For people at average risk of developing prostate cancer, there is no randomized evidence showing a benefit to initiation of routine screening for prostate cancer before 45 years of age. The randomized trials that demonstrate a benefit for prostate cancer screening (Goteborg-138 and ERSPC21) began at ages 50 and 55 years, respectively. The earlier initiation of screening is supported by observational studies that have demonstrated a prognostic value of obtaining a baseline PSA in early midlife.39, 40 A review of eight PSA studies in younger people have shown baseline PSA measurements were robust predictors of aggressive prostate cancer, metastasis, and disease-specific mortality many years later. Baseline PSA was a stronger predictor of prostate cancer risk than race and family history of prostate cancer. Median PSA levels ranged from ~0.4 to 0.7 ng/mL in patients in their 40s and from ~0.7 to 1 ng/mL in patients in their 50s.39 The prevalence of prostate cancer is low among patients aged 40 to 45 years. The modeling studies comparing various start ages have shown that lowering the screening start age to 40 to 45 years instead of 50 to 55 years slightly increased the probability of lives saved, but substantially increased the number of PSA tests.33 In the Malmö Preventive Project, the risk of prostate cancer metastases by 15 years’ follow-up was low (0.6%) for patients with PSA in the highest percentile (≥ 1.3 ng/mL) at age 40 years of age. For patients aged 45 to 49 years with PSA below the median (0.68 ng/mL), the risk of prostate cancer metastasis within 25 years was 0.85%. Patients with PSA in the highest decile (≥ 1.6 ng/mL) at ages 45 to 49 years contributed to nearly half of prostate cancer deaths over the next 25 to 30 years.40 A randomized trial of risk-adapted screening for prostate cancer comparing patients starting at age 45 versus 50 years (the PROBASE trial) is currently ongoing, with 23,301 patients having participated in screening in the first round of the trial.41 The participation rate was low (20%), and 35% with indication for biopsy refused to undergo the procedure. The prevalence of screen-detected prostate cancer in 45-year-old patients was very low (0.2%), and only 4 patients were diagnosed with aggressive prostate cancer GG3 or higher. Thus, the use of SDM is highly recommended given the uncertainty involved.