Serum Biomarkers in Patients with Mesothelioma and Pleural Plaques and Healthy Subjects Exposed to Naturally Occurring Asbestos

This study investigated the diagnostic accuracy of the serum biomarkers osteopontin and mesothelin in discriminating mesothelioma patients from those with other, benign conditions and whether levels of the biomarkers differed in subjects who had inhaled naturally occurring asbestos compared with a non-exposed control group. This cross-sectional study studied 24 subjects with mesothelioma, 279 subjects with pleural plaques, 123 "healthy exposed," and 120 control subjects. The Kruskal-Wallis test was performed to compare mesothelin and osteopontin levels of the groups, and receiver operating characteristics curves were generated to determine diagnostic yields of both biomarkers. Multiple linear regression analyses were used to identify associated covariates with osteopontin and mesothelin levels. Serum osteopontin and mesothelin levels were higher in mesothelioma than in benign asbestos-related diseases and healthy exposed subjects. Both biomarker levels were independently associated with mesothelioma, age and smoking pack years. Mesothelin levels were also associated with body mass index. The sensitivity and specificity of osteopontin in distinguishing mesothelioma from the three other groups were 75 and 86 %, respectively; those of mesothelin were 58 and 83 %, respectively. The sensitivity and specificity to discriminate mesothelioma from pleural plaques and healthy subjects were 93 and 73 %, respectively, if osteopontin and mesothelin levels were higher than their optimal cut off levels. The combination of serum osteopontin and mesothelin levels can help to distinguish mesothelioma from benign asbestos-related diseases and asbestos-exposed subjects.