PSA doubling time (PSAdt)

'PSA kinetics'

• PSA velocity (PSAv) refers to the absolute rate of PSA change over time
  
  
  • evidence has indicated that PSA may need to take into account both age and individual PSA value to optimise interpretation
  • in clinical practice, a minimum of three values is required over at least 18 months for a meaningful assessment
  • may offer prognostic information as to how an individual prostate cancer may behave after diagnosis with a rise in over 2 ng/ml in the year prior to diagnosis predicting a more aggressive disease course or higher post-therapy relapse rate (D'Amico et al. 2005)
    
    
• PSA doubling time (PSAdt)
  • refers to the time taken for a serum PSA value to double and is also emerging as useful pre-treatment marker of a prostate tumour's biological potential (Klotz 2005)
  • calculated PSAdt of less than 3 years may indicate a more aggressive tumour course

References

• D'Amico AV, Renshaaw AA, Sussman B, Chen MH. Pre-treatment PSA velocity and the risk of death from prostate cancer following external beam radiotherapy. N Eng J Med 2005; 294: 440-7
• Klotz L.Active surveillance with selective delayed intervention using PSA doubling time for good risk prostate cancer. Eur Urol 2005; 47: 16-21
• NICE (May 2019). Prostate cancer: diagnosis and management