Early prostate cancer antigen (EPCA) has been recently suggested as a novel biomarker in malignant and premalignant lesions of the prostate. This study was to examine serum expression of EPCA and to further clarify the relationship between initial serum EPCA levels and the presence of subsequent cancer in the individuals with isolated high-grade prostatic intraepithelial neoplasia (HGPIN). An indirect ELISA was used for initial serum EPCA measurement in 112 men with isolated HGPIN, who were enrolled and completed a follow-up of ≥5 years. All patients had a detectable concentration of EPCA in the initial serum, with a mean of 0.64±0.13 absorbance at 450 nm. Thirty-three patients had an initial serum EPCA level of ≥1.10, in which 31 cases were subsequently identified as having prostate cancer on follow-up. However, in the remaining 79 cases, serum EPCA levels were all <1.10, and none was diagnosed with cancer later. Statistical analysis showed a significantly higher serum ECPA level in isolated HGPIN patients with subsequent cancer than those without cancer (P<0.001). The area under the receiver operating characteristic curves showed that serum EPCA level had better predictive accuracy of cancer onset on follow-up than prostate specific antigen velocity and abnormal digital rectal examination findings. Furthermore, univariate and multivariate Cox regression analyses demonstrated the predictive performance independently by initial serum EPCA≥1.10 absorbance (relative risk, 3.32; 95% confidence intervals, 2.62–5.03, P<0.001). These preliminary findings first show the potential of serum EPCA to serve as a significant predictor for subsequent cancer in isolated HGPIN.
Increased serum level of early prostate cancer antigen is associated with subsequent cancer risk in men with high-grade prostatic intraepithelial neoplasia
