The simple answer is NO, however it should change your treatment game plan.
A member of one of my support groups who has been doing active surveillance for about 5 years recently reported that their current biopsy indicated that they now have perineural invasion (PNI). They did not understand what was the significance of this finding and they wanted to know if they now had advanced prostate cancer.
In reality, PNI is found in almost 30% of positive biopsies.
However, before I discuss the significance of this finding it is important to understand what this means. When a pathologist finds that there is PNI they are saying that they have found prostate cancer cells surrounding or tracking along a nerve fiber within the prostate. This does not mean that the cancer has left the gland.
Not withstanding this the importance of this finding , it takes on a new light when you realize that nerves within the prostate travel outside of the gland through microscopic holes in the prostate capsule. The capsule is the outer covering of the prostate gland, which for some period of time can manage to contain cancer cells within the gland. In essence it is a barrier protecting the rest of your body from prostate cancer cells.
However, the nerves do pierce the capsule and can offer an easy exit point for cancer cells from the gland to the rest of your body.
The real concern about the presence of PNI in a biopsy is it indicates that there is a higher likelihood that the prostate cancer has or will escape from the prostate gland, or become advanced prostate cancer.
There have been studies that have compared the final pathologic findings (after radical prostatectomy) to men with and men without PNI on a biopsy. These studies have shown that men with PNI have a 2-3 times higher rate of extra-capsular extension (prostate cancer outside of the gland) and nearly twice the likelihood of positive margins after prostatectomy when compared to men without PNI on their prostate biopsy.
Simply put, the presence of PNI doubles the chance of a man having T3 disease (tumors that have broken through the capsule).
The other important findings are that finding PNI on biopsy is associated with a higher Gleason grade (Gleason 8-10) or a higher grade disease even when only low grade disease (Gleason <7) is found on biopsy (possible sampling error) and that men with PNI are at a higher risk of seminal vesicle invasion and lymph node metastases.
In fact, one study demonstrated that over 40% of men with PNI and low grade disease on biopsy are subsequently found to have high grade disease on final pathology after prostatectomy.
Having PNI after a Prostatectomy has negative impact on prognosis. At Johns Hopkins there was a study that followed 1256 men with prostate cancer for an average of 3 years after radical prostatectomy. One hundred eighty eight men (188) of this population (15%) had PNI on prostate biopsy. Despite the short three year follow up period men with PNI on biopsy were found to have three times the likelihood of PSA recurrence as compared to those men without PNI. This finding has been duplicated in other studies.
What about the prognosis after radiation therapy? The story is similar; the presence of PNI on prostate biopsy has a negative implication. One study followed 381 men undergoing radiation therapy for localized prostate cancer, 86 (23%) of whom were found to have PNI on prostate biopsy. After 5 years of follow up, 69% of men without PNI were free of cancer as compared to only 47% of men with PNI.
The presence of PNI on a biopsy could instantly transform an otherwise low risk prostate cancer into a high risk disease.
Since having PNI on final pathology clearly and negatively affects prognosis its presences should influence the treatment decisions.
A study of surgical approaches in men with PNI demonstrated that removing the nerves on the side of the prostate with PNI on biopsy led to a positive margin rate of 11%. In contrast, the positive margin rate was 100% when the nerves were spared on the side of PNI.
It stands to reason that men going forward with surgery should consider not having nerve sparing surgery. In addition, given the high likelihood of positive margins and T3 disease, men with PNI on biopsy should also discuss with their doctors undergo radiation therapy following the radical prostatectomy.
Similarly, men opting for treatment with radiation with PNI should consider themselves high risk no matter what their Gleason or PSA score and opt for a combination of radiation and hormonal therapy rather than radiation therapy alone.
Perineural invasion (PNI) on biopsy is a very significant and needs to be treated as such, despite Gleason grading and PSA scores. It can indicate high risk prostate cancer, even in men with who otherwise we would consider to be low risk.
PNI is not necessarily advanced prostate cancer, but it is often associated with a poorer prognosis, leading to a higher risk of recurrent and metastatic disease.
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Joel T. Nowak, M.A., M.S.W.
