EGFR (epidermal growth factor receptor)

EGFR stands for epidermal growth factor receptor. It is a gene that provides instructions for making a protein found on the surface of cells. This protein is part of a family of receptors that help cells respond to signals telling them to grow and divide. EGFR is involved in normal cellular processes, but when it becomes abnormal (mutated), it can lead to uncontrolled cell growth, contributing to the development of cancer.

What is the normal function of EGFR in a cell?

In a normal cell, EGFR plays a crucial role in how the cell responds to growth signals. When certain molecules called growth factors bind to EGFR, the receptor activates and sends signals inside the cell to grow, divide, or repair. The normal function of EGFR is essential for maintaining healthy tissues and organs. The activation of EGFR is tightly controlled to prevent excessive cell growth.

What types of cancer are associated with abnormal EGFR?

Mutations in EGFR are commonly associated with cancers of the lung, especially non-small cell lung cancer (NSCLC). They can also be found in some cancers of the head and neck, as well as certain types of glioblastomas (a kind of brain tumor). In these cancers, mutations in EGFR cause the receptor to become overactive, resulting in uncontrolled cell growth and tumor formation.

What kinds of tests do pathologists perform to look for abnormal EGFR, and how will the tests be described in a pathology report?

Pathologists use molecular tests to detect mutations in the EGFR gene, often through a biopsy sample from the tumour. These tests typically involve methods such as next-generation sequencing (NGS) or polymerase chain reaction (PCR), which are used to identify specific mutations in EGFR. Pathologists may also use immunohistochemistry (IHC) to detect abnormal levels of EGFR protein in tumour cells.

In your pathology report, the results of EGFR testing will indicate whether a mutation has been found and, if so, which specific mutation is present. The report may also explain how the mutation affects your treatment options. Some mutations in EGFR can make cancers more responsive to targeted therapies, such as EGFR inhibitors, which block the activity of the abnormal protein and can slow or stop the growth of cancer cells.

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