ABSTRACT
Purpose To study the prevalence and feature of EGR gene rearrangement in prostatic carcinoma. Methods 242 consecu-tive core biopsies of prostatic carcinoma were evaluated. All biopsy specimens contained 6-14 cores from left and right sides separately delivered. The patient age ranged 58 to 91 years, and PSA value 5 ng/ml to more than 5 000 ng/ml. Immunohistochemistry ( IHC) for ERG protein overexpression and fluorescent in situ hybridization ( FISH) for ERG gene rearrangement were performed. Results 42 cases were detected positive for ERG by IHC ( positive rate 17. 4%) , and positive for ERG rearrangement by FISH either, with 19 ca-ses showing fusion through deletion and 23 through insertion, while no negative cases by IHC demonstrated positive by FISH. 5 cases revealed positive and negative staining in different carcinoma foci of ERG. No ERG positive staining and rearrangement were found in adjacent benign glands. Of positive cases, 12 cases were graded as Gleason score 6, 23 Gleason score 7, and 7 Gleason score 8 or more. Positive rate was 19. 6% in the group of PSA value less than 100 ng/ml, and 10% of more than 100 ng/ml, whereas 17. 2% in the group of clinical T3 stage or less, and 19% of clinical T4 and lymph node or remote metastasis. ERG rearrangement was associated with lower Gleason score, but not with PSA value, clinical stage and progression using theχ2 test analysis. Conclusions IHC is relia-ble for detection ERG rearrangement and helpful for interpretation of prostatic carcinoma. Multiple foci are common in prostatic carcino-ma. There is no significance between ERG rearrangement and disease prognosis.