Test Catalog

Test ID: HERGN    
HER2, Gastric/Esophageal, Semi-Quantitative Immunohistochemistry, Manual, No Reflex

Useful For Suggests clinical disorders or settings where the test may be helpful

Determining overexpression of HER2 protein of gastric and esophageal adenocarcinoma in formalin-fixed, paraffin-embedded tissue sections (no reflex to FISH testing)

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The HER2 (official gene name ERBB2) proto-oncogene encodes a membrane receptor with tyrosine kinase activity and homology to the epidermal growth factor receptor.


Amplification and overexpression of the HER2 gene have been associated with a shorter disease-free survival and shorter overall survival in gastric and gastroesophageal junction cancers, as well as breast, endometrial, and ovarian cancer.(1,2)

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Reported as negative (0, 1+), equivocal (2+), and positive (3+)

Interpretation Provides information to assist in interpretation of the test results

Results are reported as positive (3+ HER2 protein expression), equivocal (2+), or negative (0 or 1+)

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Pergam M, Slamon D: Biological rationale for HER2/neu (c-erbB2) as a target for monoclonal therapy. Semin Oncol 2000;27(5):13-19

2. Gravalos C, Jimeno A: HER2 in gastric cancer: a new prognostic factor and a novel therapeutic target. Ann Oncol 2008 Sep;19(9):1523-1529

3. Meza-Junco J, Au HJ, Sawyer MB: Transtuzumab for gastric cancer. Expert Opin Biol Ther 1009;9(12):1543-1551