Prognostic impact of NDRG2 and NDRG3 in prostate cancer patients undergoing radical prostatectomy

Aim: To investigate the clinicopathologic significance of NDRG2 and NDRG3, and their involvement in recurrence-free survival (RFS) and overall survival (OS) of prostate cancer (PCa). Methods: NDRG2 and NDRG3 expression in 206 pairs of primary PCa and corresponding noncancerous prostate tissue samples from the same specimens were detected by immunohistochemistry. The association of NDRG2 and NDRG3 expression with the clinicopathologic features and with the prognosis of PCa was subsequently assessed. Results: In PCa tissues, NDRG2 expression was significantly downregulated, while NDRG3 expression was significantly upregulated (both P< 0.001), compared with those in corresponding noncancerous prostate tissues. In addition, the downregulation of NDRG2 in PCa tissues was significantly correlated with advanced pathological stage (P= 0.001), positive metastatic status (P= 0.001) and high Gleason score (P= 0.003), while the upregulation of NDRG3 in PCa tissues was significantly correlated with advanced pathological stage (P= 0.006), positive metastatic status (P= 0.001) and lymph node status (P= 0.002). Furthermore, multivariate survival analysis showed low NDRG2 and high NDRG3 immunoreactivities were both significantly associated with short RFS and short OS in PCa independently of routine clinicopathological predictors. Conclusion: Our data offer convincing evidence for the first time that the aberrant expression of NDRG2 and NDRG3 may contribute to the malignant progression of PCa. More importantly, both the downregulation of NDRG2 and the upregulation of NDRG3 may be efficient prognostic indicators for PCa.