The liver is the most common organ for blood-borne metastasis of gastric cancer. After gastric cancer cells enter the bloodstream, the first organ to metastasize after passing through the portal vein is the liver, which may then metastasize to the lung and other distant organs, such as bone, adrenal gland and brain. Among patients with gastric cancer, the overall incidence of liver metastasis is about 9.9%~18.7%, among which about 70% of patients have liver metastasis when gastric cancer is discovered, and another about 30% of patients have liver metastasis discovered by regular review after gastric cancer resection. Generally speaking, the average time to develop liver metastasis after radical gastric cancer resection is about 14 months, and most patients develop liver metastasis within 2 years after surgery. Since patients with liver metastases from gastric cancer have a poor prognosis, the five-year survival rate is usually less than 20%. Therefore, even if radical gastric cancer is performed, regular liver ultrasound examination is needed after surgery to detect the problem early and treat it early. How should we treat gastric cancer liver metastasis when it is found? Surgical resection The 2019 edition of the Expert Consensus on the Diagnosis and Treatment of Gastric Cancer Liver Metastases classifies gastric cancer liver metastases into three types: resectable (Type I), potentially resectable (Type II), and unresectable (Type III). The definition of resectable is: the primary gastric foci do not invade adjacent organs and lymph node metastases can be cleared; 1-3 liver metastases with a maximum diameter of ≤4 cm (or the lesions are confined to one lobe of the liver) and do not involve important blood vessels and bile ducts. For potentially resectable patients who are not initially eligible for surgery, they can undergo targeted and systemic chemotherapy followed by tumor evaluation to determine whether they can undergo two-step resection. Targeted combination chemotherapy based on pathological molecular staging For patients with liver metastases from gastric cancer who are not initially eligible for surgical resection, systemic chemotherapy is currently the main treatment strategy. Before treatment, molecular typing of gastric cancer is performed, and individualized treatment plans are formulated based on the histopathological type and the results of genetic testing. HER2-positive gene is a unique case subtype of gastric cancer, and the treatment strategy used is different from that of HER2-negative patients with advanced gastric cancer. Because HER2-positive patients with liver metastases from gastric cancer can benefit from trastuzumab-targeted therapy, trastuzumab combined with fluorouracil/capecitabine + cisplatin is the preferred chemotherapy regimen for first-line treatment in this group of patients. For HER2-negative patients, the recommended regimen is mainly a two-drug chemotherapy regimen with fluorouracil and platinum or paclitaxel. For now, there is a lack of effective targeted drugs for the treatment of HER2-negative gastric cancer patients, and patients are encouraged to actively participate in clinical research. The anti-angiogenesis-targeted drug ramolutumab (anti-VEGFR2) alone or in combination with paclitaxel is approved by the US FDA for second-line treatment of patients who have failed first-line chemotherapy. However, ramolutumab is not yet available in China. Apatinib mesylate is a highly selective VEGFR-2 small molecule tyrosine kinase inhibitor. Previous clinical studies have shown that apatinib can prolong the overall survival of patients with advanced gastric cancer and improve the disease control rate compared with placebo, and it is currently approved as third-line targeted therapy for advanced gastric cancer in China. Immunotherapy There are also new breakthroughs in immunotherapy for gastric cancer in the past two years. Among gastric cancer patients, those with advanced gastric cancer with a combined PD-L1 positive score (CPS) >1 on pathological tissues or positive MSI-H/dMMR on genetic testing benefit more from the application of PD-1/PD-L1 immunotherapy. 2020 ASCO annual meeting was updated with the results of the Asian subgroup analysis of the KEYNOTE-062 study of first-line immunotherapy for advanced gastric cancer, and the data showed that in survival of pablizumab-treated patients was superior to systemic chemotherapy in both the Asian subgroup of patients with CPS ≥ 1 and patients with CPS ≥ 10. In another EPOC1706 study of the multitarget inhibitor lenvatinib in combination with pabrolizumab, 29 patients (27 MSS (microsatellite stable) and 2 MSI (microsatellite unstable); 14 were treated in first line and 15 in second line, with an overall efficiency of 69%. The efficiency was even higher in patients with PD-L1CPS ≥1, reaching 84% (n=19). Currently, pablizumab and nabulizumab are approved as third-line treatment for advanced gastric cancer in the United States and Japan. 4 Ablation- and intervention-based local treatment of the liver For local treatment, local radiofrequency/microwave ablation is recommended for patients who present with liver metastases from gastric cancer, if the number of metastases is small and the lesions are less than 3 cm. Previous studies have shown that patients with liver metastases from gastric cancer treated with ablation have comparable survival time with fewer complications and adverse effects compared with local palliative surgical resection. For patients with liver metastases from gastric cancer, ablation therapy followed by further combined chemotherapy is required and can significantly prolong the survival of patients. For patients with a large number of intrahepatic metastases, if the effect of systemic chemotherapy is not satisfactory, hepatic artery chemoembolization or hepatic artery perfusion chemotherapy can be considered. Interventional therapy can increase the local concentration of chemotherapeutic drugs in the tumor microenvironment and improve the local tumor control rate, while the systemic adverse effects are less than those of chemotherapy. Summary In recent years, the treatment of digestive system tumors, including gastric cancer, has entered the era of individualized treatment, precise treatment and comprehensive treatment. Combining various effective treatment strategies such as chemotherapy, targeted immunotherapy, and local therapy and applying them individually to different patients can better improve the survival of patients with advanced gastric cancer and enhance the quality of survival.