Perineurial invasion. 1 out of 10 samples cancerous. Treatment?

ASPI (Active Surveillance Patients International) just had a great Q&A with Dr. Jonathan Epstein.

He mentioned (at 1:07 - one hour seven minutes) that perineurial invasion is a marginally worse feature.

Here's the link to the video -

This Q&A was based - roughly - on Dr. Epstein's presentation "What You Need To Know About Your Prostate Biopsy on Needle Biopsy". ASPI had an issue with how many could attend, thus the followup.

You can view the original presentation here...

Here’s a 2014 paper about Perineural Invasion in the Absence of Malignancy —> https://pmc.ncbi.nlm.nih.gov/articles/PMC4772935/#:~:text=Perineural%20invasion%20(PI)%20is%20typically,4%2C5%2C6%5D

There are a number of papers about this.

I never stop learning on this Forum…funny that older papers mention PNI in the presence of PCa as being very significant for LETHAL outcomes. Yet, articles from 2022 forward, coupled with Dr Epstein’s remarks (cited by @breadmaker) show only marginal significance at worst. Amazing how you can have such diametrically opposed views on the same subject.
And these are not findings culled from bogus websites, but NIH and university research studies…
Phil

Last year I attended a webinar, where I heard the speaker (I don’t recall whether he was a urologist or an RO) say that he had never seen the presence of PNI changing a treatment decision:
> if the patient was considering a prostatectomy, PNI wouldn’t change that;
> if the patient was considering radiation, PNI wouldn’t change that.

Here’s a real-life example —> My oldest brother (78y) is starting his PC journey right now, He has PSA of 5.7, PIRADS 5, 4+3=7, with PNI, and they started him on Casodex, he just had his first Eligard injection on Friday, and will start 28 sessions of IMRT (70 Grays) in a month. I find that interesting because 4-1/2 years ago, at 65y I was diagnosed with PC, PSA of 7.9, PIRADS 5, 4+3=7, without PNI, and they started me on Casodex, Eligard injections, and 28 sessions of Proton radiation (70 Grays). So, we had pretty much the same diagnosis (except me being 13 years younger at the time), and yet him with PNI and me without PNI, and both of us have pretty much the same treatment regimen.

I’ve done a little more digging and found more articles on benign PNI as far back as 2005 and as recently as 2023:
> 2005: https://pubmed.ncbi.nlm.nih.gov/16096404/

> 2023: https://pmc.ncbi.nlm.nih.gov/articles/PMC10605475/

Seems like just one more ambiguous factor patients have to deal with.

I have perineural invasion. My team said that PNI does not affect a decision about the type treatment as that's mainly based on Gleason grade. But for 3+4, it's a secondary factor along with others such as genetics, family history, size of lesion, location of lesion, % of grade 4, cribriform, intraductal, and number of positive cores for deciding on active surveillance or treatment. For me, having PNI along with several other of those factors led me to decide treatment over surveillance.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7221308/
Ambiguity and Contradiction rules the day! Here’s another, co-authored by my RO at Sloan. I guess we are so accustomed to the word ‘invasion’ having dire consequences, we just assume it’s another nail in the coffin.
When I read my biopsy report and saw PNI on 6 out of 12 cores, I figured it was lights out for sure.
Phil

And yet PNI does not appear to be representing that cancer is more aggressive.
From the above video conclusions
‘These findings suggest that in this setting, biopsy PNI alone should not be a concern for more aggressive disease requiring pathologic confirmation or intervention.”

These are the kinds of studies that are not very interesting. They only look at favorable gleason scores at biopsy and see if PNI has an effect on upgrading, i.e., that pattern 4 was missed at biopsy. It does not say that PNI in the pathology has any independent effect on outcomes.

You’re correct, it does not say that; it does say that a finding of PNI represents a disease that is more diffuse throughout the gland, thereby making the Gleason score derived from the biopsy more of a ‘truer’ one….in other words, the urologist can’t miss!
The outcomes are really a function of the Gleason scores, don’t you think? A poorer outcome could occur, let’s say, if a surgeon goes in thinking his patient is a G3+4 and post op pathology makes it a G4+3 or G4+4.
Would he/she have been more careful at dissection? Did they leave what they thought was benign tissue and now would have taken it out in retrospect? I don’t have the answers.
But since PNI does represent more widespread, diffuse disease, EPE and broken capsules could result from this and ‘possibly’ have a negative effect on outcomes. It’s not the PNI itself (like cribriform or IDC), but what its presence signifies.
Phil

I was 11 out of 14 with a Gleason 9 and I still feel fine, though I struggle with fatigue and weight gain while on ADT…