Would you offer chemoRT to a colon cancer case with a resected polyp with positive margins if the patient wishes to avoid surgery?   

“Wishes to avoid surgery” is different than refusing surgery. Subtle difference perhaps, but I feel like with proper counseling and persuasion, it is possible to “adjust” a wish. A hard refusal is a different matter. But be it wish or refusal, I would not irradiate. Think of ...

I am assuming in my answer that the polyp as stated is actually invasive carcinoma. Unless the tumor is fixed to surrounding tissues, which seems unlikely based on what is stated, I do not think radiation is appropriate here. I would favor seeing if we can help the patient to agree to surgery or (le...

I would probably favor having GI re-scope the patient to see if the area where the resected polyp could be amenable to ESD (if available at your institution) prior to jumping directly to chemoRT. If they don't want surgery, the above option is feasible assuming very limited invasion.