title: Prostate specific antigen changes as related to the initial prostate specific antigen: data from the prostate, lung, colorectal and ovarian cancer screening trial.
abstract: OBJECTIVE
  Annual screening with PSA, although of unproven benefit, is currently used for prostate cancer early detection. A large fraction of screened men have low (less than 2 ng/ml) initial PSA. The yield over time of positive PSA screens (ie more than 4 ng/ml) in these men has not been well characterized in large cohorts in the United States.
  
  
  METHODS
  Men in the screening arm of the PLCO received baseline PSA and annual tests for 5 years. 30,495 of these men had baseline PSA 4 ng/ml or less. We estimated the cumulative probability of converting to PSA greater than 4 at years 1 through 5 as a function of baseline PSA.
  
  
  RESULTS
  Among men with baseline PSA less than 1 ng/ml, 1.5% converted by year 5 (95% CI 1.2-1.7). Among men with baseline PSA of 1.0 to 1.99 ng/ml, 1.2% (95% CI 0.9-1.3) and 7.4% (95% CI 6.8-8.1) converted by year 1 and 5, respectively. A total of 33.5% and 79% of men with initial PSA of 2.0 to 2.99 and 3.0 to 4.0, respectively, converted by year 5. Of men with baseline PSA less than 1 ng/ml converting to PSA more than 4 ng/ml, 8% were diagnosed with cancer within 2 years of conversion. About 10% of men with baseline PSA less than 1 ng/ml and negative baseline DRE had a positive DRE within 3 years.
  
  
  CONCLUSIONS
  For men choosing PSA screening, screening every 5 years for baseline PSA less than 1 ng/ml and every 2 years for PSA 1 to 2 ng/ml could result in a 50% reduction in PSA tests and in less than 1.5% of men missing earlier positive screens, but with an unknown effect on prostate cancer mortality.
authors.affiliation: Department of Urologic Oncology, University of Colorado Health Sciences Center, Denver, Colorado, Washington, DC, USA. david.crawford@uchsc.edu
authors.forename: E David
authors.initials: ED
authors.lastname: Crawford
authors.forename: Paul F
authors.initials: PF
authors.lastname: Pinsky
authors.forename: David
authors.initials: D
authors.lastname: Chia
authors.forename: Barnett S
authors.initials: BS
authors.lastname: Kramer
authors.forename: Richard M
authors.initials: RM
authors.lastname: Fagerstrom
authors.forename: Gerald
authors.initials: G
authors.lastname: Andriole
authors.forename: Douglas
authors.initials: D
authors.lastname: Reding
authors.forename: Edward P
authors.initials: EP
authors.lastname: Gelmann
authors.forename: David L
authors.initials: DL
authors.lastname: Levin
authors.forename: John K
authors.initials: JK
authors.lastname: Gohagan
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*
chemical_list: D017430:Prostate-Specific Antigen