Potential role of serum mesothelin in predicting survival of patients with malignant pleural mesothelioma

Abstract

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor survival rates. Therefore, it is essential to have effective biological markers predicting the course of the disease and prognosis. The aim of the present study was to highlight the prognostic significance of serum soluble mesothelin-related protein (Se-SMRP) in patients with MPM at diagnosis. Se-SMRP was determined in 60 patients using an ELISA commercial kit. Se-SMRP levels were subdivided into three tertile-based categories and in each category overall survival (OS) indexes were determined using the Kaplan-Meier and Cox regression analyses. The association between Se-SMRP levels and OS was also assessed by restricted cubic spline (RCS) analysis. No notable differences in the Kaplan-Meier probabilities were identified across the Se-SMRP categories (<0.66 nM, 0.66-1.46 nM, >1.46 nM) although an upward trend in death rate ratios (RR) was pointed out by comparing the higher (RR=1.95) and intermediate (RR=1.86) categories with the lower category (RR=1.00). In addition, such an increasing tendency, particularly when the biomarker exceeded 1.0 nM, was confirmed by an RCS function of Se-SMPR levels fitted to survival data using the Cox regression equation. The present study provided evidence in favor of a prognostic value of Se-SMRP in patients with MPM.

Keywords: mesothelin; mesothelioma; prognosis; serum; survival.

Figure 1.

Overall survival probabilities of patients with malignant pleural mesothelioma according to serum soluble mesothelin-related protein levels (<0.66 nM; 0.66–1.46 nM; >1.46 nM) estimated through the Kaplan-Meier survival analysis.

Figure 2.

Association between log-transformed Se-SMRP levels and malignant pleural mesothelioma RR estimated through the Cox regression analysis, adjusted for sex, age at diagnosis, disease stage, histological subtype and ECOG-PS, using a three-knot restricted cubic splines. Se-SMRP levels were log-transformed to decrease the influential effect of potential outlying data points. 95% confidence limits for RR are presented at the top of the figure. 95%-Low (RR) and 95%-Upp (RR), 95% lower and upper limits for RR. RR, mortality risk; Se-SMRP, serum soluble mesothelin-related protein.