Significance of Perineural Invasion PNI

All 3 radiation oncologists and my original medical oncologist feel that PNI can have a big impact concerning recurrance.

Oops, let me finish my answer, got put off on a long phone call.

These doctors felt strongly, that because fo PNI, that cancer cells can easily escape up the nerves and nerve bundles.  They feel this is how micro-metastises  (?)  often take place.  And why what seems to be a "clean" surgery and good post surgery pathology report, suddenly changes and turns into a case of quick recurrance.  Not pretending to be a doctor of any kind, but using our dear brother Sonny from FL, his case of having a first class surgery turn into almost instant reccurance, and now there is a "spot" on his leg bone, could very well be an example of PNI.  Certainly no way of proving or disproving it at this point.

Most of the books on PC surgery downplay the significance of PNI, including the great Walsh book if I remember correctly.  Since there are so many nerves and nerve bundles surrounding the prostate, and if you factor in the men that have really enlarged prostates, it would seem like there are many of these "tunnels" for PC cells to escape.

I remember my original medical oncologist discussing my utlra rare cancers in the past, telling me that it would take one million cancer cells to sit on the "point" of a staight sewing pin, and there would still be room for more.

That's also why most of early dx PC guys cat and bone scans truly are a waste of time and money, as with a low Gleason and a low PSA, nothing is going to be developed at that point to possibly show up on those type of tests.

Why the 3 radiation oncologist disagreed among themselves, for example, on the value of adding HT either before or after SRT, and had far ranging views on vitamins and supplements, for example, they all gave me the same answer on PNI.

I am not saying I agree or disagree, have no firm way of knowing the answer.

David in SC

logo,

these are among the many reasons and variables when trying to understand and make any attempt to define PC to some sense of logic. In most cases, it just won't let you box it in. Too many exceptions to the rules, a good reason for each man to really monitor his own PC journey closely.

Jerry, what you suggest, is exactly the aspect the 3 rad. oncologists discussed with me. It might be the very case with your situation too, but no way to prove or disprove positively. As always, good luck to you brother.

David in SC

It is interesting that some doctors put some importance to PNI and others don't. Because the article was based on surgical pathological results I found it interesting that 67.5% had PNI upon pathology. The caveat was the 95.4% of the patients in the study remained bio-chemical disease free out to 118 months (almost 10 years) and in that group 65.7% had PNI.

So what is the significance of PNI on post surgery pathology...hard to nail down however majority of men will have it and a greater majority will be progression free out to 10 years.

David I think, that what your doctors maybe referring to was when found on biopsy prior to surgery. It is a pathway for cancer to travel so could be of some importance in that setting as a pre-curser for further investigation.

The gist of the article in what I read, was that PNI when found on pathology samples obtained at surgery, isn't a significant factor in determining the disease progression. Not nearly as much as final gleason score, EPE and positive margins will have. So for those just starting their journey to maybe make them feel a little more at ease with such ominous wording as "Perineural Invasion"...sounds scary doesn't it?

My diagnosis included PNI which put us in a panic along with everything else. Our internet search seemed to indicate a higher probability of escape which created more anxiety. But my local Urologist, our second Urologist who came highly recommended, our consult with NY Langone, and our surgeon at NIH expressed no concern at all and some said they used to consider PNI years ago but studies have shown no difference in outcome. At least that put our minds at ease as we had enough concerns without considering PNI.

My overall take away from discussing this with them was it really does not change their approach to treatment and since it is inconclusive as to the long term outlook why spend time worrying about it. And in my case in particular they were already taking an aggressive approach because of other concerns. God forbid if I ever have to deal with a recurrence how can I know whether it spread from there or the initial concern of SVI or ECE?

For me it just was easier to go with the Doctors opinions and gave us one less thing to stress about...Jim