No two lung cancers are the same. There are different types, subtypes and mutations of lung cancer. Lung cancer mutations can determine options for testing and treatment. These new treatments are referred to as targeted therapies. There are dozens now available, and they work for specific groups of lung cancer patients that have a known and actionable biomarker.
One of the mutations that have new targeted therapies available in recent years is the EGFR Exon 20 insertion mutation.
Exon 20 mutations account for approximately 1 in 30 lung cancer cases and are more commonly found in nonsmoking individuals and Asian persons.
Exon 20 mutations are found in a gene called epidermal growth factor receptor (EGFR), which is involved in the growth and division of cells. The EGFR gene is responsible for creating the growth factor receptor proteins. The receptor proteins sit on the cell membrane and receive signals from outside of the cell, a set of signals are then sent within the cell to regulate the cell's growth. When this gene is mutated, the process can get disrupted. The mutation can be copied repeatedly. This can cause cells to grow and divide uncontrollably, leading to the development of tumors.
Several drugs have been shown to be effective in clinical trials and are now FDA approved in recent years. These include:
- Mobocertinib – is a single molecule that binds to the EGFR protein within Exon 20 cancer cells and blocks growth signaling within the cell.
- Amivantamab – is a monoclonal anti-body that binds on the EGFR protein and blocks signaling to the protein in Exon 20 cells and calls in the body’s immune system for additional support.
These drugs work by targeting parts of the mutated EGFR protein in Exon 20 cells, which can help to slow or stop the growth of the cancer. Chemotherapy, and Immunotherapy is often used with targeted therapies when treating Exon 20 mutations and surgery may also be an option if caught early. Some advanced cases may also need forms of radiation therapy.
How it’s Detected
Exon 20 mutations can also be difficult to diagnose, as they are not easily detected by standard genetic testing. This means that many people with Exon 20 mutations may not know they have this mutation until much later. There are new ways to detect Exon 20 called next generation sequencing (NGS), and insurance may cover these tests under certain circumstances. Carla Gonzalez, an Exon 20 patient says, “it was my decision to go through biomarker testing because the best way to treat lung cancer is through targeted therapy.” She also mentions that “not everybody knows what their mutation is, but once you learn what it is, you can match the correct drug to your biomarker mutation.”
What to do Next
This is an exciting time in scientific innovation since, until recently, treatment options for these lung cancer patients were limited. Where in the past chemotherapy was the only option, targeted treatments and various clinical trials are now available. As more mutations become detectable and actionable, and new techniques become common, we should hope to see greater overall survival for lung cancer patients with the continuous advancements in science for every targeted therapy that is approved by the FDA. If you or a loved one has an EGFR driver mutation, ask your doctor about ways to see if you have an Exon 20 mutation, and whether targeted therapies are right for you.
After Carla went through her treatment her tumor shrank noticeably and she returned to some exercise which she did often before her diagnosis. Carla’s story inspires hope for those that are also experiencing a similar journey, she mentioned to ALA that “Instead of being a shell, I wanted to live. Join a support group specific to your diagnosis because this isn’t a one-size-fits all disease.” This can improve your understanding of your specific treatment options, side effects and how to manage them, and additional benefits of camaraderie in a difficult time.
To get more information on EGFR Exon 20, please visit Lung.org/Exon20. You may also join support communities and mentorship programs that are available.
Support for this project is provided by Janssen.
Blog last updated: August 25, 2023