HER2 NEU GASTRIC/ GASTROESOPHAGEAL JUNCTION FLUORESCENCE IN-SITU HYBRIDIZATION PERFORMED ON (Case #, Block): HER-2/NEU FISH: Interpretation: NOT AMPLIFIED Average number of HER2 gene copies per cell: Average number of chromosome 17 per cell: Amplification Ratio: EQUIVOCAL Average number of HER2 gene copies per cell: Average number of chromosome 17 per cell: Amplification Ratio: AMPLIFIED: Average number of HER2 gene copies per cell: Average number of chromosome 17 per cell: Amplification Ratio: OTHER: Reference range for Her-2/neu FISH: Positive for amplification: HER2:CEP17 ratio > 2.2 Equivocal for amplification: HER2:CEP17 ratio 1.8-2.2 Negative for amplification: HER2:CEP17ratio < 1.8 Comments: TEST DESCRIPTION: Fluorescence in situ hybridization (FISH) for the detection of the Her-2/neu gene amplification in paraffin embedded tissue was performed using the Abbott Pathvysion assay. Results are interpreted utilizing the guidelines used by the ToGA trial (1). FISH analysis was performed on the invasive carcinoma. Using fluorescent microscopy, enumeration was performed on the Her-2/neu gene, located at locus (17p11.2-q12) on chromosome 17, and the alpha satellite DNA sequence, located at the centromeric region of chromosome 17 (17p11.1-q11.1). Gene amplification is based on the ratio of Her-2/neu to chromosome 17 in the tumor tissue. External positive controls were acceptable. FISH Probes: Orange LSI HER-2/neu; Green Chromosome 17: CEP 17. The performance characteristics were validated by the University of Florida Pathology Laboratories. 1. Bang YJ, Van Cutsem E, Feyereislova A, ToGA Trial Investigators: Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial. Lancet 2010 Sep 3;376(9742):687-697