PSA decreased after january test

Steelchuggin26 Member Posts: 36
edited June 2017 in Prostate Cancer #1

Hi everyone. My dad had his PSA tested in January as part of his regular scheduled post op PSA test following prostatectomy 4 years ago for T2c Nx Mx Gleason 6 prostate cancer. All tests following the operation had showed up as <0.04 ng/mL, that is until this past january when it returned as 0.13 ng/mL. 


So the doctor had scheduled a retest for May 30th, and pending the findings there, imaging studies were on stand by. Well, we got the result, and the Dr said "Good morning sir, i have good news, your PSA test today is 0.1 ng/mL. 0.1 is considered essentially 'zero'. So congratulations, you remain free of prostate cancer, and the reason why it showed up as .13 before was due to a glitch in the sampling, which is actually fairly common, and that is why we do not make a diagnosis based off one single apparent rise. You are now clear to resume the usual every 6 month interval, and if come April of next year, that being the 5th year, if it is still "zero" we will be able to cut it down to one test per year. Congratulations, we look forward to seeing you again in november, and adding another 'zero' to your file."


That definitely sounds relieving, but considering the tests before had read <0.04, which was the lowest his machine could go, is it still concerning that it is at 0.1 now? Obviously 0.1 is better than 0.13, but i just cant help but wonder if it really out to be more like the <0.04 like it was before, or at least <0.09. Thoughts?


  • GeorgeG
    GeorgeG Member Posts: 152
    Different facilities/doctors

    Different facilities/doctors have differing definitions for what constitutes cancer recurrence after your initial treatment. Most have a threshold of at least 0.2 and some are higher than that. Some also look at the doubling time (amount of time before you are at twice the reading). Lastly, others wait until so many in a row that are going up. Also, always confirm a suspicious result although these days these test are pretty reliable.

    This area of prostate cancer has some dissagreement among researchers/studies, thats why there isn't just one number. It is important to react soon enought to improve the outcome but you also don't want to overtreat because that exposes you to side effect risks unecessarily. Anything higher than undetectable is a little unsettling but it sounds like your doctor is giving you good advice. Ultimately, the best plan is to do some of your own research so that you can confirm that you have a good doctor, then trust them and let that be your final word. We are all glad to help here any way we can but if ever there was a time for a trained professional ...

  • VascodaGama
    VascodaGama Member Posts: 3,668 Member
    A glitch in the sampling or limitation in the assay

    Brandon (Steel…26)

    Your query is reasonable and I question your dad's doctor for his assertions. How can he be sure that the previous result of 0.13 was a glitch and that the present 0.1 is not?

    Probably both results are equally good and equally the same. The initial PSA post RP at <0,04 indicates that he used assays with a Lower Limit of Detection (LLD) of <0.04 ng/ml. It is also an assay that reads up to two decimal digits (supersensitive assay). The last result at one decimal place is from a different assay. This is the common and cheap assay that should never be used in RP guys, patients without a gland in place. These people would produce tiny amounts of the stuff which variations can be highly significative. No prostate no PSA.

    There is also the ultra sensitive assay (three decimal places 0.XXX ng/ml) used here by some guys but this is a controversial way to test for prostate cancer due to what is called "background noise". The very low amount (0.00x) can be a miss interpretations in the assay's reading that confuses prostatic serum by other proteins.
    The last tests of 0.1 could be a round-down/up (up to 0.14 =0.1 or, above 1.6 =2.0) of the equipment software, too.

    The other aspect regarding your dad's doctor approach is his threshold to judge recurrence. It seems that for him a PSA=0.1 means remission. However, the traditional remission thresholds are between 0.03 and 0.06 ng/ml. Surely this number would be represented as 0.1 in a common assay of one decimal digit. But as explained above the number could also go up to 1.4 depending on the machine (or laboratory standards), and this would never represent remission but biochemical failure.

    If we go back to your initial threads on your dad's story (  the pathologist mentioned on a positive margin which could be a cause of cancer escape. The probability for recurrence exists. Your dad should repeat the PSA but it should be done in a supersensitive assay (two decimal places).

    Please note that the Urological Association guidelines regard a PSA>0.20 ng/ml as recurrence. Urologists typically take the threshold of PSA=0.40 as the trigger to start a salvage treatment. Most probably your dad's PSA level will not reach this threshold till his next scheduled test (in six month time). I also would note that at such a low PSA level, PCa is difficult to be detected in traditional image studies. Your dad should be looking for a sophisticated image exam using PET (PSMA and choline).  

    I have read your posts and admire all your researches done to others. I hope to read more of your educated comments helping me and the many in this forum. Note that you are at risk 4 to PCa due to your dad's case. Get tested timely.

    Best wishes in your dad's journey.


    Please note that this forum's soft sees the spelling of a+s+s as "****". Another glitch of the CSN's IT administrator. 

  • Old Salt
    Old Salt Member Posts: 1,358 Member
    edited June 2017 #4
    Let's hope for the best

    I hate to be the pessimist, but your doctor is seeing the glass as half full. Actually, he is plain wrong in stating that 0.1 equals zero. Whereas we all hope that you are cancer free, he shouldn't say that based on your PSA data and your history. He is correct though in wanting another PSA test in six months. Best to relax in the meantime and hope for the best.


    PS: The basic message that I am trying to convey is similar to the one posted above by Vasco.