Sensitivity of urinary mesothelin in patients with malignant mesothelioma.

INTRODUCTION

Malignant mesothelioma (MM) is an aggressive, uniformly fatal tumor usually caused by exposure to asbestos. Soluble mesothelin has been intensively investigated in the serum as a biomarker for this disease. As urine is less complex and less invasive to collect than serum and may be a more acceptable specimen for large-scale screening studies of asbestos-exposed individuals, we determined whether the sensitivity and specificity for MM could be improved by measuring soluble mesothelin in the urine.

METHODS

Soluble mesothelin concentrations were determined using the MESOMARK assay in concurrent serum and urine samples from 70 patients with pleural MM, 111 patients with asbestos-related lung or pleural disease, and 45 patients with benign nonasbestos-related lung and pleural disease. Only patients with serum creatinine levels within the normal range were included in the study. Sensitivities were determined and receiver operator characteristic curves were generated to compare the diagnostic accuracy of mesothelin in the serum and urine.

RESULTS

At a specificity of 95% relative to individuals with benign lung or pleural disease, serum mesothelin had a sensitivity of 66% and area under the curve of 0.882, whereas urinary mesothelin corrected for urine creatinine concentration had a sensitivity of 53% and area under the curve of 0.787.

CONCLUSIONS

The sensitivity of urinary mesothelin does not warrant the use of urine as a biomarker specimen for MM diagnosis.