PSA post radiation: how to interpret?

PCF.org has video replay of Rising PSA after Tx dated in Jan 2023 which may be helpful.
Post radiation, there will be PSA because you still have a prostate, but you will reach a baseline, or nadir, and track from there.

Thanks. That is helpful:

"If you’ve had radiation therapy, your PSA will likely not drop to zero, as there is some normal, healthy prostate tissue that remains after treatment. Instead, there is a different low PSA level for each patient, called a nadir. The most widely accepted definition is a PSA that has risen from nadir by 2 ng/mL or more."

Of course, it means that the monitoring of PSA levels will continue to be a source of anxiety. I wonder how long it will take for PSA to reach its new "normal" level. Thanks again.

I have not yet found it on the site or in the pdf document.

Pcf.org
Dropdown Menu top right
Patient Resources >
Click (carefully) on right pointing arrow
Patient Webinars near bottom
Jan 17 2023

Good luck. Took me a while first time.

Not a medical professional so can only pass on information I learned from my treatments and research.

You should have had a base PSA test done prior to radiation treatment. This is the baseline they will use to determine how affective the radiation treatment was and with time additional test to see if going down to reflect treatment was successful.

My oncologist/radiologist and my research reveals that the radiation does not kill the cancer cells. The prostrate cancer cells are different that normal cells of prostrate. When radiation is used on the cancer cells it damages the cells and the cancer cells do not reproduce themselves nor repair themselves and will eventually die.

The regular prostrate cells also are damaged but can repair themselves and grow new cells. I was expecting to hear that the radiation killed the cancer cells but that is not the case. Again not a medical person so just passing on what I was told by medical personnel.

This information on how the radiation works on the cancer cells I see is posted by others as well. I was surprised at this. It is why my oncologist/radiologist said they treated my entire prostrate and margins so they could ensure all was treated. They said impossible for biopsies to be entirely accurate of where cancer is and you might missed an area with cancer if you only treated the areas with cancer identified by biopsies.

Thanks for your participation and thoughtful input. It also reinforces my dilemma.

As I commented, I wanted a pre-radiation PSA. The oncologist wanted to start me on Lupron right away and delay the radiation for two months. I did not want the delay, but he said the Lupron somehow potentiates [my word] the cancer to make it more susceptible to the radiation. If that's true, that would be the right thing to do since that objective is to kill the disease.

This did not make sense to me, but I did not know how to push back. Doesn't Lupron slow prostate cell growth? Yet it was always my understanding that rapidly growing cancers are much more susceptible to cancer treatments that focus on growing cells. But if that logic is true however, it suggests that a bolus of testosterone who be a better pretreatment prior to radiation. Logic can lead you down the garden path? Lupron is doing the opposite; it slows growth we are told. Cognitive dissonance? Regardless, Lupron pretreatment will destroy a chance to establish a baseline metric post radiation. Maybe a baseline level of PSA is not that helpful in clinical decision-making?

Radical prostatectomy enjoys a beautiful and powerful tool in PSA, revealing what's going on at a biochemical level, and probably more sensitive than say PSMA PET. The push to do Lupron first drove my pre-radiation testosterone to zero, and my 6.9 PSA to 3, which 3 mo. post radiation/lupron, both were now undetectable. But, that's the effect of Lupron. The effect of radiation on PSA, my most sensitive tool, is now unknown. Unlike radical prostatectomy, I have little idea of what to do when my post radiation/post Lupron PSA becomes positive. As the Lupron fades (I'm 4.5 mo. post final* injection) I would like to have had a post-radiation PSA as a baseline, or some kind of guidelines.

There are likely some big flaws in my reasoning, so I suspect this will generate some needed push back, but I find it disappointing that oncologist who do this daily don't have information more readily available to assist patients in understanding or explaining these things. Even the PCF is not fully clear, or dare I say even clumsy, in mentioning post-radiation PSA monitoring. What I'm expecting is that in the next three to six months, PSA will reappear, and begin to climb. This may be totally normal, but it may signal serious problems on my door step. I have no idea. It is being measured to a reason. Are there clinical decision points: time of appearance; rate of rise, height of the rise? I'm assuming so, otherwise, why measure it?

OK. I'm done with my grumping.

*I elected to end it at 12 mo. The doc wanted 18 mo.

I believe this is the PCF.org video mentioned above - vimeo.com/795616945. Very informative.

drj, Don't apologize for grumping. I call it getting something off your chest. It helps to do that.

I mentioned to our mentor that I am a very introverted private person and very reluctant to talk to other about my medial issues and fears. MCC allowed me to bypass this reluctance of in person talking and I vent, asked questions, seek feedback from others through MCC. So when I read the grumping comments I just smile as just what you should be doing to learn from the experience of others. Get if off your chest and that is GOOD for you.

Your PSA is a individual thing. oncologist can work with statistics but everyone is different. Everyones' prostrate will react differently. You will see some post that have no side affects from treatments and those that have significant ones.

Hormone treatments are designed to stop the growth of cancer cells. They mostly deal with stopping testosterone. This hormone feeds the cancer cells. So doing the hormone treatments causes the cancer to slow down and/or stop growing allowing radiation treatments or surgery work.

I am told, and this may have changed with new type treatments, radiation does not kill the cancer cells. What is does is damage the cells so they do NOT reproduce and grow so they die off. So you would think radiation would also do this to normal cells in your prostrate as well. Well yes they are damaging the good cells. HOWEVER the normal prostrate cells can repair themselves and grow back. That is the big difference.

If you keep your prostrate this recovery takes time and thus the differences in PSA test of those having pre radiation hormone treatments, surgeries, or just radiation. All will have different affects on the PSA readings and after treatment readings.

I listened to every oncologist, urologist, doctor who went over this with me. So is not my personal opinions but what I learned from the specialist. I keep asking though and anything I don't understand or have questions I asked. I do this through the portal system that Mayo has for patients as well as UFPTI which also has a portal. Thus I have a written responses to my question, concerns and explanations.

Good luck and again don't question or demean yourself for questioning, asking for more information from others, and getting a better understanding of the information you need!