Definition of Castration Resistant PCA

[roke]

Can someone tell me what defines mcrPC?

[6357axbz]

The cancer becomes resistant to hormone therapy and grows in spite of testosterone level being extremely low (castration level).

Initially PCa usually uses testosterone as it’s fuel. When hormone therapy (ADT) is introduced it reduces a patients testosterone level to nearly a non-existant or “castration level”. This slows down the cancer for a period of time until it learns to live off of some other bodily substance.

[VictoryPC in reply to 6357axbz]

Perfectly answered.

[tango65]

When there is progression of the cancer despite of castration levels of testosterone ( less than 50, other say less than 20). Some places require a PSA of 2 or higher.

The cancer can progress with very little exogenous testosterone. There are several mechanism, one of them (overexpression of the androgen receptor) makes the cancer very sensitive to the exogenous testosterone, that is the reason ADT should continue .

[pjoshea13]

You ask: "what defines mcrPC"? ... mCRPC (metastatic Castrate Resistant PCa)

CRPC used to be easily defined. For many, it meant Lupron, etc, had failed.

It used to be thought - before the term CRPC was coined - that ADT failure meant that PCa had become androgen-independent. In fact that is mostly not the case.

& when the term "ADT" was used, it meant specifically, deprivation of gonadal androgen - & that is how it continues to be used in many new papers. "Castrate Resistant" simply means the failure of a therapy that targeted gonad production.

A man may have CRPC yet respond to Zytiga, which targets androgen from all sources - including the gonads. And when he fails Zytiga, what is the term for that? How about CRPC+?

The problem with the term CRPC being used so restrictively, is that a patient may skip Lupron, say, & use Zytiga as primary monotherapy. The term CRPC then has no relevance.

I hope that is muddy enough.

-Patrick

[Metungboy in reply to pjoshea13]

Again when Zytiga fails him, not the other way around.

Enzalutamide however acts somewhat on the target cancer cell directly inhibiting the pathways that androgens act through.

In theory this should work better than abiraterone because it should inhibit the cancers "work around" to evade the need for androgens to grow.

Doesn't seem to though.

[depotdoug in reply to pjoshea13]

And I thought my cardiac Rhythm acronyms were tough to comprehend.

[Hidden]

I don't think there is any exact definition as far as PSA goes, but it's roughly 2 doublings after PSA of 2 or more.

[Rogersw]

Thanks everyone that cleared up a lot of questions in my head

[Union98]

My husband was declared castrate resistant by the MO in order to be prescribed Zytiga back in Dec 2017 when Zytiga was FDA approved for earlier treatment. At the time, the insurance would only cover the cost if he was considered castrate resistant. His PSA never got higher than 1.5 but it was creeping up from NADIR of >.01 after chemo. Since startubg Zytiga it's been >.06

[j-o-h-n]

It means resistance is futile.... so duck and cover.... (caution: don't hit you head on your desk)..

Good Luck, Good Health and Good Humor.

j-o-h-n Wednesday 11/06/2019 10:11 PM EST

[addicted2cycling in reply to j-o-h-n]

I'll take what's behind curtain 2 with ----

" bend over backwards and kiss you arse goodby " ;0)

[j-o-h-n in reply to addicted2cycling]

YEP, BOAKYAG method of suicide....

Good Luck, Good Health and Good Humor.

j-o-h-n Sunday 12/08/2019 6:22 PM EST

[depotdoug]

Why is it so hard for me to understand mcrPC? I’m trying to get convince my MO to help me understand that status in me. I think he doesn’t believe I’m castration resistant yet. Yes I’ll reread assimilate these 9 replies. Trying to keep this simple but tough.

[Hidden]

Yesterday someone said: “Castration resistance will occur at 18 months no matter what they tell you. ”

Is this correct??

[addicted2cycling in reply to Hidden]

Well, I had castration in April 2015 so if things go bad guess I can be 100% sure --- ;0)