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 adenocarcinoma 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 Hospital 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 characteristics. 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.