psadt in miniscular levels of psa?

Do we know for a fact that psadt, determined by very low levels of psa will hold true to the 40 points of doubling, I read from a John T post, it takes to kill you. I mean isn't it possible that the fast doubling time could be from the cells that are killed off and the refractory ones are slower. I mean we make all these decisions using studies, statistics, forum advice, ad infinitum and at certain points they be come "Gospel " but only in certain instances, Usu ally to prove a point in a discussion or worse. Since my diagnosis, I,ve been told you have all the time you need, take it slow when determining treatment, this is tru even at higher gleasons. But with a recurrence hurry up get the srt as soon as possible , the sooner the better. Same with HT, do it be fore it metastasizes, so as to increase the time to metastazation. I realize that ther are studies that push us this way and that. Imo We are individually the captains of our fate, subject to the laws of physics, known laws and those laws not known now but they will be. It will be The Snuffy Meyers, and Milkins that will make these breakthru's. I was watching a movie called Soo, recently and one of the characters said with every ounce of hhis being that he will die when He is ready. Isn't this a worthy goal to say this and believe it. What else do we have to do or think. I glean what I can from this forum, doctors, my personal beliefs etc and then try to tie it all together to promote what I believe is right for me and my loved ones. Anyway down from the soapbox, the thread really deals with the firs sentence. If we think that we have no control over this disease except what others have given us, whats the point!!

The more you find out on PCa, the more you we see there are alot half way decent generalizations, but there are enough exclusions and exceptions to the rules...that you cannot define this easily. The rate of progression or change depends more on the genetic factors, ploidy types, variant types....that can even trump Gleason score values. Patients with identical Gleason scores and even volumes of PCa...can have very different results and longevity even, this is written about even in Paact Newsletter recently 'Molecular Pathology' by Dr. Doug Chinn...photos with stains shown along with the commentaries. His conclusion is the disease is more individualized than you might realize. There are many genetic factors that could have caused your PCa...they can now identify alot of them, not all of them yet....some of those Dr. Bonkhoff/Dr. Strum have targeted therapies upon treatments for certain genetic risks or issues and have started the paved road towards this new vista in conquering PCa and they were doing so years ago...ahead of the curve.

You can read his info on line at www.paactusa.org   go to pages 9-10-11 for the Chinn article. The whole newsletter is better than ever.  Dr. Bahn has a new guideline for doing Active Survelliance and it is very complete and you probably never knew all the parameters he would say is righteous for A.S.  (worth reading).

Logo- there are cases of PCa with no doubling times or small increases and yet could even have mets happening, some PCa's (rarer versions) may not give off much Psa to measure. This is why a wise onco-doc should monitor the patient, other marker tests can catch things the Psa alone can miss.

Post Edited (zufus) : 4/11/2011 5:30:30 AM (GMT-6)

logoslidat,

Doubling time calculated with only very small PSA test results will have a large margin of error and be unreliable.

While there is no universal standard for PSADT calculation, several "practical rules" have been published. These include:
* threshold values for initiating PSADT calculation, especially in cases of PSA relapse after RP; low values are unreliable and can vary the final calculation widely  (for example, the free online MSK PSADT tool LINK accepts only values above 0.1 ng/mL)
* use measurements taken at least 3-weeks apart, and/or at least 15% different than prior values
* use same lab & same assay

edit:  added LINK

Post Edited (Casey59) : 4/11/2011 8:31:13 AM (GMT-6)

Logo,

Don't know if you saw my post last week, but I have been watching my PSA slide from <..01 to .03. I went to one the nomogram authors at Cleveland Clinic. He didn't give rip about doubling time, bur how long after surgery I had stayed BCR free. According to him, .06 is his warning bell, so we will see in 3 months if I sound the gong or not.

He went to his nomogram and pointed out to me that .03 at 2 years gave me 65 % chance at a cure rate. So, I have put SRT on hold for another few months.

Goodlife

Reachout, actually Sloan kettering center considers .05 as recurrence, those are the guys with the nomagrams, which I'm sure use .05. So if you like those MSK nomagrams, and who doesn't, i guess you have to like there BCR #, I Don't. The American Cancer society uses 3 consecutive .2's as there trigger, I like that. But if the psa is rising it is rising, just not sure that we have to rush into anything, guess thats why I do the std psa, its also my surgeons choice, Not sure if hawaii has ultra, it must, its got every ting else. goodlife,couldn't that be "noise ", whatever that means . I seen the term all the time re. ultra tests

Roche Labs, the maker of the electochemicaluminesence PSA test also prints .05 on the hard copy of test report as abnormal.

My doctor from Cleveland Clinic was a developer of the MSK nomograms.

Goodlife

Longo,
The 40 doubling times is a rule of thumb for all cancers. The start point is a single cell and the end point is where the cancer affects the organs and shuts the body down.
PSAD is not useful in very low numbers, but in most cases does give a good approximation of how fast the cancer is growing. There are many exceptions, especially with varients that don't generate any psa.
JT

Have no idea what happened there!

Well, today I found out I'm at .05 and it's getting me depressed. I was at <.014 a year ago and had three other <.1 readings but now it looks like something is growing again.

logo, thanks for the clarification. So I don't have BCR yet, I have a derectable PSA. I think that's what my doctor said also. Still, as your doc said, it's a red flag I need to watch.