However, the researchers said that inviting all men over 70 years old for PSA testing remained of ‘questionable’ merit.
Jonas Hugosson and colleagues from the University of Goteborg in Sweden followed 20,000 men over 14 years. Half of the men were invited for PSA testing every two years and half were not.
During the study, 1,138 men in the screening group were diagnosed with prostate cancer along with 718 men in the control group.
Screening reduced men’s cumulative risk of dying from prostate cancer from 0.9% to 0.5%.
Dr Hugosson and colleagues calculated that, to prevent one death from prostate cancer, 293 men would need to be screened and 12 to be diagnosed with prostate cancer.
These figures are lower than those suggested by previous studies. This may be because the men in this new trial were followed for a longer period than in previous studies, the researcher said.
Dr Hugosson and colleagues found that screening was well accepted, with 76% of men accepting invitations to screening.
Also, the benefits of prostate cancer screening, in terms of mortality reduction and numbers needed to screen, compare favourably to those for breast and colon cancer screening, they said.
But the researchers point out that the risk of overdiagnosis of prostate cancer following PSA screening is substantial, though this may be reduced if screening is restricted to men aged over 65 years.
‘As the risk of over-diagnosis and over-treatment are still the major concerns in prostate-cancer screening, inviting men over the age of 70 for PSA screening seems questionable,’ they said.
They concluded: ‘PSA screening is associated with a long and varying lead time, resulting in a risk of over-diagnosis that is substantial but still of a largely unknown magnitude.’