With the continuous research on the molecular biology of gastric cancer, molecular targeted therapy has become the focus and hot spot for the comprehensive treatment of gastric cancer. Among them, the ToGA study is the first multicenter randomized phase III clinical study using trastuzumab to treat inoperable patients with locally advanced, recurrent and/or metastatic Her-2-positive gastric cancer. The study enrolled 594 Her-2-positive patients from 3807 patients with progressive esophagogastric junction and gastric adenocarcinoma who were randomized to receive trastuzumab in combination with 5-FU/capecitabine + cisplatin (CDDP) or chemotherapy alone. The results showed a significant prolongation of median OS in the trastuzumab-combined chemotherapy group (13.8 vs. 11.1 months, P=0.0048, HR 0.74, 95% CI 0.60 to 0.91) and a significant increase in objective efficiency (47.3% vs. 34.5%, P=0.0017). In a subgroup analysis, trastuzumab treatment in Her-2 expressing IHC2+/FISH+ or IHC3+ patients resulted in a further prolongation of median OS of 16.0 months versus 11.8 months in the control group (HR=0.65); based on the results of this study, trastuzumab became the first targeted agent recommended by the NCCN guidelines for advanced gastric cancer and was approved by the US FDA and the EU. Trastuzumab has been approved by the US FDA and the European Commission for patients with primary Her-2-positive metastatic gastric cancer and gastroesophageal junction cancer. The incidence and mortality rate of gastric cancer in China remain high, and the use of trastuzumab has attracted much attention. In this paper, we present a preliminary analysis of the cases participating in the ToGA study at our center. Since the application of trastuzumab is based on the overexpression of Her-2 gene, Her-2 detection is an important factor for the application. Conventional assays include immunohistochemistry (IHC) assay to determine protein level expression and fluorescence in situ hybridization (FISH) to determine gene amplification. A total of 3280 patients in the ToGA study obtained Her-2 results, with a positive rate of 22.1%, including a concordance rate of 87.2% for positive Her-2 determination using IHC and FISH. The rate of Her-2 positivity in Chinese patients in this study was 23%, similar to that in Europe and the United States. However, it is worth noting that Her-2 positivity in the ToGA study was determined as IHC3+ or FISH+, while subgroup analysis showed that patients with IHC3+ and IHC2+/FISH+ could benefit more from trastuzumab. Therefore, trastuzumab is currently not recommended for IHC+/FISH+- and IHC2+/ISH- patients. A total of 106 patients with advanced gastric cancer were screened in our center, of which 101 had Her-2 results returned. the HER-2 positive rate was 14.9% (15/101). There were 10 cases with positive HER-2 expression (IHC3+) by IHC method, 13 cases with positive HER-2 by FISH method, and a total of 8 cases with positive results by both methods, with a concordance of 66.5%. In clinical work Her-2 detection is difficult due to common tumor heterogeneity in gastric cancer, small volume of gastroscopic biopsy specimens and glandular cavity formation in gastric cancer, so standardized process testing in qualified laboratories is required. There is also a correlation between tumor site and pathological type and the Her-2 positivity rate; the results of the ToGA study showed that the Her-2 positivity rate for adenocarcinoma of the gastroesophageal junction (33.2%) was significantly higher than that for other sites of gastric cancer (20.9%), p<0.001. 2positive rates were 15.4%, 11.1%, 13.3%, 24.0% and 0, respectively, with no statistically significant difference (P=0.726). This Lauren typing is different from the WHO typing routinely performed in China, which is based on cell morphology and histochemistry into intestinal epithelium-like intestinal gastric cancer and diffuse gastric cancer with diffuse spread. Not only the morphology and histochemistry of the two types are different, but also the prognosis is significantly different, and the prognosis of intestinal gastric cancer is significantly better than that of diffuse type. The ToGA study also found that trastuzumab combined with chemotherapy had the longest overall survival and the best efficacy in the treatment of intestinal gastric cancer, while diffuse gastric cancer had the worst efficacy. However, since Lauren typing is not used in China, our center analyzed the correlation between the pathological type of gastric cancer and Her-2 positive rate according to WHO typing, and the results showed that the Her-2 positive rate was 57.1% in hypofractionated adenocarcinoma (indolent cell carcinoma, mucinous adenocarcinoma), which was higher