The kallikrein family of proteins as urinary biomarkers for the detection of prostate cancer.

BACKGROUND Several urinary biomarkers have been assessed as showing a discriminatory ability to differentially diagnose prostate cancer, albeit with manipulation of the prostate. Here we examine the clinical utility of multiple members of the kallikrein family of proteins in non-manipulative urinary biomarker testing. METHODS Forty urine samples were collected from patients admitted for urological examination. Twenty, with a confirmed benign diagnosis and 20 with prostate cancer. The levels of 14 kallikrein proteins were measured in patient's urine and normalized for creatinine. RESULTS Ten of the 14 kallikreins tested had detectable levels in urine. However, none showed statistical significance in discriminating patients. Serum PSA was superior to urine PSA and other urinary kallikreins in separating patients with and without prostate cancer. CONCLUSIONS We were unable to distinguish men with and without prostate cancer using multiple kallikreins as urinary biomarkers. These results highlight the difficulties in diagnosing prostate cancer via urine testing for soluble biomarkers.