Value of Ki-67 immunolabelling as a prognostic factor in prostate cancer

Objective(s): The aim of the study was to analyze the results of Ki-67 immunostaining in prostatic adenocarcinoma and to assess its prognostic value. Methods: Clinical follow-up data was reviewed in 190 prostatic adenocarcinomas and the results of Ki-67 immunolabelling were correlated to standard prognostic factors and survival data of the patients. All stage and grade categories were included. Results: Ki-67 expression correlated significantly with histological differentiation of tumors, indicators of cell proliferation, perineural growth, density of tumor-infiltrating lymphocytes and TM classification. In survival analysis, Ki-67 expression was able to discriminate patients into different prognostic groups (p = 0.0035). In a separate analysis including T1-2M0 tumors, Ki-67 immunolabelling was a significant predictor of survival (p = 0.0258). In Cox's multivariate analysis Ki-67 was an independent prognostic factor in the entire cohort. Conclusions: The results show that Ki-67 expression is a potentially useful prognostic factor in prostatic adenocarcinoma and it could be used as an additional criterion in defining a correct prognostic category in this malignancy.