Confusing PSA results: Is it possible side effects could inflate PSA?

Unfortunately, you are one of those people with a 3+4 that has an aggressive cancer of some sort. Because you didn’t have a prostatectomy, you don’t really know what the true nature of your case is. There might’ve been a higher Gleason somewhere in your prostate Or you might’ve had one of the aggressive things that aren’t always caught in a biopsy.

The side effects you mentioned would not increase your PSA, That’s due to metastasis somewhere. Many times they are too small to be seen by the PSMA pet scan since it can’t see metastasis smaller than 2.5 mm and even if they are 5 mm they are difficult to be seen in the scan.

The thing is, your cancer has become aggressive, and you have had a lot of spots of metastasis so you don’t really need a test, History has proven you have a case that continues to be aggressive and you definitely have active prostate cancer. The question is what are you doing to treat it and manage it. It has to be in your bloodstream at this point, so it can reappear at any spot in your body.

Are you taking ADT or at least an ARPI like Nubeqa That can control your cancer growth without having to reduce your testosterone? You don’t mention taking anything to try to keep this under control. When my cancer came back the second time after radiation I was put on Lupron and it kept my PSA down for 2 1/2 years. I’m now on Nubeqa, After 16 years of prostate cancer and four reoccurrences, And it has kept me undetectable for the last 26 months. The drugs do work, but you need to take them.

Have you used Flomax to Help with your urinary issues? That can make a real big difference for a lot of people.

A few questions that might help provide answers:
> did you use a rectal spacer with your initial radiation treatment? (Did they overshoot your prostate?)

> with your initial 3+4, was there any mention of cribriform pattern, perineural invasion, Intraductal carcinoma, extracapsular extension, or seminal vesicle invasion in the MRI of biopsy reports?

> did you have a biomarker (genomic) test? What did that test show?

> did you have a genetic (germline) test? What did that test show?

Your PSA of 0.10 would’ve been your nadir. Certainly, as your PSA passed 1.0 and approached 2.0, they would’ve suspected biochemical recurrence.

> along with your salvage SBRT, did you also do hormone therapy?

Yes, these side-effects could be inflating your PSA. However, the PSMA PET results were definitive - the fact that the PSMA PET scan showed several spots, indicates that it is recurrence.

Have they diagnosed specifically what’s causing the side effects (constipation, difficulties urinating) in order to recommend treatments? (Urinary issues are a common side-effect with brachytherapy, especially if the seeds are near the urethra. Constipation wouid be from the radiation overshooting your prostate and hitting your intestines.)

(If the PSMA PET scan lights up, there is prostate cancer.)

Next steps would depend on the PSMA PET scan results (and the other test results mentioned earlier).

Hi @whatthef, just checking in. Did you have follow-up testing like the PSMA PET scan? Any update?

Scheduled new PSMA scan this week. Psa is stable between 2.76 and 2.95 after 5 months. SBRT didn’t reduce psa but stable 2 mos out.not sure what this means. Some info suggests it should have gone down and some info suggest it may take a little longer to notice. Original treatment in2018.

If the PSAPET scan lights up, it’s an indicator of prostate cancer, but not 100% full proof . on previous PET scan it lit up big time, however after biopsy, no cancer many things can cause it to light up and the particular tracer they use especially the 18 has a high false positive rate especially in the bones. Another scan of schedule for this week and after that I’ll make some other decisions to my treatment plan. The reason I did the SBRT what to avoid ADT therapy specially when there’s only a few small spots that they had to do and so far I really don’t have an answer yet but working on it. I’m not going to wait too long that you can rest assure.
Thanks for everyone’s input.

@whatthef Also consider that PSMA (prostate specific membrane antigen) is not really “prostate specific.” There are other organs, tissues, and fluids that naturally express PSMA (without being cancerous) and will show as avid physiologic tracer uptake on a PSMA PET scan - particularly in the lacrimal (tear) and parotid (salivary) glands, blood, liver, spleen, pancreas, ganglia, and more, as well as the kidneys, ureters and the bladder (as the body tries to quickly excrete the radioligand that was injected).
So, what might appear as a “false positive” is simply any one of those other tissues or organs natural expression of PSMA.
As long as an experienced person is reading the scan (and perhaps getting a second opinion), you’ll be on the right track,

(Does SBRT reduce the need for using a rectal spacer?)

If you’re treating the prostate gland, spacer is needed. However, if your treating a few spots away from the prostate, not needed. As in my case.
- 1st pet scan sept 24- psa of 1 - 1 small lesion in the sternum. Avid uptake. Biopsy no cancer. I also had in 2024 Esophageal cancer. Chemo, radiation, and surgery was the treatment and all cancer has gone. During the next 12 months after this PSA test scan I’ve also had two CT scans, which showed the same lesion to the sternum to be stable and no growth. confirms my thinking there is no cancer. Research suggests pc cancer to the sternum is Highly unlikely and is very rare.

-October 2025 2nd # PSMA scan completed. PSA 2.81. Two lymph nodes and a spot in a T7 vertebrae and all showed mild uptake.no biopsy. So I chose to do SBRT.we treated those three spots and the sternum just to be on the safe side. PSA 30 and 60 days out was roughly the same 2.81 to 2.95.. Just before I did the second PET scan I also had a cold or something. coughing and runny nose, etc. and could contribute to inflammation of the lymph nodes since they are for the immune system. The T7 region of my back has already had problems. All 12 vertebrae’s are fused and I also have arthritis in my lower back and since I am 75 years old, there’s a good chance that the arthritis getting a little worse. And again it’s a mild uptake and it’s in the bone. I believe it to be a false positive. After this scan if there are spots and we can get to them, I will do a biopsy to confirm. That’s really the only way. The two lymph nodes that lit up a little bit Were too difficult to get to, If you know any other tests to confirm pc let me know.

so now we’re back to another PET scan and see what happens. I may have to do some type of therapy. I really don’t want do but I want to confirm I have cancer because I do have some issues I’ve had for many years( poor urination, and constipation) Which could cause my PSA to elevate because it doesn’t go away. Scar tissue may have worsened over time and may contribute to this problem (stricture)as well. We’ll see, it may be wishful thinking, but I’d rather eliminate that and be sure before I put myself through more cancer crap and side effects that I already have. Thanks for your thoughts. They are appreciated.