Hi Kelly,

Thanks for saying I've taken an analytical approach to the problem. The comment really speaks to who I am. Ever since I was a small child (and had a crush on my 4th grade math teacher), I have approached problems analytically... its a source of pride really.

I understand (and agree with) the gist of what you are saying, but even the doctors know that probabilities have everything to do with this. They are constantly weighing probabilities as well as costs. In this case, one of the costs is death while the other cost is quality of life (since ND surgery can lead to lifelong shoulder pain and weakness as well as other unpleasant side effects). [Mathematically, what we're talking about is Bayesian analysis.]

There is a certain probability that I have live cancer cells in my neck. The questions are: (1) What is that probability for me, and (2) Is that probability large enough to warrant having the ND? If the average healthy Joe (who is not a cancer patient) walks in off the street and asks the doctor if he should have ND, the doctor (of course) will say no... because the probability that Joe has live cancer cells in his neck is miniscule. However, if for any reason this probability gets above 5 or 10 percent, the doctor is likely to recommend ND. If he recommended ND at the 0.1% level... it means he's caused 999 people to suffer the ill-effects of surgery just to have the *possibility* of saving 1 life.

The reason the doctors do all their tests is to try and ascertain what the probabilities are. No test is perfect but a good test will have a low probability of a false negative AND a low probability of a false positive; medical lingo uses the terms "sensitivity" and "specificity"... in communications they refer to a "receiver operating characteristic (ROC)". Unfortunately, the tests the doctors have to detect live cancer cells in my neck are NOT very good. So far, there is nothing to suggest that I have live cancer cells in my neck other than the fact that my nodal mass is still fairly large: it doesn't seem to be growing and the PET/CT result is negative - but the worry is that this result might be a "false negative". I'll have a biopsy done but, even if that's negative, we'll still worry that this too could be a false negative.

I'm now starting to dig into the medical technical literature on this and have found a bunch of interesting links:

http://www3.interscience.wiley.com/journal/117914986/abstract
http://www3.interscience.wiley.com/journal/104535343/abstract
http://www.springerlink.com/content/6144q68r7m763867/
http://linkinghub.elsevier.com/retrieve/pii/S0194599807002811
http://archotol.ama-assn.org/cgi/content/extract/134/10/1122
http://jco.ascopubs.org/cgi/content/abstract/24/9/1421
http://clinicaltrials.gov/ct2/show/NCT00720070
http://www.issoonline.com/content/1/1/6

As I read more, I become more convinced that I should go ahead and have this surgery just to be safe. But its unfortunate that we don't know more. For example, the statistics I've seen do not distinguish between HPV+ and HPV- patients. For example, if I see a statistic that says (I'm making this up):

"30% of HNSCC patients who started with N2 or N3 disease, and underwent chemoradiation treatment to at least 70 Gy, were subsequently found (after neck dissection) to have residual disease in the removed lymph nodes"

I wonder: Were these patients HPV+ or were they HPV- ??? We know that HPV+ patients respond much better to chemoradiation treatment than HPV- patients so, if they were all (or mostly) HPV- patients, its still quite possible that the 30% figures drops to less than 5% if the patients are HPV+ like me. Unfortunately, its only recently that HPV status has been shown to be an important factor in HNSCC patients, so (to my knowledge) the studies haven't been done yet.

So what is the probability for me? I don't know. That's what I'm trying to figure out. Yes, its likely that I'll find this probability is large and so will end up choosing to have the surgery... but as I take time to do this research, I'll also try to figure out who I should choose to do the surgery and what, if anything, can be done to mitigate (or avoid) any bad side-effects of the surgery. I'll do everything I can with the time I have available to try and get the best possible outcome. No sense being cavalier about this.

Rob