than that of 29.9% in intermediate differentiated adenocarcinoma and 13.0% in highly differentiated adenocarcinoma, but the difference was not statistically significant (P=0.110). Lauren typing, in addition to being associated with the rate of Her-2 positivity, was also associated with the expression of genes related to antitumor drugs and with the efficacy of certain chemotherapeutic agents, so more attention is needed in clinical work. Patients with advanced gastric cancer generally have a poor quality of life, so the ToGA study focused more on the quality of life of patients along with the survival benefit. The evaluation showed that out of 584 randomized patients, 563 completed the EORTC QLQ-C30 scale and QLQ-ST022 quality of life assessment. The results showed good patient compliance, and overall quality of life scores improved in both the trial and control groups after receiving drug therapy and remained stable during the first 13 weeks of chemotherapy. Functional scores also remained stable in both groups. Trastuzumab is therefore considered to provide survival benefit to patients with advanced gastric cancer without increasing drug toxicity. And unlike previous treatment modalities, patients in the ToGA study group received 6 cycles of XP/CP in combination with trastuzumab and then stopped chemotherapy and switched to single-agent trastuzumab for maintenance treatment until tumor progression. During the targeted drug maintenance treatment, patients' quality of life was further improved due to the absence of chemotherapy drug side effects. The results of the ToGA study showed that trastuzumab significantly benefited patients in terms of efficiency, FPS and OS. Moreover, the poor general condition of patients with advanced gastric cancer was significantly improved and the quality of life was enhanced. Behind such encouraging results, we need to pay more attention to the reasons for the results and look for the main factors that benefit patients. This requires a review of previous treatments for advanced gastric cancer: often a treatment regimen was used until it was ineffective or not tolerated by the patient, and while improvements in efficiency could be seen with changes in different chemotherapy regimens or the addition of new chemotherapeutic agents, improvements in PFS and OS were extremely limited. in the ToGA study, in addition to the addition of the new targeted agent trastuzumab a new treatment modality maintenance therapy was introduced. Fifteen patients were enrolled in our center for analysis, nine of whom were treated with XP in combination with trastuzumab regimen with an efficiency of 50%. The median OS was 17.7 months. The median PFS for first-line treatment was 10.37 months, significantly longer than for trastuzumab combined with chemotherapy (4.5 months). Therefore, the survival benefit for patients considered was not excluded from maintenance therapy with targeted agents in addition to the three-drug combination. However, such an inference needs to be confirmed by more prospective clinical trials in the future. In addition, there are many chemotherapeutic agents available for chemotherapy of advanced gastric cancer, and there is no definite first-line treatment option. Meta-analysis showed that the survival advantage of the three-drug combination was obvious, but the toxic side effects were greater. In the ToGA study, the CF/XP regimen was applied in combination with trastuzumab. In clinical practice, the choice of chemotherapy regimen in combination with trastuzumab does not have to be rigid, but needs to consider both the physical condition and economic status of individual patients, and also the efficiency, type and degree of toxicity of the chosen regimen, weighing the pros and cons of efficacy and toxicity. Individualized treatment should be achieved. In conclusion, ToGA trial is the first clinical trial that led to improved quality of life and survival of more than 1 year for patients with advanced gastric cancer, which reflects the advantages of individualized treatment and is a milestone in targeted therapy for gastric cancer. However, because the action characteristics of molecular targeted drugs are different from traditional cytotoxic drugs, it is important to fully understand the characteristics of molecular targeted drugs and identify the hot issues in the treatment of gastric cancer with molecular targeted drugs. In particular, the understanding of new concepts such as "maintenance treatment with targeted drugs after the onset of chemotherapy" and "continuation of targeted drug therapy after the progress of combination therapy" requires more medical practitioners to devote their efforts and continue to conduct prospective clinical trials to confirm.