Decision Matrix Conundrum

[MateoBeach]

So I completed IMRT to my left hemi-pelvis with boost to 2 nodes there that lit up on Ga-PSMA scan last October. Used adjuvant ADT with degarelix plus estradiol patches. Approximately 5-6 months until T levels recovered. Post RT my PSA fell by about half (.25 to .15 and staying there for 3 months now). I do not know if this is a true nadir, or if the currently slow-growing cancer is hanging fire and may drop lower over a year or two as treated cancer cell divisions take place?

I stopped the ADT on advice of doctor at Australia Theranostics who is offering me 177-Lu-PSMA-I&T treatment(s) in Sydney also combined with idronoxil (Veyonda) to trigger abscopal response. This is being provided under "compassionate use" outside of the LuPIN clinical trial(s) because I am technically still HSMPCa. Because of this I would be more likely to increase PSMA expression while off ADT. So I have been holding off resuming ADT in the hopes of soon being able to travel to Sydney for the first treatment cycle.

This is complicated by two factors: Travel to Australia is currently closed to me as a non-citizen. However, if my PSA were to resume rising rapidly (PSADT<6 mo) then I could get medical exception to travel to Australia. So this would favor staying off ADT for awhile longer to see if it rises.

On the other side of the equation is the apparent relative protection afforded by ADT from COVID-19 infection from TMPRSS2 down-regulation. Not sure exactly the best course right now. I have recheck on PSA and T levels in 2 weeks.

Also, I have qualified for the free F18-DCFPyL PET scan (a PSMA scan) for veterans at the VA in West Los Angeles on June 2nd. (Thanks for that lead Tall_Allen).

My other question is whether using estradiol (alone or with other ADT such as degarelix) would afford the same benefit via TMPRSS2 in men with PC, as women have increased rather than decreased TMPRSS2 from testosterone suppression apparently. It gets curiouser and curiouser.

[Hidden]

Wow Mateo ! Adt now or no adt now? Thanks think the good news is that low PSA for now .I wound sick that you’d have to let your PSA rise in order to go to treatments... that doesn’t sound like the right avenue . I pray that things go you way and you get what you need when you need it .. Enjoy the season 😎🌵

[Tall_Allen]

If you're going to be traveling, consider ADT instead of estrogen monotherapy. (High levels of estrogen reduce immune function.) For about a month after restarting ADT, your PSMA expression may increase.

[noahware]

I saw this:

"Increasing estrogen also may reduce TMPRSS2 levels, but because some studies in cultured cells show that increasing estrogen causes TMPRSS2 levels to briefly spike before levels ultimately decline, the possibility that estrogen could be associated with a transient increase in expression of TMPRSS2 suggested to us that, at least in men, reducing testosterone would be the better therapeutic option,"

PS - Love the title of your post.

[MateoBeach in reply to noahware]

Thank you. That is helpful perspective.