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KRAS (including G12C) testing: what it means for you

Waiting on test results can feel like one more hard thing, for you and the people who love you. Here's what the KRAS (including G12C) test looks for and how it can help your care team pick the treatment most likely to work for you.

ℹ️ General information to help you and your loved ones talk with your care team, not medical advice. Read our disclaimer.

Matters most in: Lung cancer, Colorectal cancer

Why it matters

In lung cancer, KRAS G12C can be treated with targeted pills after other treatment. In colorectal cancer, any KRAS (or NRAS) mutation means drugs that block EGFR, such as cetuximab and panitumumab, won't help, so testing guides which drugs to use.

Treatments it can point to

• KRAS G12C inhibitors such as sotorasib or adagrasib (in colorectal cancer, given with an EGFR antibody)
• In colorectal cancer, chemo regimens like FOLFOX or FOLFIRI, sometimes with Avastin (Avastin (bevacizumab), Eloxatin (oxaliplatin), Camptosar (irinotecan))

Only your care team can say which treatment fits you. Drug approvals depend on cancer type, stage and prior treatment.

Tissue vs. blood testing

Tissue or blood.

Most tests use a piece of tumor tissue from a biopsy or surgery. Some can also use a blood sample (a 'liquid biopsy') that looks for tumor DNA floating in the blood. Blood tests are easier and faster, but they can miss a change that a tissue test would find, so a negative blood test is often followed by a tissue test.

❓ Questions you and your loved ones can ask

• Which KRAS change do I have?
• Does my KRAS result rule out any drugs for me?
• When will my results be back, and will treatment wait for them?
• Will my insurance cover this test?

Written by the Cancer Side Effects Guide team from FDA labels and leading cancer centers. Not medical advice. · Last updated: October 15, 2026 · How we write