Expression of clusterin in prostate cancer correlates with Gleason score but not with prognosis in patients undergoing radical prostatectomy without neoadjuvant hormonal therapy

Abstract

Objectives: To determine whether the expression level of clusterin in prostate cancer could be used as a prognostic predictor in patients who have undergone radical prostatectomy (RP).

Methods: This study included 172 consecutive patients undergoing RP for clinically organ-confined prostate cancer without neoadjuvant hormonal therapy. Immunohistochemical staining was performed in RP specimens obtained from these patients to evaluate the expression level of clusterin protein. The cell proliferative activities and apoptotic features in these specimens were investigated using Ki-67 immunostaining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay, respectively.

Results: Varying levels of clusterin expression were noted in 169 of 172 prostate cancer specimens; 32 of the 172 normal prostatic tissue specimens did not exhibit any clusterin staining. Clusterin expression in prostate cancer tissue was significantly related to the Gleason score, but not to the other parameters, including age, serum prostate-specific antigen level, pathologic stage, perineural invasion, tumor volume, and lymph node metastasis. In addition, cell proliferative activity in the prostate cancer specimens was significantly associated with clusterin expression; however, no correlation was found between the apoptotic index and clusterin expression. In this series, 34 (19.8%) of 172 patients developed biochemical recurrence. No significant difference was found in biochemical/recurrence-free survival between patients with strong clusterin expression and those with weak expression.

Conclusions: Despite its detection in most prostate cancer tissue, clusterin expression failed to show a significant association with prognosis in patients undergoing RP without neoadjuvant hormonal therapy. This suggests a limited role for clusterin in the progression of clinically organ-confined prostate cancer in the absence of proapoptotic stimuli.