KLK3 and prostate cancer: Moreover, the high variability in reported effect sizes of BCR suggests that only certain patient subgroups with BCR might be at an increased risk of mortality.2 In a recent systematic review of the literature, Van den Broeck et al3 found that higher International Society of Urological Pathology (ISUP) Gleason Grade Group (GG), shorter time from treatment to recurrence, and shorter PSA doubling time (PSA-DT) are associated with prostate cancer–specific mortality (PCSM) in patients with BCR.