KLK3 and pure red-cell aplasia: These updated classifications of aggressive PrCa may consider varying combinations of Gleason score (typically one of Gleason score ≥7, Gleason score ≥8 or Gleason grade group ≥3), T stage (generally either T4 or ≥T3), nodal invasion, metastatic spread, extreme PSA measurements, young age at diagnosis (generally defined as diagnosis at age < or ≤55 years, with ages 60 or 65 also frequently used as cut-offs), and death from PrCa.