Screening reduces risk of prostate cancer

Older men who undergo prostate specific antigen (PSA) tests are less likely to have prostate cancer that has spread to other sites in the body. Researchers from the University of British Columbia, Vancouver, Canada found that there was a 35 percent reduction in risk among those who were screened. There was a reduction in risk for both men under 60 years of age and those 60 years or greater, although the effect appears to be stronger in younger men. The investigators conducted a population-based study involving 236 cases of metastatic prostate cancer - i.e., cancer that had spread beyond the prostate. They were compared with 462 similar men drawn from the metropolitan Toronto area who did not have metastatic prostate cancer, although they could have localised prostate cancer. Based on the medical records, the rate of PSA screening was significantly lower in men with advanced prostate cancer than in the comparison group. In those between 45 and 59 years of age, screening reduced the odds of having metastatic cancer by 48 percent, and in men between 60 and 84 years old, by 33 percent. It was found that the value of PSA screening is debated, because it hasn't been shown to reduce mortality rates from prostate cancer. This study contributes to this debate in an important way because it offers new evidence that screening with PSA can reduce the risk of death from prostate cancer. The evidence is indirect as the outcome was metastatic cancer rather than death.