Full disclosure up front: I don't have metastatic PCa (as far as I know). I had RARP about 2 months ago, and I'll get my first post-RP PSA test in about a month. Obviously hoping for an undetectable value.
I know that the test I will get will be from a Hybritech/Beckmann Access 2 assay. The pre-RP tests I have had say that the lower limit of detection is 0.01 ng/mL, so I am pretty sure that I won't see a number like 0.009 (or less).
If that's the case -- ie my result is < 0.01 -- I'll chat again with my oncologist next month to see if I can can get a result reported to 3 figures after the decimal.
But for now, I thought I would bounce this idea off of everyone: if my oncologist can't help me in this regard, why not just purchase a uPSA independently from my regular care?
Can anyone say why this might be a bad idea? Or if it's not a bad idea, can anyone recommend a walk-in or mail-in service that is reliable, reproducible, and not too pricey?
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It can't be a "bad idea" if that is information you really want, and intend to take action upon if you feel action (radiation?) is warranted by certain uPSA results.
But for myself, that would just be info that would lead to obsessing over PSA. Since I have read (and believe) that many/most men have disseminated micro-cancer by the time they get RP, I would assume some cancer cells are still hanging around, and would concentrate on lifestyle changes that might help keep those cells quiet. Part of that might be: don't worry about PSA too much. Easier said than done, I know!
Thanks for the advice. I'm a moderately obsessive person by nature, so I just take it for granted that I'm going to obsess over the PSA numbers. So in that case I'd just like to have as much data as possible. I'm a PhD biochemist so I am accustomed to working with imperfect numbers.
It's also true that there's not much more I can do in terms of lifestyle changes. I'm already a long-distance runner, BMI 18.5 and almost vegetarian (we eat some fish). I'm increasing the proportion of fruit and veg in my diet, and I think I'll add the Pomi-T antioxidant/polyphenol supplement even though I know my SOD2 alleles are Ala/Val (there's reason to believe that the POMI-T might work better if your SOD2 alleles are Ala/Ala).
A bit off-topic, but I am also wondering whether RT-PCR from circulating tumor cells (CTCs) might eventually become a more sensitive and/or useful assay than the uPSA assay for post-RP guys. I've seen some work along these lines but it seems controversial, and I am not aware of any current trials testing this approach as a diagnostic.
A runner? Almost a vegetarian? Have you read about Dr. Ruth Heidrich? Dr. Laurence Klotz? Dr. Greger? Dr. Charles "Snuffy" Meyers? Dr. Joel Furhman?
Pomi-T coincidently uses the four ingredients that a study funded by a non-profit found to kill prostate cancer cells. Dr. Greger has a YouTube video about the study. Funding for the study was exhausted when results were obtained using these four ingredients. Could a better result be obtained if more supps were added? I have my own list of supps I have put together combing more than the four that the non profit found to be effective. Pomi-T is a proprietary blend which is fine. I prefer to source my own supps and the amounts and---pick up where the study ended.
Dr. Everett Storey and Cell Food? That will be an interesting read for you.
Yes - 3 decimals is certainly a bad idea. At the third decimal point, there are non-prostatic sources of PSA (as in breast tissue, for example) that will cause it to bounce around. This is a source of anxiety and overtreatment. Your question suggests you are prone to anxiety anyway, and this will only make it worse. Furthermore, it serves no medical purpose. Values under 0.03 have no prognostic value.
Thanks TA. A portion of my anxiety comes from my relative youth -- I am 55. I definitely would be less anxious if I were older. The other reasons for my anxiety are that I had a rapidly rising PSA (4.6 to 7.6 in 3 months) before RP, as well as a family history of PCa.
Anyway, thanks again & I'll check out the prostate-cancer-community site too.
Yes, I have looked at Han tables and multiple nomograms, and it seems pretty clear that, even if I get rapid BCR and then clinical mets, I would have to be extremely unlucky to not live to 70. With my metrics (pT2c, G3+4, no adverse pathology, last pre-RP PSA 7.6) I figure my chances for BCR at 10 years post-RP are somewhere between 15-40%. From what I have seen the family history is not a good thing, and the relevance of the rapid pre-RP PSA rise is more controversial.
From the perspective of a biochemist, it's a disappointing that genomic/personalized diagnostics and therapeutics are not farther along -- I didn't realize. I am paying attention now!
I learned to practice mindfulness, which helps me a lot in dealing with things as they come insteadd of rehearsing fictional scenarios in my head. "Being prepared" is a myth. It is a recipe for feeling pain multiple times instead of just once, if ever.
There are genomic tests for men who are on the fence about salvage treatment. Save them for if you get to a point where you are on the fence.
