PSADT!

PSADT reflects the aggressiveness of the cancer. It takes about 42 doublings for any cancer to go from cell creation to death. For a patient with a PSADT of 3 years, which is common for most low risk cancers, it would take 126 years to cause death. This is the reason that death is rare for low risk patients. PDATD, or growth rate, as well as Gleason grade is programmed into the DNA of the cancer cells and rarely changes during ones lifetime.
Higher grade or more aggressive cancers are also much more likely to already have escaped the prostate at treatment time and take a higher dose of radiation to kill than lower risk cancers. A true G6 is not capable of living outside the prostate or metastasizing. Only higher grades with a higher PSADT metastasize.

My PSADT was pretty consistent at 3 years. I missed typed PDATD it should have been PSADT so it's no wonder you never heard of it. According to Dr Strum he said he had never seen a case of a PSADT of less than 12 years not eventually be Dxed for PC. Dr Klotz uses a PSADT of 3 years or less as the cutoff for Active Surveillance. A fast doubling time of less than 3 years should be a concern as it indicates an aggressive cancer.

Thank you both for your advice and information. When entering psa readings into an on line PSAdt calculator, how many readings are necessary for accurate output?

I ask this because some calcs will only allow two, which I assume to be my last two, while others (kittering Sloan) allow more.

This represents an important distinction in my case of another year, plus!

I disagree that psa derivatives and kinetics are useless in pre treated men.

http://prostate-cancer.org/what-every-doctor-who-treats-male-patients-should-know/

The article by Dr Strum explains how to use various psa derivatives and kinetics in Dxing PC and eliminating other cause of high psa.
The use of any one psa kinetic is not reliable, but the use of them all together over time will give a pretty good picture of what is happening.

There is a mathematical relationship between Gleason grade and tumor volume expressed in psa. There are tumor volume calculators that can estimate the size of your tumor using psa, Gleason grade and core samples. This is valuable information in determining a treatment and oncologists like Strum and Scholz use these calculators as a part of initial staging.

The problem is that most doctors don't know how to use these tools and when they do they only use one or two of them. Taken together over a period of 3 psa tests 3 or 6 moths apart an experienced doctor can learn a lot. Psa density, psa doubling time, free psa and psa velocity along with tumor volume calculators are valuable tools. They even give a better picture when benign psa due to prostate size is subtracted and the psa being measured is then directly related to the tumor volume and the tumor growth rate.
This is the "art" part of being a good MD (medical detective).

Post Edited (John T) : 6/20/2014 1:09:39 PM (GMT-6)

PDA density is still used as a cut off for AS eligibility.

PSA Density is a very important measure, but not PSA kinetics.