Is there a role for serum human tissue kallikrein in detection of prostate cancer?

Objectives: To retrospectively evaluate the diagnostic performance of a serum human tissue kallikrein 11 (hK11) assay to predict the presence of prostate cancer in a screened population of men with a total prostate-specific antigen (PSA) level between 2.5 and 10.0 ng/mL.

Methods: Frozen serum samples from 114 men with a total PSA level between 2.5 and 10.0 ng/mL who had undergone transrectal prostate ultrasound-guided biopsy with at least 10 cores were retrospectively analyzed for hK11. The performance characteristics of hK11, PSA, hK11/PSA ratio, and hK11 density (hk11/prostate volume) were analyzed for their ability to differentiate cancer from noncancer. The results obtained were analyzed using the Mann-Whitney U test, chi-square test, and receiver operating characteristic curves.

Results: Prostate cancer was diagnosed in 36 (32%) of the 114 men whose serum samples were analyzed. No significant differences were found in hK11 (median 0.71 ng/mL versus 0.69 ng/mL), PSA level (median 3.9 ng/mL versus 4.1 ng/mL), hK11/PSA ratio (median 0.15 versus 0.17), or hK11 density (median 0.015 versus 0.016) between men with and without prostate cancer. A comparison of the areas under the curve for hK11 (0.491), PSA (0.540), hK11/PSA ratio (0.505), and hK11 density (0.589) showed no significant differences.

Conclusions: In this retrospective study, hK11, hK11/PSA ratio, and hK11 density showed no diagnostic advantage compared with PSA in differentiating cancer from noncancer in men whose total PSA level was in the range of 2.5 to 10.0 ng/mL.