EGFR Status

            Epidermal growth factor receptor (EGFR) status is related to human epidermal growth factor receptor 2 (HER2) status. [MB1] HER2 and EGFR are both genes that make proteins that promote growth; therefore, breast cancers tend to grow and spread quickly if these genes are amplified and many proteins are made. EGFR may also be referred to as the HER1 gene. Testing for EGFR status is not done regularly, but it is starting to be done more. In other cancers affected by EGFR status such as colon cancer, EGFR-positive tumors can be treated with EGFR-targeted therapies. These targeted therapies are currently being tested for use in EGFR-positive breast tumors.[1]

About 50% of cases of inflammatory breast cancer (IBC) and triple-negative breast cancer (TNBC) are EGFR-positive.[2] These two types of breast cancer tend to be more aggressive and fast-growing than other types of breast cancer.3,4 IBC is defined as having the cancer cells spread to the skin, so it is always locally advanced at the time of diagnosis.[3] TNBC is characterized as being HER2-negative and hormone receptor-negative.[4] Estrogen and progesterone are hormones that can increase cancer growth if the tumor has receptors for them.[5] An EGFR inhibitor would be beneficial for treating these aggressive types of cancer.[3,4] Additionally, TNBC has limited treatment options due to the inability to utilize hormone therapy or HER2-targeted therapy, so using an EGFR-targeted therapy in EGFR-positive tumors would increase treatment options.[4]

References

1.     EGFR Status https://www.breastcancer.org/symptoms/diagnosis/egfr (accessed Jun 29, 2021).

2.     Masuda , H.; Zhang, D.; Bartholomeusz, C.; Doihara , H.; Hortobagyi , G. N.; Ueno , N. T. Role of epidermal growth factor receptor in breast cancer https://pubmed.ncbi.nlm.nih.gov/23073759/#:~:text=The%20epidermal%20growth%20factor%20receptor%20%28EGFR%29%20is%20one,breast%20cancer%20have%20been%20evaluated%20in%20several%20studies. (accessed Jun 30, 2021).

3.     Inflammatory Breast Cancer: Details, Diagnosis, and Signs https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/types-of-breast-cancer/inflammatory-breast-cancer.html (accessed Apr 27, 2021).

4.     Triple-negative Breast Cancer: Details, Diagnosis, and Signs https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/types-of-breast-cancer/triple-negative.html (accessed Apr 27, 2021).

5.     Types of Breast Cancer: Triple Negative, ER-Positive, HER2-Positive https://www.webmd.com/breast-cancer/breast-cancer-types-er-positive-her2-positive (accessed Apr 30, 2021).  

 [MB1]Link to ‘hormone and HER2 status article’