title: Towards an optimal interval for prostate cancer screening.
abstract: BACKGROUND
  The rate of decrease in advanced cancers is an estimate for determining prostate cancer (PCa) screening program effectiveness.
  
  
  OBJECTIVE
  Assess the effectiveness of PCa screening programs using a 2- or 4-yr screening interval.
  
  
  METHODS
  Men aged 55-64 yr were participants at two centers of the European Randomized Study of Screening for Prostate Cancer: Gothenburg, Sweden (2-yr screening interval, n=4202), and Rotterdam, the Netherlands (4-yr screening interval, n=13 301). We followed participants until the date of PCa, the date of death, or the last follow-up at December 31, 2008, or up to a maximum of 12 yr after initial screening. Potentially life-threatening (advanced) cancer was defined as cancer with at least one of following characteristics: clinical stage ≥T3a, M1, or N1; serum prostate-specific antigen (PSA) >20.0 ng/ml; or Gleason score ≥8 at biopsy.
  
  
  METHODS
  We compared the proportional total (advanced) cancer incidence (screen-detected and interval cases), defined as the ratio of the observed number of (advanced) cancers to the expected numbers of (advanced) cancers based on the control arm of the study.
  
  
  METHODS
  The proportional cancer incidence from the second screening round until the end of observation was compared using a 2- or 4-yr screening interval.
  
  
  CONCLUSIONS
  From screening round 2 until the end of observation, the proportional cancer incidence was 3.64 in Gothenburg and 3.08 in Rotterdam (relative risk [RR]: 1.18; 95% confidence interval [CI], 1.04-1.33; p=0.009). The proportional advanced cancer incidence was 0.40 in Gothenburg and 0.69 in Rotterdam (RR: 0.57; 95% CI, 0.33-0.99; p=0.048); the RR for detection of low-risk PCa was 1.46 (95% CI, 1.25-1.71; p<0.001). This study was limited by the assumption that PSA testing in the control arm was similar in both centers.
  
  
  CONCLUSIONS
  A 2-yr screening interval significantly reduced the incidence of advanced PCa; however, the 2-yr interval increased the overall risk of being diagnosed with (low-risk) PCa compared with a 4-yr interval in men aged 55-64 yr. Individualized screening algorithms must be improved to provide the strategy for this issue.
authors.affiliation: Department of Urology, Erasmus University Medical Center, Rotterdam, The Netherlands. p.vanleeuwen@erasmusmc.nl
authors.forename: Pim J
authors.initials: PJ
authors.lastname: van Leeuwen
authors.forename: Monique J
authors.initials: MJ
authors.lastname: Roobol
authors.forename: Ries
authors.initials: R
authors.lastname: Kranse
authors.forename: Marco
authors.initials: M
authors.lastname: Zappa
authors.forename: Sigrid
authors.initials: S
authors.lastname: Carlsson
authors.forename: Meelan
authors.initials: M
authors.lastname: Bul
authors.forename: Xiaoye
authors.initials: X
authors.lastname: Zhu
authors.forename: Chris H
authors.initials: CH
authors.lastname: Bangma
authors.forename: Fritz H
authors.initials: FH
authors.lastname: Schröder
authors.forename: Jonas
authors.initials: J
authors.lastname: Hugosson
mesh_terms: D001706:Biopsy; D055088:Early Detection of Cancer; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D009426:Netherlands / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000401:mortality / Q000473:pathology; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
chemical_list: D017430:Prostate-Specific Antigen