What is an Exon 20 insertion mutation?
EGFR exon 20 insertions are one type of lung cancer biomarker. They are a type of EGFR mutation that leads to uncontrolled cell growth.
Who is likely to have an EGFR exon 20 insertion mutation?
Patients who test positive for an EGFR mutation may have an exon 20 insertion mutation. The true frequency of EGFR exon 20 insertion mutations in NSCLC is unknown, but likely ranges from 1-10%, with 3-4% being widely reported. It is more commonly found in people who never smoked and in Asian populations.
How do you know if you have an EGFR exon 20 insertion mutation?
EGFR exon 20 mutations can sometimes be harder to detect with traditional biomarker testing techniques known as polymerase chain reaction-based markers (PCR). Newer advanced biomarker tests known as next-generation sequencing (NGS) can often have a higher chance of detecting the mutation.
Learn more about the different types of biomarker tests.
What are the treatment options for EGFR exon 20 insertion mutation patients?
Exon 20 mutations are resistant to typical EGFR tyrosine kinase inhibitors (TKIs), which are drugs that block cancer growth. If you are diagnosed with the EGFR exon 20 mutation, your first-line treatment option will likely be chemotherapy with amivantamab (Rybrevant) (a type of targeted drug called a monoclonal antibody).
If your cancer grows after being treated, you should get another biopsy to see if you have a different biomarker. If you do, your doctor will recommend a targeted therapy to treat that biomarker.
If you don’t, your doctor may recommend one of the following options:
- Chemotherapy alone or with amivantamab (if you haven’t already received it)
- Chemotherapy with another monoclonal antibody called bevacizumab (Avastin)
- Immunotherapy
All lung cancer patients should ask their physicians if they are eligible to participate in a clinical trial.
What Should You Do Next?
If you are diagnosed with NSCLC, but have not received biomarker testing, ask your doctor about comprehensive biomarker testing.
Work with your doctor to discuss your goals and options each time you have to make a treatment decision. The three big questions to ask are:
- What is the goal of this treatment?
- What are the potential side effects?
- What other options do I have?
Research is happening at a rapid pace and your doctor should be up to date on the recommendations for your specific type of lung cancer. If you don’t feel comfortable with the answers you are receiving, do not hesitate to seek out a second opinion.
Where can I get support?
- Join our free Lung Cancer Survivors and/or Exon 20 Warriors online support communities on Inspire.
- Request a patient or caregiver mentor.
- Call our free Lung Helpline to talk to a healthcare professional.
- Connect with the EGFR Resisters Group.
- Connect with the Exon 20 Group.
- It is important to work closely with your physicians to help monitor your medication side effects. Ask about connecting with a supportive/palliative care doctor at the beginning of your treatment to help ensure your side effects are well managed.
View the EGFR Exon 20 Infographic
Lung cancer research can move at a rapid pace. Always speak with your doctor about the most up-to-date treatment guidelines.
Page last updated: October 1, 2024
