Novel Predictive Biomarkers for Non-Small Cell Lung Cancer - Episode 2
Gregory J. Riely, MD, PhD: As we aim to get the right material for our patients with non—small cell lung cancer and try to identify all the predictive biomarkers, it’s really a team effort. We have to work together. Whether it’s an interventional radiologist, surgeon, pulmonologist, oncologist, or whoever is requesting the biopsy, or whoever is doing the biopsy, we need to have the perspective of the pathologist brought into all of this.
With all these people involved, the biggest challenge is communication. When our pathologists get a tissue sample from the interventionalist, they don’t know what it’s going to be used for. If they don’t know what it’s going to be used for, they can’t process the tissue appropriately. One of the best examples of this is a bone biopsy. When we do bone biopsies, if we want to do molecular testing from a bone biopsy, that sample can’t be decalcified. Decalcification is a routine process in pathology for bone biopsies. As a consequence, that communication needs to happen immediately. It needs to be conveyed by the requesting physician. When you ask the interventional radiologist for a biopsy, you have to tell them that you want to do molecular testing, if that’s your goal. If they’re going to do molecular testing, that interventional radiologist has to let the pathologist know that you want to do molecular testing so they don’t decalcify that specimen.
It’s critical that everybody know what the ultimate goal for that biopsy procedure is. When everybody knows the ultimate goal, we can get the right piece of material, or tissue, and do the best thing for the patient.
With the difficulties in getting tissue that we need to determine all the predictive biomarkers, many people have explored the idea of using circulating tumor DNA, or circulating tumor cells. This is very much in its infancy in patients with non—small cell lung cancer. We don’t have a lot of data to say that the methods are good and that any particular method is the best. But I think we’re learning a lot about this method and, in particular, circulating tumor DNA. This is sometimes referred to as a liquid biopsy, or plasma biopsy. We’re taking patients’ blood and are getting rid of all the white blood cells and red blood cells and are only looking in the plasma for pieces of DNA that have been shed from the tumor. Very sensitive DNA sequencing techniques can identify those bits of DNA. In about 60% of people with non–small cell lung cancer, we can identify those bits of DNA and find the mutations that are driving those tumors. If you’re looking for an EGFR mutation, your tumor sample isn’t good enough to do mutation testing. One path forward may be to use a plasma biopsy, or a plasma test for circulating tumor DNA, to find the EGFR mutations.
Again, this is very much in its infancy. There are probably more tests out there, that are developed, from the ones that are really good. I think it’s definitely an exciting area, and we certainly look forward to more data in that area.
Transcript Edited for Clarity