Detection of bladder cancer in patients with asymptomatic hematuria by urinary matrix protein 22, voided cytology and cystoscopy

The purpose of this prospective study was to evaluate the diagnostic efficacy of urinary nuclear matrix protein 22 (NMP22) analysis as an adjunct to voided urine cytology and cystoscopy for detecting bladder cancer in patients with asymptomatic hematuria. A single voided urine sample was obtained from 56 patients prior to cystoscopy, with biopsy of any suspicious lesion. Urinary NMP22 concentrations were measured with a quantitative enzyme immunoassay with a cut-off level of 5 U/mL. Results were compared to single cytology and pathologic findings. NMP22 detected 15 of the 21 biopsy-confirmed bladder cancers with a sensitivity of 79% and a specificity of 71%. NMP22 outperformed cytology by identifying 10 of the 14 well-differentiated (grade I and II) tumors and 13 of the 17 non-invasive stage pTa and T1 tumors. NMP22 sensitivity was higher among subjects with known bladder cancer risk factors such as age ≥ 50 years (83%) and cigarette smoking (80%). This study demonstrates the utility of urinary NMP22 as an adjunct to cytology and cystoscopy for detecting early-stage urinary tract cancer in patients with incidental hematuria.