Mapping of TMPRSS2-ERG fusions in the context of multi-focal prostate cancer.
ABSTRACT TMPRSS2-ERG gene fusion leading to the androgenic induction of the ERG proto-oncogene expression is a highly prevalent oncogenic alteration in prostate tumor cells. Prostate cancer is a multi-focal disease, and the origins as well as biological contribution of multiple cancer foci remain unclear with respect to prostate cancer onset or progression. To assess the role of TMPRSS2-ERG alteration in prostate cancer onset and/or progression, we have evaluated the status of fusion transcripts in benign glands, prostatic intraepithelial neoplasia (PIN) and multiple cancer foci of each prostate. Quantitative expression of TMPRSS2-ERG fusion type A and C transcripts was analyzed in benign, tumor and PIN areas, selected from whole-mount radical prostatectomy slides. TMPRSS2-ERG expression was correlated with clinicopathological features. Overall, 30 of 45 (67%) patients exhibited TMPRSS2-ERG fusion transcripts in at least one tumor focus. Of 80 tumor foci analyzed, 39 had TMPRSS2-ERG fusion (type A only: 30, type C only: 2, both types A and C: 7), with predominant detection of the TMPRSS2-ERG fusion type A (27/30, 90%) in the index tumors. Of 14 PIN lesions, 2 were positive for type A fusion. Frequent presence of the TMPRSS2-ERG in index tumors suggests critical roles of ERG alterations in the onset and progression of a large subset of prostate cancer. However, heterogeneity of the TMPRSS2-ERG detection in the context of multiple cancer foci and its frequency in PIN also support the role of other genomic alterations in the origins of prostate cancer.
Article: Detection of TMPRSS2-ETS fusions by a multiprobe fluorescence in situ hybridization assay for the early diagnosis of prostate cancer: a pilot study.[show abstract] [hide abstract]
ABSTRACT: Fusion of the prostate-specific and androgen-regulated transmembrane-serine protease gene (TMPRSS2) with the erythroblast transformation-specific (ETS) family members is the most common genetic alteration in prostate cancer. However, the biological and clinical role of TMPRSS2-ETS fusions in prostate cancer, especially in problematic prostate needle core biopsies, has not been rigorously evaluated. We randomly collected 85 specimens including 50 archival prostate cancer tissue blocks, 15 normal prostate specimens, and 20 benign prostatic hyperplasia specimens for TMPRSS2-ETS fusion analyses. Moreover, the fusion status in an additional 20 patients with initial negative biopsies who progressed to biopsy-positive prostate cancer at subsequent follow-ups was also characterized. Fluorescently labeled probes specific for ERG-related rearrangements involving the TMPRSS2-ERG fusion as well as TMPRSS2-ETV1 and TMPRSS2-ETV4 were used to assess samples for gene rearrangements indicative of malignancy under a design of sequential trial. Rearrangements involving TMPRSS2-ETS fusions were detected in 90.0% of the 50 postoperative prostate cancer samples. The positive rate for the rearrangements in the initial prostate cancer-negative biopsies of 20 patients who eventually progressed to prostate cancer was 60.0% (12/20). Our preliminary study demonstrates that the clinical utility of TMPRSS2-ETS fusion detection as a biomarker and ancillary diagnostic tool for the early diagnosis of prostate cancer is promising, given this approach shows significant high sensitivity and specificity in detection.The Journal of molecular diagnostics: JMD 09/2010; 12(5):718-24. · 3.48 Impact Factor
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ABSTRACT: Early detection of prostate cancer is problematic, not just because of uncertainly whether a diagnosis will benefit an individual patient, but also as a result of the imprecise and invasive nature of establishing a diagnosis by biopsy. Despite its low sensitivity and specificity for identifying patients harbouring prostate cancer, serum prostate specific antigen (PSA) has become established as the most reliable and widely-used diagnostic marker for this condition. In its wake, many other markers have been described and evaluated. This review focuses on the supporting evidence for the most prominent of these for detection and also for predicting outcome in prostate cancer.Cancers. 01/2010;