In reply
We are very happy that for Dr Casner the diagnosis and treatment of prostate cancer resulted in no adverse effects. However, the probability that screening with prostate-specific antigen (PSA) saved his life is highly unlikely. We present a few numbers taken mostly from the most optimistic randomized controlled trial of prostate cancer screening, the European Randomized Study of Screening for Prostate Cancer,1 which evaluated PSA screening among 182 000 men aged 55 to 74 years. The study demonstrated a reduced risk of dying of prostate cancer among men screened with PSA, but a much higher rate of diagnosis and treatment of prostate cancer—and treatment results in significant adverse effects in 20% to 30% of those treated. Other large randomized trials, including those done in the United States, showed no reduction in death from prostate cancer associated with PSA screening.