The characteristics of c-MET and HER2 expression in gastric carcinoma and its correlation with clinical-pathological parameters.

Abstract

e15566 Background: The aim of this study was to determine whether overexpression of c-MET or HER2 had an effect on the clinical-pathological parameters and / or the prognosis of gastric carcinoma, as well as a direct correlation among those parameters. Methods: 134 gastric resectates were archived between 2007-2012 and retrospectively examined for c-MET and HER2 expression via immunohistochemistry (IHC). The HER2 status IHC2 + was additionally verified by means of Chromogenic in situ hybridization (CISH). Statistical data analysis was performed on the basis of the parameters acquired in the prospective multicentre observation study QCGC'07 / 09. Results: A total of 71 patients (53%) were found to express c-MET low and 63 patients (47%) expressed c-MET high, 122 patients (91%) were found to be HER2 negative and 12 persons (9%) were HER2 positive. C-MET high was significantly more pronounced in the Lauren intestinal type (63.8%, p = 0.001) and moderately to poorly differentiated tumour tissue (G2 50.9%, G3 43.9%, p = 0.038) as well es tissue with lymph vessel infiltration (L1 59.1%, p = 0.039). HER2 showed no significant effect on the clinical-pathological parameters. The median overall survival was shown to be shortened for the c-MET high-expressing (c-MET low 56 months, SD: ± 24.67; 95% CI: 7.65-104.36 vs. c-MET high 32 months, SD: ± (median-OS HER2 negative 38 months, SD: ± 14.11, 95% CI: 10.35-65, p = 0.839), and HER2 negative, 65, median-OS HER2 positive not reached, p = 0.305) patients. 8/134 resectates (5.97%, p = 0.135) were high and positive in both expression patterns, showing no significant difference to the OS (p = 0.393). Conclusions: In our studies, c-MET high or HER2 negative expression was associated with a poorer OS. However, no direct correlation between HER2 and c-MET could be demonstrated