182 Background: TMRSS2-ERG fusion is the most frequent genetic abberation in prostate cancer. Till now its expression is not associated with a poorer prognosis. In cell line models the fusion can be induced by exogenic factors as hormonal treatment or radiotherapy. Additionally its expression leads to different sensitivities to radiotherapy in different cell line models. We analyzed TMPRSS2-ERG fusion for the first time in patients with salvage radical prostatectomy and correlated it to radical prostatectomy specimen without prior treatment. Methods: 38 radical prostatectomy specimen of patients formaly treated with radiotherapy and recurrent disease and 38 primary RPEs were analyzed for ERG expression (15 external RT, ERT, 18 LDR, 5 HDR). ERG expression was detected by a highly sensitive monoclonal antibody as described recently. Results: Median PSA preoperatively was 3.6 (0.1-27) ng/ml. More patients had locally advanced dieseasae in the final pathologic specimen (17:21). In 18 (47,4%) patients (8 (44,4%) in LDR, 3 (60%) in HDR, 7(46,7%) in ERT) an ERG expression was detected. There is no difference in the ERG expression compared to an independend cohort of radical prostatectomy specimen (47,4% versus 47,4%). Conclusions: We are the first to analyze ERG expression in salvage radical prostatectomies. In this cohort there is no difference in the ERG expression rate after applied radiotherapy. The risk of inducing a gene fusion by external influence as seen in cell cultures cannot be transferred to daily practice.
Prospective analysis of prostate cancer local staging with [18F]PSMA PET/MRI combined with multiparametric MRI – A comparison to histopathology in the radical prostatectomy specimen. – ProStaPET –
