In prior analyses, in addition to finding reductions in incidence (likely associated with decreased PSA screening), researchers were able to identify how changes in the incidence of prostate cancer after guideline recommendation changes differed by age, between African American and White individuals,6,7,8,10 and by ethnic group.8 Using join point regression, we were able to identify differences by race and ethnicity in when age-adjusted rates of prostate cancer started to decrease relative to guideline publication. This evidence concerns the gene KLK3 and prostate carcinoma.