Does a biopsy of a recurrent LN will help in anything ?

[CarlosBrasil]

Hi all, short version of my Bio: RP in 2019 followed by 33 sessions SBRT with short term ADT (6 mo). Reccurence in 2021, SRT to one LN in 2022, 5 sessions with short term ADT (6 mo). As soon the ADT stopped the PSA started rising, it´s 0.53 now.

A new PSMA PET last week showed a bunch of small points in LNs and three ribs. MO, RO and URO agreed that I should start ADT for life, including a second line AR. No more RT.

According to a specialist I´ve talked, one paraortic LN could be reached for a biopsy. Do you think that there is any kind of test that could find something to help my treatment, now or in the future ?

I appreciate your experience and thoughts in this possibility.

Carlos O.

[Hidden]

You could get it tested for certain genetic properties. If your pca has specific mutations (e.g. MSI/H….microsatellite instability high, or others) there are immunotherapies that can provide amazing results (e.g Keytruda). The tests are not cheap.

[tango65]

The test may add info about genomic changes which could make the cancer susceptible to treatment with olaparib, rucaparib, keytruda BAT and immunohistochemical studies indicating the cancer may respond to cabazitaxel plus platinum compounds.

I have the impression para aortic nodes are not easy to reach. You need to discuss how they are planning to reach the nodes

[CarlosBrasil in reply to tango65]

The Doc which does the biopsy evaluated the PET and said he can reach it, using CT guided procedure.

Not so easy, that´s why I was wondering if the results worth it. Thanks you for your heads up.

[GP24]

The biopsy will probably be done with ultrasound imaging. This will not show the small mets detected with a PSMA PET/CT. So he will likely miss the node.

Also the nodes will have different mutations so you cannot be sure the genetic results of this node applies to all others. Usually for genetic testing the existing biopsy probes (in your case from surgery in 2019) are used which your pathologist should have available still.

[CarlosBrasil in reply to GP24]

The biopsy would be done guided by CT, there is one bigger LN which the Doc thinks he could get.

The fact that the LN could have different mutations, after being through two RTs plus ADTs was the reazon that I am thinking about the biopsy. Don´t you think at this point the genetic from the LN would be better than the original prostatic and vesicular material ?

[GP24 in reply to CarlosBrasil]

There could be a small difference. But the results from the prostatic material gained from surgery is usually sufficient so you can avoid this biopsy. There are somatic mutations and germline mutations. To test both you will also need a genetic test based on a blood draw or saliva.

[CarlosBrasil in reply to GP24]

The blood test I´ve done already, with no finds.

At this point if there is no real benefit in the biopsy I will skip it for sure ! It seems the the material from the surgery is a better option, it´s already available, at no risk.

Thank you for your insights, I really appreciate your help.

[GP24 in reply to CarlosBrasil]

Here is an overview of the two kinds of testing:

Germline or somatic testing

[KocoPr]

Good point GP24 makes. They can do a next generation DNA sequencing done on your prostate tissue and also do a germline DNA sequencing. Make sure you don’t wait any longer as i had waited 5 years and although they got some important results the tissue samples were to degraded to do a full sequencing.

[CarlosBrasil in reply to KocoPr]

Thank you for your response.

That´s what I was looking for, DNA sequencing and germline DNA sequencing, I am going to look at them more closely.

GP24 raised a good question really, my understanding was that the more recent tissue you have the better, no matter from where, not so sure now.

[KocoPr in reply to CarlosBrasil]

GP24 is correct that the most recent the better. I myself had not undergone any ADT, just radiation so the ADT wouldn’t have created any new mutations thus having my original tumor tested was beneficial. As it turned out my tumor had TMPRSS2/ERG fusion (approx. 50% advanced PCa have that) and also i had a unusual MSH6-LOSS. My germline only had RAD50 mutation of uncertain significance. So i failed to get into the rucaparib trial back a few years ago.

I would ask your oncologist but it would not hurt to have your original tumor sequenced along with germline.

[CarlosBrasil in reply to KocoPr]

Thanks for sharing your experience, and your advice.

[E2-Guy]

Perhaps you could try applying Transdermal Estradiol (tE2) as ADT.

[Tall_Allen]

It will probably not be useful, but you can do it on the small chance that it might be.

[CarlosBrasil]

Following the comments and advice from your answers, I decided not to do the biopsy, but to ask for the somatic testing of the RP material.

It turns out to present "relevant" variations on genes CHEK2 e ETV1, as noted in the result. I had done a couple years ago the genomic testing with no mutations.

My next appointment with MO is next week, where we will discuss the start of the ADT.

Do this finding change anything at this point ? I appreciate all your help.

[TeleGuy]

I think that when you have a chance to do a biopsy and genetic sequencing of the sample, you should do it. I'm 8 years in and last year I did a biopsy of an aortocaval lymph node and got really useful information that shaped my treatment. The biopsy showed that the cancer is beginning neuroendocrine differentiation which suggested adding carboplatin to what would otherwise be a course of docetaxel. (Platinum-based chemo is supposed to be more effective on neuroendocrine cells.) You can't get this information from your prostate that was taken out years ago because PCa is a moving target. I did another biopsy this year as things started taking off again and am awaiting the genetic sequencing to see what has happened during the last year.

Below is a link to what I wrote last year when I got the biopsy. The interventional radiologist was able to squish my intestines out of the way and get a straight shot. There's an ultrasound image where you can see the needle:

healthunlocked.com/advanced...