KLK3 and neoplasm: Although no consensus is available regarding this, most reports refer to tumors with Gleason scores ≥7, adverse pathological patterns (such as cribriform), and increased tumor size (>0.5 cm3) to be at risk for progression.26 The traditional cut-off for an abnormal PSA level in the major screening studies has been 4.0 ng/mL.27–30 Screening studies best characterize PSA cut-off levels based on the proportion of men with an elevated PSA who eventually are diagnosed with cancer (positive predictive value, PPV).