TMPRSS2-ERG fusion is frequently observed in gleason pattern 3 prostate cancer in a canadian cohort

Purpose: TMPRSS2-ERG gene fusion was recently reported as the most common gene rearrangement in prostate cancer (PCA). Results: In this cohort 41% of the patients showed positive gene fusion status in their PCA. The TMPRSS2-ERG gene fusion status was homogenous within the same cancer focus and 82% of fusion positive PCA were present in GS 6 or 7 vs. 14% in GS 8 ( p = 0.004). Moreover, TMPRSS2-ERG fusion was present in 42% of Gleason pattern 3 vs. 27% of Gleason pattern 4 ( p = 0.014). However, in this study, no significant association was noticed between TMPRSS2-ERG fusion status in relation to pathological stage, surgical margin or biochemical failure. Experimental design: Using break-apart FISH assay to indirectly assess the fusion of TMPRSS2-ERG. We sought to characterize the incidence, pathological features and clinical parameters of TMPRSS2-ERG gene fusion in a cohort of 196 Canadian men treated by radical prostatectomy for localized PCA, and to investigate its potential as a biomarker in PCA. Conclusion: The higher association of TMPRSS2-ERG with Gleason score 6 and 7 should be further investigated. If confirmed, this could have significant clinical impact in further stratifying patients with PCA should the TMPRSS2-ERG be confirmed as a prognostic biomarker.