Clinicopathologic Features and Prognosis of HER2- Positive Gastric Cancer

Background: The role of human epidermal growth factor receptor 2 (HER2) overexpression has been well established in breast cancer, with corresponding targeted therapies. In contrast, the clinicopathologic features and prognosis of HER2 overexpression in gastric cancer remain inconclusive. Methods: In this study, 334 patients with gastric cancer who received surgical resection between May 2017 and June 2021 were enrolled at a single medical center in Taiwan. HER2 status was determined by immunohistochemistry (IHC) staining or fl uorescence in situ hybridization (FISH). The clinicopathologic features and survival curves of the HER2positive and HER2-negative gastric cancer patients were analyzed. Results: The HER2-positive ratio was 7.2%. HER2-positive gastric cancer was associated with more differentiated tumors (P P = 0.016), more Lauren intestinal type (P P = 0.010), and a higher portion of Ming expanding type (P P = 0.033) in the univariate analysis, but only Lauren intestinal type was an independent factor in the logistic regression model (P P = 0.015). The overall survival and disease-free survival between the HER2-positive and HER2-negative groups were not significantly fi cantly different. Patients with HER2positive gastric cancer were more likely to have distant lymphatic recurrence than those with HER2-negative gastric cancer (P P = 0.026). Conclusions: HER2-positive gastric cancer is associated with intestinal histologic type and distant lymphatic recurrence, but HER2 is not an independent prognostic factor.