title: [A case-control study on the efficacy and the optimum interval of mass screening for prostatic cancer].
abstract: OBJECTIVE
  The efficacy and the optimum interval of mass screening for prostatic cancer were investigated by a case-control study.
  
  
  METHODS
  A matched pairs analysis by 1:5 was conducted between 31 cases of advanced prostatic cancer in stage C and D detected by mass screening and 155 controls of normal subjects selected at random. In all cases and controls, the history of taking part of the mass screening for last 3 years, then the estimates of odds ratios (OR) and 95% confidence intervals (95% CI) were calculated on discordant pairs of the matched analysis.
  
  
  RESULTS
  OR to suffer from advanced prostatic cancer was 0.22 (95% CI: 0.07-0.70) in the group to submit to mass screening 1 year ago in comparison with the group not to submit once for 3 years. According to the analysis on the interval of submission to mass screening, the effect of screening to prevent the progression to advanced stages might be valied for 1 year.
  
  
  CONCLUSIONS
  Mass screening for prostatic cancer every year might be efficient to reduce the number of patients progressing to advanced stages.
authors.affiliation: Department of Urology, Kyoto Prefectural University of Medicine.
authors.forename: S
authors.initials: S
authors.lastname: Nakagawa
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D018450:Disease Progression; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000517:prevention & control*; D013997:Time Factors