Is it possible for the drug Casodex(50 mg/daily)  to lower  PSA from
1500 to 750 in 3 days( as lab results say it did) or is this a lab
error

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Request for Question Clarification by pafalafa-ga on 21 Nov 2005 04:50 PST

I've had a look at a number of the review studies on casodex.  I
didn't see anything that said such a a lowering of PSA was
impossibile, but nor did I see anything that said it's a likely
outcome.  It certainly seems that such a rapid and dramatic change
would have been noted in the literature on the drug, if it had been
observed during medical research.

What has the patient's doctor had to say about the PSA test results? 
If there's more information or context you can provide here, it may
help in researching this further.

Thanks,

pafalafa-ga

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Clarification of Question by elizabethfaiella-ga on 21 Nov 2005 05:29 PST

Thank you so much for your help. The lab tests show this result. One 
doctor says this is possible though unusual, another says it is
impossible and a lab error.. It is critical to find something either
way in the literature.. but I have struck out,,,Does this help or do
you need more info? Elizabeth

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Request for Question Clarification by pafalafa-ga on 21 Nov 2005 08:07 PST

Elizabeth,

Thanks for your reply.

It does help, but I'm not sure if we can find what you need.  I just
have not seen anything in the literature to confirm or refute the
possibility of such a quick and large change in PSA.

Perhaps it would help to understand your need for the information. 
You wrote that "...It is critical to find something either way in the
literature..".

Why?  What makes this so important?  I'm not asking to pry, but
perhaps knowing the reason may suggest an alternative way to approach
the question.

Thanks,

paf

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Clarification of Question by elizabethfaiella-ga on 21 Nov 2005 08:35 PST

Certainly.I represent the widow of a man who died of prostate cancer 
which was not diagnosed for 18 months despite a rising PSA, urinary
sympoms, wnd finally weight loss and bone pain. His oncologist told
him that he could have saved him if he had been able to start
treatment a year earlier., particularly because the tumor was hormone
sensitive. As proof thereof, he points to the  dramatic drop in PSA
immediatley after Casodex was started. The defense has retained an
expert who says that the delay made no difference, that the tumor was 
 hormone resistant, an that such a dramatice drop in PSA is unheard
of, ( as the half life of PSA is 5-7 days)and should be discounted as
a lab error. No other PSA's were done  during the last two months of
his life, and there are no  other ways to prove whether the tumor was
resistant to treatment, so I neede to see if there was any medical
literature on point.. Does this help?  Elizabeth

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Request for Question Clarification by pafalafa-ga on 21 Nov 2005 10:54 PST

Thanks...that's a big help.

This paper may get you half way there, at least:


http://www.jurology.com/pt/re/juro/fulltext.00005392-199710000-00035.htm;jsessionid=DCUvhs1kcSQGHI2tg9E9bzgPD4nSi1NXia5pXZy4P4MpIJyhFP8u!-181702980!-949856144!9001!-1
SERIAL TISSUE POLYPEPTIDE SPECIFIC ANTIGEN DETERMINATIONS IN THE
FOLLOWUP OF HORMONE TREATED CARCINOMA OF THE PROSTATE



It tracks changes in PSA as well as a sort-of surrogate measure, TPS,
in patients receiving Casodex.

Search the text for the word [ sharp ], and you'll find several
mentions of sharp drops in either PSA or TPS levels.  The fastest drop
document occurs in the space of two weeks (for TPS).  However:

--that certainly suggests that drug-induced changes in the course of
days are plausible

--the absence of a faster drop is most likely the simple absence of
any testing prior to two weeks

--the drops observed span orders of magnitude, which again is strongly
suggestive that a 'mere' drop of 50% in a few days is within the range
of reason.


The overall sense I get from going over the literature is that PSA
levels generally aren't monitored just days after initiation of
treatment...the first post-treatment monitoring seems to typically
occur a month after treatment begins.

If that's the case (and I'm not a medicial professional, mind you!),
then it certainly seems irresponsible for anyone to say that such a
drop is unreasonable, since there are no published observations on
which to base such a statement.

Let me know if this is helpful at all...and good luck!


pafalafa-ga

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Clarification of Question by elizabethfaiella-ga on 21 Nov 2005 12:31 PST

This helps so much.... You are great. This gives me a starting point 
at least.Is there something I have to do to make sure you are paid?  I
have never used this  format before.. Also

 May I ask for  your help again? Elizabeth Faiella

Elizabeth,

Thanks for your reply, and I'm very happy to hear that the paper I
found got you off to a good start.

There isn't anything you need do at this point...with my posting a
formal answer here, your account will be automatically charged.


Since you're fairly new to the process, let me mention a few things:

--This particular Q&A is open for as long as you'd like it to be.  If
there's anything else you need, just post a Request for Clarification,
and I'll do my best to help you out.

--I spent a good deal of time looking for this study as well:

Liebertz Casodex, Kelly WK, Theodoulou M, et. al. 
High dose Casodex for prostate cancer(PC): PSA declines in
patients(PTS) with Flutamide withdrawal responses.
Proc Am Soc Clin Oncol 14:232, 1995.

I couldn't find it online, or in any of the databases I have available
to me, but it seems worth hunting down, just the same.


--You are certainly welcome to direct future questions to my
attention.  Just include something like "Attn: pafalafa-ga" in both
the Subject of the question, as well as the Question itself.

Be aware, though, that if I'm out of commission for any reason (busy,
sick, vacation, etc) your question may languish for a while.


Again, don't hesitate to let me know if there's anything else I can do for you.


paf


search strategy -- searched Google and several medical databases for:

casodex psa

casodex psa "sharp drop"

thank you so much    elizabeth faiella

Thank you too, Elizabeth.


paf