Any association between rising PSA and falling T during BCR?

[shueswim]

To recap briefly - 65YO, G9 PCa, RP in '16 followed by RT/ADT. BCR in '18...detected in pelvic LNs via PSMA clinical trial. Then RT to that region and 18 months of ADT. No treatment since that ended June '20. Undetectable PSA from Jan '19 thru Oct '21. PSA creeping up from 0.03 in Oct '21 to 0.20 in March. Awaiting results from yesterday's test. BTW, my plan is to have a PMSA scan when the PSA hits 0.50.

We also test my T levels along with the PSA, and that result is in from yesterday. Post ADT my T had recovered from <10 to about 400 in 10 months and stayed there until the month at which my PSA became detectable. It then dropped to 200... and now the last two tests: 175 in March and 125 yesterday. Again...I've been off ADT for 2 years.

Just curious - is there relationship between rising PSA (and presumably increasing PCa) and naturally falling T levels? Just spitballing...does the PCa "consume" the T? Does the body down regulate T production in the face of the growing threat? Interestingly, when I was first Dx'd with PCa my T level dropped from my "normal range" (from prior annual exams) 500 to 145. At the time, it was more concerning than my modest rise in PSA. Of course that changes after the subsequent biopsies.

[Blueslover]

Good luck Gene. Both still fighting the Beast!

[Tall_Allen]

I've never heard that. What is your free T? Any changes in diet? Phytoestrogens?

[shueswim in reply to Tall_Allen]

Free T: Not sure...they've always ordered the total testosterone test. I'll discuss getting the free T test with MO at next visit.Diet: No changes...I'm pretty consistent with a good (not great diet).

Phytoestrogens: I'll admit to not knowing what that is. After a quick google search...I don't think my diet is particularly high in foods that cause issues.

[Tall_Allen in reply to shueswim]

Things like soy and flaxseed are phytoestrogens. They can depress T.

[Hidden in reply to Tall_Allen]

Can you point me to some good trials or data that shows that? I've spent hours looking and found some studies that show a reduction, some studies that show no effect, and some that show an increase. Thye were all rather weak studies though so I don't put much stock in any of them.

The CDC cited some old research that concluded phytoestrogens could reduce steroid biosynthesis (and also inhibition of angiogenesis). But then the CDC stated that studies have inconsistent and inconclusive results.

[Tall_Allen in reply to Hidden]

That soy and flax seed are phytoestrogens or that exogenous estrogen reduces testosterone output? Both are well established.

[Hidden in reply to Tall_Allen]

The reduction of testosterone studies or trials. Specific studies if you have them.

The devil is in the details. If it takes 1 lb of ground flaxseed a day to move testosterone down by 1% that of course isn't the same as if it takes 1 oz of ground flaxseed to move testosterone down 25%. The data source of course matters too. I haven't found any good clinical trials with a primary endpoint of testosterone reduction.

[Tall_Allen in reply to Hidden]

Estrogen was found to reduce testosterone in the PATCH/STAMPEDE RCT:

thelancet.com/journals/lanc...

[cancerfox]

You know, my regular general practioner doctor told me my testosterone was kind of low right about the time I started having problems getting up a lot at night to go to the bathroom, which is when I think I first started showng signs of prostate cancer. I was wondering the same thing as your spitballing.....was the cancer absorbing my testosterone at the time causing lower levels of it. My doc almost talked me into doing something to increase my testosterone at the time, which probably would have been the worst thing to do in retrospect. Anyway, just idle speculation. 🤔