Prostate specific antigen changes as related to the initial prostate specific antigen: data from the prostate, lung, colorectal and ovarian cancer screening trial.
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.
Crawford
E David
ED
Department of Urologic Oncology, University of Colorado Health Sciences Center, Denver, Colorado, Washington, DC, USA. david.crawford@uchsc.edu
Pinsky
Paul F
PF
Chia
David
D
Kramer
Barnett S
BS
Fagerstrom
Richard M
RM
Andriole
Gerald
G
Reding
Douglas
D
Gelmann
Edward P
EP
Levin
David L
DL
Gohagan
John K
JK
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*
D017430:Prostate-Specific Antigen