Validation of the diagnostic value of nuclear matrix protein 22 depending on tumoral stage and grade.

Objectives: The aim of the present study was to validate the sensitivity and specificity of the NMP22® BladderChek® test in our group of patients according to the tumoral stage and grade and to identify the patient categories that might benefit from the non-invasive nature of NMP22® BladderChek® test. Methods: Voided urine samples from 266 patients with imagistic suspicion of bladder cancer were collected to perform the NMP22® BladderChek® test. The nuclear matrix protein 22 (NMP22) levels were measured by a lateral flow immunochromatographic qualitative assay, using 10 U/ml as the cut-off value. After this patients underwent transurethral resection of bladder tumors (TUR-BT) follewed by histologic grading and tumor staging for a proper and optimal patient management. Sensitivity specificity and positive predictive value of the NMP22® BladderChek® test were defined for different tumoral stage and grade. Results: Two hundred thirty-eight of the 265 patients had urothelial malignancies (76 pTa, 81 pT1, 37 pT2, 32 pT3, 12 pT4, 27 pT0; 118 G1, 54 G2, 64 G3). The sensitivity was 0.629 [0.612; 0.629] for the NMP22® BladderChek® test while the specificity was equal to 1 [0.851; 1]. Positive predictive values was 1 [0.973; 1], and the negative predictive value was 0.235 [0.200; 0.235]. Conclusions : The results demonstrate that the even if the NMP22® BladderChek® is an easily applied test, giving diagnostic findings within 30 min, cannot be recommended for screening or surveillance in clinical routine use in non muscle invasive bladder cancer because of its poor sensitivity.