Clinicopathological features and Borrmann classification associated with HER2-positive in primary gastric cancer

PURPOSE: Human epidermal growth factor receptor 2 (HER2) assesment is important for patients with advanced gastric cancer (GC) to determine trastuzumab therapy is being considered. A study was performed to evaluate the rate of HER2 positivity in patients with primary gastric cancer and to assess the relationship between HER2-positive and Borrmann classification. PATIENTS AND METHODS: Four hundred and sixty-one patients with gastric or gastroesophageal junction cancer were confirmed as having adenocarcinoma between 2005 and 2016. HER2 status was assessed using immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). Tissues were considered to be HER2-positive when assessment revealed either an IHC score of 3+ or IHC score 2+ accompanied by a positive FISH result. RESULTS: The HER2-positive rate was significantly higher in men than in women (19% vs 9%; p=0.006). In our study, HER2-positive gastric tumors with differentiated histology were significantly higher. The proportion of HER2-positive gastric tumors of Borrmann classification III or IV was significantly higher than tumors classified as I or II. CONCLUSIONS: HER2-positive gastric cancer tends to be associated with male gender, differentiated histology, and Borrmann tumor classification of III or IV.