HER2/neu expression in gastric carcinoma and its association with Helicobacter pylori infection and other clinicopathological parameters

Abstract

Gastric cancer is the 5 most common malignancy and 3 leading cause of cancer death worldwide. Most cases are diagnosed in advanced stages making treatment difficult. International regulatory agencies have recently approved trastuzumab therapy in locally advanced and metastatic gastric adenocarcinomas expressing HER2.To find HER2/neu expression in adenocarcinoma of stomach and correlate with clinicopathological features and study H.pylori positivity in HER2 positive cases.The ambispective, observational study was conducted in the department of Pathology (July 2017 to June 2019).Seventy eight cases of gastric adenocarcinoma were studied, both endoscopy guided biopsy or gastrectomy. Expression of HER2/neu and detection of Helicobacter pylori was done using immunohistochemistry. HER2 expression was correlated with clinicopathological parameters and H.pylori infection.Fisher’s exact test, chi square test and p value <0.05 was considered significant.HER2/neu was positive in 26.92% of cases, 16.67% were equivocal and 56.41% were negative. 55.13% of intestinal type were HER2 positive. Grade 1 tumor showed more HER2 positivity (42.31%). HER2 positivity was independent of other parameters like age, sex and location of tumor. H.pylori was positive in 24.36% of HER2/neu positive cases.HER2 positivity correlated with Lauren’s intestinal type and grade 1 of tumor.HER2 is an independent biomarker regardless of other clinicopathological features. Though few Her2 positive cases showed H. pylori positivity, more larger studies are required to establish statistically significant association between HER2 positivity and H.pylori infection.