The usefulness of phosphorylated-signal transduction and activators of transcription 3 in detecting prostate cancer from negative biopsies

AimsTo avoid the misdiagnosis of prostate cancer (PCA), many patients receive repeated biopsies, despite receiving prior negative biopsies for PCA. Signal transduction and activators of transcription 3 (STAT3), a component of the JAK-STAT signaling pathway, can be activated by tyrosine phosphorylation as P-STAT3 and involved in the regulation of cellular growth, survival and oncogenesis. We aimed to assess the reliability of detecting PCA from the expression of P-STAT3 in prostate tissue previously designated as a negative biopsy.MethodsProstate tissues were obtained from the biopsies of 52 patients with localized PCA as well as from the biopsies of 80 patients free of PCA. Expression of P-STAT3 in these specimens was examined by immunohistochemical staining (IHC) and used to distinguish tissue with PCA from tissue designated as benign during a biopsy procedure.ResultsP-STAT3 staining intensities in all samples (initial negative biopsies, cancer positive cores and other negative cores from the same-batch biopsies) of PCA patients was significantly higher than that of benign patients (F = 23.664, P < 0.001). Analysis of the receiver operating characteristics (ROC) curve showed that the area under curve (AUC) for P-STAT3 staining was 0.785. When positive immuno-labeling of P-STAT3 in samples from initial biopsies was used as a marker for PCA, it showed relatively high sensitivity (80.8%) and specificity (76.3%).ConclusionsIHC of P-STAT3 could be utilized to detect PCA patients with initial negative biopsies. As a result, it can be a potential adjunctive tool for current PCA diagnostic programs. P-STAT3 can predict the onset of PCA up to 40 months earlier than currently used diagnostic approaches.