PS02.092: HER2 EXPRESSION AND GENE AMPLIFICATION CORRELATES WITH BETTER SURVIVAL IN ESOPHAGEAL ADENOCARCINOMA.

Background Targeting Her2 is highly established in cancers of the upper gastrointestinal tract, since clinical studies showed a survival benefit in Her2-positive gastric cancer. To date there is conflicting data concerning the impact of Her2 expression and gene amplification in esophageal adenocarcinoma (EAC), as most studies do not differ between cancers of the esophagus, gastroesophageal junction and stomach. The aim of this study was to analyze the expression and gene amplification of Her2 in EAC in correlation to clinical and pathological data to verify the prognostic impact. Methods We analyzed 506 patients with esophageal adenocarcinomas that underwent thoraco-abdominal esophagectomy between 1997 and 2013 using a tissue micro array (TMA) for the expression of Her2 by immunohistochemistry (IHC) according to the guidelines. Fluorescence-in-situ-hybridization (FISH) was performed for IHC score 2. The Her2-status was correlated with clinical and pathological data. Results Her2-positivity was found in 11.7% (n = 59) of all EAC (IHC score 3 + or IHC score 2 + with amplification) and demonstrated a significant better overall-survival (OS) in correlation to Her2-negative tumors (median OS 55.0 vs. 22.7 months, P  < 0.0001) (Figure below). Overexpression of Her2 was associated with lower tumor stages (pT1/pT2, P  = 0.038), absence of lymph node metastases (pN0/pN + , P  = 0.030) and was significantly associated with tubular and/or papillary tumor growth pattern (P  = 0.029). View large Download slide View large Download slide Conclusion We demonstrated a positive prognostic impact of Her2 expression and gene amplification in a large cohort of EAC, contrary to other solid malignancies including gastric cancer, but according to a large study of EAC from 2012. Her2-positive tumors significantly have a tubular and/or papillary tumor growth pattern, indicating a marker of differentiation in EAC. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]