Cytokeratins (UBC and CYFRA 21-1) and molecular protein matrix as urinary tumor markers in the diagnosis of bladder cancer

BACKGROUND: The development of urinary tumor markers such as UBC, CYFRA 21- 1 and NMP22 appeared to be non invasive alternative methods for the detecti on of bladder cancer. We compared the individual and combined sensitivity o f the urinary tumor markers in the detection of bladder cancer, contrasting them with the conventional diagnostic procedures. PATIENTS AND METHODS: 237 voided urines from subjects under risk for bladde r cancer were collected immediately before the endoscopic examinations: 44 patients under suspicion of a primary bladder tumor and 193 patients under follow-up of a previous bladder cancer were included. UBC and NMP22 were me asured by enzyme-immunoabsorbent-assays and CYFRA 21-1 by an electrochemilu miniscent-immunoassay. RESULTS: Taking the cutoffs of 9.7 mu g/l for UBC, 5.4 ng/ml for CYFRA 21-1 and 10.0 U/ml for NMP22 sensitivities were 70%, 69% and 67% for UBC, CYFRA 21-1 and NMP22 at specificities of 95%, 94% y 80%, respectively. All tumor markers showed higher sensitivities than urinary cytology (7%), microhemat uria (62%) and gross hematuria (10%) at specificities of 99%, 78% and 99%, respectively. The combinations of NMP22 plus CYFRA 21-1 reached the highest sensitivity (79%), slightly lower than simultaneously measuring the three tumor markers (80%). CONCLUSIONS: The sensitivities of the urinary markers UBC, CYFRA 21-1 and N MP22 appeared to be high enough so as to substitute urinary cytology. The d iagnostic similarity between cytokeratins individually and in each type of patients might not recommend their simultaneous determination. The combined measurement of NMP22 and one cytokeratin marker (CYFRA 21-1 or UBC) appear ed to be the most recommended.