Development of non-invasive kit for use in diagnosis of prostate cancer based on prostate cancer antigen 3

Prostate cancer is one of the most prevalent cancers seen in men. Biomarkers are used for diagnosis because of the fact that biopsy applied to patient for the diagnosis of prostate cancer is laborious and uncomfortable. Detection of Prostate Specific Antigen (PSA) in serum sample is the most commonly used a non-invasive method. However, this method is weak in terms of sensitivity and specificity. Aim of this study is to develop a novel kit with high sensitivity and specificity for the detection of Prostate Cancer Antigen 3 (PCA3) mRNA in urine as an alternative for the serum PSA level used in the diagnosis of prostate cancer. Following rectal examinations of 82 subjects aged 55 to 70 years who were applied to Kartal Training and Research Hospital the serum PSA levels were quantified and then presence of prostate cancer was evaluated by biopsy. Among the subjects attended to study 64 were prostate cancer and 18 were healthy. PCA3 expression (mRNA) level in urine samples collected from the subjects were detected by our developed kit based on Real Time Polymerase Chain Reaction (RT-PCR). Then, the PCA3 levels were compared with the results of PSA and biopsy. When PCA3 mRNA levels were compared with results of biopsy that is gold standard sensitivity, specificity, positive predictive value (PPV) and negative predictive value (PPV) of the test were found 63%, 100%, 100% and 43% respectively. As a result of analysis findings, while PCA3 expression incidence was 63% (n=40) in patient group who diagnosed as prostate cancer by biopsy results it was not observed in healthy group. It was determined that the PSA level averages between patient group and healthy group were significantly different statistically (p<.001). PSA level of patient group was found higher as compared to healthy group accordingly. Negative predictive value refers to the percentage of being healthy indeed in subjects who are determined healthy by the test. Therefore, it could not be understand that whether 18 of 42 subjects who were recorded healthy according to PCA3 level in this study were really healthy or not without the biopsy. Our developed PCA3 detection kit was not found sensitive sufficiently to detect prostate cancer alone. But evaluation of kit's results with the results of PSA and biopsy together was seen significant.