Overview: HER2 ERBB2 Immunohistochemistry TestIntroduction: The HER2 ERBB2 Immunohistochemistry Test detects HER-2 protein to diagnose breast cancer, causing lumps or pain. Following 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 breast cancer.
Other Names: HER-2 IHC Assay, Breast Cancer HER-2 Test.
FDA Status: FDA-approved for breast cancer diagnostics, ensuring high reliability in laboratories.
Historical Milestone: HER-2 testing began in the 1990s with breast cancer research. Immunohistochemistry-based methods improved in the 2000s, enhancing precision for targeted therapies.
Purpose: Detects HER-2 to diagnose breast cancer, guides treatment, and evaluates patients with lumps or pain.
Test Parameters: 1. HER-2 Protein
Pretest Condition: No fasting required. Collect tissue via breast biopsy or surgery. Report history of breast lumps, pain, or family history of breast cancer.
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 breast lumps, pain, nipple discharge, or family history of breast cancer. Include current medications, especially trastuzumab.
Consent: Written consent required, detailing the tests purpose, cancer implications, and risks of biopsy or surgery.
Procedural Considerations: Uses immunohistochemistry to detect HER-2 in breast tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for HER-2-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 HER-2 staining (3+) confirms HER-2-positive breast cancer, guiding trastuzumab or chemotherapy. Equivocal results (2+) require FISH testing.
Specialist Consultation: Consult an oncologist or breast surgeon for result interpretation and treatment planning.
Additional Supporting Tests: HER2 FISH, ER/PR IHC, or mammogram to confirm breast cancer diagnosis.
Test Limitations: Equivocal results require confirmatory testing. Not specific to breast cancer; other tumors may express HER-2.
References: NCCN Breast Cancer Guidelines, 2023; American Journal of Surgical Pathology, Hammond ME, 2022.
