KLK3 and metastatic neoplasm: Similarly, no significant difference in time to PSA progression was observed between men with a PSA doubling time ≤ 10 months versus > 10 months, men aged < 75 years versus ≥ 75 years, and men with a Gleason score < 8 versus ≥ 8 in our study, consistent with findings that shorter PSA doubling time (≤ 6 months), older age (≥ 65 years), and higher Gleason score (≥ 8) were not significant predictors of metastatic disease for patients enrolled in SPARTAN [17].