Hi, my dad is taking Casodex and if it doesn't work with him, he has to move to Zytiga. Do you know if there is any cross-resistance between Casodex and Zytiga? I read from this forum and understand that Zytiga and Xtandi are cross-resistant and Casodex and Xtandi are both Lutamide. Therefore, I am a little bit concern. Do you see Zytiga is quite effective for a long time when you have taken Casodex right before Zytiga?
Thank you for your sharing in advance.
Dawn
Before you plan your fathers migration to Zytiga you might want to read the following. It took 3 months but it was effective for me nearly 30 months....pubmed.ncbi.nlm.nih.gov/753...
I couldn't quite translate that. What specifically did you do?
In tissue culture resistance to bicalutamide may be related to the AR-V7 which is also associated with resistance to enzalutamide and to zytiga. I do not know if the same could happen in vivo.
Casodex and zytiga work in different ways. There should not be any problems. I took casodex for 5 years. Then after a few years took zytiga.
Same here. Took Casodex for over a year until it stopped working (or maybe it never worked), had metastasis to my spine, then radiation. Been on Xytiga/Prednisone for maybe 2 years with Xgeva shots monthly and so far PSA is <0.003. Only problem so far is weight gain.
What type of PSA test are you having and where do you get it that reports down to <0.003?
At several different institutions I get < 0.1. Or <0.064
Then I can get <0.014 with Labcorp ultrasensitive. But that is as sensitive a test as I've found.
Sorry, I'm not really knowledgeable about all these. All I know is what was reported on my test result, which stated PSA (ECLIA) result <0.003 ng/ml with a comment 'value obtained is below machine detection limit of 0.003 ng/ml. Specimen rechecked, result verified.'
Good luck for many more years on Zytiga.
Thanks. To us both and the many other brothers on this fight.
You never took Lupron?
I had the orchiectomy so lupron was not an option.
I knew that was an option, but no doc ever mentioned that as an option.
Back when I had my orchiectomy there were no other options.
Did you take Casodex alone (monotherapy) for 5 years or in combination with ADT.
Casodex alone. I had the orchiectomy so Lupon was not needed.
Casodex and Xtandi are both anti-androgens, but that's where the resemblance ends. Casodex is like a pea shooter; Xtandi is like a .44 magnum. Casodex not only creates resistance, it actually eventually may feed the cancer. No one prescribes Casodex anymore, except to prevent T flare at the start of Lucrin therapy. . Zytiga, like Xtandi, is much more powerful. Hopefully, it will overcome any resistance.
I am curious about your comments on Casodex (creates resistance, may feed the cancer). My oncologist has just started me on it. I have been on Zoladex for over 2.5 years with my PSA below 0.5 for that time (103.0 at diagnosis). During the last 4 months my PSA has been steadily increasing. This week it hit 1.0. My oncologist said adding bicalutamide may bring the PSA back down but likely only for a few months. We both think I will end up on abiraterone if the PSA keeps rising. I had docetaxel after diagnosis.
I think you have answered your own question. Chances are the cancer will begin to feed off the Casodex after a while. You will then need to stop the Casodex.Best wishes.
So why waste time with Casodex?
I'm assuming that the oncologist thinks it will buy me a few more months of cancer suppression before we move on to the next treatment. You have much more knowledge of this than I do. Are there studies I can reference if I talk to the oncologist about skipping this step?
It's not a "step" within the standard of care. He can look up the NCCN guidelines, the AUA guidelines, or the ASCO guidelines.
Hi What is a reference study for Casodex feeding cancer? After what length of time does it do it and at what dosage? I read on this site that there are a few people on it for several years and seem to be doing alright.
It's called "bicalutamide withdrawal syndrome" - known for decades- look it up.
Thank you. I have only had to look at these concepts since my husband's diagnosis in August 2020. Here is a link to one of the articles I read for anyone else like me who has not come across this concept. erc.bioscientifica.com/view...
Although the urologist has prescribed Casodex, it has worked well so far with ADT to deal with the early T flare, and we do not need to worry (at least yet) about it feeding the cancer.
