Is there any relationship between Helicobacter pylori infection and human epidermal growth factor receptor 2 expression in gastric cancer?

Purpose: Helicobacter pylori(HP) is a significant causative agent of gastric cancer (GC). However, the underlying mechanisms involved in its pathogenesis and association with oncoproteins are unclear. The aim of the present study was to evaluate the relationship between HP infection and human epidermal growth factor receptor 2 (HER2) expression in GC patients. Materials and Methods: Surgery (173) or endoscopic biopsy (35) specimen of 208 patients diagnosed with GC was evaluated for the presence of HER2 and HP. HER2 expression was assessed by fluorescence in situ hybridization (FISH) method, whereas HP status was evaluated histologically. Giemsa stain was used to identify HP status, in case HP could not be recognized in routine H and E-stained sections despite careful examination Results: The median age was 63 years (27-91), and most patients were male (male/female: 149/59). Of all the 208 patients, HP was positive in 87 (41.8%) and negative in 121 (58.2%) patients. FISH positivity for HER2 was observed in 41 (19.7%) patients, whereas FISH negativity was observed in 167 (80.3%) patients. According to the Chi-square test, patient distribution was 21 in HER2-positive HP-negative group, 20 in HER2-positive HP-positive group, 100 in HER2-negative HP-negative group, and 67 in HER2-negative HP-positive group. No correlation was found between HP and HER2 status (P = 0.314). HP positivity had significant effect on median overall survival (27.4 vs. 12.9 months, P = 0.046). Conclusions: Our results suggest that there is no relationship between HP infection and HER2 status in patients with GC.