How would you approach treatment for cT4 stage IIIC colorectal cancer that is d-MMR and not amenable to surgery due to volume of disease?

As my more learned colleagues here suggest, an evidence-based approach if this is colon cancer, is to use chemotherapy alone, as we lack high-level data for immune checkpoint inhibitors in this scenario. If rectal cancer, then I think emerging data from MSKCC would suggest better response to concurr...

This is not an uncommon scenario. Before KEYNOTE-177, if it was unresectable, I have had a few instances where I started them on FOLFOX (no biologic) and then added immunotherapy. Peeled away the chemo soon thereafter.

Several trials are ongoing in this space.

I have now 1 gastric, 1 gastroesophageal...

It would be helpful to know exactly why this tumor is not resectable, but generally, yes, neoadjuvant chemotherapy with FOLFOX +/- bevacizumab would be a preferred approach. One of the more common scenarios would be abdominal wall involvement, and if so, yes, 6 months of chemo is indicated. If it is...

I agree that establishing the reason for unresectability is important, since upfront resection is the preferred therapy for non-metastatic colon cancer. Also, it would be of interest to know the etiology of the mismatch repair deficiency (related to Lynch syndrome, BRAF mutation, or other?). If the ...

It’s unlikely we will ever have a trial to address this situation. Neoadjuvant chemo as in FOxTROT, though the study was for resectable colon cancer. And I agree ICI therapy should be included. But I believe the question is should we give ICI alone? I agree with @Dr. First Last that it would be bett...

As the data continues to unfold in neoadjuvant approach to colon cancer, neoadjuvant chemotherapy and/or immunotherapy will find their place in the treatment of locally advanced dMMR and pMMR colon cancer. Molecular characterization of tumors, along with the radiologic and pathologic responses to tr...