Her-2/neu gene amplification in esophageal adenocarcinoma and its influence on survival.
BACKGROUND
HER-2/neu (c-erbB-2, HER2) gene amplification and protein overexpression have been associated with poor prognosis in several solid tumors, including breast and gastric cancer. Its incidence and significance in esophageal adenocarcinoma is unknown.


METHODS
Tissue microarrays were successfully constructed from 89 paraffin-embedded archival specimens of esophageal adenocarcinomas for HER2 gene amplification by silver-enhanced in situ hybridization (SISH). No patients had undergone neoadjuvant therapy. Protein overexpression was tested with immunohistochemistry (IHC) using automated immunostaining (Ventana Benchmark). Incidence of HER2 positivity, correlation to clinicopathological variables in esophageal cancer patients, and concordance between SISH and IHC were determined.


RESULTS
True HER2 gene amplification was detected in 14 esophageal cancer specimens (16%), and 92% of those with high-level HER2 amplification showed positive HER2 protein overexpression. No significant associations were found among gene amplification and clinicopathological factors. The 5-year survival rates were 57% for esophageal cancer patients with HER2 amplification compared with 32% without, but the difference in overall survival was not significant (P = .37). The correlation between SISH and IHC was statistically significant (P < .0001).


CONCLUSIONS
While molecular targeting may be possible for approximately 16% of esophageal adenocarcinoma patients, HER2 oncogene amplification did not influence survival in this study.
Discipline of Surgery, University of Adelaide, Adelaide, SA, Australia. sarah.thompson@adelaide.edu.au
Sarah K
SK
Thompson
Thomas R
TR
Sullivan
Ruth
R
Davies
Andrew R
AR
Ruszkiewicz
D000230:Adenocarcinoma / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D000368:Aged; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D016629:Esophagectomy; D005260:Female; D005500:Follow-Up Studies; D005784:Gene Amplification; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015996:Survival Rate; D046888:Tissue Array Analysis
D018719:Erb-b2 Receptor Tyrosine Kinases