Overexpression of Her1 (EGFR) in Gastric Cancer: A Saudi Regional Population Based Study*

Background: Gastric cancer is one of the commonest malignant tumor worldwide. Its treatment remains a challenge for physicians. Epidermal growth factor receptor (EGFR) inhibitors have played a significant role in the management of solid malignancies including colorectal cancer. In this study we aimed to determine EGFR expression in gastric adeno-carcinoma by standardized immunohistochemistry in a Saudi regional population based cohort and also to evaluate Ki-67 proliferating index and p-53 mutation status. Materials and Methods: Gastric carcinoma (GC) cases comprising surgical resection specimens and endoscopic biopsies, were selected, from the pathology archives of King Fahd Hospi-tal of the University of Dammam (KFHU), spanning a time period of 6 years. The histological GC type was delineated according to Laurens classification and immunohistochemical (IHC) protein analysis for EGFR, Ki-67 and p-53 was carried out. Results: 42 cases of gastric GC were analyzed and EGFR overexpression was demonstrated in 4.76 % of cases. Out of these 2.38 % had membranous and the remaining demonstrated predominantly cytoplasmic along with focal membranous positivity. Ki-67 proliferation index ranged from moderate to high and and p-53 mutation status was negative in these cases. Conclusion: Low EGFR expressivity could be reflective of regional variation in cancer charac-teristics. The study also highlights the inadequacy of the currently employed gastric EGFR interpretation criterions and stresses on development of standardized and uniform EGFR evaluation protocols tailored for gastric needs