Androgen Receptor Gene Copy Number and Protein Expression in Treatment-Naïve Prostate Cancer.

To evaluate the androgen receptor (AR) gene copy number in androgen deprivation therapy (ADT) treatment-naïve prostate cancer (PCa) patients and to evaluate the corresponding AR protein expression and assess the association between these features and prognostic factors.

Chromosome X and AR gene copy number, using fluorescence-in-situ-hybridization, and epithelial-stromal AR expression, using AR immunohistochemistry, were analyzed in 62 ADT treatment-naïve PCa patients and 8 castration-refractory patients.

In ADT treatment-naïve PCa patients, the AR expression was higher in tumor epithelial cells versus surrounding stromal cells (p < 0.001) and versus normal epithelium in the same patient (p = 0.043). The difference between tumoral AR expression and expression in normal epithelium was higher in patients with ≥15% of tumor cells with increased AR copy number (p = 0.019). Peritumoral stroma had lower AR expression in patients with lymph-node or distant metastases compared to those without metastases (p = 0.038).

This research evaluates the link between AR gene status, expression profile, and possible prognostic factors. Furthermore, it highlights the importance of the peritumoral environment in PCa. Additional research is needed to further clarify the role of stromal AR in PCa dissemination and identify possible therapeutic strategies to target this mechanism.

Urologia internationalis. 2017 Jan 05 [Epub ahead of print]

Filip Poelaert, Candy Kumps, Nicolaas Lumen, Stephanie Verschuere, Louis Libbrecht, Marleen Praet, Sylvie Rottey, Tom Claeys, Piet Ost, Karel Decaestecker, Gert De Meerleer, Charles Van Praet

Department of Urology, Ghent University Hospital, Ghent, Belgium.