Relation of ERG and CER B2 expressionswith gleason scoresin prostate adenocarcinoma

Introduction: Prostate cancer is a common malignant tumor of the male genital system. ERG is a transcription factor gene located on chromosome 21. Fusion of the TMPRSS2 gene to ERG, which is a proto-oncogene, has been reported in patients with prostate carcinoma. CerbB2 is a transmembrane tyrosine kinase receptor that uses the MAPK and PI3K molecular signaling pathways, both of which are involved in prostate cancer, and plays an important role in the growth, differentiation and motility of cancer cells. CerbB2 is associated with poor prognosis in breast and ovarian cancers. In this study, we aimed to determine ERG and cerbB2 expression in patients with adenocarcinoma of the prostate and investigate the association of these proteins with tumor growth and/or Gleason scoring, which is the main prognostic marker in these patients. Material & Method: Radical prostatectomy materials of 59 patients with acinar adenocarcinoma were included in the study. Immunohistochemical analysis for ERG and cerbB2 was performed on the tumor blocks of these patients. The association of ERG and cerbB2 expressions with ISUP grade, tumor volume and patient age was investigated. Results: The mean age of the 59 patients was 68.6 years. ISUP grade was 1 (equivalent to a Gleason score of 6) in 23 tumors while the rest of the cases were Gleason score >6 tumors. ERG expression was detected in 37.3% of the cases. None of the cases had cerbB2 expression. There was no significant difference in ERG staining between the low-risk (ISUP 1) and highrisk (ISUP >1) groups (p=0.602). Evaluation of all ISUP groups with the Kruskal-Wallis test showed no significant difference across the groups in terms of ERG expression (p=0.374). Discussion: The present study reflects the ERG expression rate (37.5%) in patients with carcinoma of the prostate in Turkey. To the best of our knowledge, this is the first published study to investigate ERG expression in patients with prostate cancer in Turkey. Our findings support that ERG overexpression is involved in the pathogenesis but has no association with histological grade in prostate carcinoma. Key Words: Prostate carcinoma, gleason score, ERG, CerbB2