With IDC-P, you should consider a heavier hitter than bicalutamide.
Thanks. We are waiting to see a specialist to talk about options.
Scandavian study found benefits to Casodex.
Not relative to more powerful antiandrogens. For example:
Is he taking Lucrin as well? Zytiga will be more effective than Casodex. If you can afford it, I would not try Casodex now but start with Zytiga right away. The reason for that is not a possible cross-resistance but simply to take the more effective drug.
PCa drugs that target the androgen receptor [AR] axis become resistant in time. There is overlap in how these drugs commonly become resistant.
When Zytiga & Xtandi came on the scene, they were super-efficient at what they do (Zytiga targets all androgen production & Xtandi the AR itself), so much so that there is no benefit in combining them. However, when you build a better mousetrap, you select for smarter mice. The treatment-emergent adaptations for Zytiga & Xtandi have great overlap (which reduces the chance that one would be effective after the other has failed). However, some of these common survival mechanisms were not really encountered before.
So, to answer your question, I would not expext cross-resistance between Casodex & Zytiga.
-Patrick
Casodex may be an older drug but I would not dismiss it. If you can get a few years out of it then move on to the newer stronger Zytiga and then Xtandi for more years, why not.
I did casodex and Lupron together for 6 months, then just Lupron....psa has been good since then.i also did 38 radiation treatments
I was diagnosed stage 4, with bone metastases in 1918. I went on Cadodex for 1 month then Lupron and Zytiga. Today I am PSA .01 or undetectable. This is STOC and I am looking forward to several more years of controlled treatment. I am 82.
Great report. Hang in there
1918?
Good Luck, Good Health and Good Humor.
j-o-h-n Sunday 02/07/2021 11:47 PM EST
😁 2018, I was just testing you J-o-h-n to make sure you are still cognitive.🍸🍸🤠
I missed it completely my wife caught it.......... I am still NONcognitive, UNcognitive, MIScognitive and Shitfaced.....
Good Luck, Good Health and Good Humor.
j-o-h-n Monday 02/08/2021 1:33 PM
You are so much fun, I once said you are this sites (class) clown. Still so!🍸🍸🤠
I'm worried cause I heard that cannibals call clowns "A Happy Meal".🍸🍸🤠
Good Luck, Good Health and Good Humor.
j-o-h-n Friday 02/19/2021 6:16 PM
The protocol here is to add Casodex to ADT when it fails. I began ADT in 2010, but had 2 pauses of a few months to see if was doing anything, and Testosterone went up, Psa went up, so I went back to ADT and have not been off it now since 2015. But i 2016, when ADT failed, I started Cosadex and got 6 months before it stopped working. I waited a month and started Zytiga, next on listed protocol Psa went down, then up after 8 months, so I waited a month and began Docetaxel, next on protocol list, but after 3 months Psa went up 4 times. I quit that, waited a month, Psa halved to 25. Then I began Lu177, and this was the first therapy to actually kill a lot of Pca cells, and it was not normal oncologist protocol.
All the time from 2016 to 2018 while I had a number of PsMa scans, the tumors and their size increased.
Lu177 did all it could do with 6 doses, then no soft mets could be seen, only bone mets, so I am now booked for Ra223. The old way was to soldier on with 10 doses of chemo, and by then a man is so wrecked he may not have anything else, and chemo does not have high chance of providing a fix for Pca. Some might get remission by this stage in their treatment. But I don't read of many here getting a fix; they get to their end, and there's no point writing to us.
On the other hand, although Lu177 did not fix all my bone mets, it looks like Ra22 might work, and I am both healthy and cheerful, and a doc thinks Ra223 could work well, and I know how it works, and sure, there will be side effects, but most are temporary and if I get rid of my bone mets, then possibly I get a long term fix. Hoo Noze ? I don't know unless I try.
Patrick Turner.
Casodex 
If casodex switches to feeding PCA
Monotherapy to gain extra survival.
Xtandi and Zytiga Given Together
Re-sensitizing Zytiga and Xtandi
