Circulating Tumor DNA as a Biomarker of Progression in Colorectal Cancer - Episode 6

Next Steps in Using ctDNA as a Biomarker in CRC


Drs Liliana Bustamante and Richard Kim react to limitations surrounding biomarkers used in colorectal cancer and consider how to best study the role of ctDNA moving forward.

Richard Kim, MD: So, some of the next, important next step is that obviously, I think this paper and maybe the other paper that's currently out there has- have some established role of ctDNA in colorectal cancer as a more of a prognostic biomarker. If it's positive, most likely tumor will reoccur, and it's associated with inferior overall survival and disease-free survival. I think that's been sort of established based on many papers. But I think the question is how we can use to- use this circulating tumor DNA to justify the treatment. So can we make this a more predictive biomarker. In other words, if I give- if the ctDNA is positive, if I give chemo right away, does that affect over survival, just as Dr. Bustamante mentioned. Is that going to affect an overall outcome or not? And I think using this DNA to make our decision, clinical decision will be the next step. And I think some of the trials that are ongoing right now, and whether is rectal cancer and colon cancer, are you trying to use the ctDNA to be a decision point. So, whether it's positive or negative, randomized to one arm or to the other arm. And I think that's the key in the future to decide to use this, not only as a prognostic marker, but also as a predictive marker. Any last thoughts Dr. Bustamante?

Liliana Bustamante, MD: No, I agree completely with what you said. I think this is the kind of the theme of our discussion today. I think it's a- the ctDNA is going to be kind of the future of how we try to make these decisions, or at least help know prognosis for this patients. And then hopefully as we incorporate this in clinical trials, you just mentioned, we're going to be able to use it clinically with more backup of the decisions that we're making.

Richard Kim, MD: I want to thank you, Dr. Bustamante for joining me in this discussion regarding metastatic colorectal cancer. And I hope you, the viewers enjoyed this Between the Lines journal club experience. Thank you for tuning in.

Liliana Bustamante, MD: Thank you for having me.

Transcript edited for clarity.