Swedish Trial Finds Prostate-Cancer Screening Saves Lives

But the 20,000-man study, published online by The Lancet Oncology, found that for every prostate-cancer death prevented, 293 men were invited to participate in the screening program and 12 were diagnosed with the disease. That circles back to the conundrum surrounding PSA tests — given that there’s no clear way to determine which cancers are dangerous and which are not, many men likely receive unnecessary treatment, complete with unpleasant side effects such as impotence and incontinence.