Because the definite Gleason grade obtained from the prostatectomy specimen is more precise than the Gleason grade from the pre-surgical biopsy (which is prone to sampling errors and consequent under-grading in more than one-third of cases [29]), we added a fourth scenario, in which the preoperative Gleason grade obtained on the original biopsy was combined with preoperative PSA and clinical (cT) tumor stage. Here, KLK3 is linked to neoplasm.