Trying to understand MSI-H/dMMR in right-sided CRC
"Microsatellite Instability-High (MSI-H) / Deficient Mismatch Repair (dMMR)" colorectal cancer.
I haven't even seen a surgeon or oncologist yet (I am scheduled), I've just been gathering info from many sources. My pathology report shows "MMR abnormal, MSI-H / dMMR due to loss of MLH1." So my tumor is MSI-H.
I'm stage 2 right-sided colon cancer on CT, which of course could actually be early stage 3 and we wouldn't know. Tumor is 6cm in my cecum and distinct, but colonoscopy biopsies from all other parts of my colon show no dysplasia.
I only got diagnosed with cancer last week so this is all very new to me... and I am wary of Dr. Google. Could anyone here help me shed light on this finding? The initial GI surgeon I spoke to at the hospital when the discovery was made said I would be looking at total colectomy because I also have ulcerative colitis, but I heard that MSI-H might mean a different approach that is more organ-preserving. Ahead of the appointment, I have been mentally preparing myself for having to live with an ileostomy.
My UC is active but mild currently. Before the CRC diagnosis, my UC was actually recovering, but then the tumor pain was what led me to the hospital. The interventions in the hospital (antibiotics, colonoscopy prep, colonoscopy itself + the weird hopsital food) set it off again, but it's still not too bad.
Does anyone with more knowledge in this game have an idea? I'm not asking for a "what should I do" or medical advice. I mostly just want to know what this MSI-H thing means and what kind of research I should maybe do next to find out more. Also if anyone else here is dMMR/MSI-H and has a personal experience to share, I'd love that.
Sorry for the long post, I wanted to cover everything. Thank you so much!