Prognostic significance of HER2 expression and associated clinical characteristics in esophageal adenocarcinoma

• Published in: Journal of clinical oncology Vol. 31; no. 4_suppl; p. 114
• Main Authors: Chan, Ellie, Alkhasawneh, Ahmad, Duckworth, Lizette Vila, Zuluaga Toro, Tania, Hou, Wei, Yan, Hui, Hughes, Steven J., George, Thomas J.
• Format: Journal Article
• Language: English
• Published: 01.02.2013
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2013.31.4_suppl.114

Abstract only 114 Background: The incidence of adenocarcinoma of the esophagus (EA) and gastroesophageal junction (GEJ) is on the rise. Her2Neu (HER2) is overexpressed in 20-25% of gastric cancers and is associated with poor prognosis. However, the prognostic significance of HER2 in EA/GEJ is less clear. Methods: This retrospective analysis included all sequential patients (pts) with EA or GEJ who underwent primary resection at the University of Florida from 2001 to 2011without neoadjuvant therapy or HER2 inhibition. Demographics, risk factors, tumor features, and outcome data were analyzed. Central blinded immunohistochemistry (IHC) was performed on paraffin embedded tumor specimens with HER2 expression scored as negative (-) (0 or 1+), indeterminate (2+) or positive (+) (3+). Results: 56 pts were eligible for analysis (45 M/11 F) with median age 67 years (37-83). Mean BMI was 29.6±6.6 and 43 pts (92%) had underlying Barrett’s esophagus. Most tumors (60%) were stage I (T1N0). Overall testing revealed tumors to be HER2 + (38%), indeterminate (21%) or - (41%). 50% of Stage I, 18% of stage IIA, 33% of stage IIB, and 14% of stage III tumors were HER2 + (p=0.035 for stage I compared to other stages). Underlying Barrett’s esophagus was associated with HER2 + (60 vs. 0%; p=0.045). The median follow up of the entire cohort was 2.9 years. Overall survival (OS) at 3 years was 80% for stage I, 50% for stage IA, 40% for stage IIB and 50% for stage III (p= 0.153). 3 year OS for HER2+ pts was 64% vs. 70% for HER2- (p=0.63). Univariate analysis did not show significant correlation among tobacco use, BMI, disease progression, survival and HER2 expression. Conclusions: This data suggests that HER2 overexpression is more frequent in early stage disease with underlying Barrett’s esophagus. Our data do not support HER2 as a prognostic factor in EA/GEJ. The relationship of HER2 overexpression in the development of early stage GEJ, particularly in the setting of Barrett’s, is of clinical interest. Further investigation is warranted.