% Free PSA as predictor of advanced tumor 10 years later

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

RonL - 12 Feb 2006 14:12 GMT

In the following article:

http://tinyurl.com/dynrn

The following excerpt is found:

"Investigators at the Brady Urological Institute and the Baltimore
Longitudinal Study of Aging discovered that free PSA is predictive of the
aggressiveness of prostate cancers. Using frozen serum samples to measure
PSA and free PSA long before the diagnosis of cancer was made, it was found
that the percentage of free PSA (PSA in the blood not bound to proteins)
distinguished between aggressive (high grade) cancer and non-aggressive
cancer 10 years before the cancers were diagnosed. The percentage of free
PSA in the blood fell as the tumors progressed toward the date of diagnosis.
A percent free PSA of 15 or lower was predictive of the diagnosis of
aggressive prostate cancer 10 years later.
Dr. Epstein demonstrated in another study that a percent free PSA higher
than 15 was predictive of the presence of small volume disease in men with
PSA detected prostate cancer. And in a study from Washington University in
St. Louis, investigators found that a percent free PSA lower than 15 was
predictive of more extensive, higher grade disease at the time of radical
prostatectomy. So, three separate studies with very different designs have
concluded that percent free PSA is predictive of the biology of the tumor.
Based on these data, we are less enthusiastic about expectant management in
men who have a percentage of free PSA that is consistently less than 10-15.
"

My searching so far indicates that this statement is based on retrospective
analysis of frozen blood samples by Partin, Epstein et al on a relatively
small number of patients back in the late 90's. Does anyone have any more
recent info or references?

Many thanks, RonL

Reply to this Message

Alan Meyer - 13 Feb 2006 05:36 GMT

...

> Based on these data, we are less enthusiastic about expectant management in men who have
> a percentage of free PSA that is consistently less than 10-15.

...

Ron, how do you interpret that sentence?

Do you think they're saying that men with free PSA below 10, and maybe
below 15, are likely to fail treatment?

One obvious question it raises in my mind is whether it would benefit
men with very low free PSA to be treated early. For example, they might
have their prostates removed at the very first sign of cancer or,
conceivably, even before then.

The studies appear to show that free PSA is predictive of aggressive
cancer, but they don't seem to say whether it's predictive of cancer
at all. In other words, men who have cancer and have low free PSA
apparently have aggressive cancers. But do all men with low free
PSA values get cancer? If the answer is yes, then maybe prophylactic
treatment is desirable for them.

Alan

Reply to this Message

RonL - 13 Feb 2006 13:05 GMT

> ...
>> Based on these data, we are less enthusiastic about expectant management
[quoted text clipped - 20 lines]
>
> Alan

Alan, thanks for the response. The sentence you quote, indeed the entire
section I quoted, is in the context of a descriptive article about the
"expectant management" program at Hopkins - ie. their version of watchful
waiting. There are several criteria a patient needs to meet. Apparently,
one of them is a history of "high" free psa. (I meet all criteria except
that one.) So it's not clear, but it appears if you have a history of
"low"free psa, you are less likely to be acceptable to their expectant
management program. I was concerned that I may have more aggressive tumors
than my bG(3+3), one core, 20%, T1c, PSA 5.1 indicates, since I had free PSA
of 15% in 1999. I expressed this concern last night by e-mail to my
surgeon. His exact (and rapid!) response: "I would not put too much weight
on the % free PSA despite the paper you cited. It is used more to predict
the presence rather than the nature of cancer. It is not an independent
predictor of outcome after treatment."

That makes me feel better. Nevertheless, in another thread, I listed a
sequence of reasons why I favor RRP over other forms of treatment. My free
PSA history is another reason why I've committed to have the surgery soon
after diagnosis.

But yes, your premises and interpretation seem internally consistent. You'd
think that would have been a very important finding by the Hopkins group and
pursued as a possible new standard for treatment. The papers were published
in the late 90's - even referenced in the Strum book - but they don't seem
to have been pursued by other researchers, and, as you see, are not taken
seriously as a prognosticator of severity, by at least one reputable uro
surgeon.

I don't really know what to make of the Hopkins statement. (Which is why I
was asking if anyone here can.) Perhaps folks here in direct contact with
Epsten, Partin, et al, can add some enlightenment.

Regards, -RonL

Reply to this Message