PSA velocity
The PSA velocity (PSAV) is a statistically-derived measure of how the prostate specific antigen (PSA) changes over time, and has been used as a marker of how prostate malignancy progresses or regresses.
Any cancer grows over time and relative changes of tumor markers, such as PSA, would seem to be more informative than absolute measurements. However the use of PSA velocity is controversial and evidence is lacking for its effectiveness as an independent prognostic marker .
Calculation
Calculating PSA velocity, or similar measures of PSA kinetics, is fraught with difficulty and many different ways of calculating this parameter have been used. PSA velocity is measured in ng/mL/year .
A related parameter is the PSA doubling time, simply the time for the PSA level to double, usually expressed in the number of months.
History and etymology
The concept of calculating PSA kinetics was introduced in a paper by H Carter et al in 1992, although the term PSA velocity was introduced later .
See also
