Diagnostic value of microRNAs in prostate cancer patients with prostate specific antigen (PSA) levels between 2, and 10 ng/mL.

OBJECTIVE: Prostate specific antigen (PSA), used for the early diagnosis of prostate cancer (PCa), is one of the best tumour markers known so far. However, in situations when PSA is between 2-10 ng/mL, which is named as grey zone, PSA falls short of distinguishing benign prostate diseases from PCa. On the other hand, it was demonstrated in many previous studies that microRNA (miRNA) could be a marker for cancer. Therefore, in this study, it was aimed to enhance the diagnostic power of PSA, especially with grey zone patients, by the use of miRNA.

MATERIAL AND METHODS: Ninety-four patients included in the study were divided into three groups as "control group" (n=44, PSA=2-10 ng/mL and benign), "PCa 1 group" (n=37, PSA=2-10 ng/mL), and "PCa 2 group" (n=13, PSA >10 ng/mL), according to their pathological results and PSA levels. Free PSA (fPSA) and total PSA (T-PSA) levels were measured with chemiluminometric sandwich immunoassay method. Expressions of miRNAs were analyzed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) method. The most appropriate specificity, sensitivity and prediction values were found by drawing the receiver operating characteristic (ROC) curves of total PSA, free/total PSA (f/T PSA) ratio, and miRNAs, and the diagnostic powers were compared with each other.

RESULTS: Diagnostic powers of the f/T PSA ratio and miRNA were compared in PCa 1 and the control groups to determine the marker with higher area under the curve (AUC). It was shown that the diagnostic power of the combination of miR-16-5p and f/T PSA was higher than that obtained when they were used separately.

CONCLUSION: As a result, while making the the discrimination between benign and malignant prostate in patients with grey zone, it was determined that the combination of miR-16-5p and f/T PSA was more valuable than T-PSA or f/T PSA alone. It was thought that diagnostic role of miRNAs in the early diagnosis of the different stages of PCa needed to be examined in further studies with larger groups.