Blood-Based Biomarkers in NSCLC

Mark A. Socinski, MD: What about monitoring patients for recurrence? Typically, we have our surveillance strategies that are ctDNA [circulating tumor DNA] based for the most part. Is any potential for earlier detection with plasma-based approaches?

Chaitali Nangia, MD: At ASCO [American Society of Clinical Oncology Annual Meeting] 2021, there was a good abstract presentation talking about the feasibility of doing ctDNA even in patients with early stage lung cancer. They were able to get samples from the LUCID trial patients. Though the representation of stage I was 50% of those samples, the detection rate in that stage was 24% if you look at it stage by stage. We all know that as the stage goes higher, so does the detection rate. They collected data before the diagnosis, and then they did it at landmark time at 3 months and then at 4 months, 6 months, 9 months, and 17 months. They were able to show with a super strong hazard ratio of 0.20 that if you detected it, then it did relate to an early relapse. Almost all the patients who were detected were ctDNA positive. And the lead time was anywhere from 120 to 200 days. There was another interesting abstract…that also showed they were more successful in picking up these MRD [minimal residual disease] patients and predicting for relapse. We all understand that this may be a predictive marker. The bigger question remains, how can we up the game in this sense? Can we detect it more reliably and not just in factional patients? The other question would be, we picked it up, now what do you do with that? Do you start them on therapy? If you do, based on what? There are no data to use. They’re more prognostic, but I would like them just to become more predictive.

Mark A. Socinski, MD: Yeah, we have a lot of work in front of us in terms of proving the clinical utility. At the end of the day, we have to prove clinical utility and that it does make a difference. It certainly is an exciting time.

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