Biomarkers for mesothelioma

Mesothelioma is an incurable cancer and its global incidence continues to increase. There has been strong interest in the search for a biomarker that would be of value for the diagnosis, prognosis and disease monitoring of mesothelioma. Large series evaluating the use of novel candidate markers have recently been published.

To date, global gene profiling studies have failed to find a molecule that reliably captures all subtypes of mesothelioma, and differentiates it from benign pathologies and metastatic carcinomas. Soluble mesothelin-related peptide (SMRP), osteopontin and megakaryocyte potentiating factor have been assessed as markers. SMRP testing is clinically available and provides reasonable diagnostic sensitivity and specificity when applied to serum or pleural fluid. Elevated SMRP levels can occur in metastatic, especially ovarian and pancreatic, adenocarcinomas. False negatives are common with sarcomatoid mesothelioma. SMRP levels may reflect tumor load and disease progression. The role of SMRP in predicting mesothelioma development in subjects exposed to asbestos has raised interest. Osteopontin lacks specificity as a diagnostic marker for mesothelioma but may have value in disease monitoring.

The proposed markers have insufficient accuracy to replace cytohistology as the gold standard for diagnosis for mesothelioma. Elevated SMRP levels raise suspicion of mesothelioma although negative values do not exclude disease. Its role in disease monitoring in patients and in predicting disease development in at-risk individuals warrant further study.