Comparison of urinary telomerase, CD44, and NMP22 assays for detection of bladder squamous cell carcinoma

Squamous cell carcinoma (SCC) of the bladder is common in many regions around the world. Prognosis is very poor, as most cases are diagnosed at an advanced stage due to a lack of affordable and valid screening markers for this type of cancer. The diagnostic accuracy of urinary nuclear matrix protein-22 (NMP22), telomerase activity, and CD44 were evaluated in urine samples of patients with bladder SCC.

We conducted a case-control study comprised of 60 consecutive newly diagnosed bladder SCC patients diagnosed by cystoscopy and histopathological examination, and controls were 60 outpatients with benign urologic conditions and healthy clinic visitors. Urine samples collected from each subject underwent testing for NMP22, telomerase activity, and CD44. Descriptive and correlational statistical analysis of cases and controls were carried out and receiver operating characteristic curve analysis was used to determine optimal cut-off points for the three assays.

Area under the curve was calculated at 0.96, 0.93, and 0.62 for NMP22, telomerase, and CD44, respectively. Urine levels of NMP22 and telomerase activity were significantly higher in the SCC group compared to controls (p < 0.001). Urine CD44 levels were not significantly higher in the SCC group compared to controls (p = 0.111). The overall sensitivity of NMP22, telomerase, and CD44 was 96.7%, 87%, and 45%, respectively, while the specificity was 85%, 88.6%, and 86.7%, respectively.

Urinary telomerase activity, followed by NMP22 urine levels, showed high diagnostic yield and could hold potential promise as urinary biomarkers for the diagnosis of bladder SCC.