Question about PSA Nadir

Hi everyone,

My father has been on Zytiga and Lupron since May 2018 and his PSA has slowly dropped from 42 to 9.5 but has now been around 9.5 for the past couple of tests (aprox for a month). He had his prostate removed in January but unfortunately his PET PSMA showed multiple mets shortly after. His doctor says that as long as his PSA isn't rising, they won't change his treatment but I thought that the goal was to lower the PSA to undetectable levels and 9.5 seems fairly high. Does this mean that 9.5 is his PSA nadir or is it possible that his PSA will continue to lower? If it is his nadir, is it worth changing his treatment? Does this fairly high nadir have any significance in terms of OS? He Gleason is 8 (4+4) and is 72 yo. He had bad side effects from the Zytiga so they had to take him off/on a couple of times and change the dosage so he's only been back on the full dose for about a month.

Thanks so much

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Nalakrats

a year ago

I cannot prescribe--not a Doctor--but I would start a conversation--demanding--what technology your MO has/knows that will reduce the PSA--if unsatisfied, it is time for a second opinion--with a MO who only specializes in Pca, and is at a big center of excellence--as related to Cancer. In other words not being in your shoes--I would not be happy with the response of the Doctor--In my life I have fired about 6-7 Doctors over the last 30 years. Most recently a GP--who claimed to be Integrated--was not--we got into it, he called me some names, I called him back, some; had him put in front of a Peer Review board--and they moved him out of town. I do not take C*** from Doctors--I have played golf with them for 40 years at various country clubs--and when their ass itches in the locker room they scratch it like any other man.

Nalakrats

4 likes

ronronHU

in reply to charlesmeyers1964

a year ago

Charles,

I have previously commented on comparing PSAs in men who have 'elevated PSAs >4.0, BPH, or in those who have been diagnosed with PCa and have not undergone treatment'...with men who have had RPs or RT. You can NOT compare the results since PSAs 'should' be substantially different after treatments than before; hopefully, if treatments are successful, remain at levels far below 4.0. Please read the following:

Understanding PSA Numbers

After the surgical removal of the prostate, or prostatectomy, PSA 'should' drop to virtually undetectable levels, (less than 0.1). This is effectively 0, but by definition can never get all the way to zero, given the sensitivity of the test and the fact that, at very low readings, other proteins may be misread as PSA protein. In contrast, because normal healthy prostate tissue isn’t always completely killed during radiation therapy, the PSA level rarely drops to 0 with this treatment. Rather, a different low point is seen in each individual, and that low point, or NADIR, becomes the benchmark by which to measure a rise in PSA. Usually, a rise by more than 2.0 ng/mL 'is typically cause for concern.'

Because the starting point is different whether you had surgery or radiation therapy, there are 2 different definitions for 'DISEASE RECURRENCE' as measured by PSA following initial therapy.

Following a prostatectomy, the most widely accepted definition of a RECURRENCE is a confirmed PSA level ≥0.2 ng/mL. In the post-radiation therapy setting, the most widely accepted definition is a PSA that is seen to be rising from the lowest level (nadir) by at least 2.0 ng/mL.