A 20-year study has revealed that the rate of death from prostate cancer did not differ significantly between men who had been screened for the disease and men who had not.
In 1987, 1,494 men (aged 50 to 69 years) in the Swedish city of Norrköping were randomly selected to begin a prostate-cancer screening program, and the remaining 7,532 men became the control group. They were invited to be screened every third year from 1987 to 1996. The first two screenings employed digital rectal examination (DRE) only. In 1993, DRE was combined with prostate-specific antigen (PSA) testing, using 4 μg/L as the cutoff point. The fourth screening, held in 1996, included men aged 69 or younger only.
Prostate cancer developed in 5.7% of the screened group and in 3.9% of the control group by the end of 1999. Tumors were generally smaller and more often localized among the screened men than among the controls. But survival, tracked through the end of 2008, was not significantly longer for the screened cancer patients than for the unscreened cancer patients, nor was there a significant difference in overall survival between these two groups.
“The risk ratio for prostate-cancer-specific death did not indicate significant benefit from prostate-cancer screening,” the investigators wrote in their concluding statement (BMJ. 2011;342:d1539). “Although the population size in our study is not sufficient to draw definite conclusions, the power is sufficient to show major differences in prostate-cancer-specific survival.”