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What does EGFR positive mean?
Epidermal growth factor receptor (EGFR) is a protein found on the surface of body cells. A person with EGFR-positive lung cancer has cancer with the EGFR mutation.
What is EGFR-positive lung cancer?
According to the Lung Cancer Foundation of America (LCFA), the EGFR protein is mostly found in skin cells, although it can also be present in other cells of the body.
A person with EGFR mutation lung cancer has EGFR proteins that do not function as they would normally.
This article will go into detail on what EGFR mutation lung cancer is, as well as its symptoms, prevalence, and treatments.
What is it?
The function of EGFR is to help cells grow and divide. If an EFGR mutation is present, then the EGFR protein will not work correctly.
An EGFR mutation occurs when there is an error in the DNA that makes up the protein. These errors are also a type of biomarker. A biomarker is a biological molecule that can be an indicator of a certain condition or disease, according to the National Cancer Institute.
A person with EGFR-positive lung cancer has EGFR proteins that are constantly signaling for cells to grow and divide. Rapid cell creation leads to abnormal cell growth, which is what cancer is.
There are various mutations EGFR proteins can have. Mutations in EGFR DNA can occur in the following ways:
- insertions, where additional code is inserted into a DNA sequence
- deletions, where the DNA is missing certain sequences
- point mutations, where a single nucleotide is altered
The most common EGFR mutations are EGFR 19 deletion or EGFR L858R point mutation. Rarer mutations, such as EGFR exon 20 insertions, have different treatments compared to other EGFR mutations.
How common is it?
The American Lung Association (ALA) states that EGFR mutation lung cancer occurs in around 10–15% of lung cancers in the United States. The LCFA notes that about 50% of these EGFR mutations occur in young adults with lung cancer.
According to the American Cancer Society, the two main types of lung cancer are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).
NSCLC accounts for around 80–85% of all lung cancers. Research from 2020 estimates that 32.4% of NSCLC cases have the EGFR mutation. On the other hand, EGFR mutations in SCLC are rare.
Adenocarcinoma is a subtype of NSCLC which forms in cells that normally secrete substances such as mucus. The American Lung Foundation notes that EGFR mutations generally occur in adenocarcinoma.
What are the symptoms?
EGFR mutation lung cancer does not have specific symptoms. Instead, EGFR mutation lung cancer will show symptoms of the overall type of lung cancer to which is it connected.
According to the American Cancer Society, most lung cancers do not have symptoms until they have spread. Occasionally, people in the early stages of lung cancer do have symptoms, which can include:
- persistent cough that may get worse
- coughing up blood or rust-colored sputum, which can be spit or phlegm
- chest pain that worsens with deep breathing, coughing, or laughing
- hoarseness
- loss of appetite
- unexplained weight loss
- shortness of breath
- feeling weak or tired
- infections such as bronchitis or pneumonia that keep returning or will not clear
- wheezing
If a person’s lung cancer spreads, they may experience:
- bone pain
- headache
- weakness or numbness of the arm or leg
- dizziness
- balance problems
- seizures
- jaundice, a condition of the liver that can cause yellowing of the skin and eyes
- swelling of lymph nodes
If a person notices any of these symptoms, they should contact a doctor as soon as possible. The earlier a healthcare professional diagnoses lung cancer, the easier it is to treat.
Who does it affect?
Anyone can develop EGFR mutation lung cancer. However, it is more common in certain groups, including:
- non-smokers, or people who smoke very little
- people who have lung adenocarcinoma
- females
- young adults with lung cancer
- people with an Asian or East Asian ethnic background
Treatment
There are various treatments available for a person with EGFR mutation lung cancer, such as:
- surgery to remove the cancer
- chemotherapy
- immunotherapy, which helps the immune system fight the cancer
- clinical trials, where a person takes part in a trial for an investigational drug used to treat cancer
Additionally, a person may receive targeted therapies to treat the EGFR mutation lung cancer. Targeted therapies target the specific genes or proteins of a cancer type.
Targeted therapy for EGFR mutation lung cancer involves a person receiving drugs called EGFR inhibitors. An EGFR inhibitor blocks, or targets, the signals from the EGFR protein that encourage cell growth. EGFR inhibitors include:
- afatinib
- gefitinib
- erlotinib
- osimertinib
- necitumumaab
- dacomitinib
EGFR inhibitors may be prescribed at any stage of lung cancer. For example, the ALA notes that osimertinib can treat stages 1–4 lung cancer. In some cases, a healthcare professional may prescribe osimertinib after chemotherapy.
Although EGFR inhibitors can be effective treatments, they can only control the growth of the EGFR mutation lung cancer for several months or years. After a certain amount of time, a person’s EGFR mutation lung cancer may become resistant to the EGFR inhibitor.
The American Cancer Society notes that EGFR inhibitors can cause certain side effects, including:
- skin problems, such as an acne-like rash
- diarrhea
- mouth sores
- loss of appetite