Hi Joel, once again a great article and information I wish I had known this (or doctors who would have told me this) when I had my biopsy. I had PNI but was told I had negative margins after surgery and did not have radiation until two years later after recurrence. Unfortunately that was too late and now I have metastatic advanced disease. I will go to my grave always wondering if I could have been cured if not for the doctors who refused to do tests and then doctors who chose not to give you all the information they may have known. I relied on the information and suggestions they provided and because I did not go that extra step and look out for myself I now find myself in this situation where I will never know if I could have been cured. I hope men who get a positive biopsy take more control of their treatment and don;t wind up like me.Good job, Joel
Ron,
I understand your feelings, they are legitimate. However, one thing that I have learned is that there is no reason to look back, what has transpired has happened and there is nothing we can do to change the situation. What we can and must do is learn from our errors so that we don’t repeat them again and try and teach from our experiences so that another man will not fall into the same trap. – Joel
Great article that answered my nagging doubts concerning pni. I had been told not to worry thst I had pni in my pathology. As pt2n0m0 and g6 I was confident its all gone. Wil take care now to be monitored each year. Lots of people still say to ignore pni which adds to confusion.
This article was very informative and clear about the definition of PNI. My husband has just been diagnosed with Stage II, t2c with PNI in 5 of the biopsies. He will have an MRI & bone scan within the next day or two to find out if it has spread. The waiting and not knowing is difficult. When you know, you can focus and plan for what is coming.
When a pathology reports indicated that there is perineural invasion this means that cancer cells were seen surrounding or tracking along a nerve fiber within the prostate. The nerve fiber goes through an open area which MIGHT allow for easier spread of the cancer outside the gland. This means that you are at an increased risk for a spread, but it doesn’t mean that it has spread.
You should have a very careful discussion with your doctor as you are at an increased risk of having a recurrence. You should explore with the doctor the possible risks and rewards of additional treatment (radiation) or in the alternative, beginning a very aggressive surveillance program to make sure that your PSA becomes and stays unmeasurable.
Radiation is not free as it always comes with side effects. I don’t like it when it is described as a non-invasive treatment modality.
Joel
Very good article. Thx. I am 52 years old and had Radical Prostectomy on 3/23/15. The Surgical Pathology Report listed “Present” for Perineral Invasion. Do I anything to worry about or need Radiation? My gleason as 3+4, 7.
Thanks,
Tim
Thanks Joel. I spoke with my Urologist and he kinda blew if off and just said we would check my PSA again in 90-days. In addition, I contacted my surgeon and he agreed that waiting another 90-days to re-check my PSA levels. (My Urologist and Surgeon are two different doctors in two different cities), However my Urologist did start the conversation with “other doctors may want you to do Radiation, but let’s wait”. Should I insist on the radiation or take the doctors advice to wait. The waiting gets to you and I find myself thinking about it often and researching more an more things on the web, which is very extensive. Surgical Pathology report also stated “Focal extraprostatic extension into the anterior bladder neck”. The surgeon underlined it and circled it, but really don’t know what is means. By the way, Gleason grad 3+4=7 with focal extraprostatic extension ino teh bladder neck; Pathologic statging pT3a pNX. Lots of stuff that I do not know what to do. Thx. Tim
Joel,
I will send you a PDF of the Surgical Pathology Report if you want to provide an email address and you believe it might be beneficial/informative to you assisting me. Thanks,
Tim
Hi, I had 3 PSA tests, each approx 3months apart, 4.8 (5/15), 4.4 (9/15) and the latest 4.3 (12/15). My biopsy showed 2/5 malignant on the LHS, with 5% malignant with largest length 2mm and no PNI or extraprostatic spread. But the RHS has 4/5 malignant with70% malignant with largest length 11mm and PNI invasion, however, again no extraprostatic spread. My Gleason is 3+4=7. and I’ve been told I’m between T2 and T3, no real a, b or c stated though.
I was only diagnosed and confirmed by the biopsy in August 2015. I want active survelliance to at least get some idea of rate of growth before I do anything urgently, and later feel that surgery for a prostraectomy, possibly the radiation late to hopefully stop/prevent reoccurance.
However, the doctors don’t tell you much and are always in a rush to see the next patient, but without telling me in the detail I wish to know, they want to do 3months of hormonal therapy immediately, followed by 7 weeks of radiation. What is your advice as to what I should do now?
Keith,
The very first thing you should do is have a second opinion on your biopsy slides. To learn how to do this go to the Malecare web site, specifically to:
http://malecare.org/second-opinion-on-biopsy-slides/
Then go back to the Malecare main page (www.malecare.org) and click through and read all the information, paying special attention to the section called “newly diagnosed.” There is a wealth of information you need to have prior to making any treatment decisions.
Joel