Urinary calprotectin: Can
it be the best tumor marker in detecting urothelial carcinoma of the bladder?
Although, there have been many serum and urine biomarkers described for
diagnosis and follow-up of bladder cancer, none of these could have eliminated
the need for cystoscopy and cytology. The present study investigates whether
calprotectin may serve as a urinary biomarker in the detection of urothelial
and Methods: Urine and tissue calprotectin levels of patients with primary bladder
cancer (52 patients, study group) and benign prostate hyperplasia (30 patients,
control group) were measured and compared. Tissue samples were obtained with
transurethral resection and measurements were performed using ELISA test.
The mean urinary calprotectin concentrations were significantly higher in
patients with bladder cancer (432.7±456.6 ng/mL) compared to controls
(50.5±71.6 ng/mL) (p<0.001). Similarly, the mean tissue calprotectin concentrations were significantly higher in cancer group (26.5±43.5 ng/mgtotal protein) compared to controls (5.6±14.0 ng/mg total protein) (p=0.008). In subgroup analyses, high grade and muscle invasive tumors were associated with significantly higher urinary calprotectin concentrations compared to low grade and noninvasive tumors (p=0.001 and p=0.0007, respectively). Taking a cut-off value of 100.9 ng/mL determined by ROC analyses, the urine calprotectin test resulted to have a sensitivity of 100% and specificity of 96.7%. Conclusion: The present study revealed that increased urinary calprotectin concentrations may have a diagnostic value for predicting the bladder cancer. Furthermore, the increased calprotectin levels detected in tumor tissue affirms this opinion. Thus, urinary calprotectin may be a novel marker, an alternative to cystoscopy and cytology in diagnosis and follow-up of bladder cancer. Still, further randomised clinical trials with more patients are needed. Keywords: Urinary bladder neoplasm, calprotectin, biological tumor marker.