EGFR Exon 20 Insertion Mutation

Medically Reviewed by Paul Boyce, MD on April 06, 2024
6 min read

If your doctor thinks you have non-small-cell lung cancer (NSCLC), they will usually look for a change (they may call it a mutation) in a gene called the EGFR gene.

Normally, EGFR helps healthy cells grow and spread. A change in it can make some cells grow too quickly and lead to cancer. There are more than 100 changes that can happen to EGFR. One is an exon 20 insertion. This mutation has few effective treatments.  

But we're getting to know EGFR changes better, so new treatment options can help people with the exon 20 insertion mutation live longer with a better quality of life.

You’re not born with an exon 20 insertion mutation. Instead, a bit of genetic material is accidentally added to the EGFR gene sometime during your life. No one is sure why this happens.

Exon 20 insertion mutation isn't normally tied to smoking. But you’re more likely to have this mutation if you:

  • Have a type of NSCLC called adenocarcinoma
  • Are a woman
  • Are a young adult with NSCLC
  • Are of Asian descent

Doctors usually check for gene mutations by taking a sample of cells (called a biopsy) from your tumor. To get the cells, they might use a needle or bronchoscope, a thin tube passed through your mouth or nose into your lungs. Sometimes, they test the tumor itself if it was removed during surgery. When there’s not enough tissue for a sample or you can’t have a biopsy, your doctor might do a blood test called a liquid biopsy.

The test by itself doesn’t tell your doctor if you have lung cancer. But in the future, it may become a way to both diagnose cancer and monitor treatment.

Not all tests for EGFR can find exon 20 insertion mutations. Ask the people working at your lab to use a process called next generation sequencing on your tissue or blood sample. This can help them figure out exactly what condition you have, how to treat it, and what your chances of recovery are.

Once you learn you have an exon 20 insertion mutation, it’s important to have frank conversations with your doctor and care team. They can give you the information you need to make the best decisions for yourself. Here are some questions to consider:

  • What kind of testing did you use to check for gene mutations?
  • Do I need to see a different specialist for this kind of cancer?
  • I’d like to get a second opinion. Who do you recommend?
  • What are my treatment choices? What are the risks and side effects of each one?
  • What is the goal of treatment? How soon do I need to choose a treatment option?
  • Will I be able to continue my daily activities during treatment?
  • How will I know if the treatment is working?
  • How can I manage side effects?
  • What side effects should I call you about? What if I need to reach you at night or on weekends?
  • What type of follow-up will I need?
  • What’s my prognosis?

This mutation once had few effective treatments, but that’s quickly changing. New options can help you live longer with better quality of life.

Unlike other EGFR mutations, exon 20 insertion tumors don’t respond to certain drugs that target the EGFR protein.

Your doctor might suggest:

Chemotherapy drugs like carboplatin, cisplatin, and pemetrexed.  Your doctor may give you these along with a type of immunotherapy called an immune checkpoint inhibitor.

There are also new options, such as medicines that specifically target exon 20 insertion mutations. Your doctor may try them if chemotherapy doesn’t work for you. These drugs are:

Amivantamab-vmjw (Rybrevant). Approved in May 2021, this drug keeps tumors from growing. But it’s not chemo or immunotherapy. It’s an antibody that targets two proteins that help cancer cells grow. You get it as an IV into a vein, usually in a clinic. Possible side effects include serious lung, skin, and eye problems. If you notice these side effects, call your doctor right away.

Medications that are in clinical trials. A clinical trial is when scientists want to test a medicine to see if it works well. If you’re interested in participating in one, talk to your doctor to see if one is a good fit for you.

A lot of what you should expect depends on the stage of your cancer and how you respond to treatment. Your cancer care team can tell you more about what's to come.

Your care team is made up of specialists who work together to ensure you get the best care possible. It may include:

Your medical oncologist. This is a medical doctor who treats cancer with chemotherapy, immunotherapy, and targeted therapies. They decide what medicine you should get, how much, and how often. They may also coordinate your care with other members of your team

Your interventional pulmonologist. This is a lung doctor with advanced training in techniques to take tissue samples and stage lung cancer.

Your pathologist. This doctor studies your tissues or blood to learn the type of cancer you have.

Your dietitian or nutritionist. This specialist shows you how to eat to help manage side effects and get all the nutrients you need.

Rehabilitation specialists, including physical therapists and occupational therapists. These experts keep you on track with exercise as well as teach you techniques to manage side effects and improve your quality of life.

Your pharmacist. This trained professional can tell you how to use your medicines and advise you about side effects.

Your palliative care doctor. This specialist helps manage your pain and improve your overall quality of life.

Your psychologist or psychiatrist. These specialists can help you handle the emotional challenges of cancer.

These tips may help you manage side effects and feel your best during and after treatment:

Get quality sleep. It’s common to have trouble sleeping during cancer treatment, yet insomnia can make pain and anxiety worse. Make sure your bedroom is cool and dark. Stay away from caffeine, late-day exercise, and electronic devices right before sleep, too. If these techniques don’t help, talk to your doctor.

Stay active. Exercise has huge benefits for people living with cancer. Among other things, it can help you feel better, stronger, and healthier. It can also improve your quality of life and ease treatment side effects like nausea and fatigue. Try to get at least 300 minutes of activity each week. If you were active before cancer, you may have to slow down a little. If you’re new to exercise, a physical therapist or exercise specialist can get you started.

Eat well. No diet can cure lung cancer, but healthy eating can help you feel stronger and respond better to your treatment. Eat lots of fresh fruits and vegetables along with some lean protein and whole grains. Try to stay away from red meat, sugar, saturated fat, and salt. If mouth sores or nausea make it hard to eat, a dietitian can work with you to manage side effects and get the nutrients you need.

People with lung cancer often turn to family, friends, and their care team for support during and after treatment. You may also get emotional and practical help from lung cancer support groups -- people who know exactly what you’re going through. The groups can be in-person or online. There might be one at the place where you get your treatment.

The American Lung Association sponsors several general lung cancer support groups. Others are specifically for people with EGFR and exon 20 insertion mutations. There are also some online support group options. Your doctor can help you find some that can help.