Correlation of HER2 expression with clinicopathological characteristics and prognosis in resectable gastric cancer

Results from the Trastuzumab for Gastric Cancer (ToGA) trial highlighted the clinical significance of trastuzumab in the treatment of HER2 (Human Epidermal Growth Factor Receptor type 2)-positive gastric cancer. However, whether expression of HER2 is related to prognosis of gastric cancer is still controversial. A total of 360 consecutive patients with gastric cancer who underwent surgical resection in our Department from 1994 to 2007 were analyzed. We performed immunohistochemical analysis of HER2 expression. HER2 expression level was classified into four scores (0, 1+, 2+ and 3+). There were 37 (10%) patients with a score of 3+. A score of 3+ was defined as being HER2-positive. Recurrence-free survival was worse in HER2-positive cases (p=0.045). When the analysis was conducted with intestinal types of cancer, RFS was considerably worse in the HER2-positive group (p=0.011). HER2 expression may have potential as a prognostic factor for intestinal cancer types. Further research is warranted.