Is my tumor MSI-High or MSS, and how does this affect treatment

Q: Is my tumor MSI-High or MSS, and how does this affect treatment

To answer your question, I would need: - Your pathology report or tumor testing results - Any molecular testing reports like immunohistochemistry, PCR, or sequencing results - Lab reports that specifically mention "MSI" microsatellite instability status Once you share those documents, I can explain: - Whether your results show MSI-High or MSS microsatellite stable - What that finding means in plain language - How it typically influences colorectal cancer treatment decisions --- MSI Status Basics

Colorectal CancerJuly 13, 2026Navis AI

Ask Navis about your situation

This answer is general. Get one about your specific case — no signup, answered right here.

or Upload your records for answers about your actual case

For informational purposes only

This answer was generated by AI grounded in NCCN guidelines and published medical literature. It is not medical advice. Always consult your oncologist or care team before making treatment decisions.

Sources & medical oversight

Grounded in NCCN Guidelines for Patients: Colon Cancer — the same guidelines oncologists use.
Developed under the medical oversight of OpenCancer’s physician-scientist team (Chris Apfel, MD/PhD/MBA, CMO · Kaumudi Bhawe, PhD, CSO).
Last updated July 13, 2026. Informational only — not a substitute for your oncology team.

To answer your question, I would need:

Your pathology report or tumor testing results
Any molecular testing reports (like immunohistochemistry, PCR, or sequencing results)
Lab reports that specifically mention "MSI" (microsatellite instability) status

Once you share those documents, I can explain:

Whether your results show MSI-High or MSS (microsatellite stable)
What that finding means in plain language
How it typically influences colorectal cancer treatment decisions

Quick Educational Context (While You Gather Records):

MSI Status Basics: According to CancerPatientLab educational resources, microsatellite instability (MSI) refers to errors in your tumor's DNA that aren't being corrected properly. Think of it like a typewriter without spell-check—mistakes accumulate and aren't fixed.

MSI-High tumors typically respond well to immunotherapy drugs (like pembrolizumab/Keytruda)
MSS tumors usually follow different treatment pathways

This distinction is important because it's one of the first "tissue-agnostic" biomarkers approved by the FDA—meaning the treatment recommendation is based on what the tumor is made of, not just where it started in your body.

Please upload your test results, and I'll provide a detailed educational interpretation.

This information is for educational purposes only. Always consult your healthcare team for personalized medical advice and decisions.

Ask Navis about your case

That answer is general. Ask about your specific situation — no signup, answered right here.

or Upload your records for answers about your actual case

Facing this with someone you love?

Keep the whole picture in one private place: records, a plain-language summary of where things stand, questions, and the people helping. Navis keeps it up to date so no one has to re-explain the story. Free, and only the people you invite can ever see it.

Start a care circle →