The clinical and prognostic significance of HER2 and Ki67 expression in 2062 Chinese patients with resectable gastric cancer: a retrospective study

Abstract Background The purpose of this study was to assess the prognostic value of the expression of human epidermal growth factor receptor 2 (HER2), Ki67, and their combination levels in the prognosis of Chinese patients with resectable gastric cancer (GC). Methods A total of 2062 Chinese GC patients were recruited with HER2 and Ki67 expression being evaluated using immunohistochemistry. Patients were divided into four groups according to HER2 and Ki67 expression. The distributions between HER2 and Ki67 expression levels and clinicopathological characteristics were compared using the Chi-square test. The relationship between HER2 and Ki67 expression level and overall survival were evaluated with the univariate and multivariate Cox regression analysis. Results There was no statistical differences between the overall survival (OS) rate and the expression level of HER2 (P = 0.748) or Ki67 (P = 0.063), but there were significant relationships between the OS rates and the combining expression levels of HER2/Ki67 (P < 0.05). Further, Ki67, sex, T stage, N stage, TNM stage, and adjuvant chemotherapy were significant and independent risk factors for GC survival (P < 0.05). Conclusions Our study illustrated that Ki67, but not HER2 acted as an independent prognostic factor in Chinese resectable GC patients. The evaluation of the combining expression levels of HER2/Ki67 may be more useful to assess patient prognosis with resectable GC.