So, Dr. Scholz. When it comes to hormone therapy, you know, a patient goes on hormone therapy—at
what time frame should they see a decline in the PSA and what would be considered a
good PSA if you're on hormone therapy?
So, we're talking about hormone therapy, usually, we mean something like Lupron or Firmagon
and the patients will have the PSA decline about 90% in the first month. It would be
a typical reaction, and then, ideally, the PSA will drop down to less than 0.1 within
five months. So, there's all kinds of variations and you can't really track it out as being
the same from patient to patient, but those are sort of the thresholds and the milestones
that I expect to see. About a 90% decline after a month and then to less than 0.1 or
undetectable levels within five months.
Getting the PSA undetectable on Lupron or Firmagon or one of the other agents is one
of the most powerful indicators for prognosis for prostate cancer—it's called PSA nadir—and
most men respond extremely well to hormone therapy. Their PSAs do become undetectable.
The patients that can't their PSAs to undetectable levels with Lupron have more serious types
of cancer and maybe even early hormone resistance. Thank God that's not common in newly diagnosed
men, but it certainly is an issue that needs to be addressed if the PSA is not going all
the way down within the first five months or so of initiating treatment.
Is there sort of—I've heard of PSA flares or PSA bumps or Lupron flares. Can you speak
to that?
So, Lupron, not Firmagon, causes a brief increase in testosterone a week or two after its initial
injection. Then the testosterone drops down to close to 0 and remains there as long as
you continue on Lupron shots. It's only for the first shot that you can have a rise in
testosterone for a week or so and then a decline. So this is how Firmagon was marketed, saying,
"well we don't with our product have any increase in testosterone" which is undesirable. We're
trying to get rid of testosterone, not increase it. You can argue that a week or two of increased
testosterone doesn't have a whole lot of negative impact, but the usual policy is to give some
Casodex for the first couple of weeks or a month to block the testosterone during that
time period. The issue becomes very important if someone is starting on Lupron who has very
advanced cancer in their bones because having a short increase in testosterone could be
disastrous in those patients. For men that have localized disease, it's probably not
that big of an issue, but it's, you know, good practice to give a little Casodex or
maybe for the first injection give some Firmagon and then if you don't like the monthly injections
(Firmagon can cause some problems with rashes on the tummy) you can switch over to Lupron
on subsequent injections.
So, the flare is not so much a PSA flare. It's a testosterone flare. If you were checking
the PSA every three or four days, you might be able to see a slight uptake during PSA
during that first week or two, but it's really a testosterone flare.
How often should a patient be checking their PSA when they're on hormone therapy?
We usually check them after a month or two and then every three months while they're
on treatment. If something dynamic is happening, then we would check them more frequently,
but the typical policy is about every three months.
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