I'm aware that the Decipher and Prolaris tests can be used by post-RP guys. I thought about doing one of these now, or soon, with the hope that one of these tests might be able to stratify post-RP guys with low risk (who are good candidates for watchful waiting) from higher-risk guys (who might want adjuvant radiation or ADT rather than waiting for salvage or early salvage). From a bit of reading, I have the impression that the accuracy (please substitute more appropriate metric here) of these tests isn't great. I asked my oncologist whether he would change his recommended treatment for me if one of these tests indicated a higher risk. He said he would not. I assume that he will advocate WW if my PSA is undetectable next month. With my status (pT2c, no adverse pathology, G3+4, pre-op PSA 8) I am pretty sure my insurance would not cover either test anyway.
But you're right, further down the road the tests can be used in a different way. In a situation where any small additional data can help make a decision -- a "tie-breaker", if you will -- such a test might be more helpful.
Decipher is for either AS (on biopsy cores) or for salvage radiation post-prostatectomy (on prostate tissue). Prolaris is only for AS, using biopsy cores. I agree, Decipher is only for use as a deal-breaker post-prostatectomy, if one is needed (usually it is not needed).
so many young guys on this site. definitely agree with allen that values under 0.03 have no value & will only drive you crazy. i'm prone to anxiety, so i know what i'm talking about. as for ctc markers, i have no idea why doctors don't use them. my husband is dealing with a recurrence (after surgery + radiation), and we requested the ctc test, and our oncologist said it wasn't necessary. allen, do you know why this is?
It's because CTC counts are very unreliable. They increase or decrease unpredictably. CTC or cell-free DNA genomic tests are only useful if CTCs have been detected - often not the case, even when there are metastases.
The only reason to ever have a test is if there is a treatment decision that may change because of the outcome. Having a test just because one wants to know or tests for a very low probability event is a very bad (and expensive) idea.
what do you think of senolytics and senostatic for scenscence prostate cancer cells and stem cells ...especially work of Michael Lisanti on antibiotics....a snake oil???
The same interventions that may work against PCa (e.g., CXCR4 inhibitors) may also affect cellular senescence. So what? What really matters to the patient is the clinical effect. In general, I pay no attention to lab studies because I do not work for a pharmaceutical company developing drugs. I'm only interested in the clinical effectiveness and safety of such drugs.
You can check LabCorp and Qwest for uPSA pricing, it's probably around $80-100. Here's one by LabCorp, which uses the Roche assay. Stick with one provider due to variance in processes. Also, try to take your test at the same time of day, and fast as if you were doing a lipid test, as there are some studies showing PSA changes diurnally and within four hours after a meal.
From their certification documents I was able to learn that, one of the two labs I use, employs the "Automated analyzer Cobas 8000 e801-1, e801-2, Roche" (ECLIA) for the PSA test. Going through the specs of "Cobas Elecsys total PSA" assay, I stumbled upon two groups of numbers:
"Lower detection limit" of 0.002 to 0.003 depending an the analyzer's head and "Functional sensitivity" an order of magnitude higher, i.e. 0.02 to 0.03, also head dependant.
The first numbers are for repetitive tests at the manufacturer's test lab, on at least two analyzers, 20 times on each one (what did I write about oversampling?), while the second at any lab-anywhere, once only and thus "can be reproducibly measured with an intermediate precision CV of <=20%"
The second lab that enquired, through text message, responded: "Our analyst is capable of seeing the third decimal digit, but we will never put it on paper".
Summing up, there are three descriptive words, usually ommited, that make quite a difference:
I see, so the reports we see are a magnitude higher than the assay actually tests for. Makes sense that the lower boundary uses a “<=“ sign to avoid any ambiguity, since the lab is interested in reporting reproduce-able numbers rather than the most significant numbers. It would be nice to know the tech to maybe get that last digit just out of curiosity’s sake!
You have to be friends with the chief analyst. He will have to dig into the primary data of the automated analyzer plus add some correction data out of his experience regarding calibration, batch and history of the assay used.
I am an electrical engineer having spent my professional life with TV. This I my take. The absolute value of PSA is close to useless. What is important is its rate of rise. At the lowest detectable values it's true value is masked by process precision and the quantisation noise. To surcomb these limitations there is one way that is bread and butter for communication systems. Oversampling. With oversampling random noise contribution is reduced and aggregated values are drilled down. The rule is beyond any doubt: Each downsampling by half adds an additional least significant bit on the measured value. Consequently, it will be better for you to take more frequent 2 decimal digit PSA tests than try finding a 3 decimal digit one. In fact you should have taken one by now. I use monthly tests for the mentioned reasons and interpolate.
This a study was done in 31 patients at John Hopkins using ultrasensitive PSA test after RP,
"they found that at three months after surgery, all patients who ultimately had a rise in PSA had an AccuPSA level of 0.003 ng/ml or greater. By standard measures, this number would be considered undetectable. Among patients whose PSA levels never went back up, 75 percent had AccuPSA levels less than 0.003 ng/ml."
