Bruce Robinson from Sir Charles Gairdner Hospital, Perth, Australia, and colleagues developed a test to assess blood concentrations of proteins expressed by mesothelioma cells (soluble mesothelin-related proteins [SMR]). The test had a high level of specificity: 37 (84%) of 44 patients with mesothelioma had raised concentrations of SMR compared with three (2%) of 160 patients with other cancers or other inflammatory lung or pleural diseases, and with none of 28 controls who had not been exposed to asbestos.
The investigators suggest that SMR could be a useful way to monitor the tumor's growth as concentrations correlated with tumour size and increased during tumour progression.
Bruce Robinson comments: "On the basis of our data we propose that measurement of SMR concentrations in serum is a useful adjunct in the diagnosis of mesothelioma. Blood SMR concentrations should be monitored in asbestos-exposed individuals who are at risk of developing mesothelioma to determine if early therapeutic intervention improves patients' outcome."
He adds: "Importantly for the hundreds of thousands of asbestos-exposed people who are at risk of this cancer, the test can detect the cancer several years before it presents. Of seven asbestos-exposed individuals who had increased blood concentrations of SMR, three developed mesothelioma and one developed lung cancer within 1-5 years whereas none of the 33 asbestos-exposed participants whose blood samples had normal concentrations of SMR developed mesothelioma in that time."
Contact: Sharene Chatfield, Public Relations Manager, Sir Charles Gairdner Hospital, Perth, Australia;
Lancet 2003; 362: 1612-16