So, what is the deal with perineural invasion (PNI)?

[I_will_fight]

Hi all,

I am kind of a newbie, so please correct me if I say something incorrect.

I understand Colon Cancer is typically graded based on TNM criteria and this grade is mapped into a more simplistic "Stage"

As part of TNM they take into account the tumor growth, the invasion of nearby areas, organs, lymph nodes and distant metastases.

I was personally pretty happy when my doctor told me my TNM was T3N0M0, in fact I almost cried from joy during the appointment when I learnt I had no limphatic Nodes involvement, no limphatic invasion and no spread to the spleen. Doctor said, that my case would be looked into in the committee session, but it was not certain that chemo would be recommended.

But then, upon reading my report I see "perineural invasion present".... I googled it and it appears it is a predictor of poor prognosis, not different from limphatic invasion, in fact according to a few studies, it is a risk factor and enough to recommend chemo in Stage II patients.

Do you guys know much about this perineural invasion? I see many people don´t have any mentiont to it in their signature, also most studies about it are fairly recent.

Is it that bad? Have people here managed to remain NED (or cured) even with PNI present?

Thanks to all, BR

JC

[Beckster]

I am a T3N0M0, Stage 2A. I did not have PNI, but I did have LVI. Because of this risk factor, I was on chemo for 6 months. I took Xeloda, which is a pill form of 5FU. I have not regrets and wanted to do everything possible to make sure the cancer did not come back. My onc is part of MD Anderson, and I went by his suggestion. If you have any questions, feel free to message me. I have been NED for almost 4 years and my chance of recurrence is now less than 5%.

[I_will_fight]

Thanks for your reply Beckster,

I am very glad you did so well!

I think they will also recommend chemo for me. Not sure which one.

Apparently since I am MSH6- deficient Platinum-based chemos are not very effective, so I might well end up on Xeloda, as you did.

Let see if someone with PNI can share an equally uplifting story.

Best Regards,

JC

[Carboxo]

My sister has slight perineural invasion. Her cancer was first thought to be early stage 1 but was upgraded to stage 3A upon surgical path. She did chemo first then chemoradiation. She just did her reversal May. She just had her first clear colonoscopy but has diversion colitis and rectosigmoid colitis along with 2 ulcers at the anastomosis site.
Good luck

[I_will_fight]

My sister has slight perineural invasion. Her cancer was first thought to be early stage 1 but was upgraded to stage 3A upon surgical path. She did chemo first then chemoradiation. She just did her reversal May. She just had her first clear colonoscopy but has diversion colitis and rectosigmoid colitis along with 2 ulcers at the anastomosis site.
Good luck

Thanks Carboxo,

Did they mention how relevant the perineural invasion was to the staging? Or not at all?

I hope your sister gets well.

Best regards,

JC

[I_will_fight]

Giving this a little bump, as it is not geetting much attention.

Best regards

JC

[I_will_fight]

Thanks for your reply Beckster,

I am very glad you did so well!

I think they will also recommend chemo for me. Not sure which one.

Apparently since I am MSH6- deficient Platinum-based chemos are not very effective, so I might well end up on Xeloda, as you did.

Let see if someone with PNI can share an equally uplifting story.

Best Regards,

JC

Just for the sake of correctness and completeness... My previous post was wrong.

5FU appears to be innefective for dMMR cancer cells, but Oxiloplatin makes the tumor sensitive to Capecitabine, or so my oncologist explained to me.

So I ended up taking 4 cycles of CAPOX.

Thank you, BR

[hwr]

The prognosis value of perineural invasion varies depending on the cancer type. I had appendix cancer which was utimately staged like yours at IIA with perineural invasion. My oncologist offered adjuvant chemo but said he would not take it if he were in my shoes. The tiny benefit does not outweigh the side effects, in his opinion and that of many others. A small majority believe it should be taken.

Since your doctor did not mention to you that perineural invasion is a predictor of worse outcomes in your case I would assume he/she does not think it is significant. Researching on the internet has its value but it can also lead us to make incorrect assumptions about our disease.

I am being treated now by one of the leading appendix cancer doctors in the country and he didnt mention my perineural invasion. He thinks I have a very good chance of not having a recurrance so I assume he does not consider the perineural invasion to be that significant.

[I_will_fight]

The prognosis value of perineural invasion varies depending on the cancer type. I had appendix cancer which was utimately staged like yours at IIA with perineural invasion. My oncologist offered adjuvant chemo but said he would not take it if he were in my shoes. The tiny benefit does not outweigh the side effects, in his opinion and that of many others. A small majority believe it should be taken.

Since your doctor did not mention to you that perineural invasion is a predictor of worse outcomes in your case I would assume he/she does not think it is significant. Researching on the internet has its value but it can also lead us to make incorrect assumptions about our disease.

I am being treated now by one of the leading appendix cancer doctors in the country and he didnt mention my perineural invasion. He thinks I have a very good chance of not having a recurrance so I assume he does not consider the perineural invasion to be that significant.

Thanks HWR, that helped.

After talking to two different Oncs,

My onc said that without PNI he would not have recommended 3 months CAPOX of chemo - which I am doing, better to err on the side of caution.

The scecond onc tells me he personally would not have taken the chemo either way.

Also the ESMO (the european equivalent of ASCO) cosiders it to be "medium risk factor" along with "CEA over 5 ng/ml" or "histological grade 3" which i think means poor differenciation