Androgen receptor expression in clinically localized prostate cancer: immunohistochemistry study and literature...

To evaluate androgen receptor (AR) expression in clinically localized prostate cancer (PCa).

Specimens were studied from 232 patients who underwent radical prostatectomy for clinically localized prostatic adenocarcinoma without neoadjuvant hormonal therapy or chemotherapy at our institution between November 2001 and June 2005. Immunohistochemical study was performed using an anti-human AR monoclonal antibody AR441. The mean AR density in the hot spots of different histological areas within the same sections were compared and the correlation of malignant epithelial AR density with clinicopathological parameters such as Gleason score, tumor, nodes and metastases (TNM) stage and pre-treatment prostate-specific antigen (PSA) value was assessed.

AR immunoreactivity was almost exclusively nuclear and was observed in tumor cells, non-neoplastic glandular epithelial cells and a proportion of peritumoral and interglandular stromal cells. Mean percentage of AR-positive epithelial cells was significantly higher in cancer tissues than that in normal prostate tissues (mean +/- SD, 90.0% +/- 9.3% vs. 85.3 +/- ?9.7%, P < 0.001). The histological score yielded similar results. The percentage of AR immunoreactive prostatic cancer nuclei and histological score were not correlated with existing parameters such as Gleason score, tumor, nodes and metastases stage and pre-treatment PSA value in this surgically treated cohort.

The results of the present study suggest that there may be limited clinical use for determining AR expression (if evaluated in hot spots) in men with localized PCa.