AZGP-1 immunohistochemical marker in prostate cancer: potential predictive marker of biochemical recurrence in post radical prostatectomy specimens

One of the major challenges in prostate cancer research is to identify prognostic/predictive factors to distinguish aggressive disease from indolent one. To select prognostic/predictive markers of postoperative biochemical recurrence (BCR) that could be easily performed in daily pathology practice, the expression of 6 immunohistochemical markers including zinc-α-2-glycoprotein (AZGP-1), hCAP-D3, mucin 1, vimentin, E-cadherin, and ERG was assessed in a tissue microarray of 400 radical prostatectomy specimens. The expression levels were correlated with clinicopathologic factors and BCR. During the median follow-up period of 55 months, BCR occurred in 70 cases (17.5%). Low expression of AZGP-1 was noted in 76 cases (19.0%), whereas high expression of hCAP-D3, mucin 1, vimentin, and ERG was observed in 205 (51.3%), 81 (20.3%), 33 (8.3%), and 58 (14.5%) cases, respectively. Aberrant E-cadherin expression was noted in 29 cases (7.3%). By univariate analysis, BCR was associated with low expression of AZGP-1, high expression of hCAP-D3, and aberrant expression of E-cadherin. By multivariate analysis, only AZGP-1 remained an independent immunohistochemical factor, in addition to age, preoperative serum prostate-specific antigen level, Gleason score, tumor stage, and resection margin status. These results show that AZGP-1, hCAP-D3, and E-cadherin are potentially useful immunohistochemical markers to predict BCR, and that AZGP-1 can be used as an independent prognostic marker of aggressive prostate cancer.