High expression of KLK14 in prostatic adenocarcinoma is associated with elevated risk of prostate-specific antigen relapse.

OBJECTIVE Reliable prognostic tools for prostate cancer are still needed and KLK14, a young member of the growing family of human kallikrein-related peptidases, has been estimated to become a new significant marker. It is the aim of this study to analyze the clinical value of immunohistochemical expression of KLK14 in prostate cancer tissue samples. METHODS Protein expression of KLK14 was assessed immunohistochemically in 186 tissue samples from radical prostatectomies. Areas of normal prostatic tissue, of prostatic epithelial neoplasia and of prostatic adenocarcinoma were checked in relation to clinicopathological parameters of the patients. Expression of KLK14 mRNA was quantified in 25 matches of normal and cancerous prostatic tissue, collected by laser capture microdissection. Real-time reverse transcriptase polymerase chain reaction analysis was used to supplement the immunohistochemical data. RESULTS Expression of the KLK14 protein correlated with the pathological tumor status in prostate cancer and was associated with disease progression defined by prostate-specific antigen relapse in univariate Kaplan-Meier analysis. The multivariate Cox proportional hazards regression model proved KLK14 to be an independent prognostic factor in prostate cancer. CONCLUSION In conclusion, we consider KLK14 to be a suitable prognostic marker for the detection of cases at risk of disease progression after radical prostatectomy.