title: The cutoff level of free/total prostate specific antigen (f/t PSA) ratios in the diagnosis of prostate cancer: a validation study on a Turkish patient population in different age categories.
abstract: We investigated an optimal cutoff level of free/total PSA ratios (f/t PSA) in predicting prostate cancer in different age groups, focusing on the avoidance of unnecessary prostate biopsies. A total of 4955 men were enrolled into the study. Serum tPSA, fPSA, and f/t PSA ratios were determined for the study population. All males who had suspicious digital rectal examination and tPSA > 4 ng/mL underwent transrectal ultrasonography-guided prostate biopsy. Receiver operating characteristic (ROC) curves for each group were generated by plotting the sensitivity versus 1-specificity for the f/t PSA ratio. The sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were obtained using various f/t PSA ratio cutoffs for different age groups. There were 657 patients with a PSA level of 4-10 ng/mL. According to sensitivity and specificity f/t% PSA cutoff points were determined to be 10%, 15%, 15%, and 10% in 50-59 years, 60-69 years, >70 years, and all ages categories, respectively, in patients with initial PSA level of 4-10 ng/mL. f/t PSA ratio had an area under the curve (AUC) value of 0.81 (95% confidence level: 0.80-0.82) for all age groups in detecting prostate cancer. f/t PSA ratio has an AUC value of 0.669 (0.632-0.705) in detecting prostate cancer among patients with a PSA level of 4-10 ng/mL. Ten percent of f/t PSA ratio had the highest specificity with PLR and 30% f/t PSA ratio had the highest sensitivity with lower NLR in the all-age categories. The current study shows that the use of f/t PSA ratio in patients with PSA levels of 4-10 ng/mL should enhance the specificity of PSA screening and decrease the number of unnecessary biopsies. The age-related changes warrant further investigation in a large, multicentric, and multinational population to improve the clinical use of f/t PSA cutoffs.
authors.affiliation: Department of Urology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey. Electronic address: erolbulent@yahoo.com.
authors.forename: Bulent
authors.initials: B
authors.lastname: Erol
authors.affiliation: Department of Urology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey.
authors.forename: Murat Tolga
authors.initials: MT
authors.lastname: Gulpinar
authors.affiliation: Department of Urology, Faculty of Medicine, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Gurdal
authors.initials: G
authors.lastname: Bozdogan
authors.affiliation: Department of Pathology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey.
authors.forename: Seyma
authors.initials: S
authors.lastname: Ozkanli
authors.affiliation: Department of Urology, Faculty of Medicine, 19 Mayıs University, Samsun, Turkey.
authors.forename: Kadir
authors.initials: K
authors.lastname: Onem
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Görkem
authors.initials: G
authors.lastname: Mungan
authors.affiliation: Department of Pathology, Faculty of Medicine, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Sibel
authors.initials: S
authors.lastname: Bektas
authors.affiliation: Department of Urology, Faculty of Medicine, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Husnu
authors.initials: H
authors.lastname: Tokgoz
authors.affiliation: Department of Urology, Faculty of Medicine, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Bulent
authors.initials: B
authors.lastname: Akduman
authors.affiliation: Department of Urology, Faculty of Medicine, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Aydin
authors.initials: A
authors.lastname: Mungan
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014421:Turkey
chemical_list: D017430:Prostate-Specific Antigen
keywords: Prostate cancer; Sensitivity; Specificity; f/T PSA ratios