title: Preventing Unnecessary Invasive Cancer-Diagnostic Tests: Changing the Cut-off Points.
abstract: BACKGROUND
  To determine a cut-off point of tPSA and PSAD to prevent unnecessary invasive cancer-diagnosing tests in the community.
  
  
  METHODS
  This study was performed on 688 consecutive patients referred to our center due to prostatism, suspicious lesions on digital rectal examination and/or elevated serum PSA levels. All patients underwent transrectal ultrasound guided biopsies and obtained PSAD. Serum levels of tPSA and fPSA were measured by chemiluminescence. Comparisons were done using tests of accuracy (AUC-ROC).
  
  
  RESULTS
  Prostate cancer was detected in 334 patients, whereas the other 354 patients were suffering from benign prostate diseases. The mean tPSA in case and control groups were 28.32±63.62 ng/ml and 7.14±10.04 ng/ml; the mean f/tPSA ratios were 0.13± 0.21 and 0.26±0.24 in PCa and benign prostate disease groups; the mean PSAD rates were 0.69±2.24, 0.12±0.11, respectively. Statistically significant differences were found (P <0.05). Using ROC curve analysis, it was revealed that AUC was 0.78 for tPSA and 0.80 for f/tPSA. Sensitivity was 71% for the cut-off value of 7.85ng/ml. For f/tPSA ratio, the optimal cut-off value was 0.13 which produced the sensitivity of 81.4% and for PSAD, it was15%.
  
  
  CONCLUSIONS
  As this trial is different from the European and American values, we should be more cautious in dealing with the prostate cancer upon the obtained sensitivity and specificity for PCa diagnosis (7.85ng/mL for tPSA, 15% for PSAD and 0.13 for f/tPSA ratio).
authors.affiliation: Urology Research Center, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: G
authors.initials: G
authors.lastname: Pourmand
authors.forename: R
authors.initials: R
authors.lastname: Ramezani
authors.forename: B
authors.initials: B
authors.lastname: Sabahgoulian
authors.forename: F
authors.initials: F
authors.lastname: Nadali
authors.forename: Ar
authors.initials: A
authors.lastname: Mehrsai
authors.forename: Mr
authors.initials: M
authors.lastname: Nikoobakht
authors.forename: F
authors.initials: F
authors.lastname: Allameh
authors.forename: Sh
authors.initials: Sh
authors.lastname: Hossieni
authors.forename: A
authors.initials: A
authors.lastname: Seraji
authors.forename: M
authors.initials: M
authors.lastname: Rezai
authors.forename: F
authors.initials: F
authors.lastname: Haidari
authors.forename: S
authors.initials: S
authors.lastname: Dehghani
authors.forename: R
authors.initials: R
authors.lastname: Razmandeh
authors.forename: B
authors.initials: B
authors.lastname: Pourmand
keywords: Cut-off Point; PCa diagnosis; PSAD; Prostate cancer; tPSA