Post right hemi-colectomy. Refused chemo. Now discovered residual cancer in fatty tissue next to anastomosis. How do you treat this?

The patient underwent hemicolectomy without chemotherapy and had a locoregional, anastomotic recurrence.  

First, for proper staging, a PET CT should be performed. This is not an uncommon location for recurrence in patients who haven't undergone chemotherapy, though data is limited.

Repeat surgical resection, if the cancer is in fact localized to the are near anastomosis, should be the next step, along with evaluations by medical and radiation oncology who will coordinate care with the surgeon.

Chemotherapy, and possibly radiation therapy, should be strongly considered either before or after surgery.