Were you looking for Estimated Glomerular Filtration Rate, also known as eGFR? If so, see the article on the eGFR test.
At a Glance
Why Get Tested?
When to Get Tested?
When you have been diagnosed with certain invasive cancers and your health practitioner wants to determine whether EGFR is being over-expressed in the tumor
A sample of tumor tissue obtained during a biopsy
Test Preparation Needed?
The Test Sample
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.
How is the sample collected for testing?
A sample of cancer tissue is obtained by doing a biopsy. The biopsy procedure required depends on the organ(s) affected.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
Ask a Laboratory Scientist
This form enables you to ask specific questions about your tests. Your questions will be answered by a laboratory scientist as part of a voluntary service provided by one of our partners, American Society for Clinical Laboratory Science. If your questions are not related to your lab tests, please submit them via our Contact Us form. Thank you.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Most Recent Review
Kuriyan, J. (2006 June 16). Researchers Learn How Epidermal Growth Factor Receptor Is Activated. Howard Hughes Medical Institute [On-line information]. Available online at http://www.hhmi.org/news/kuriyan20060615.html through http://www.hhmi.org. Accessed on 7-30-08.
American Cancer Society [On-line information]. (2007 May 14, Revised). Detailed Guide: Laryngeal and Hypopharyngeal Cancer. What's New in Laryngeal and Hypopharyngeal Cancer Research and Treatment? Available online through http://www.cancer.org. Accessed on 7-30-08.
Chu, E. et. al. (2007 July 25). Expanding Scientific Evidence for Epidermal Growth Factor Receptor-Directed Therapy in Colorectal Cancer and Squamous Cell Carcinoma of the Head and Neck CME. Medscape Today [On-line information]. Available online at http://www.medscape.com/viewprogram/7463 through http://www.medscape.com. Accessed on 7-30-08.
Dacic, S. et. al. (2006 June 6). Significance of EGFR Protein Expression and Gene Amplification in Non-Small Cell Lung Carcinoma. Medscape from Am J Clin Pathol. 2006;125(6):860-865 [On-line information]. Available online at http://www.medscape.com/viewarticle/532262 through http://www.medscape.com. Accessed on 7-30-08.
Grody, W. (2007 January 30). ASCP 2006: Applications of Molecular Methods in Surgical Pathology CME/CMLE. Medscape [On-line information]. Available online at http://www.medscape.com/viewarticle/551100 through http://www.medscape.com. Accessed on 7-30-08.
Sources Used in Previous Reviews
Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.
(2004 April). EGFR by FISH. ARUP Technical Bulletin [On-line information]. PDF available for dowload at http://www.arup-lab.com/media/pdf/testing/tech_bulletins/egfr_apr04.pdf through http://www.arup-lab.com.
(© 2004). EGFR by FISH. ARUP's Guide to Clinical Laboratory Testing [On-line information]. Available online at http://www.aruplab.com/guides/clt/tests/clt_a213.jsp#3635067 through http://www.aruplab.com.
Check, W. (2004 January). New school of FISH: solid tumor testing. CAP Cover Story [On-line journal article]. Available online at http://www.cap.org/apps/docs/cap_today/cover_stories/0104NewSchoolOfFISH.html through http://www.cap.org.
(2004). Epidermal Growth Factor Receptor Assay, Iressa (Gefitinib) responsiveness in lung cancer, EGFR Gene Analysis. Clinical Molecular Diagnostic Laboratory [On-line information]. Available Online at http://www.cityofhope.org/cmdl/EGFR.asp through http://www.cityofhope.org.
(© 2003). Epidermal Growth Factor Receptor (EGFR), Breast Cancer. LabCorp [On-line test information]. Available Online at http://www.labcorp.com/datasets/labcorp/html/chapter/ through http://www.labcorp.com.
(2004 April 29). Discovery Promises Better Use of Iressa for Lung Cancer. American Cancer Society, ACS News Center [On-line article]. Available online at http://www.cancer.org/docroot/NWS/content/NWS_1_1x_Discovery_Promises_Better_Use_of_Iressa_for_Lung_Cancer.asp through http://www.cancer.org.
Ang, K. et. al. (2002 December 15). Impact of Epidermal Growth Factor Receptor Expression on Survival and Pattern of Relapse in Patients with Advanced Head and Neck Carcinoma. Cancer Research 62, 7350-7356 [On-line journal]. Available Online at http://cancerres.aacrjournals.org/cgi/content/full/62/24/7350 through http://cancerres.aacrjournals.org.
(2004 April 29). Presence of Gene Mutation Tightly Linked to Drug Effectiveness in Lung Cancer. National Cancer Institute [On-line news]. Available Online at http://www.cancer.gov/newscenter/pressreleases/IressaMutation through http://www.cancer.gov.
Billingsley, J. (2003 December 6). New Clue to Breast Cancer Mortality, Growth factor identified with poorer outcomes in patients. Henry Ford Health System [On-line news]. Available Online at http://www.henryfordhealth.org/110736.cfm through http://www.henryfordhealth.org.
Langreth, R. (2004 April 29). Gene Predicts Cancer Drug Effectiveness. Forbes.com Pharmaceuticals [On-line article]. Available Online at http://www.forbes.com/2004/04/29/cx_rl_0429cancer_print.html through http://www.forbes.com.
(2003). Epidermal Growth Factor Receptor Status in Breast Cancer Metastases to the Central Nervous System - Comparison With HER-2/neu Status. CAP [On-line Abstracts From the College of American Pathologists 2003 Annual Meeting (CAP '03)]. Available Online at http://www.cap.org/apps/docs/archives_pathology_lab_med/this_month.html through http://www.cap.org.
Weaver, C. and Maxon, J. (1998- 2004). Targeting Epidermal Growth Factor Receptor Pathways. CancerConsultants.com Current Topics in Oncology [On-line information]. Available online at http://www.411cancer.com/syndication/veContent.jsp?ArticleID=egfr_02&ArticleTypeID=CTON through http://www.411cancer.com.