PSE Test for Prostate Cancer Before an MRI and for Re-Occurrence

Hi, thanks for your reply. Just to clarify, the EpiSwitch PSE test analyses immune cells in the blood that have been at interplay with prostate cancer (or not). Your PSA value only makes up a small portion of the results of the test. There are other very informative biomarkers assessing the presence or absence of PCa included in this test. So yes, EpiSwitch PSE can still be used with a very low PSA score, and can still detect prostate cancer without PSA shedding. Therefore, the test can be used before, after and during treatment - even after complete prostate resection. In your case, a 'low likelihood' result could potentially help you avoid things like PSMA scans if your PSA indeed rises over time. A 'high likelihood' result could be indicative of recurrence, irrespective of low PSA.

Thank you for the reply. Just to verify, would the test have any added value with an undetectable PSA (< 0.01) while on Relugolix and Apalutamide? Or is it (as I think you wrote) something I'd use once my PSA started rising?

Hello. Thanks again for reaching out. I think PSE would still be useful as it can detect prostate cancer in patients with PSA (< 0.01), as PSA cannot detect cancer alone. The other biomarkers in the PSE test can detect the presence of PCa together. And yes, I do believe it would be prudent to order if PSA starts to rise. All the best.

Not sure I understand the technicalities, but i just had a prostatectomy. I have IDC and a bit of grade 5. so i am all over diligent surveillance and early identification of recurrence. it is my understanding that this PSE test can 1.) tell me now if i have cancer cells in my bloodstream (which nothing else can do) and 2.) provide better accuracy on PSA tests going forward. Is this correct? Should I just use PSE for all my 3 month tests and not bother with "standard" PSA tests? Will traditional PSA/recurrence evaluation models be based on the same PSA results?

Another question i have is how do you compare the results of "old" PSA versus "new" PSE results. Comparing a PSE results over time to a "standard PSA" result might show higher (or lower) results, as it is more sensitive - right? Wouldnt that possibly unnecessarily skew the results over a period of time? In other words, if you do a "standard PSA" test in month one and a PSE in month 6, if may show your PSA has gone up, only because of the accuracy of the PSE. if the PSE was applied to both month a and month 6 tests, they might yield the same result.

Hope this makes sense....

The PSE test is to detect whether or not there are cancer fragments in your blood. It is very expensive compared to a PSA test so it would not replace that test. Used before or after treatment, once each could be useful.

The test is not approved by the FDA for after treatment so insurance would probably not pay for it.

If the cancer goes dormant neither test can see it but it can come back.

I don’t expect the PSA to be different between tests. PSA Tests can come back with small differences I’ve done at different labs. If you were to do a PSA test and a PSE At the same time, they would probably come back very close in results. Results can vary at different times during the day.

The Decipher test is the one you take to find out the chance of a reoccurrence, Not really the PSE test. There’s a lot of discussion about that in this forum you might do a search at the top level for decipher test to get more points of view.

As previous comments have mentioned, PSE can't actually test for circulating tumour cells (CTCs), but it does add a genetic "Episwitch" test to the regular PSA screening test, looking for for chromosome changes often associated with prostate cancer.

There's speculation that PSE might also be useful for detecting recurrence, but that's still unproven and off-label (unapproved) at this point; the main approved use of PSE is to reduce false positives when screening people who've never had prostate cancer (if the chromosome changes are also present, it's more likely that an elevated PSA result is caused by prostate cancer, and vice-versa).

So its value for monitoring people who've already been confirmed to have had prostate cancer isn't yet established. That could change, though, and certainly the Episwitch people themselves are optimistic.

thanks. while we are on the subject of PSA, should I use the standard PSA test or the ultra sensitive PSA test for post RP checkpoints?

I did use the PSE test for reoccurrence but Here is the comment made by Joe Abdo, the VP of Clinical Diagnostics for Oxford Biodynamics further clarifying the PSE test:

"Just to clarify, the EpiSwitch PSE test analyses immune cells in the blood that have been at interplay with prostate cancer (or not). Your PSA value only makes up a small portion of the results of the test. There are other very informative biomarkers assessing the presence or absence of PCa included in this test. So yes, EpiSwitch PSE can still be used with a very low PSA score, and can still detect prostate cancer without PSA shedding. Therefore, the test can be used before, after and during treatment - even after complete prostate resection. In your case, a 'low likelihood' result could potentially help you avoid things like PSMA scans if your PSA indeed rises over time. A 'high likelihood' result could be indicative of recurrence, irrespective of low PSA."

That is a matter of your level of patience and anxiety.

I used the standard test for all of the monthly tests I’ve had for the last eight years. 15th year with PC.

We just had somebody come in this forum who was worried that their PSA had risen from undetectable to .02. These type of changes happen frequently, I attend weekly advanced prostate cancer meetings, where people come in and asking about very small changes in their PSA because they are using ultra sensitive tests. Usually, the PSA goes right back down and we don’t hear from those people about it again.

I myself don’t need that type of information after all this time. I’ve been undetectable for 19 months. That means I’m < .1. What matters is, if it ever exceeds that number, and does it for more than one month? If I had the ultra sensitive test, I might be freaking out about my PSA rising .05 to .07,. It can fool you into taking action.

So…..what is your level of anxiety about your PC.

It is possible (but extremely rare, like "struck by lightning" rare) for prostate cancer to progress significantly without becoming detectable on the regular PSA test. So far, I have not found a single report of prostate cancer progressing without becoming detectable on the uPSA test.

As soon as your PSA is detectable, it doesn't matter which test you use — 0.7 means the same thing on PSA and uPSA. The only benefit of uPSA, as @jeffmarc mentioned, is earlier warning if something starts to happen. I never asked, and didn't even know I was on the uPSA test at first; I guess it's just the default for monitoring at my cancer centre.