Would you consider circulating DNA assay in resected node-negative deficient MMR colon cancer off-trial to guide your treatment?

Hello. It appears you are asking about a stage II MMR deficient/MSI-High colon cancer. The recurrence rate for stage II mismatch repair deficient (dMMR) colon cancer is generally lower than that for mismatch repair proficient (pMMR) tumors. Studies have shown that the 5-year recurrence rate for stag...

I do not use ctDNA in these cases outside of a clinical trial. The predictive ability of ctDNA has not been confirmed (yet). A recent study (COBRA) was halted early because it met its pre-specified stopping rules. COBRA was a phase II/III study designed to compare 2 adjuvant treatment strategies in ...

Yes, I would offer baseline ctDNA and monitoring if the patient understands it could change the cadence of scans and perhaps increase the chance for early (curative) surgery. This assumes they have at least a 5-year expected baseline survival and would be a surgical candidate, etc.

Updated 5-year results from the DYNAMIC study of stage II colon cancer who were randomized to either ctDNA-guided management or standard management showed that recurrence free survival (RFS) rates were 88% and 87% and 5-year overall survival (OS) rates were 93.8% and 93.3% for ctDNA-guided versus st...

The analysis by Dr. @Dr. First Last is quite nuanced and recognizes many of the issues here. In addition, the combined analysis by Dan Sargent from the ACCENT data base suggested use of 5FU may be detrimental for MMRd colon cancer (Sargent et al., JCO 2014 and previous) but in the end, concluded tha...

One must make a recommendation based on the known data in 2024. In this setting, I would tell the patient that positive ctDNA probably suggests a higher risk of recurrence even though the patient is MSI high. If the patient were to ask me what I would do, I would offer FOLFOX adjuvant with the hope ...