Significance of Plasma Osteopontin Levels in Patients with Bladder Urothelial Carcinomas

Abstract

Previous studies have suggested that the plasma level of osteopontin may be a biomarker for cancer metastases and clinical prognosis; however, its role in bladder urothelial carcinoma (BUC) remains unknown. The purpose of this study was to explore the significance of plasma osteopontin levels in evaluating the pathologic features of BUC and its potential as a prognostic marker in BUC patients. A total of 225 patients with BUC were enrolled in this study, and 230 age-matched and sex-matched healthy volunteers were enrolled as control subjects. The histologic classification of BUC, clinical stage of the disease, and plasma osteopontin levels were determined at admission. Patients with non-muscle-invasive BUC underwent transurethral resection, while those with muscle-invasive BUC underwent radical cystectomy. Patients receiving transurethral resection and radical cystectomy were followed up to determine their tumor-free interval and overall survival, respectively. The mean plasma osteopontin levels were significantly higher in BUC patients than in controls, significantly higher in patients with high-grade BUC than in those with low-grade BUC, and significantly higher in patients with muscle-invasive BUC than in those with non-muscle-invasive BUC. Patients with bladder-confined disease had the lowest osteopontin levels, while those with lymph node-positive disease had higher osteopontin levels, and those with metastatic BUC had the highest osteopontin expression. Kaplan-Meier analyses showed that a higher plasma osteopontin level was associated with a lower overall survival rate in muscle-invasive BUC patients receiving radical cystectomy. Our results show that the plasma osteopontin level is associated with the clinical features of BUC and predicts the prognosis of muscle-invasive BUC in patients receiving radical cystectomy.