title: EPCA-2: a highly specific serum marker for prostate cancer.
abstract: OBJECTIVE
  To describe 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.
  
  
  METHODS
  Serum 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, non-organ-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.
  
  
  RESULTS
  Using 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).
  
  
  CONCLUSIONS
  The results 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.
authors: Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors: Eddy S
authors: ES
authors: Leman
authors: Grant W
authors: GW
authors: Cannon
authors: Bruce J
authors: BJ
authors: Trock
authors: Lori J
authors: LJ
authors: Sokoll
authors: Daniel W
authors: DW
authors: Chan
authors: Leslie
authors: L
authors: Mangold
authors: Alan W
authors: AW
authors: Partin
authors: Robert H
authors: RH
authors: Getzenberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C504719:early prostate cancer antigen, human