Dr. Mark Socinski, University of Pittsburgh Medical Center, describes the different types of stage III (locally advanced) NSCLC, and states which of these types tend to be resectable.
Let’s start by defining, or explaining, the heterogeneity of stage III disease. In my mind, the two major types of stage III patients are those that have lesions that start to invade structures, and certainly T3 lesions that may invade the chest wall, the pericardium, the diaphragm — associated with N1 disease, are stage III disease but they are generally considered resectable. Then, we have those lesions that are more invasive and invade vital structures and are so-called T4 lesions, which for the most part, are not resectable, with some rare exceptions with regard to resection of vital structures and reconstruction and those sorts of issues.
The second major group is the development of mediastinal lymph node involvement by the cancer. The mediastinum is full of lymph nodes, they’re obviously the major draining site for many cancers. We divide the mediastinal nodes into N2 nodes, or nodes that are on the same side as the cancer, versus N3 nodes that are on the opposite side of the cancer.
You can think of the range of patients that you would see, either with larger invasive disease, or disease involving mediastinal lymph nodes. Another area is where patients have multiple nodules in either the same lobe, or a different lobe on the same side, and those would be the difference between T3 and T4 lesions, which would also be categorized within stage III disease.
So, you can see that this patient population encompasses a wide range of patients, each of which demands, really, a different approach and an individualized approach based on what type of subset you’re in, with regard to stage III disease.