Highlights

In my practice, these are probably less than 20% of patients, more like 15% of patients, who will have a molecular driver that can be treated, so the majority will not have something that we can treat, they may have KRAS, or may have something against which there are no approved drugs. So, then the decision as to what regimen to use for Stage IV disease will be based on the PD-L1 expression. If PD-L1 expression is high, meaning more than 50%, I discuss with the patient whether we should use single-agent immunotherapy with pembrolizumab, or a combination of chemotherapy plus pembrolizumab, and I’m saying specifically pembrolizumab because this is the most commonly used checkpoint inhibitor for lung cancer in the first line.

So, we had a discussion several years ago with this reflexive system, it’s difficult for the pathologists to know what stage the patient has, because they have the biopsy but they don’t have the staging information. So, we decided that all patients with NSCLC will get tested regardless of the stage, but all patients with non-squamous histology, so we don’t reflexively test squamous cell. The big academic institutions test both squamous and non-squamous, and many of the smaller groups they test only Stage IV disease. So, the practice kind of varies.