[Relation of HER2 status and prognosis in gastric cancer patients].

Human epidermal growth factor receptor-2 (HER2) became one of the most important biomarkers for gastric cancer patients with the results of ToGA trial which proved the benefits of trastuzumab treatment in HER2-positive advanced or recurrent gastric cancer patients. Many investigations have been conducted on HER2 as a prognostic factor. Although there have been no universal conclusions, the positive result of HER2 status appears to be poor prognostic factor according to current evidences. All the studies have encountered problems such as small sample size, diversity of patient characteristics,methods of HER2 tests and diagnosis of HER2 status. Furthermore, few studies were conducted in advanced or recurrent gastric cancer patients. Biomarker analysis including HER2 status on the patients enrolled in ACTS-GC trial which evaluated S-1 in resectable gastric cancer patients is underway, and we are planning biomarker analysis of HER2 status as a prognostic factor on advanced or recurrent gastric cancer patients. These results would clarify the role of HER2 as a prognostic factor.