Anyone “below detection" with an ultra sensitive PSA test?

A level of 0.-anything is cause for celebration.
It's not the number - it's if the number is increasing each time - and by how much.
Very little is done unless it reaches 0.2
Prostate cancer is one of the slowest-growing cancers, so it can stay at 0.-something for years & is nothing to worry about.

It's the rate of increase (if any) that they look at.
Worry is a waste of imagination.

Very good article here:
https://www.pcfa.org.au/news-media/news/psa-levels-after-treatment-all-you-need-to-know/

Yes, my PSA has been < 0.01 on the uPSA test for over 4 years.

Background:

De-novo stage 4b diagnosis in October 2021, single large metastasis to thoracic spine (big enough to cause paraplegia for a while)

Emergency debulking surgery to spinal lesion.

20 gy post-op radiation to to thoracic spine

60 gy radiation to prostate

On ADT+Apalutamide continuously since 2021

PSA is produced by some other glands too , like salivary, periurethral glands, even breast tissue. Also, sometimes some benign prostate tissue is left behind especially with nerve sparing surgery. All of that said, those amounts from other glands are minuscule.

@northoftheborder
Great to hear!

'Glands and Tissues Producing PSA (Prostate-Specific Antigen):
While PSA is primarily a marker for prostate epithelial cells, it is also expressed in other tissues, often known as extraprostatic production:
Paraurethral (Skene's) glands: Found in women, these are the primary source of extraprostatic PSA.
Salivary Glands: PSA has been detected in the serous cells and ducts of the parotid and submandibular glands.
Apocrine Sweat Glands: Located in areas such as the axilla (armpit).
Breast Tissue: Detected in both normal and cancerous breast tissues.
Perianal Glands: Small amounts are produced in these areas.
Bulbourethral Gland: Another male gland that can produce small amounts of PSA.
Placenta: Expresses PSA during pregnancy.
National Institutes of Health (.gov)
National Institutes of Health (.gov)
+6
Glands Producing Testosterone:
Testicles (Leydig cells): The primary source of testosterone in males.
Ovaries: The primary source of testosterone in females.
Adrenal Glands: Produce small amounts of testosterone in both males and females.
Prostate Cancer Cells: Some advanced prostate cancer cells can acquire the ability to produce their own testosterone. '

it seems both men and women have backup hormone secretion in various glands of the body...in women, estrogen is produced primarily in their ovaries and inmen, testostrone is produced in testes...
so once you block/remove suppress this hormmonal activity in the major glands, in some folks, more of their respective hormone can be produced...which is why inmen, some never reach a nadir of < .01 ( almost zero) ..their bodies have a stronger backup system for hormone production..I noted the last sentence that in some cases, the cancerous cells learn to produce their own testostrone I assume even after radiation or even prostate removal...and why cancer is difficult to eradicate..

( btw, for anyone who still cares about sex stuff, the Skene's gland in women is what makes them squirt..and some of that is PSA fluid..who knew ? my former pre ADT self.." Tom let's go find one and see !" present day ADT Tom " yawn..is it too early for supper..can I maybe have 2 suppers..but dont ant to take my Nubeqa too late..")

@surftohealth88 Yes, I recall that from a 1997 paper now that you mentioned it, at least about the periurethral glands and breast tissue. Which then raises the question, why bother measuring PSA to three decimal places? If other organs can produce even minuscule amounts of PSA, can anything meaningful regarding prostate cancer be inferred from a PSA trend that goes from 0.003 to 0.009? I am not stressing out over this personally, I just don’t see the point of measuring PSA to such limits if it is not medically meaningful.

@peterj116 Yes, I agree 100% with everything you said. I am just curious about the sources of PSA beyond the prostate. Given that, as other folks have noted, there are other sources of PSA, even if what is produced is minuscule, why then even bother with measuring PSA out to three decimal places? I see no clinical value in such high precision data. I would expect a high potential for instrumental/lab error in such fine measurements as well.

Personally, I am quite happy and relived if my PSA remains below 0.1, as is my RO and urologist.

@melvinw There's a good discussion here, from guys here who have had it:
https://connect.mayoclinic.org/discussion/ultrasensitive-psa-vs-standard-psa-readings/
Not sure I'd bother unless there was a family history.

@peterj116 Yes, good discussion there—thanks for that link. Just days before I started my salvage radiation last fall, I had the opportunity to have back-to-back blood draws for Quest’s standard PSA test, and Labcorp’s ultra sensitive test.

Quest came back at 0.11—the same as three months earlier when I went started down the path of diagnosis for recurrent PSA.

Labcorp came back at 0.094. Basically, I read these both as 0.1. No significant difference. However, it interesting to note that if I had done the uPSA test back in June 2025, and got a < 0.1 value (instead of 0.11 from Quest), no alarms would have gone off and my docs would have told me to come back in a year. That could have been a fateful decision because both PSMA PET and MRI scans confirmed that a small, palpable nodule in my prostatic fossa was favored to be cancerous.

Three months after RT, my first uPSA Labcorp test yielded 0.086. Another data point is needed to see if that is the start of a downward trend, which hopefully it is. But like I said, if I just stay at 0.08-0.09 for the rest of my days, I’d be happy with that (no further treatment needed).

I pressed both my RO and urologist on small changes in uPSA values and if doubling time really means anything if someone goes from 0.02 to 0.04. Neither thought it did, but acknowledged that there was a lack of consensus among medical professionals. I 100% agree though that trends are significant, just like with regular PSA tests.

< 0.02 at 9 month post-RARP