KLK3 and cancer: Multivariate analysis revealed that “ISUP grade group at SM ≥ 5” (HR 3.37, 95% CI 1.48–7.68), “Maximum length of cancer at SM ≥ 4 mm” (HR 2.59, 95% CI 1.27–5.32), and nadir-PSA ≥ 0.03 (HR 8.66, 95% CI 4.66–16.1) remained significant factors that predicted BCF.