KLK3 and prostate cancer: In addition, the BRFSS does not distinguish explicitly between PSA tests used for screening or monitoring of known prostate diseases.28 To account for this, we excluded patients with a known prostate cancer diagnosis; however, the patients who were diagnosed with prostate cancer after a routine PSA screen may have been excluded and, as there is no time component, it was not possible to determine whether the PSA screen preceded and/or initiated a prostate cancer diagnosis.