KLK3 and prostate cancer: Conversely, the European Randomized Screening for Prostate Cancer trial demonstrated a benefit in PCSM associated with PSA screening but also warned of a significant risk of overdiagnosis.18 Initial results after a median follow-up of 9 years found that the number needed to screen was 1410 and the number needed to treat was 48 to prevent 1 prostate cancer death.