"In addition to this pilot study, larger tests are needed to confirm the results. These initial findings suggest that you could have an AccuPSA test three months after surgery. If your PSA level is less than 0.003 ng/ml, you could be confident that all your cancer has been removed. On the other hand, if your PSA level is greater than 0.003 ng/ml, you might choose to be monitored more closely for PSA recurrence in the immediate years following your surgery."
tango65, yes, I saw that study too, and though it surely needs confirmation, this study is a part of why I'd like to get a three-digit uPSA done next month. That said, if I do get a three-digit test done soon, I'll bear in mind Allen's point about small PSA contribution from non-prostatic tissue. Also, I'm familiar enough with real-world data that I wouldn't bet the farm on any single measurement.
You both missed the important part of this study. It refers to a measurement 1000 times more sensitive to the standard one. This brings the sensitivity of this method, surely not the one of our discussion, to the forth (4) decimal digit. It is elementary in all measurements that the meter should have, at least, one order of magnitude higher sensitivity over the measured value, else the measurement procedure resembles a random number generator.
I am sorry, but I do not understand what you mean about missing the important part of this study and that "it is elementary in all measurements that the meter should have, at least, one order of magnitude higher sensitivity over the measured value, else the measurement procedure resembles a random number generator"
The paper is based on the: "Quanterix AccuPSA" which (quoting the study) "is 1,000 times more sensitive than standard PSA tests".
This test, if it finally gained market viability, is totally different to the ultrasensitive PSA that we are disicussing:
"In preliminary validation studies across multiple runs and reagent batches, the AccuPSA assay exhibited a limit of detection (LOD) of 0.01 pg/mL, and a limit of quantification of less than 0.05 pg/mL." [1]
Do not get fooled by the numbers, notice the units that are in _pico_ grams, in contrast to the _nano_ grams per ml of today's conventional 1or 2 or3 decimal digit PSA tests.
2nd subject
It would be highly irresponsible from the part of the researchers to quote a cut-off value like 0.003 derived from measurements made with equipment of equal sensitivity class. Only untrained people would have done such a gross mistake. In is common, nowadays, for the general public to take figures to the 8th decimal point as granted, because the computer printed them out or they appeared on a long form numerical display.
In principle, ANY measurement is a comparative process. It tries to count-up/gauge how many times the under measurement quantity is greater to the minimal reference quantity of the metering apparatus. If it is less than ten (an order of magnitude) than even a single digit result is a product of a guesswork. Give you a simple example to help you understand. You have a meter tape that has gradations only every 10 cm and you want to measure the length of your bed. You see that the bed aligns somewhere between the gradations of 1.9 and 2.0 meters. You can take a guess and say it is closer to the 1.9 mark, so it shoud be 1.93. This is guesswork, not measurement. If you wanted to be abslolutely certain regarding the length of your bed, you would get a meter tape with millimetrer gradations measure and drop the millimetres, so that you would be certain that the centimetres are correct.
Single readings of PSA are practically useless for treatment decisions. It's the PSA trajectory that counts. The only value I see in an additional decimal point is if you've decided that you will have additional treatment sooner than a two decimal point trajectory might indicate (depending on whatever treatment trigger you choose). My PSA was <0.01 for 7.5 years after salvage IMRT. When it when to 0.06, I had more IMRT, Taxotere, and Lupron. I'm now 3+ years into another remission with PSA bouncing back and forth between <0.01 and 0.02. Both of my oncologists are optimistic that that I might be "cured".
Would you be kind enough to furnish us with more of your bio info. AGE? LOCATION? TREATMENT CENTER(S)? DOCTOR'S NAME(S)? Thank you! All info is voluntary but it helps us help you and helps us too.....
I can't speak specifically to your questions, but at first blush it seems OTT. Don't jump the gun. See what your first PSA post op is and assess accordingly.
Hope you are undetectable. Almost 3 and a half years now with extensive bone mets. Psa <0.1 No progression. (Yet). When my Xgeva injection was changed to once ever 3 months, I asked that blood work be once every 3 months. Will change that when psa starts heading upwards. I kicked anxiety to the curb. I was never good with decimals. Enjoy.
Hi, also a scientist I obsessed with PSA. Had 2.5 years <0.03 then 0.05, now 3 years up and down between 0.034 and 0.056 (they've gone an extra dp now in UK). Last was 0.049. I used to spot trends that would fit with a definition of recurrence, but my high was 9 months ago. Now I'm finally more chilled, my research shows me to wait until 0.1 before doing Salvage RT, I could have gone SRT earlier but don't want the additional side effects as my RP already gave me all side effects!
It is based on a paper from Finland, the link leads to an online application which goes beyond the usual regressions, employing spline curve fitting to do a comparison with a database of historical cases.
Up to now, my PSA values are smoothly ascending. If they started bouncing, like yours, I could try a Kalman filter. It is not an original idea, Google returns some papers, especially for people being on ADT, like these recent ones:
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as for ctc markers, i have no idea why doctors don't use them. my husband is dealing with a recurrence (after surgery + radiation), and we requested the ctc test, and our oncologist said it wasn't necessary. allen, do you know why this is? 
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