PSA numbers and what they really mean.

Can someone explain in layman terms the difference, if any between PSA doubling time and PSA velocity? Thank you.

[Bryan_Metcalf_UK]

Doubling time is just another way of expressing velocity.

[cbc-ppml]

Doubling time is an expression of the time it takes for the PSA to double (e.g. “ 8 months”). Velocity is an expression of the amount the PSA increases over a given period of time (e.g. “0.1 ng/dL per year”).

Doubling time may be a more useful measure for PSA that increases at a relatively rapid rate, while velocity may be more useful for PSA that increases very gradually.