Soluble Mesothelin-related Protein in the Diagnosis of Malignant Pleural Mesothelioma

American Journal of Respiratory Critical Care Medicine. 2006 Feb 2; [Epub ahead of print] [Link]

Scherpereel A, Grigoriu BD, Conti M, Gey T, Gregoire M, Copin MC, Devos P, Chahine B, Porte H, Lassalle P.

INSERM Unit 774, Institut Pasteur de Lille, Lille, France; Pulmonary and Thoracic Oncology Department, University Hospital of Lille, Lille, France.


Background: Diagnosis of malignant pleural mesothelioma is a challenging issue. Potential markers in mesothelioma diagnosis include soluble mesothelin-related peptides (SMRP) and osteopontin but no subsequent validation have been published yet.

Methods: We prospectively evaluated SMRP in serum and pleural effusion from patients with mesothelioma (n=74), pleural metastasis of carcinomas (n=35), or benign pleural lesions associated with asbestos exposure (n=28), recruited when first suspected for mesothelioma.

Findings: Mean serum SMRP level was higher in mesothelioma (2.05 +/- 2.57 nM/l – median +/- interquartile range) than in metastasis (1.02 +/- 1.79 nM/l) or benign lesions (0.55 +/- 0.59 nM/l) patients. The area under the receiver operating characteristic curve (AUC) for serum SMRP was 0.872 for differentiating mesothelioma and benign lesions; cut-off= 0.93 nM/l (Sensitivity= 80%, Specificity= 82.6%). The AUC for serum SMRP differentiating metastasis and mesothelioma was 0.693; cut-off= 1.85 nM/l (Sensitivity = 58.3%; Specificity = 73.3%). SMRP values in pleural fluid were higher than in serum in all groups (mesothelioma: 46.1 +/- 83.2 nM/l; benign lesions: 6.4 +/- 11.1 nM/l; metastasis: 6.36 +/- 21.73 nM/l). The AUC for pleural SMRP differentiating benign lesions and mesothelioma was 0.831; cut-off= 10.4 nM/l (Sensitivity = 76.7%, Specificity = 76.2%). The AUC for pleural SMRP differentiating metastasis and mesothelioma was 0.793.

Interpretation: We show that SMRP may be a promising marker for mesothelioma diagnosis when measured either in serum or pleural fluid. The diagnostic value of SMRP was similar in both types of samples, but pleural fluid SMRP may better discriminate mesothelioma from pleural metastasis.