title: False-positive screening results in the European randomized study of screening for prostate cancer.
abstract: BACKGROUND
  Screening for prostate cancer (PC) with prostate-specific antigen (PSA) has been shown to decrease mortality, but has adverse effects, such as false-positive (FP) screening results. We describe the frequency of FP results and assess their relation to subsequent screening attendance, test results and prostate cancer risk in a large randomized trial.
  
  
  METHODS
  We included data from five centres of the European Randomized Study of Screening for Prostate Cancer, altogether over 61,000 screened men. Men were screened with PSA test at a 2-7 year interval depending on the centre; PSA cut-off was 3.0-4.0 ng/ml. A positive screen with no histologically confirmed PC in biopsy within 1 year was defined as an FP result.
  
  
  RESULTS
  Of the 61,604 men who were screened at least once, 17.8% had one or more FP result(s). Almost 20% of men who participated at all screening rounds had one or more FP result(s). More than half of the men with an FP result had another FP if screened again. Men with FP results had a fourfold risk of PC at subsequent screen (depending on the round, 10.0% versus 2.6-2.7% of men with negative screen, risk ratio 3.8-3.9). The PCs following an FP result were in 92.8% of cases localised and low-grade versus 90.4% following a screen-negative result.
  
  
  CONCLUSIONS
  Our results show that FP results are common adverse effects in PC screening, as they affect at least one in six screened men. False-positive men are more prone to be diagnosed with PC but are also likely to have consistently high PSA levels.
authors.affiliation: Dept. of Urology, Tampere University Hospital and University of Tampere, Finland. tuomas.kilpelainen@uta.fi
authors.forename: Tuomas P
authors.initials: TP
authors.lastname: Kilpeläinen
authors.forename: Teuvo L J
authors.initials: TL
authors.lastname: Tammela
authors.forename: Monique
authors.initials: M
authors.lastname: Roobol
authors.forename: Jonas
authors.initials: J
authors.lastname: Hugosson
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciatto
authors.forename: Vera
authors.initials: V
authors.lastname: Nelen
authors.forename: Sue
authors.initials: S
authors.lastname: Moss
authors.forename: Liisa
authors.initials: L
authors.lastname: Määttänen
authors.forename: Anssi
authors.initials: A
authors.lastname: Auvinen
mesh_terms: D000368:Aged; D005189:False Positive Reactions; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis*
chemical_list: D017430:Prostate-Specific Antigen