The proliferation marker Ki67, but not neuroendocrine expression, is an independent factor in the prediction of prognosis of primary prostate cancer patients

Abstract

Background

Neuroendocrine markers may help in detecting particularly aggressive variants of prostate cancer. Also Ki67 is a well-known marker in oncology for defining tumor proliferation. They all have already been found to associate with clinical outcome of prostate cancer. The aim of this study was to investigate the prognostic value of the expression of those markers in primary prostate cancer patients.

Material and methods

NSE, ChrA, Syp and Ki67 staining was performed by immunohistochemistry. Then, we investigated the prognostic impact of their expression on overall survival in 166 primary prostate cancer patients by using univariate and multivariate analyses.

Results

NSE (neuron specific enolase), ChrA (chromogranin A), Syp (Synaptophysin) and Ki67 were positive in 50, 45, 54 and 146 out of 166 patients, respectively. In Kaplan-Meier analysis only diffuse NSE staining (negative vs diffuse, p = 0.004) and Ki67 (≤ 10% vs > 10%, p < 0.0001) were significantly associated with overall survival. Ki67 expression, but not NSE, resulted also an independent prognostic factor for overall survival in multivariate analysis. A prognostic model incorporating Ki67 expression along with clinical-pathological covariates could provide additional prognostic information. Thus, Ki67 may improve prediction of prostate cancer outcome based on standard clinical-pathological parameters improving prognosis and management of prostate cancer patients.