Patients with advanced gastric cancer should all be tested for HER2 at diagnosis, and trastuzumab will be a treatment option for patients with HER2-positive advanced gastric cancer. New treatment option for HER2-positive advanced gastric cancer The importance of the ToGA study, reported at this year’s ASCO Annual Meeting, was recognized by Professor Yung-Jue Bang of Seoul National University School of Medicine in Korea. The study was the first to attempt conventional chemotherapy plus trastuzumab-targeted therapy in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer, and demonstrated that the therapy significantly improved patient survival. Professor Fang said that all patients with advanced gastric cancer should be tested for HER2 at diagnosis, and trastuzumab will undoubtedly be the treatment of choice for patients with HER2-positive advanced gastric cancer, and trastuzumab can be used directly for IHC2+, FISH+ and IHC3+ patients. However, for patients with IHC+/- or FISH-, there is no clinical research evidence to support the efficacy advantage of chemotherapy in combination with trastuzumab treatment. In China, second-line chemotherapy for advanced gastric cancer is highly prevalent, with irinotecan monotherapy, docetaxel monotherapy, paclitaxel weekly regimens or three-week regimens, or combinations of these agents in use, and standard regimens have not been established. Second-line chemotherapy for advanced gastric cancer will be one of the hot spots for future research. The multicenter randomized phase III clinical trial ToGA study enrolled 3,883 gastric cancer patients, 22.1% of whom were HER2-positive, and the HER2-positive rate among the 590 Chinese patients enrolled was approximately 25%. Stratified analysis showed that for patients who were IHC2+, IHC3+ or FISH+, OS was prolonged by at least 4.2 months with the addition of trastuzumab on top of chemotherapy. However, the efficacy of trastuzumab in patients with IHC+/- or FISH- remains to be further investigated.