EPCA-2: A highly specific serum marker for prostate cancer: Leman ES, Cannon GW, Trock BJ, Sokoll LJ, Chan DW, Mangold L, Partin AW, Getzenberg RH, Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD

Objectives cribe the initial assessment of early prostate cancer antigen (EPCA)-2 as a serum marker for the detection of prostate cancer and to examine its sensitivity and specificity. s samples were obtained from 385 men: those with prostate-specific antigen (PSA) levels less than 2.5 ng/ml, PSA levels of 2.5 ng/ml or greater with negative biopsy findings, benign prostatic hyperplasia, organ-confined prostate cancer, nonorgan-confined disease, and prostate cancer with PSA levels less than 2.5 ng/ml. In addition, a diverse group of controls was assessed with an enzyme-linked immunosorbent assay to detect an epitope of the EPCA-2 protein, EPCA-2.22. s a cutoff of 30 ng/ml, the EPCA-2.22 assay had a 92% specificity (95% confidence interval 85% to 96%) for healthy men and men with benign prostatic hyperplasia and 94% sensitivity (95% confidence interval [CI] 93% to 99%) for overall prostate cancer. The specificity for PSA in these selected groups of patients was 65% (95% CI 55% to 75%). Additionally, EPCA-2.22 was highly accurate in differentiating between localized and extracapsular disease (area under the curve 0.89, 95% CI 0.82 to 0.97, P < 0.0001) in contrast to PSA (area under the curve 0.62, 95% CI 0.50 to 0.75, P = 0.05). sions sults of our study have shown that EPCA-2 is a novel biomarker associated with prostate cancer that has high sensitivity and specificity and accurately differentiates between men with organ-confined and non-organ-confined disease.