Ok, "once more unto the breach"! (Did you know that's actually Shakespeare? Henry V.).
Last night (3/28/17), speaking with Rick Davis over at US TOO, he suggested this approach with sort of a napkin sketch of the idea. It's a rather interesting way to look at the PSA trends following radiation therapy with neoadjuvant hormone therapy for varying periods. I think it provides hope.
Check out this graph.There is a foundation of a hypothetical radiation-only trend, not far off possibly from my actual situation. The "bounce" around 18 months is sheer conjecture, but that is a known phenomenon and could have happened. However, being on ADT masks that whole trend; no information is available.
So, let's say one is on ADT for 36 months until it "expires". Beginning shortly thereafter, the PSA would begin rising as testosterone rises. Even at this modeled 3 month doubling rate, it would take a year to reach what is the actual post-radiation nadir, assumed as 0.9 ng/ml in this case. So, during that year one could be increasingly concerned at this apparent recurrence. However, it could cap off quite suddenly once it hits the true nadir value.
You can see the same thing for 24 months, and 18 months, with 18 months even more alarming due to the level it could reach before trending down again. It would follow the radiation-only contour at that point, and eventually decline to the same nadir of 0.9.
So, this helps me to much more calmly wait for my next PSA check. This is entirely possible, and would match my available information. There is no study that Rick was aware of on such a thing, and he's talked to medical professionals about
doing something like this. It seems no one has.
It would be unfortunate to launch into salvage therapy (like more ADT) prematurely and unnecessarily, which one could do if the PSA follows this pattern and one didn't wait long enough to find out.
So, can benign, irradiated prostate tissue respond in this exponential-rise, log slope fashion to the restoration of testosterone in one's system? My roughly 30g prostate, with maybe 1/3 of it as tumor tissue destroyed by radiation, still has viable tissue and still makes PSA at some rate. (It doesn't make much of what else it used to make, so a greatly reduced PSA production seems plausible.)
Would it all switch on suddenly upon testosterone being available? Or, would it slowly rise on a log slope, mimicking the exponential rise a recurrence would also show? At what rate? Three months? More?
I guess the only way I'll know is watching the next couple of PSA checks. If they flat-line, then we'll know it's actually controlled by the initial curative therapy. If the numbers keep rising, well then we'll know that's recurrence. Hence the importance of waiting until a value such as nadir+2 before doing anything else, as a bunch of smart doctors already concluded.
Anyway, for anyone worried about
what's going on during this ambiguous year of rising PSA following RT+ADT, I'd say be patient and hopeful. It may very well be just fine!