KLK3 and prostate carcinoma: This study shows that there is no prostate cancer–related mortality benefit of organized annual screening compared with opportunistic screening.2 By contrast, the European Randomized Study of Screening for Prostate Cancer involved 182,000 men aged 50 to 74 years randomized to the screening arm and offered PSA testing, on average, every 4 years, or to the control arm with no intervention offered.