HER2+ advanced gastric cancer: Current state and opportunities (Review)

Human epidermal growth factor receptor 2 (HER2)+ gastric cancer (GC) is a distinct subtype of GC, accounting for 10-20% of all cases of GC. Although the development of the anti-HER2 monoclonal antibody trastuzumab has markedly improved response rates and prognosis of patients with HER2+ advanced GC (AGC), drug resistance remains a considerable challenge. Therefore, dynamic monitoring of HER2 expression levels can facilitate the identification of patients who may benefit from targeted therapy. Besides trastuzumab, DS-8201 and RC48 have been applied in the treatment of HER2+ AGC, and several novel anti-HER2 therapies are undergoing preclinical/clinical trials. At present, combination immunotherapy with anti-HER2 agents is used as the first-line treatment of this disease subtype. New promising approaches such as chimeric antigen receptor T-cell immunotherapy and cancer vaccines are also being investigated for their potential to improve clinical outcomes. The current review provides new insights that will guide the future application of anti-HER2 therapy by summarizing research progress on targeted therapy drugs for HER2+ AGC and combination treatments.