title: Prostate-specific Antigen (PSA) Density and Free to Total PSA Ratio in Diagnosing Prostate Cancer with Prostate-Specific Antigen Levels of 4.0 ng/ml or Less.
abstract: BACKGROUND
  We aimed to value the usefulness of free to total prostate-specific antigen and Prostate-specific antigen (PSA) density for prostate cancer in the patients with PSA levels of 4.0 ng/ml or less.
  
  
  METHODS
  A total of 343 subjects with PSA levels of 4.0 ng/ml or less were biopsied. All patients were divided into four groups according to the PSA levels: 0 to 1.0 ng/ml, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml, and 3.1 to 4.0 ng/ml. The reliability of cancer detection in relation to the f/t PSA ratio and PSAD were estimated.
  
  
  RESULTS
  Overall, 65 people were diagnosed with prostate cancer. The detection rate was 16.28%、17.17%, 21.82%, 25.00% in subjects with PSA levels of 0 to 1.0 ng/ml, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml, and 3.1 to 4.0 ng/ml, respectively. The f/t PSA ratio was significantly lower in patients with prostate cancer and PSA levels of 2.1 to 4.0 ng/ml (P<0.05). The PSAD had no statistical significance between the two groups.
  
  
  CONCLUSIONS
  Routine prostate biopsy should be undertaken if the f/t PSA ratio less than 15% with /without abnormal DRE/TRUS findings.
authors.affiliation: Ultrasonography Department of Nan Lou Clinical Medicine Division, Chinese PLA General Hospital, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: Dept. of Ultrasonography, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Tang
authors.affiliation: Dept. of Ultrasonography, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Fei
authors.affiliation: Dept. of Ultrasonography, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, China.
authors.forename: Qiu-Yang
authors.initials: QY
authors.lastname: Li
keywords: Biopsy; PSA ratio; PSAD; Prostate cancer; Prostate-specific antigen