Casodex causing an increase in PSA

[Scootman]

Has anyone heard of Casodex to cause an increase in PSA ?

[noahware]

Yes, but typically only after a significant enough period of time for some resistance/mutations to develop (a few years?), or after stopping its prolonged use and then restarting it again at a later date.

As for a sustained rise in PSA being CAUSED by Casodex, early on in a first-time use of Casodex as part of an initial therapy, I expect that would happen rarely if ever.

[Scootman in reply to noahware]

I had used Casodex last year after my initial diagnosis prior to radiation and then again after my PSA went up.

[Tall_Allen]

Casodex may become food for the androgen receptor. If that is the case, stopping casodex will cause PSA to go down. This is called "bicalutamide withdrawal syndrome" and is well known.

[Scootman in reply to Tall_Allen]

Is it known how long after stopping the Casodex it gets out of your system so it can stop feeding the cancer. Oncologist called me this morning and stated that I might have had a flare between the time of my Psa in March and starting the Xtandi which is a month now. Also was on the Casodex for a month in between. He stated the Xtandi may have not really kicked in yet. I hoping this is the case not wishful thinking.

[16starsky]

My Husband started on 50mgs of Caxodex in Dec (PSA 4.7)next PSA result 8 wks later 3.9, nest PSA 12 weeks later 4.5.OC has upped the dose to 150mgs, we see him in June, but to be honest I cant see it working now.

[pjoshea13]

Bicalutamide [Casodex] can switch from being an androgen receptor [AR] antagonist to AR agonist, but there is no timetable. Apalutamide does not switch, so you could consider that.

-Patrick

[MateoBeach in reply to pjoshea13]

That is very interesting Patrick. I was on bicalutamide with dutasteride for nearly 5 years without (as an option to) Lupron (or similar) ADT to which I did not tolerate. When my PSA began to rise I did stop it and PSA fell, so I had the "withdrawal effect" and can no longer use it. I am interested in this possibility of using apalutamide in its place as an ADT alternative rather than with it to see if I could get more mileage fro my HSMPC.

Do you have a link for a study showing that apalutamide does not switch to stimulating the androgen receptor? Thanks. -Paul

[pjoshea13 in reply to MateoBeach]

From 2018:

"Apalutamide (ARN-509) is an antiandrogen that binds selectively to androgen receptors (AR) and does not show antagonist-to-agonist switch like bicalutamide."

pubmed.ncbi.nlm.nih.gov/293...

"With increased knowledge of androgen receptor structure and its biological functions a new generation of antiandrogens without agonist activity was designed to provide more potent inhibition of the androgen receptor. Randomized clinical trials in patients with metastatic, castration resistant prostate cancer showed significant survival benefits, which led to the approval of enzalutamide in August 2012. Apalutamide was recently approved while darolutamide is not yet approved in the United States."

pubmed.ncbi.nlm.nih.gov/297...

-Patrick

[MateoBeach in reply to pjoshea13]

Perfect. Thank you.

[Magnus1964]

There is some research on casodex that shows after it fails, Pca can feed on it.

[j-o-h-n]

Not me...........

Good Luck, Good Health and Good Humor.

j-o-h-n Tuesday 05/12/2020 9:44 PM DST