HER-2/neu Over-expression and Gastric Cancer Prognosis - A Meta-analysis

Gastric cancer is one of the most common tumors and the second leading cause of cancer mortality in the world (Kamangar et al., 2006) . In China, it is the leading cause of morbidity and mortality of neoplasm in digestive system. Until now, clinical surgery is the mainstay of gastric cancer treatment and only can cure parts of patients in the early-stage, but for the patients in the advanced stage, even though surgery combined with postoperative chemoradiotherapy, their survival rate is still low (Cunningham et al., 2006). TNM staging is admitted as the most important factor which effects on the prognosis of gastric cancer, but patients with similar TNM-stages have different clinical outcomes; thus, except the traditional method of staging, we need other standards to identify individual case of patients with gastric cancer especially at advanced stage. Over the last twenty years, the most frequently studied molecular biological prognostic factors in gastric cancer is human epidermal growth factor receptor 2 (HER-2/neu). The HER-2 protein (p185, HER-2/neu, ErbB-2) is a 185kDa transmembrane tyrosine kinase (TK) receptor and a member of the epidermal growth factor receptors (EGFRs) family, binding of different ligands to the extracellular domain initiates a signal transduction cascade that can influence many aspects of tumor cell biology, including cell proliferation, apoptosis, adhesion, migration, and