What is being tested?EGFR is one of a family of cell membrane receptors that help regulate cell growth, division, survival and death. In a variety of cancers, there is an increased amount of EGFR present in the
tumor tissue. This can be due to
amplification and
over-expression of the receptor that leads to excessive signaling for growth. Tumors that have increased EGFR protein tend to grow more aggressively, are more likely to
metastasize, and are more resistant to standard chemotherapies. Patients with these tumors tend to have a poorer outcome. Consequently, targeting the EGFR is a valuable molecular approach in cancer therapy. EGFR-specific antibodies that bind to the receptor and prevent signaling are used to treat some of the malignancies.
There are two main ways to test tumors for amplified or over-expressed EGFR: one method measures the amount of EGFR protein present; the other looks at the genetic level for gene amplification - it evaluates the number of copies of the gene present.
