title: [Examination of prostate biopsy among Japanese with less than 4.0 ng/ml prostate specific antigen--usefulness of free/total PSA ratio].
abstract: The low specificity of the prostate specific antigen (PSA) test is considered to be a problem when PSA measurement alone is performed to detect cancer. Therefore, we examined a method to decrease the number of unnecessary biopsies while maintaining the power of the test by using PSA, PSA free/total ratio (PSAf/t), and digital rectal examination (DRE). The subjects were 232 patients with PSA levels of 4.0 ng/ml or less who underwent biopsy for prostate cancer. An endorectal ultrasound perineal biopsy was conducted, and the average biopsy core number was 21. Cancer was detected in 37 of the 232 subjects. Receiver operating characteristic curves of PSA and PSAf/t were subsequently determined. Although the area under the curve (AUC) was 0.56 for PSA alone, the AUC increased to 0.75 when the factor of positive data in DRE was taken into account. Although the AUC was 0.62 for PSAf/t alone, when the factor of positive data in DRE was added as for PSA, the AUC increased to 0.79. In addition, as a result of examining the combination of PSA, PSAf/t and DRE, the condition of the biopsy for prostate cancer in the cases with PSA of 4.0 ng/ml was determined as follows: PSA should be 3.1 ng/ml or more and PSAf/t 27% or less, or the result of DRE should be positive. Based on these criteria, the sensitivity, specificity and detection rate of cancer increased to 0.919, 0.436 and 23.2%, respectively. We consider that this approach will be useful.
authors.affiliation: Department of Urology, Yamagata Prefectural Central Hospital.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tsukigi
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Kenzi
authors.initials: K
authors.lastname: Numahata
authors.forename: Kunio
authors.initials: K
authors.lastname: Ono
authors.forename: Osamu
authors.initials: O
authors.lastname: Sugano
authors.forename: Senji
authors.initials: S
authors.lastname: Hoshi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Tomita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D014408:Biomarkers, Tumor / Q000097:blood*; D001706:Biopsy / Q000706:statistics & numerical data*; D051517:Digital Rectal Examination; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen