Expression of Ki-67 and PCNA as proliferating markers in prostate cancer

Prostate carcinoma (PCa) is the most common male cancer in industrialized societies and represents a serious public health problem. The aim of our study was the immunohistochemical evaluation of Ki-67 and proliferating cell nuclear antigen (PCNA) expression in prostate cancer (PCa) following radical prostatectomy and analysis of its relationship to chosen anatomo-clinical and morfological parameters of the tumours. Archival sections from 28 PCas were immunostained with monoclonal antibodies against Ki-67, and proliferating cell nuclear antigen (PCNA). Immunolocalization of Ki-67 and PCNA was performed using LSAB method. No statistically significant correlation was found between the expression of Ki-67, PCNA and preoperative PSA level, lymph node metastases, capsular penetration, seminal vesicle invasive and positive or negative surgical resection margins. However, a strong statistically significant correlation between Ki-67 positive and T stage was found. We also found relationship between Gleason score 7 or above and high expression of Ki-67 and PCNA in prostate cancers (p < 0.004, p < 0.02 respectively). These results suggest that PCNA and especially Ki-67 may be useful as tumour markers in prostate carcinoma, but further studies on larger group are required.