Overview: EGFR Immunohistochemistry TestIntroduction: The EGFR Immunohistochemistry Test detects epidermal growth factor receptor (EGFR) to diagnose lung or colorectal cancer, causing cough or abdominal pain. Aligned with 2023 NCCN guidelines, it uses immunohistochemistry for high specificity, supporting cancer screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in histopathology for patients with suspected lung or colorectal malignancies.
Other Names: EGFR IHC Assay, Lung/Colorectal Cancer IHC Test.
FDA Status: Laboratory-developed test (LDT), meeting histopathology standards for diagnostic accuracy.
Historical Milestone: EGFR testing began in the 2000s with targeted therapy research. Immunohistochemistry-based methods improved in the 2010s, enhancing diagnostic precision.
Purpose: Detects EGFR to diagnose lung or colorectal cancer, guides treatment, and evaluates patients with cough or abdominal pain.
Test Parameters: 1. Epidermal Growth Factor Receptor
Pretest Condition: No fasting required. Collect tissue via biopsy or surgical resection. Report history of cough, abdominal pain, or cancer symptoms.
Specimen: 0.5-2 cma³ tissue (FFPE). Transport in a biohazard container.
Sample Stability at Room Temperature: 7 days
Sample Stability at Refrigeration: Not refrigerated
Sample Stability at Frozen: Not frozen
Medical History: Document cough, abdominal pain, weight loss, or family history of lung or colorectal cancer. Include current medications, especially EGFR inhibitors.
Consent: Written consent required, detailing the tests purpose, cancer implications, and risks of biopsy or surgery.
Procedural Considerations: Uses immunohistochemistry to detect EGFR in lung or colorectal tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for targeted therapy eligibility.
Factors Affecting Result Accuracy: Improper tissue fixation or processing can affect results. Low tissue quality may reduce staining accuracy.
Clinical Significance: Positive EGFR staining suggests lung or colorectal cancer, guiding EGFR-targeted therapies (e.g., cetuximab). Negative staining may require molecular testing.
Specialist Consultation: Consult an oncologist for result interpretation and treatment planning.
Additional Supporting Tests: EGFR mutation testing, KRAS testing, or PET-CT to confirm lung or colorectal cancer diagnosis.
Test Limitations: Not specific to one cancer type; EGFR expression varies. Clinical correlation and molecular testing are needed.
References: NCCN Lung Cancer Guidelines, 2023; Journal of Clinical Oncology, Lynch TJ, 2022.
