Immunohistochemical Expression of Ki-67 Antigen, Cox-2 and Bax/Bcl-2 in Prostate Cancer; Prognostic Value in Biopsies and Radical Prostatectomy Specimens

Purposes: To elucidate the prognostic value of the immunohistochemical (IHC) expression of Bcl-2, Bax, Cox-2 and Ki-67 antigen in biopsy cores (C) and surgical specimens (SP) of prostate cancer (PC) and to determine the C to SP reproducibility.

Material And Methods: The IHC study was carried out in 91 patients operated by means of radical prostatectomy (RP) with available formalin-fixed paraffin-embedded material from both C and SP.

Results: The IHC expression of Bcl-2 in C and SP was very low (5%). Bax was expressed in almost all the patients and did not show any prognostic value. We observed a good reproducibility between C and SP for all molecules except with Bax. In prostate C, Ki-67 and Cox-2 were considered positive in 42.9% and 67% of the patients respectively, and were related to disease-free survival in the univariate analysis. The expression of these two markers in SP was observed in 51.6% and 79.1% of the patients and the expression of Ki-67 in SP maintained its independence as prognostic factor in the multivariate analysis related to disease-free survival.

Conclusions: The IHC expression of Ki-67 and Cox-2 proteins in our study do offer valuable prognostic information, mostly the first one. Thus, we think these markers might be studied in larger series of patients for its further validation as prognostic factors in prostate biopsies.