Reply to Kathryn L. Penney, Massimo Loda, and Meir J. Stampfer's Letter to the Editor re: Melissa Assel, Anders Dahlin, David Ulmert, et al. Association Between Lead Time and Prostate Cancer Grade: Evidence of Grade Progression from Long-term Follow-up of Large Population-based Cohorts Not Subject to Prostate-specific Antigen Screening. Eur Urol 2018;73:961-7.