The clinical relevance of urinary soluble fas (sFas) for diagnosis of bilharzial bladder cancer

Background: Fas/CD95, a membrane-bound type I protein, plays a key role in induction of apoptosis and in tumorigenesis. Objective: We adapted and evaluated measurement of urinary sFas using enzyme-linked immunosorbent assay and compared the results with voided urine cytology. Materials and Methods: Voided urine samples were provided from 203 individuals (120 bladder cancer [112 bilharzial]; 43 benign urologic disorders [20 bilharzial dysplastic lesions]; and 40 healthy volunteers). Urine sediment was used for cytology and the supernatant for estimation of sFas by ELISA. Results: A receiver operating characteristic curve (ROC) was used to determine the best cutoff value for urinary sFas. Positivity rates and mean rank levels for sFas showed significant difference among the three investigated groups (p < 0.0001), and was related to bilharzial infection, pathological type, clinical stages, and histological grades (p < 0.01). The sensitivity of sFas for early detection of bladder cancer, especially those with superficial and low grades tumors, was superior to urine cytology; moreover, results from sensitivity of urine cytology were improved when combined with sFas. Conclusion: Urinary sFas may be used as a novel noninvasive diagnostic marker for bilharzial bladder cancer patients. Further multicentric studies are warranted to corroborate these findings and to establish an optimal sPas cut-point.