Definition of biochemical recurrence

On_A_Journey
On_A_Journey Member Posts: 96 Member
edited December 2022 in Prostate Cancer #1

Hello all, first post.

Brief history: Diagnosed in 2015 and underwent RP that year. Surgical report stated "Gleason 3+4, Stage T3a, negative resection margin." The last part indicated to me that surgery was successful.

Unfortunately, my first PSA test 3 months after surgery was 0.53 and a follow-up 3 months later was 0.75. Salvage radiation consisting of 33 sessions followed soon after that and I finally reached my nadir of 0.04 in May 2018. It slowly increased since then and reached 0.20 in January this year and is still rising. I get a blood test and consult with my oncologist every 3 months. I'll probably get another PET scan in a couple of months and I'm looking down the barrel of ADT if nothing is found.

I'm wondering, technically, did I experience a biochemical recurrence (a) straight after surgery, or (b) in January this year? I'm having trouble determining whether I should avoid focusing on the post-op results and only concentrate on the post-nadir results, or not? I've only thought of this concept recently and I don't see my oncologist until February, so for me, it would be nice to know now. Thanks in advance.

Comments

  • VascodaGama
    VascodaGama Member Posts: 3,641 Member
    #2

    AUS defines Biochemical Recurrence following radical prostatectomy as; PSA ≥0.2 ng/mL, and following radiation therapy as; PSA rise of ≥2 ng/mL above the nadir.

    Accordingly, your 0.20 ng/ml would still be considered in remission by the professionals. However, not everybody follows those thresholds. My doctor prefered to set biochemical recurrence from radiation therapy at 3 rises since nadir, of PSA tests done at three months intervals. He also used the doubling time of PSA that should be greater than 12.

    My experience with a case of RT (after failed RP), and a PSAdt of 14, the doctor set a threshold of PSA=1.0 ng/ml to start Hormonal Treatment (ADT).

    Surely we can't compare our cases. Your PSAdt is longer at 19 months and the last PSA is still very low, which will be considered by your doctor to determine the next intervention, if any. Not much would change till your next consultation of February/March.

    Regarding the PET scan, this should be done if you still aim cure. That means, if you are interested in another attack with spot radiation (oligometastic treatment) to those metastases identified in the scan, and if these are located at convenient areas.

    The 68Ga PSMA PET is the best when the PSA is above 0.70 ng/ml. Less prone to false results.

    Best wishes and luck in this journey.

    Merry Christmas

    VGama

    https://pubmed.ncbi.nlm.nih.gov/30642810/


  • On_A_Journey
    On_A_Journey Member Posts: 96 Member
    #3

    Thanks, VG. Merry Xmas to you too.

    To clarify, my reading was 0.18 in September last year and 0.20 in January this year measured the 'old' way . By that, I mean until then, the result was given as PSA Atellica. Now, the result is given as PSA Alinity, and the two readings are not equivalent. My 0.20 Atellica was also displayed as 0.33 Alinity. Subsequent tests are now only shown as PSA Alinity. I'm not sure if there is a simple linear relationship between the two readings, but if there is, my current PSA Alinity reading of 0.48 might be equivalent to 0.29 Atellica. Either way, I know I am definitely considered to be experiencing biochemical recurrence now.

    You are correct regarding the purpose of a PET scan. My radio-oncologist is looking for something to treat and does not want to see me begin hormone therapy unless there is a reason to. A threshold has not been discussed yet; it will be determined according to reading and doubling time, as it should. What he has hinted at though is that if and when I do head down that path, it will more than likely consist of intermittent treatment.

  • VascodaGama
    VascodaGama Member Posts: 3,641 Member
    edited December 2022 #4

    Hi again,

    Well, by rule one shouldn't alter assays or laboratories in PSA tests. Even using the same maker (Siemens Atellica or Abbott Alinity) the PSA is subject to tiny differences.

    In any way, the values you comment above provides a PSAdt greater than 12 (approximately 19) which gives peace of mind in regards to the need of an urgent intervention. In my lay opinion you have plenty of time.

    The oligometastic treatment is not a pilot therapy. Many guys have benefited from it and some have not. It all depends on the truest detection of those metastases.

    Isotopes made of PSMA have been used to diagnose these spots. I have experiences with 18F choline and 68Ga PSMA. The 18F managed to detect lymph nodes but the 68Ga did not. I belive that the negative result of the 68Ga PSMA PET was due to the blurred image at the prostate base area because of urine excretion at the timing the picture was taken. The 68Ga is excreted with the urine and the half-life is short.

    I think that the 18F PSMA PET is better for those cases when the recurrences are judged to be at the prostate bed area or bladder.

    To avoid false negatives this PET scan should be done when the PSA is higher than 1.20 ng /ml.

    I am on intermittent hormonal treatment since 2010. I started a vacation period (off drugs) in 2012 and still haven't reach the threshold of PSA=2.5 ng/ml to restart it again.

    Please note that I am not a doctor. But, my opinion regarding ADT, is that, in similar cases to yours or mine, it can be started at any PSA level lower than 5.0 without prejudice to the treatment outcome.

    I recommend you to do some researches on your next steps, moving forward coordinatly.

    Best,

    VGama

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