Cut-off value for KLK3 gene expression from urine sediment to rationalize diagnosis of prostate cancer

Although prostate cancer accounts for the highest number of newly diagnosed cases of cancer in men, it represents a specific diagnostic challenge in modern oncology. The standard diagnosis of prostatic carcinoma begins with the screening of serum concentrations of PSA (Prostate Specific Antigen). If the concentration of serum PSA levels is above 4ng/mL, the patient is further referred to a digital rectal examination in order to determine an increase in prostate volume. In cases where enlargement of the prostate is observed, the next step is biopsy of prostate tissue. This physically painful and invasive approach to confirm the diagnosis is often unnecessary because, in many cases, the patohistologic analysis determines diagnosis of benign prostatic hyperplasia, and not a tumor. In this study, we investigated the possibilities of detection and measurement of the relative level of gene expression of the KLK3 (Kallikrein-related peptidase 3), PCA3 (Prostate Cancer Gene 3) and TEMPRSS: ERG (Transmembrane protease serine2 and in-ETS erythroblostosis virus E26 oncogene homolog) genes from the urine samples of patients with prostatic diseases and healthy controls. Urine was the sample of choice because it is taken in a non-invasive manner, and could potentially serve to make better selection to biopsy. One of the selected genes (KLK3) differed significantly in the samples of various pathological conditions of the prostate, and therefore we consider that its further investigation is reasonable.