KLK3 and benign prostatic hyperplasia: This result is thought to be the effect of a lead time bias, as described by Link et al. [7] Benign prostatic hyperplasia (BPH) can lead to an increased PSA level, so patients with BPH are more likely to be diagnosed at a relatively early stage; in addition, prostate biopsy is performed more often in patients with BPH than in those without BPH [18].