Saturday, August 30, 2014

A new lymph node station in lung cancer?

Earlier this week in our morning didactics session we had an interesting discussion about advanced stage non-small cell lung cancer (NSCLC). Now, there is certainly a LOT to discuss about advanced stage NSCLC, and there is a lot of uncertainty in how to treat it with the multitude of new targetted agents coming on the market for mutations like ALK, KRAS, N-RAS, BRAF, EGFR, etc...  and the trials that have been run are often difficult to interpret because of changes in standard of care, stage migration due to novel imaging modalities (PET) and other things.

To add to all the uncertainty in treatment, the staging guidelines (AJCC in this case) can change. When I started my residency in 2009, we were on the 6th edition, and now it's the 7th. While the changes are usually small, they matter, because the trials that are now having results reported were often stratified using earlier editions of the staging guidelines, once again clouding the picture for patients needing treatment decisions today.

One thing that hasn't changed, and never will (?) however, is the location of nodal stations. Right? Maybe not! As a refresher, we care about a number of nodal stations when staging lung cancer. Here is the picture we all know and love (also available from the AJCC in poster form here):

Please direct your attention to the lymph node station labelled #7 - this is the sub-carinal station, and one that is often involved, and often biopsied because of the relative ease of access (bronchoscopically). Notice it is, by definition N2. However, it is also considered mediastinal. 

Now, this is all well and good, until you have a patient present, as we did at our cancer center several weeks ago with a Left sided T2 NSCLC with station 7 involved TO THE RIGHT OF MIDLINE. We went through the imaging carefully, it was NOT station 8R, it was station 7, creeping down and crossing midline to the RIGHT.

So, now the patient has, by one definition, T2N2 disease (there were no other contralateral nodes or other nodes to make him N3) by virtue of his involvement of station 7. HOWEVER, he could also have T2N3 disease by virtue of having contralateral mediastinal involvement! This is not a trivial difference as it is the difference between IIIA and IIIB, resectable and unresectable.

What to do? Well, he had poor performance status, so surgery was out either way, so we opted or combined, definitive chemo-radiation. However, this uncertainly raise the possibility of a need for more detail in the staging system. Sort of in jest, we proposed a change for the 8th edition - maybe we should have a station 7.5R/L dichotomy for significant involvement, or possibly a 7C/R/L trichotomy?

Saturday, August 2, 2014

Re-entry into the clinic and my first evolution paper!

Sorry for the long radio silence - I re-entered my residency after a 3 year hiatus to pursue full time research and things have been busier than anticipated. While I am on a light rotation (sarcoma), which requires only 50% of my time actually in clinic, I had forgotten what being a #resident is like, and more importantly, what having a pager is like!!!

My personal research efforts have slowed somewhat - with my efforts now divided between the clinic, being a dad and thesis writing. I've changed my focus to writing up what I have currently, rather than chasing after new results, so I haven't much to report. A student I'm working with, however, +Daniel Nichol , recently finished up a paper that he and I have been working on for some time. He is going to write a full blog post about the work, but this will take some time. In the mean time, I thought I'd at least let the community know we've finally submitted our paper to the +bioRxiv Preprints site, as well as a journal (contemporaneously), which you can find here:

In this paper, my first personal foray in theoretical #evolution we build on theory from some exciting theoretical and experimental papers from Steven Weinreich (Weinreich et al. Science) and +Jeff Gore (Tan et al. PRL) to explore the concept of 'steering' evolution as a method of preventing the emergence of resistant strains of bacteria (or cancer!).

I look forward to putting Dan's proper post up, but until then, enjoy the #preprint - we welcome comments!

We were flattered, as well, to see another blog pick up our preprint - yet another reason to use the bioRxiv or arXiv!