Rare Drivers in Metastatic Non-Small-Cell Lung Cancer with a Focus on EGFR Exon 20 Insertion Mutations - Episode 1

Lung Cancer: Molecular Testing

Alexander Spira, MD, PhD, FACP, shares an overview of the molecular testing needed for non–small cell lung cancer and his preferences for testing.

Alexander Spira, MD, PhD, FACP: The field of lung cancer has changed dramatically over the last few years, with the focus on not just the typical mutations we were seeing a few years ago. The most common one, of course, is EGFR with exon 19 or exon 21 mutations or fusions. But there’s been a slew of other rarer ones, specifically NTRK, KRAS, RET, exon 14 skipping, and they have revolutionized the field because there are a lot of mutations that need to be tested for, No. 1. And secondarily, they respond very well to treatment. It changed the field in that it’s mandated that we as oncologists check everyone with almost full molecular panels. I use full next-generation sequencing panels.

I perform molecular testing on my patients with lung cancer at diagnosis because it’s important to know your tumor. I check it on everybody because you never know what you’re going to get. For example, it’s very common to get a rare mutation, and you want to be able to find the right treatment for that patient to be able to treat them appropriately, even if it’s very rare. Occasionally, I check at resistance [to therapy], or when they have tumor growth, looking for either new mutations or clinical trials, but I try to check everybody at diagnosis. I do both tissue and blood; I get blood-based testing when it’s easy, because we can always guarantee that you’ll get a blood sample, although it’s not as specific as the tissue. But tissue can take a lot longer to get, and sometimes you’ll run out of that sample. So I often check patients for both.