title: Value of prostate specific antigen alpha1-antichymotrypsin complex for the detection of prostate cancer in patients with a PSA level of 4.1-10.0 ng/mL: comparison with PSA-related parameters.
abstract: BACKGROUND
  The aim of the present study was to evaluate the usefulness of prostate specific antigen alpha1-antichymotrypsin complex (PSA-ACT) in the differential diagnosis of prostate cancer in patients with a PSA level of 4.1-10.0 ng/mL compared to several PSA- and PSA-ACT-related parameters.
  
  
  METHODS
  Serum samples were obtained from 103 patients with no evidence of malignancy on biopsy and 29 with histologically confirmed prostate cancer. All patients had pretreatment serum PSA levels between 4.0 and 10.0 ng/mL. The different forms of serum PSA, including total PSA (tPSA), free PSA (fPSA) and PSA-ACT were measured using immunofluorometric techniques with different monoclonal antibodies against PSA and ACT. Furthermore, tPSA and PSA-ACT densities of the whole prostate (PSAD and ACTD, respectively) and the f-to-tPSA and the f-to-PSA-ACT ratios (F/T ratio and F/ACT ratio, respectively) were calculated.
  
  
  RESULTS
  The differences between patients with prostate cancer and benign prostatic disease were significant with respect to all six parameters examined in this study. Analysis of receiver operating characteristics revealed that the areas under the curve for PSA-ACT, ACTD and the F/ACT ratio were larger than those for tPSA, PSAD and the F/T ratio, respectively. However, there were no significant differences in discrimination between benign and malignant diseases among these six parameters.
  
  
  CONCLUSIONS
  In patients who have an intermediate serum PSA level, PSA-ACT and its associated parameters may not be significantly superior in the differential diagnosis between prostate cancer and benign prostatic diseases compared to tPSA and its traditional relatives.
authors.affiliation: Department of Urology, Kobe University School of Medicine, Kobe, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Miyake
authors.forename: S
authors.initials: S
authors.lastname: Hara
authors.forename: M
authors.initials: M
authors.lastname: Nomi
authors.forename: S
authors.initials: S
authors.lastname: Arakawa
authors.forename: S
authors.initials: S
authors.lastname: Kamidono
authors.forename: I
authors.initials: I
authors.lastname: Hara
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011469:Prostatic Diseases / Q000175:diagnosis; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D000514:alpha 1-Antichymotrypsin / Q000097:blood*
chemical_list: D000911:Antibodies, Monoclonal; D000514:alpha 1-Antichymotrypsin; D017430:Prostate-Specific Antigen