title: Individualized prostate-specific antigen threshold values to avoid overdiagnosis of prostate cancer and reduce unnecessary biopsy in elderly men.
abstract: OBJECTIVE
  To individualize prostate-specific antigen threshold values to avoid overdiagnosis of prostate cancer and reduce unnecessary biopsy in elderly men.
  
  
  METHODS
  A total of 406 men aged over 70 years old with prostate-specific antigen levels between 4.0 and 20.0 ng/ml, normal digital rectal examination results and diagnosed by transrectal needle biopsy were retrospectively analyzed. The patients were divided into a no/favorable-risk cancer group or an unfavorable-risk cancer group based on their Gleason score and the number of positive cores. Prostate-specific antigen levels, percent free prostate-specific antigen level, prostate transition zone volume and the number of previous biopsies were used to discriminate between the two groups. The optimal individualized prostate-specific antigen threshold values based on the other variables that gave a sensitivity of 95% for the detection of unfavorable-risk cancer were calculated using a boosting method for maximizing the area under the receiver operating characteristic curve.
  
  
  RESULTS
  A total of 66 men had favorable-risk cancer, and 139 had unfavorable-risk cancer. The area under the receiver operating characteristic curve of the combination model determined by the boosting method for maximizing the area under the receiver operating characteristic curve was 0.852. The sensitivity and specificity of the threshold values for the detection of unfavorable-risk cancer were 95 and 36%, respectively. By using the threshold values, 100 (25%) of the subjects with no/favorable-risk cancer could have avoided undergoing biopsies, with a <5% risk of missing the detection of unfavorable-risk cancer.
  
  
  CONCLUSIONS
  These individualized prostate-specific antigen threshold values may be useful for determining an indication of prostate biopsy for elderly men to avoid overdiagnosis of prostate cancer and reduce unnecessary biopsy.
authors.affiliation: Department of Urology, Aichi Medical University, Nagakute kent.kanao@gmail.com.
authors.forename: Kent
authors.initials: K
authors.lastname: Kanao
authors.affiliation: The Institute of Statistical Mathematics, Tokyo.
authors.forename: Osamu
authors.initials: O
authors.lastname: Komori
authors.affiliation: Department of Urology, Tokyo Medical University, Tokyo.
authors.forename: Jun
authors.initials: J
authors.lastname: Nakashima
authors.affiliation: Department of Urology, International University of Health and Welfare Mita Hospital, Tokyo and.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohigashi
authors.affiliation: Department of Urology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kikuchi
authors.affiliation: Department of Urology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Miyajima
authors.affiliation: Department of Urology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: The Institute of Statistical Mathematics, Tokyo.
authors.forename: Shinto
authors.initials: S
authors.lastname: Eguchi
authors.affiliation: Department of Urology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Oya
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D001707:Biopsy, Needle; D006801:Humans; D008297:Male; D057285:Precision Medicine / Q000379:methods*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000601:surgery; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D019564:Unnecessary Procedures / Q000639:trends
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
keywords: elderly; individualized threshold values; overdiagnosis; prostate cancer; prostate-specific antigen