Enhanced Expression of Heat Shock Protein 27 Following Neoadjuvant Hormonal Therapy is Associated with Poor Clinical Outcome in Patients Undergoing Radical Prostatectomy for Prostate Cancer

Abstract

Background: The objectives of this study were to characterize changes in the expression of heat shock protein 27 (HSP27) in prostate cancer before and after androgen withdrawal therapy and to assess the prognostic significance of HSP27 expression in patients undergoing radical prostatectomy (RP) following neoadjuvant hormonal therapy (NHT). Materials and Methods: This study included 97 patients with clinically localized prostate cancer who received NHT followed by RP. Paired needle biopsy and corresponding RP specimens obtained from these patients were analyzed for expression of the HSP27 protein by immunohistochemical staining. These findings were evaluated with respect to several clinicopathological factors. Results: HSP27 expression in the RP specimens following NHT was significantly up-regulated compared with that in the corresponding needle biopsy specimens. The expression level of HSP27 in the biopsy specimens was significantly associated with the biopsy Gleason score, but not with other factors available before RP. HSP27 expression in the RP specimens was significantly correlated with the pre-operative value of serum prostate-specific antigen and pathological stage, but not with other pathological factors. Biochemical recurrence-free survival in patients with strong HSP27 expression in the RP specimens was significantly lower than that in those with weak HSP27 expression; however, the expression level of HSP27 was not an independent predictor of biochemical recurrence. Conclusion: Despite the lack of independent significance, the expression level of HSP27 in prostate cancer tissue after NHT, which may inversely reflect the therapeutic effect of NHT, could be a useful parameter predicting biochemical recurrence in patients undergoing RP.