KLK3 and cancer: Among men entering the screening group of the PLCO Cancer Screening Trial at age 55 to 60 years, the risk of being diagnosed with a clinically significant PCa during a median of 11.7 years of follow-up (and an actuarial follow-up of 13 years) differed significantly among those in different baseline PSA level groups and was lowest among men with a baseline PSA level of 0.49 ng/mL or lower.