Objective: This study was performed to examine the expressions of Ki-67 antigen, bcl-2 and p53 oncoprotein and to assess their capacity to predict the short-term response to the initial endocrine treatment and disease progression in prostate cancer.
Methods: Formalin-fixed and paraffin-embedded tumor tissues from a total of 73 patients with untreated prostate cancers were collected by transrectal ultrasound-guided biopsy. All patients with stage C or D prostate cancers had received continuous endocrine treatment. Ki-67 antigen, p53 and bcl-2 oncoprotein were detected by immunohistochemical methods.
Results: Short-term response to initial endocrine therapy judged at 3 months showed a significant correlation with Ki-67 labeling index (LI) and bcl-2 expression. Multivariate analysis showed that only a high Ki-67 LI was an independent potential predictor of prostate-specific antigen failure or the appearance of new metastasis.
Conclusions: The findings suggested that the Ki-67 LI was the most useful parameter to predict disease progression after the initial endocrine treatment. Additional studies must be performed to evaluate the prognostic significance of both cell proliferation and apoptosis in detail.