has my cancer returned?

jmikew
jmikew Member Posts: 21
in Prostate Cancer #1

quick back story...diognosed with prostate cancer at 50 back in 2012. Gleason score 4+3. Had Di Vinchi surgary at MD Anderson.  Clean margins (but not by much) but did have possible seminal vessal spread.  was undetectable PSA for several years...then kind of forgot about cancer...ended up not getting a PSA for 2 years...then when I got one it came back at .9.  Did 6 months of hormone theropy and 8 weeks of high dose radiation.

After 6 months past treatment PSA came back at 0.0.  I just had my next PSA test (from a different lab and hospital)  The results read <.06.  I'm not sure how to read this, does it mean that's as low as they test for? or does it mean it's >.05 but less than .06?  Is this the first sign that my cancer has come back again?

I realize that the one test doesn't mean much since my only treatment option would be to go back on hormone theropy (oh boy!) and that they probably wouldn't start that until is was up around 0.2 or so.  My next test in 3 months will give me a better idea of whats going on...but was hoping someone on here would say "don't worry <.06 is the same as 0"

thanks

 

Mike

Comments

  • Clevelandguy
    Clevelandguy Member Posts: 1,180 Member
    #2
    More tests needed?

    Hi Mike,

    Yeah I would wait for at least a couple more PSA tests to see if you have a trend going and take it from there.  You are correct the reoccurrence level is .2.  With radiation your PSA number could bounce around a little as the cancer dies off.  There are still a couple of tricks left in your bag such as chemo or more hormone therapy.  Do any scans(MRI,PET) show any evidence of metastasi? In my opinion if you do start to show signs of reoccurance a second opinion from another hospital system might be worth while.

    Dave 3+4

  • Georges Calvez
    Georges Calvez Member Posts: 547 Member
    edited July 2020 #3
    No

    Hi there,

    The short answer is no.
    The long answer is no because the second assay is equivalent to the first.
    I am not sure why labs give out zero readings because they are just not true.
    Each type of assay has a limit of detection, anything less than this is under the limit of detection.
    The first lab set the machine so anything less than 0.0 would be regarded as zero.
    The second lab used their limit of detection which is > 0.06.
    Anything less than 0.06 is below the limit of detection, anything above is positive eg 0.07, 0.1, etc.
    That said as you get close to the limit the assay becomes a bit less accurate.
    So sit back and have a beer your cancer isn't here!
    Good innit?

    Best wishes,

    Georges

  • Flyer83948
    Flyer83948 Member Posts: 34
    #4
    In scanning throuhg these

    In scanning throuhg these forums awhile ago, I seem to recall one of the more knowledgeable posters here (maybe "VascodaGama"?) mentioning that there is at least one other organ or tissue in the human body other than the prostate that makes a very small amount of PSA chemical so expecting that a PSA test can give a reading of absolute "0" even after a prostatectomy is not realistic. 

  • jmikew
    jmikew Member Posts: 21
    #5
    Georges Calvez said:

    No

    Hi there,

    The short answer is no.
    The long answer is no because the second assay is equivalent to the first.
    I am not sure why labs give out zero readings because they are just not true.
    Each type of assay has a limit of detection, anything less than this is under the limit of detection.
    The first lab set the machine so anything less than 0.0 would be regarded as zero.
    The second lab used their limit of detection which is > 0.06.
    Anything less than 0.06 is below the limit of detection, anything above is positive eg 0.07, 0.1, etc.
    That said as you get close to the limit the assay becomes a bit less accurate.
    So sit back and have a beer your cancer isn't here!
    Good innit?

    Best wishes,

    Georges

    Yep

    That's the answer I was looking for!...but i'm gonna have more than one beer!...cheers and thank

  • Georges Calvez
    Georges Calvez Member Posts: 547 Member
    #6
    Can of worms

    Hi Flyer,

    That really is a whole can of worms.
    PSA is not totally prostate specific, depending on the individual men who have had bladder cancer so the whole shebang; bladder, prostate, etc has been fished out may have a PSA of around 0.1 as do some women.
    Happily cows do not have PSA or it seems anything much like it so the baseline standard is bovine serum.
    Seminal serum, which is rich in PSA, is then added to it.
    This gives you a calibration line for the reagent and apparatus that you can then use as your standard.
    A small problem is that this cocktail does not behave quite like normal human serum with PSA in it.
    Another problem is that there is not a one to one relationship between PSA and the reagent.
    So if you run a sample on two different machines from different manufacturers you will get different results.
    You will get different results by changing the seminal serum from batch to batch.
    Biochemists like to talk about assays like potassium, sodium, etc where things are pretty controlled and reproducible.
    PSA? Still out on the wild frontier.
    I worked on the assay of immunoglobulins for a year, we could differentiate between normal serum and abnormal serum, the difficult thing was showing how abnormal the abnormal serum was. Different assays would give different results because we were not measuring the same thing.
    Transition metal chemistry, lovely stuff; colours, identifiable structures that can be characterised, chemist's dream.

    Best wishes,

    Georges

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