ERG expression in prostate cancer biopsies with and without high-grade prostatic intraepithelial neoplasia: a study in Jordanian Arab patients

Abstract

Background: High-grade prostatic intraepithelial neoplasia (HGPIN) is the most likely precancerous lesion for prostatic adenocarcinoma (PCa). Recent molecular studies have shown that HGPIN can harbor TMPRSS2-ERG fusion, a genetic marker also associated with PCa, which may provide an additional risk stratification tool for HGPIN, especially when present as an isolated lesion. Our aim was to assess the frequency of HGPIN and ERG expression in a cohort of prostatic needle core biopsies from Jordanian-Arab patients with PCa. Materials and methods: We studied 109 needle core biopsies from patients with PCa. Clinical data, including age and preoperative prostate specific antigen (PSA) level, were obtained from patients' medical records. Results: HGPIN was present in 31 (28.4 %) of the 109 cases. Of the HGPIN cases, 13 (41.9%) expressed ERG immunostain. ERG expression in HGPIN was independent of patient age at presentation (P=0.4), pre-operative PSA (P=0.9), and the grade, using the novel Grade Groups (P=0.5). Conclusion: The frequency of HGPIN in our cohort appears similar to the one found in the Western patient populations and demonstrates a comparable frequency of ERG expression in these lesions.

Keywords: ERG; high-grade prostatic intraepithelial neoplasia; immunohistochemistry; prostate carcinoma.

Figure 1

H&E and corresponding ERG immunostaining in high-grade prostatic intraepithelial neoplasia (HGPIN) with adjacent invasive adenocarcinoma. Notes: (A) HGPIN lesion at the lower left with accompanying invasive adenocarcinoma at the upper right (H&E, 200×). (B) ERG immunostain for the same case, showing positive staining in both HGPIN (lower right) and the invasive component (upper left)(200×). (C) Another case with HGPIN (upper right) and adjacent small malignant glands (lower left) (H&E, 200×). (D) ERG immunostain for the same case, showing negative staining in HGPIN (lower right), while the accompanying invasive component was positive (upper left) ( 200×).