Zahra Heidari - Infectious Diseases and Tropical Medicine Research Center, Zahedan University of Medical Sciences, Zahedan, IR Iran
Hamidreza Mahmoudzadeh-Sagheb - Department of Histology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, IR Iran
Nadia Sheibak - Department of Histology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, IR Iran
Mehran Panahi - Department of Histology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, IR Iran

Introduction & Aim: Importance of Human Epidermal Growth Factor Receptor-2 (HER-2) testing in cancer is increasing and in the other hand, there is a hypothesis about roles of Helicobacter pylori (H. pylori) in gastric cancer (GC) development. We seek to investigate the HER-2 expression in the presence of H. pylori infection in patients with gastric GC and precancerous lesions. Methods: From 224 archived blocks, 58 samples with chronic gastritis, 58 intestinal metaplasia (IM), 58 gastric dysplasia and 50 gastric adenocarcinoma cases were selected as our principal groups. Each group was subdivided into H. pylori positive and negative subgroups. Immunohistochemical method was performed for detection of HER-2 expression in gastric biopsies using a polyclonal antibody. The staining intensity was quantified and differences among groups were compared using Mann-Whitney U and Kruskal-Wallis tests. P values less than 0.05 was set as significant. Results: Results showed that HER-2 expression among the four principal groups was statistically significant (P<0.05). There was a significant Increase of immunohistochemical expression of HER-2 in H. pylori positive chronic gastritis in comparison with H. pylori negative subgroup (P<0.05). Difference of HER-2 expression between H. pylori positive and H. pylori negative subgroups in dysplasia, IM and GC groups was not statistically significant (P> 0.05). Conclusion: The present study proposed that HER-2 overexpression in gastric tissues probably had important roles in the progression of cancer and above-mentioned process was probably associated with H. pylori infection in the early stages of precancerous lesions.

Adenocarcinoma; HER-2; Gastric cancer; Gastritis; Helicobacter pylori.