Purpose: We evaluate the diagnostic efficacy of nuclear matrix protein-22 (NMP22, Matritech, Newton, Massachusetts), fibronectin and urinary bladder cancer antigen (UBC, IDL Biotech, Borlange, Sweden) compared with voided urine cytology in the detection of bladder cancer.
Materials and methods: A total of 168 patients provided a single voided urine sample for NMP22, fibronectin an ideal monoclonal for urinary bladder cancer and cytology before cystoscopy. Cystoscopy was done for all patients as the reference standard for identification of bladder cancer. Biopsy of any suspicious lesion was performed for histopathological examination. Of the 168 cases 100 were histologically diagnosed as bladder cancer, whereas the remaining 68 had benign urological disorders. A group of 47 healthy volunteers were also enrolled in this study. Voided urine was evaluated by NMP22, fibronectin and UBC, and their values were expressed relative to mg. creatinine.
Results: The optimal threshold values for NMP22, fibronectin and UBC were calculated by receiver operator characteristics curves as 27 units per mg. creatinine, 198 mg./mg. creatinine and 13 ng./mg. creatinine, respectively. The levels and positive rates of the 3 parameters were significantly higher in the malignant group compared to either the benign group or normal controls. Of the entire group NMP22, fibronectin and UBC were positive in 93.2%, 91% and 68.2%, respectively in bladder cancer cases with positive cytology. Moreover, these positive rates were significantly higher in bilharzial bladder cancer cases (58.8%, 67.5%, 58.8%, respectively) compared to nonbilharzial cases (35.6%, 36.3%, 31.1%). Overall sensitivity and specificity were 85% and 91.3% for NMP22, 83% and 82.6% for fibronectin, 67% and 80.8% for UBC and 44% and 100% for voided urine cytology. Combined sensitivity of voided urine cytology with the 3 biomarkers together was higher than either combined sensitivity of voided urine cytology with 1 of the biomarkers or than that of the biomarker alone.
Conclusions: Our data indicate that NMP22 and fibronectin had superior sensitivities compared to UBC and voided urine cytology, while NMP22 and voided urine cytology had the highest specificities. The combined use of markers increased the sensitivity of cytology from 44% to 95.3%. The higher sensitivities of markers in bilharzial than nonbilharzial bladder cancer highlight their clinical use in screening patients with urinary bilharziasis.