BCR and PSA increasing...or not? <.05, 0.15, 0.29, 0.16

[PGDuan]

Thanks to all who shared comments after I posted that my PSA was increasing after a few years of undetectable readings (following RALP and then adjuvant EBRT and ADT+Zytiga for 18 mo, all after GS 4+3, PSA ~14, pT2n0m0).

Just thought I'd share another test result from last week and it was half the reading of a few weeks earlier.

May wait a little longer before the PSMA PET/MRI at Stanford given the suggestions to wait until the PSA is closer to 0.5 or 0.8. Of course hoping this is long away, and starting to wrestle with the question of when systemic treatment may be appropriate.

Plenty of studies confirm the value of early aggressive systemic treatment at initial BCR, but I haven't found much to clarify the path when BCR after primary and adjuvant treatments fail.

[Tall_Allen]

There was just a STAMPEDE trial that found a benefit to starting on abiraterone when SRT failed and still M0.

[Justfor_]

You understand that you don't have a clue regarding your present PSA value. Do you? 50% PSA decline is concidered proof enough for a successful treatment. But you are not under any sort of treatment. Are you? If not, than the only reasonable explanation is that your lab is for the dogs. Not such a remote possibility as it sounds. I use two labs interlaced and when their numbers differ by more than 20% a third one in a majority vote arbitration. Recommend that you do something similar.

[PGDuan in reply to Justfor_]

Interesting point. I really don’t have a good sense as to what it is. I just know that it isn’t undetectable anymore which is a bummer.

Have you been using two labs for a while so you can compare between the over time?

[Justfor_ in reply to PGDuan]

I am 28 months out of RP. I have almost equal number of tests from 5 different labs. Two of them have been banned for erroneous results (one 600% up the other 300% less). From each of the main two I have 10 to 12 time samples. One month I use lab A next lab B and so forth. In the begining the rounding error for PSA less to 0.06 was masking the interlab variance. From 0.08 onwards this became evident. The interesting thing is that although the two time series diverge, they provide doubling times close enough. This is very important in building confidence in their numbers as it is well known that the derivative of a time series is one order of magnitude less accurate than the "mother" values. Take for example your case: A while ago you thought that you had a DT of one month, now this became MINUS one month. Would I trust such numbers? Definitely NOT!

[treedown in reply to Justfor_]

There are different test assays and my tests state as much as 20% difference than others. Just curious if your taking this into account?

[Justfor_ in reply to treedown]

Surely I do and when such a discrepancy exceeds the 20% nominal margin, a third lab is called in for resolving the ambiguity. It has happened twice until now (0.08 vs 0.11 -> 31% and 0.12 vs 0.15 -> 22%)

[Jvaughan0]

PSA is not the cancer and PSA tests can surely test your patience and sanity. Take a moment and smile at the lower number, but you know that smile comes with a big "grain of salt." Some times doing nothing is still counterintuitively doing something. Is it the right thing to do? -- only hindsight holds that answer.

[PGDuan in reply to Jvaughan0]

Yes, definitely a sanity and patience test! For now I’m just doing the research— trying to get all the available info to make the best decision. I definitely have a healthy respect for the cancer, and take the little bit of “good” news with a big grain of salt. I set my expectations low on this, and then I’ll just wait and see…

[BigTom123]

Thanks for sharing this. Many are in the same boat!