Expert perspectives on molecular profiling strategies that may help overcome barriers to testing in non–small cell lung cancer.
Roy S. Herbst, MD, PhD: For the initial diagnosis, you still need tissue. I hate to call lung cancer just based on a blood-based assay, so you still have to have the tissue. It still, in this day and age, is more sensitive to do molecular testing on tissue, however, there are other factors in play at the initial diagnosis. Did you get enough tissue to do the full molecular profile? Sometimes you have not, even though you can make a histologic diagnosis of lung cancer. Or if you’re seeing someone in the clinic and it’s taking a while for the tissue to come back, liquid biopsies are amazing. We typically send this off to one of the vendors and get the results back within a week or less since we don’t do that in house yet here in New Haven, [Connecticut,] at Yale [School of Medicine]. Finding an actual mutation on a liquid biopsy is as good as finding it in the tissue blot, and you can go with it. If it is negative and you don’t find one, then I would still want to have, at least at the initial diagnosis, the tissue result, which is still a little more sensitive. But every minute of every day things are getting better as far as molecular testing and guidelines. I think there is hope for doing all of the testing in the liquid in the future.
The other thing about blood-based markers is you can do it easily. You can do it sequentially, you can use it to follow response, you can look at quantitative amounts of the DNA. You can look at the presence or absence of a mutation, does it go away, have you been successful with your therapy? Has a new mutation developed, do you need to change your therapy because of resistance? All of these things are possible with real-time monitoring. Then of course in early disease, in someone who hasn’t had a surgery, you can look for ctDNA [circulating tumor DNA]. There are still limits in the detection, but they are getting even more and more sensitive, as I mentioned. Then you can decide who needs more therapy and who doesn’t. Liquid is the future, but don’t forget the tissue—what should I say, tissue is the issue.
Barriers are access and cost. They are not exactly the same. There are a great deal of issues with disparities. If someone gets to an oncologist, with the educational programs that are being done such as this and others, they are aware that molecular testing is critical, not just in lung cancer, by the way, it’s across the board. But there are patients with lung cancer who might be diagnosed in a community setting where they never even get to an oncologist, maybe the internist. You can’t expect a general internist to be familiar with all of this, there is so much. It’s hard for me as an oncologist to understand lung cancer, and this is all I do every day of the week. I think that it’s a matter of making sure that someone thinks about testing, they get in to be tested, CMS [Centers for Medicare & Medicaid Services] pays for testing, it’s got to be ordered, and you need to have a facility where you can get enough tissue to do it. Many times, the early biopsies, the first responders, so they say, have to understand the importance of getting enough tissue for this biopsy. Blood biopsies and liquid markers are now possible, so it’s a matter of access.
Then of course there is cost and reimbursement. I don’t think that’s as big of an issue, and certainly not if people have more private insurance. The government insurances should cover it as well, but it’s getting people into the health care system and getting them profiled. I’ll tell you when you look at some of the databases and the demographics, most of the patients who have been profiled are not from underrepresented minority populations equal to the amount of their presence in the community. There are disparities and access issues, and those have to be fixed because you don’t want to miss an opportunity to diagnose something that could be used to treat a patient more effectively, more safely, and give them a better quality of life. This is our goal, to constantly push to get more and more people profiled, and then access to the drugs that can help them with their disease.
Transcript edited for clarity.