ERG expression and prostatic adenocarcinoma

Abstract

ERG gene rearrangement has been identified as a highly specific alteration that is present in 40-50 % of prostate carcinomas. The standardization of an immunohistochemical assay with a novel anti-ERG antibody recently described would have significant diagnostic value. The aims of this study were to identify the incidence of this rearrangement in a Spanish population and to test the specificity of immunohistochemical ERG evaluation for prostate carcinomas. Three prostate tissue microarrays were constructed using radical prostatectomy specimens and related to grade, local invasion, and regional invasion. In addition to samples from malignant cases (160), specimens of prostatic hyperplasia (26) and high-grade prostatic intraepithelial neoplasia (10) were included. Tissue microarrays of 270 samples from most common malignant tumors (breast, colon, lung, and bladder) were also tested. All were analyzed by immunohistochemistry. Seventy-five out of 154 evaluable cases (49 %) of prostate carcinoma showed ERG expression; 52/75 showed strong staining. No ERG expression was observed in any of the high-grade prostatic intraepithelial neoplasia. ERG expression was independent of Gleason score (p = 0.160), extent of invasion (p = 0.517), and regional lymph node involvement (p = 0.816). No ERG expression was found in any other type of tumor, with the exception of one bladder cancer sample that showed focal and weak expression. The frequency of ERG detected in our study correlated with the results published for other Caucasian populations. Strong ERG protein expression was exclusively detected in prostate carcinomas, corroborating the specificity of ERG rearrangements for these tumors. Thus, detecting ERG using immunohistochemistry may be useful in routine practice in pathology departments.

Frequency of ERG-positive prostate carcinoma in Poland

“…Also in the preliminary analysis of the present study, and with similar sample size to that of the van Leenders et al study, we were not able to detect a relationship between ERG and grade, which became evident when the study group expanded. Verdu et al [13] found that 49% of Spanish PCs show ERG positivity. In their material no relationship with Gleason grade or stage was present.…”

Immunohistochemistry of soft tissue tumours – review with emphasis on 10 markers

“…They result in immunohistochemical ERG positivity, which does not seem to occur otherwise in carcinomas. Therefore, immunohistochemical evaluation of ERG may be a useful test to evaluate the possible prostatic origin of metastatic carcinomas …”

“…Therefore, immunohistochemical evaluation of ERG may be a useful test to evaluate the possible prostatic origin of metastatic carcinomas. 48,51,55 K I T KIT receptor tyrosine kinase is a key cell signalling molecule, also referred to as CD117. It becomes normally activated (phosphorylated) when binding of its ligand stem cell factor links together two KIT molecules which then cross-phosphorylate each other's KIT tyrosine kinase domain, making it ready to phosphorylate downstream targets in the KIT signal transduction cascade.…”

Newly Available Antibodies With Practical Applications in Surgical Pathology

“…On immunostaining, 33% to 61% of all prostatic carcinomas are shown to be immunoreactive for ERG (Figure 5). 23,24,26,29-33 When positive, practically all neoplastic cells are labeled strongly. There is excellent correlation of ERG immunohistochemistry with presence of ERG gene fusion.…”