Long-Term Outcome of a Single Intervention Population Based Prostate Cancer Screening Study.

Abstract

We evaluated the long-term effect of screening for prostate cancer. In 1988 we randomly selected 2,400 men from a background population of 27,464 men. The 2,400 men were invited to undergo screening, of whom 1,779 (74%) accepted and were examined with digital rectal examination, ultrasound and prostate specific antigen measurement. Biopsy was performed if there were suspicious findings on ultrasound or digital rectal examination, or prostate specific antigen was greater than 10 ng/ml. The subpopulations have now been reassessed after 20 years. Participants had a decreased overall mortality rate compared to the source population (IRR 0.93, 95% CI 0.86-0.98). Nonparticipants had an increased overall mortality rate (IRR 1.25, 95% CI 1.14-1.37). There was no difference between the groups in prostate cancer specific survival. The incidence of prostate cancer remained higher in the screened population throughout followup. A single screening intervention in men 50 to 75 years old using prostate specific antigen, digital rectal examination and transrectal ultrasound, and a prostate specific antigen cutoff of 10 ng/ml for biopsy carried a significant risk of prostate cancer detection without a concomitant reduction in prostate cancer specific mortality after 20 years. This intervention should not be considered for public screening. Nonparticipants were at greater risk for death of all causes. In addition to being a single intervention trial, the limitations of this study include an outdated prostate specific antigen cutoff for biopsy. Despite the outdated screening method the source population failed to reach the same level of prostate cancer incidence as the screened population even after 20 years.