Gastric cancer is a common solid tumor. Among solid tumors, the lymphatic metastasis rate of gastric cancer is high while the hematogenous metastasis rate is relatively low, and how to control gastric cancer locally is still a major problem in the treatment of gastric cancer. Therefore, the surgical treatment of gastric cancer has an irreplaceable position in the treatment of gastric cancer so far. As early gastric cancer accounts for only 7.5% of gastric cancer cases found in China, and most of them are progressive gastric cancer, it is especially important to perform standardized radical gastric cancer surgery. The standardization of gastric cancer surgery refers to the concretization of the principles of gastric cancer surgery, which refers to the selection of the best surgical treatment plan according to the different stages, preoperative status, intraoperative conditions and even different hospital conditions and doctors’ level of the patient. Some concepts of radical gastric cancer surgery have also changed, formerly R stands for “radical” which is the abbreviation of Radical, but now R refers to the residual tumor after surgery, which is the abbreviation of Residual. The degree of lymphatic clearance surgery is indicated by D, which is the abbreviation of Dissection. D0 means the first station lymph nodes were not completely cleared; D1 means the first station lymph nodes were cleared; D2 means the first and second station lymph nodes were cleared; D3 means the first, second and third station lymph nodes were cleared. The 13th edition of the Japanese statute for the management of gastric cancer divided the regional lymph nodes into 3 stations, N1, N2, and N3, based on the tumor site, and classified the lymph nodes beyond the region as distant metastasis (M1) and removed N4. Accordingly, lymph node clearance was divided into D0, D1, D2, and D3, and D4 clearance was eliminated. However, the scope of D2 and D3 clearance in the 13th edition has been expanded compared with that in the 12th edition. I. Early gastric cancer Early gastric cancer refers to gastric cancer that occurs in the mucosa (M) and submucosa (SM) of the stomach. The study of early gastric cancer has been reported more in Japan. In various statistics, the recurrence rate of early gastric cancer is close to 10%. Recurrence after treatment of early gastric cancer is mainly due to the presence of a certain rate of lymph node metastasis in early gastric cancer. 2.3% of lymphatic metastasis was reported by Shimada et al. for intramucosal cancer, which was basically N1 metastasis, and 19.8% for submucosal cancer, which was N1 and N2 metastasis. The difficulty of preoperative and intraoperative diagnosis of lymphatic metastases makes the choice of surgical approach problematic. For intramucosal carcinoma, studies have found that lymph node metastasis occurs essentially in cases with ulcer formation or ulcer scarring. It is now believed that although the mucosal layer of the stomach does not contain lymphatic tissue, submucosal lymphatic vessels can invade into mucosal tumors during the healing, inflammation and vascularization of ulcers, scars and granulomas, resulting in the metastasis of intramucosal cancer. A study on submucosal early gastric cancer found that if the submucosal layer was divided into 3 equal parts SM1, SM2 and SM3, and then SM1 was divided into SM1a and SM1b, the lymphatic metastasis rate of SM1b, SM2 and SM3 layers was significantly higher than that of SM1a layer. Knowledge of the above studies helps us to select the surgical approach. Endoscopic mucosal resection (EMR) is only suitable for well-differentiated intramucosal carcinoma without ulceration or scar formation, and the diameter is usually not more than 3 cm; for other M carcinomas, D1 clearance should be performed; for SM carcinomas, except for SM1a, D1 clearance can be chosen, and other types of SM carcinomas should be chosen for D2 clearance. Considering the survival quality of patients, partial gastrectomy with or without pylorus preservation should be performed for early gastric cancer. The research on early gastric cancer in China is still immature, and there are still some problems in early gastric cancer surgery. One is the problem of preoperative diagnosis. Many hospitals are not yet mature in endoscopic ultrasound (EUS) and pathological diagnosis, and the diagnosis of early gastric cancer should be cautious. Secondly, in terms of treatment, when the diagnosis is not yet perfect, minimally invasive and quality of survival (QOL) cannot be pursued at the expense of survival of some patients. Therefore, the diagnosis and treatment of early gastric cancer need to be further standardized, and minimally invasive treatment of early gastric cancer should be limited to experienced hospitals. Progressive gastric cancer The main goal of surgery for progressive gastric cancer is to achieve R0 resection in order to prolong the patient’s survival as much as possible. In gastric cancer surgery, lymphatic debridement occupies an important position, firstly, because among solid tumors, gastric cancer has more lymphatic metastases and less hematogenous metastases; in addition, recurrence of lymphatic metastases is also an important factor affecting the survival of gastric cancer patients. In terms of the scope of lymphatic clearance, there has been a debate between the East and the West, with Europe and the United States advocating D1 clearance, while Asian countries emphasizing more extensive clearance. The debate is mainly due to the Western view that complications and mortality after D2 and higher debulking are significantly higher than D1 debulking, and there is no evidence that D2 debulking increases the long-term survival of patients with gastric cancer, while in Eastern countries such as Japan, it is believed that expanded debulking improves survival and controls complications well, and most of the conclusions are also based on extensive retrospective analyses. The results of a multicenter randomized controlled study concluded that there