Mesothelioma Program at Brigham and Young Women’s Hospital of Boston and researchers from Genentech performed this analysis.
Raphel Bueno, MD, a Brigham and Young researcher, said, “This is by far the largest and most comprehensive genetic analysis of this cancer, and it pretty much establishes what genetic mutations exist in mesothelioma. Some were previously known, but some were not.”
With this comprehensive genomic analysis, mesothelioma mutations were identified that current drugs can target. This finding alone could change the methods of treatment, even if only for a small percentage of mesothelioma tumors, but there are other significant findings as well.
The researchers also discovered that the mutational signature for mesothelioma most closely resembles that of ovarian cancer as both originate from the mesoderm. A third finding showed almost one-third of mesothelioma tumors have gene fusions identifiable at the RNA level – a fact previously unknown. Dr. Bueno stated, “This is important because, down the line, if we can find these in blood, this may prove to be a novel way to screen for mesothelioma.”
“These [overall] results substantially expand on previous genomic studies and provide a comprehensive genomics profile of mesothelioma,” the researchers wrote. “Incorporating genomic analysis for the detection of actionable alterations as part of MPM patient care will help in developing rational individualized therapy.” Dr. Bueno said,”The thinking has been that there is no point in sequencing mesothelioma clinically like we now sequence patients with other cancers because there are no target therapies. I believe mesothelioma patients should be sequenced. Even if only 2% or 3% or 4% have actionable mutations, we may be able to significantly improve survival in these patients.”
This is encouraging news.