Hopes and failures in front-line advanced HER2-positive gastric cancer therapy.

Human epidermal growth-factor receptor 2 (HER2) was an important therapeutic target in gastric cancer. Through the last decade, strategy with trastuzumab-based chemotherapy remains the first-line standard of treatment in advanced HER2-positive gastric cancer. Based on the Trastuzumab for Gastric Cancer trial, trastuzumab plus systemic chemotherapy of cisplatin and fluoropyrimidine as the backbone was established as the first-line therapy in advanced HER2-positive gastric cancer. Since then, studies have explored the optimization of the front-line strategy, including the dose of trastuzumab, chemotherapy regimen and maintenance therapy. A large number of clinical trials were conducted to explore the optimal front-line therapy regimens, such as lapatinib and pertuzumab. Safe and effective first-line regimens are still lacking. Recently, two phase II studies of combining immune checkpoint inhibitor in first-line treatment of advanced HER2-positive gastric cancer showed promising results. The progress of immunotherapy has gradually promoted the development of front-line treatment of advanced HER2-positive gastric cancer to potential chemotherapy-free strategies. Therefore, this article reviewed these significant clinical trials and focus on the front-line treatment strategies for HER2-positive gastric cancer.