Gene and marker tests
EGFR mutation (exon 19 deletion, L858R)
Also written as EGFR positive, EGFR exon 19 deletion, Exon 19 deletion, L858R, Exon 21 L858R, EGFR mutated
What it means
The EGFR gene helps cells grow and divide. Some cancers have a change (mutation) in it, which can make cancer cells grow faster. Exon 19 and exon 21 are named parts of the gene, and some EGFR drugs are made for changes in them.
Why it matters
Drugs called EGFR inhibitors can block the EGFR signal and slow or stop growth. The best choice depends on the exact mutation, the stage and your health. Your oncologist decides.
Ask your oncologist
"Which exact EGFR change do I have, and which EGFR medicines fit it?"
From Cancer Research UK: Targeted and immunotherapy treatment for lung cancer and American Cancer Society: Targeted Drug Therapy for Non-small Cell Lung Cancer. Not medical advice: your oncologist decides.