Defining resectability in stage III lung cancer really needs to be under the supervision of a qualified thoracic surgeon. Ultimately, I say that no one but a surgeon should make the distinction of whether a patient is resectable or unresectable. Medical oncologists shouldn’t do it, pulmonologists shouldn’t do it, and radiation oncologists shouldn’t do it. These are specialties that are often involved, but really, the surgeon is the ultimate decision maker. Now, obviously we can collaborate and discuss issues with regard to resectability with the surgeon, but I think ultimately, it comes down to that decision making process.
Now, obviously, resectability has to focus around two things — can you remove the primary tumor, and as we previously mentioned, T3 lesions that involve the pericardium, the diaphragm, the chest wall — these can typically be resected en bloc, taking part of the chest wall or part of the pericardium. I think that for experienced thoracic surgeons, that is not a difficult procedure. I think there are many questions when you start to have T4 lesions that involve vital structures such as the esophagus, the trachea, the great vessels, perhaps the spinal column, bony disease in that area — there are highly selected situations in which one may consider that with obviously, reconstruction of the vital structures. But, these are very few and far between, they need to be done by very experienced surgeons and a team of medical oncology and radiation oncology before I would embark on that sort of decision. T3 is a little bit easier than T4.
The second issue, and more common issue, is with regard to the mediastinal lymph nodes. Now obviously, if you have bilateral mediastinal involvement, and this would be both N2 and N3 — N2 being in the same side as the cancer, N3 being on the opposite side of the cancer, then we would say that patient is not resectable. N3, by definition, should preclude surgery and really is treated optimally with chemoradiation. The real issue centers down to those patients who have isolated N2 disease.
Now, there’s not universal agreement about what’s resectable and what’s not resectable. Certainly, if you have small lymph nodes measuring less than 2cm, and particularly if it’s only in one site, I think most people would consider those patients potentially resectable. The question starts to evolve when one gets into a situation of what we refer to as bulky lymph node involvement. Bulky is a bit of a random definition, most of us use over 2-3cm, and if you have that bulk, as particularly in multiple nodal stations, besides the trachea or the subcarinal area. I think with most of those patients, the likelihood that surgery is going to be able to completely sterilize the mediastinum is quite low, and I would consider that those patients would not be resectable, in that they should be best served by the combination of chemoradiotherapy, which still offers patients a chance at being cured, and as I have previously mentioned, it’s not clear in this population that surgery improves the overall cure rate of this subset of patients.
So I think, really in the non-bulky, particularly isolated, one-site lymph node involvement — that would be a patient that we may consider for preoperative treatment, either chemotherapy or chemoradiation as we talked about before; those would be considered potentially resectable patients.