Lung Cancer Update, Issue 3, 2016 (Video Program) - Video 30Multiplex testing in squamous cell NSCLC
3:07 minutes.
TRANSCRIPTION:
DR BLUMENSCHEIN: I think the serum assays are exciting, so looking at circulating free DNA. And it’s roughly about an 80% correlation with the tissue biopsy, and it’s much faster. So we can, literally, draw blood, send it off and have an answer within 2 weeks. Generally, in my practice, I’ll send off the blood for molecular analysis and also order a biopsy to obtain that information, because again, it’s an 80% correlation, not 100%. But, for example, I’ve identified patients with T790M that way, with — DR LOVE: But what about people with squamous cell? Is it really worth doing? DR BLUMENSCHEIN: I think we’re looking. And there are anecdotal reports of this as well, that some patients have a mixed histology or will actually have an EGFR mutation, although I’ve not seen it. There have been reports in the literature of patients having EGFR mutation, although they have a squamous cell cancer. So I think there are probably mixed histologies out there that just weren’t captured. So I think it’s a reasonable thing to do. But you’re right, we don’t have an established biomarker that requires tissue testing in order to get a therapy. But I think to make that door open to patients, I think testing now is a way to go as these new studies are coming along and these new drugs are coming along. I do think with the positive data in the front-line setting with single-agent PD-L1 in heavy-expressing patient population, the greater than 50%, express PD-L1 in their tumor — greater than 50% of cells have expression. That’s going to lead to more testing, not just in the nonsquamous, but also in the squamous. DR LOVE: And I’m curious. What kind of gets you to think more about being aggressive about testing when you have a “squamous cell patient”? You mentioned the issue of sampling, the fact that you do 1 biopsy. Is that representative? Also, the issue of mixed adenosquamous. Do you ever see nonsmokers who are labeled as squamous? DR BLUMENSCHEIN: I haven’t seen that, but I’ve seen small cell lung cancer patients who were nonsmokers. I’ve had colleagues who have seen squamous cell patients who were nonsmokers. I think the more information you gather, the better decisions you can make for patients. And as we get that genetic information, it may correlate or dovetail with the clinical trial that’s opening. Right now, in terms of general practice, aside from looking at PD-L1, to use 3 drugs in the front-line setting, there’s not an approved therapy that requires that testing. But I think, as we’re developing new compounds — a good example is the DLL3 — starting to test in other tumor types where it makes sense is really the way we should be going. |