Biomarker Testing in Lung Cancer - Episode 7
Dr. Vamsidhar Velcheti provides an expert’s insight on the testing and staging that must be performed during a diagnosis of non-small cell lung cancer.
Vamsidhar Velcheti, M.D.: I know you mentioned you had a PET [positron emission tomography] scan. What did they find on the PET scan? What did they tell you when they were doing a PET scan?
Allison Collins: I had to go back and read; I think I was so upset at the time. There was a tumor at the top of my lung, it had a very high uptake. Then there was an area in the mediastinum that had uptake as well. After [the doctor] did the biopsy, she felt like it probably had spread, so then they ordered first a CT [computed tomography] scan of my brain. They saw two or three tumors on the CT scan, so that very same day they said, “Well, we saw something on the CT scan, so we want to do an MRI [magnetic resonance imaging] because the MRI will show more.” They found I had seven tumors on my brain.
Vamsidhar Velcheti, M.D.: Allison, for the audience I just want to highlight a few things here. Whenever patients are found to have a lung nodule or something that’s suspicious for lung cancer, we as oncologists and physicians taking care of patients with cancer, the first thing that we always want to know is where else is the cancer, and what is the stage of the cancer? Because it’s really important to know how far the cancer has spread from where it has started in order to come up with a good treatment plan for our patients. Doing a PET scan was absolutely the right and necessary thing to do at that point given that there was perhaps some spread to the lymph nodes in the mediastinum. The mediastinum is actually the part of the chest between the two lungs. There are a lot of lymph nodes there that drain the lung, and if the cancer had spread to any of the lymph nodes, the likelihood of the cancer spreading elsewhere outside of the chest is high. An MRI of the brain is necessary to make sure there’s no spread of the cancer to the brain, and it looks like that’s exactly what you had.
Once we establish the stage of the cancer, let’s say if the cancer is actually limited to the lungs, then potentially surgery could be a good option. You take the tumor out and then dissect the lymph nodes to see if the cancer had spread to the lymph nodes. In some cases when there are lymph nodes that are very close to the lungs, we call them hilar lymph nodes, which are essentially lymph nodes within the lung, if those lymph nodes are involved you can still do surgery, but you would need chemotherapy after surgery to help eradicate these cells. But once the cancer spreads to the lymph nodes, which are a little further away, then that makes it a stage III lung cancer. In that situation sometimes surgery may not be an option. Chemotherapy and radiation and immunotherapy treatments would be the right treatment approach for those patients. But sometimes when the cancer has actually spread outside of the chest to other organs, including the brain or liver or adrenal glands, then the treatment would involve a more systemic therapy, which could be either chemotherapy, immunotherapy, or targeted therapy based on the genomic biomarkers.
Transcript edited for clarity.