Blood Test for Mesothelioma

A new study provides promising results on a blood test to identify people with mesothelioma. Mesothelioma is a deadly tumor of mesothelial tissue surrounding the lungs, often caused by exposure to asbestos.

Malignant mesothelioma is a highly aggressive tumor. The incidence of this cancer is increasing because of widespread exposure of many individuals in developed countries to asbestos. In general, mesothelioma is resistant to chemotherapy and radiotherapy and is rarely cured by surgery. Mesothelioma is also difficult to diagnose.

Researchers from Sir Charles Gairdner Hospital in Perth, Australia, have developed a test to help detect mesothelioma. They say the test looks at the blood concentrations of proteins expressed by mesothelioma cells called soluble mesothelin-related proteins, or SMR. To evaluate the new blood test researchers used serum samples from 44 patients who had mesothelioma and 68 healthy individuals, 40 of whom had been exposed to asbestos. They also tested blood from 160 patients with other malignant lung diseases.

Study authors report the test had a high level of specificity. Overall, 37 of the 44 patients with mesothelioma had raised concentrations of SMR compared with three of 160 patients with other cancers. Also, none of the 28 patients who had not been exposed to asbestos had raised SMR levels. Researchers say the test could also be used to test the progression of the tumor in patients with mesothelioma.

Furthermore, investigators say the SMR test could be used to detect the cancer several years earlier. Of the seven asbestos-exposed individuals who had increased blood concentrations of SMR, three developed mesothelioma and one developed lung cancer. They also say none of the 33 asbestos-exposed patients whose blood samples had normal SMR developed mesothelioma after five years.

Researchers conclude the determination of SMR in serum could be a useful marker for diagnosis of mesothelioma and to monitor disease progression. They say it might also prove helpful in future screenings for early evidence of mesothelioma.