[NMP-22 in the diagnosis of bladder cancer]

To evaluate the usefulness of the NMP-22 test in the diagnosis of bladder cancer; to calculate the ideal cutoff and to compare the results among NMP-22, voided urine cytology and cystoscopy.

166 patients having clinical suspicious of bladder cancer or in follow-up due to a previous one. The exclusions criteria were: other urological conditions, radiotherapy in the last three months, systemic chemotherapy in the last month, recent vesical trauma or indwelling catheter. Prior cystoscopy a recent voided urinary sample was sent to the pathology and biochemistry laboratory to perform cytology and NMP-22. A TUR was performed in patients with bladder tumour. The cutoff was calculated with ROC curves. For each test we calculate sensitivity, specificity, positive and negative predictive value. We use the McNemar test to compare the results, all of which are expressed with a confidence interval of 95%.

The ideal cutoff was 6 U/ml. We have a global sensitivity of 82.75% for NMP-22 and 67.9 for cytology (p = 0.0118); the specificity was 80% and 94.12% respectively (p = 0.0018). By grade the sensitivity was 72.22% G1, 70.97% G2 and 100% G3 for NMP-22 and 44.44%, 58.06% and 90.62% for cytology. By stage it was 68.42% Ta, 83.33% T1 and 100 T2 or more for NMP-22 and 36.84%, 75% and 85.71% for cytology. With the cystoscopy we obtained a 100% sensitivity and 89.41% specificity.

The NMP-22 is a useful test for the diagnosis of bladder cancer; is more sensitive and less specific than cytology. We think it can replace the cytology in the diagnosis and follow-up of bladder cancer. The ideal cutoff is 6 U/ml.