Timing of MRD Testing in Lung Cancer Affects Patient Outcomes

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EP: 1.Timing of MRD Testing in Lung Cancer Affects Patient Outcomes

Oleg Gligich, MD, assistant professor at the Columbia University Division of Hematology/Oncology at Mount Sinai Medical Center, discusses utilizing circulating tumor DNA (ctDNA) to assess patients with lung cancer.

With ctDNA testing, various stages of cancer treatment can be assessed for minimal residual disease, including in the neoadjuvant, adjuvant, and metastatic settings. Gligich explains that ctDNA testing is performed before chemotherapy and after each subsequent cycle of therapy. This testing can be prognostic and correlates with pathologic complete response (CR).

Testing is recommended immediately after surgery in the adjuvant setting, according to Gligich. Following key time points to monitor efficacy, plus using longitudinal testing is emphasized to improve test sensitivity. After completing therapy, testing every 3 months is recommended to detect recurrence.

TRANSCRIPTION:

0:10 | ctDNA can be done in the neoadjuvant space, it can be done in the adjuvant space, and it could be done in the metastatic space for monitoring of either worsening disease or recurrence. In the neoadjuvant space, we like to test patients before the initiation of chemotherapy, especially if you have enough tissue. Then we like to test with each subsequent cycle, because we know that that's very prognostic.... We know from prospective observational data that patients who clear their ctDNA by cycle 2 day 1 will do significantly better as compared to patients who don't. We also know that cycle 4 day 1 correlates very well to pathologic CR and that most likely will be a much better surrogate marker as compared to doing pathological response rates after surgery.

1:05 | In the adjuvant setting, I like to test right after surgery, so your landmark time points in most clinical trials will be day 10 to day 120 and I think it's crucial that testing occurs, because then you'll have something to follow, whether that's ctDNA positivity or negativity. If it's positive, you definitely know you have a lot more work to do, and maybe your treatment algorithms may not be appropriate if you don't clear. Then what's important is that you continue following. We've learned that longitudinal time points are super important to improve the sensitivities of your tests. So I follow until completion of therapy, and then subsequently every 3 months to determine recurrence. We know that that lead time for lung cancer is about 6 months.