Protein test shows promise in detecting early-stage mesothelioma
In a key test of a new biomarker for identifying early-stage pleural mesothelioma, researchers from the National Cancer Institute say they detected proteins secreted by cancerous tumors in 15 of 19 cases of the disease.
The findings are important because pleural mesothelioma, an incurable cancer of the lungs caused by asbestos exposure, is typically diagnosed in advanced stages. Earlier detection could make existing treatments, such as surgery and chemotherapy, more effective and lead to better therapies down the road.
The proteomic assay was developed by SomaLogic Inc., a Colorado company, to detect disease by examining proteins in a drop of blood. The Multiplex SOMAmer Assay uses chemically modified sDNA molecules that are designed to bind to specific proteins.
In a blinded test, researchers examined 170 blood samples from 90 patients diagnosed with pleural mesothelioma and 80 participants in a control group who had been exposed to asbestos. Computer modeling was used to detect biomarkers — proteins whose concentration in the blood reflects the presence of disease — to distinguish blood samples of the cancer patients from the control group.
Researchers say the 80 percent detection rate means the test was extremely accurate, and that there were no false positives.
The research was presented at the annual meeting of the American Association for Cancer Research in Orlando by Harvey I. Pass, director of the division of thoracic surgery and thoracic oncology at NYU Langone Medical Center and the NYU Cancer Institute in New York.
Malignant pleural mesothelioma causes an estimated 15,000 to 20,000 deaths annually worldwide, usually within 14 months of diagnosis. Experts believe that, because asbestos use peaked in the 1970s and the disease doesn’t usually emerge until decades after asbestos exposure, the incidence of the disease will continue to rise until about 2020.
Pass said the new test could find the cancer early enough to effectively treat it.
“The only patients that seem to benefit from therapy in mesothelioma are those that are found in stage 1, and this is only 10 to 15 percent of patients,” Pass said. “Moreover, when found early, the magnitude of the operation necessary to reduce the burden of disease may be less, making the patient better able to cope if the disease recurs and the patient needs more aggressive therapy.”