Table of Contents
Definition / general | Clinical features | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Molecular / cytogenetics imagesCite this page: Pernick N, Roychowdhury M. EGFR. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsegfr.html. Accessed November 28th, 2023.
Definition / general
- Epidermal Growth Factor Receptor
- Also called HER1, c-erb-B1; on 7p
- Member of epidermal growth factor receptor family (also HER2)
- 170 kDa transmembrane receptor that induces tyrosine kinase activity affecting cell growth
- Activated by epidermal growth factor and transforming growth factor alpha
- Lung adenocarcinoma patients with specific mutations may have clinical response to gefitinib (targets EGFR kinase)
- Brain: amplification is favorable prognostic factor in glioblastoma multiforme (Arch Pathol Lab Med 2005;129:624)
- Breast: 6% of breast carcinomas show EGFR amplification (7 - 18 copies) associated with EGRF protein overexpression but not HER2 status
- Patients may be responsive to EGFR therapy (Mod Pathol 2005;18:1027)
- Colon: present in 60 - 80% of colorectal carcinomas but these tumors lack gene amplification (Mod Pathol 2005;18:1350) and patients don't respond to gefitinib
- Lung: mutations are associated with terminal respiratory unit type adenocarcinoma of lung (Am J Surg Pathol 2005;29:633)
- EGRF tyrosine kinase inhibitors (gefitinib) show rapid clinical response in 10% of lung cancer patients
Clinical features
EGFR expression is associated with these breast cancers:
- Basal-like (BMC Genomics 2007;8:258)
- Metaplastic (76%, Breast Cancer Res 2005;7:R1028), carcinomas with squamous differentiation (87%, Int J Surg Pathol 2005;13:319)
- ER negative tumors (Pathol Res Pract 1988;183:25, Breast Cancer Res 2008;10:R49)
- Phyllodes tumors (all types-19%, malignant-75%, Lab Invest 2006;86:54)
- Sarcoma NOS (5 of 7, Am J Surg Pathol 2006;30:450)
- 6% of breast carcinomas show moderate to low level EGFR amplification associated with protein overexpression, and may be responsive to anti-EGFR therapy (Mod Pathol 2005;18:1027), currently used for lung cancer patients
- EGFR expression is more common in breast tumors in younger and black women
- EGFR expression associated with lower hormone receptor levels, higher proliferation, genomic instability, HER2 overexpression, higher risk of relapse (Cancer 2010;116:1234), poor survival (J Clin Oncol 2007;25:4405)
Microscopic (histologic) images
Contributed by Semir Vranić, M.D., Ph.D.
Images hosted on other servers:
Positive staining - normal
- Endometrial stromal cells
Positive staining - disease
- Endometrial stromal sarcoma (Am J Surg Pathol 2005;29:485)
- Adenosarcoma, MMMT, squamous cell carcinoma of lung, 80% of non-small cell lung cancers