was no significant difference in 5-year survival between D2 surgery and D1 surgery, whereas D2 surgery had higher postoperative complications, but there was a difference between D2 clearance and D1 clearance for patients with UICC stage II and stage IIIa. D2 debulking has now been adopted as a routine procedure for patients with feasible R0 resection gastric cancer in Asian countries and is also gradually recognized by Western scholars as the recommended standard procedure for patients with stage Ib, II, IIIa and some stage IIIb gastric cancers. For stage IV patients with N3 and T4N2, D3 debulking can be an appropriate choice for surgery, but due to the complexity of the operation, high complication rate and mortality, D3 surgery can only be performed in a few study centers and should not be a routinely recommended procedure. For progressive gastric cancer, D2 lymphatic dissection of gastric cancer is now tending to be accepted as the standard radical procedure for gastric cancer. D2 lymphatic dissection should be performed extracapsularly from the anterior lobe of the transverse mesentery to the pancreatic envelope, with resection of the anterior lobe of the transverse mesentery, greater omentum, and hepatogastric ligament of the pancreatic envelope, complete removal of the lymph nodes at stations 1 and 2, and ligation of the involved vessels at the root. Of note is the current emphasis on group 12 lymph node dissection in D2 dissection, i.e., pulsation of the hepatoduodenal ligament, especially for lower gastric cancer, where group 12 lymph node dissection reduces residual and increases the safety of duodenal resection [5]. Many scholars have suggested the inclusion of group 12 lymph node dissection in standard radical surgery for D2; and in the Japanese statute for gastric cancer, 12a lymphatic dissection has been included in the routine of D2 dissection for gastric cancer except for simple upper gastric cancer. Previously, splenectomy was often advocated for D2 surgery for upper gastric cancer, but now it is advocated that the spleen should be preserved as much as possible for stage I, II, and IIIa gastric cancer, unless the tumor invades the spleen or splenic hilum. In addition to increased postoperative complications due to splenectomy, studies have found that the spleen of gastric cancer patients has anti-tumor cytotoxic activity. In patients with lymph node metastasis in the splenic hilum, the 5-year postoperative survival rate was higher in the splenectomized group than in the unsplenectomized group; however, the 5-year survival rate in the prophylactic splenectomy group was lower than that in the spleen-preserving group. However, in stage IIIb and IV patients, increased endogenous PGE2 was found to inhibit lymphokine-activated killer cell activity; therefore, splenectomy may be beneficial in these patients.Okajima et al. reported 1-year and 5-year survival rates of pancreatic splenectomy for radical and palliative surgery when gastric cancer directly invades the pancreas to be 55.6% and 42.9% and 11.1% and 0, respectively.Therefore, palliative Maruyama et al [8] concluded that there is no possibility of lymphatic metastasis in the pancreatic parenchyma; therefore, unless the tumor directly invades the pancreas, pancreatic splenectomy is generally inappropriate. There is a basic consensus on the indications for total gastrectomy in patients with gastric cancer, including diffuse gastric cancer, trans-regional gastric cancer, upper gastric cancer with lymph node metastasis above and below the sinus, cancer in the sinus body involving the lymph nodes around the fundus and multicenter primary cancer, superficial extensive early cancer, etc. However, it is still controversial whether total gastrectomy should be performed for upper 1/3 of the stomach, because after all, the absence of stomach and nutritional problems after total gastrectomy has a greater impact on the patient postoperatively. Some scholars currently advocate upper 1/3 gastric cancer as an indication for total gastrectomy, but preserving the distal stomach is one of the surgical options for upper gastric cancer. The proportion of progressive gastric cancer at the time of diagnosis is high in China, and the surgery for gastric cancer in many hospitals still remains at the level of major gastric resection plus omentectomy, so it is imperative to vigorously promote the standard radical surgery for D2 gastric cancer. Hospitals with conditions can select appropriate cases for D3 surgery. For cases invading the spleen, splenic hilum and pancreas, pancreatic splenectomy must be performed; for tumors in the upper 1/3 of the large curved side of the stomach, the indications for resection of the spleen and the tail of the pancreas can be relaxed due to the high rate of metastasis of group 10 lymph nodes. In China, group 10 and 11 lymph node dissection with spleen and pancreas preservation is also being carried out, but only in a few large institutions with conditions. Palliative resection for gastric cancer Palliative resection for gastric cancer has been advocated since 1980s, and since then many reports have suggested that palliative resection for gastric cancer is beneficial to improve patients’ survival and postoperative quality of life. However, until now, almost the same number of scholars still believe that palliative resection for gastric cancer cannot bring any benefit to patients. To date, reports endorsing palliative surgery have been based on retrospective analyses, and many analyses have attributed postoperative microscopic residual gastric cancer to the palliative resection group compared with the failure to resect group, which is obviously difficult to obtain statistical support; in addition, subjective differences in retrospective analyses, such as the operator, the judgment of staging, and the judgment of whether resection is possible, are hardly convincing that the two groups of patients are comparable. Recently, Kahlke et al. analyzed the results of 169 cases of palliative surgery for gastric cancer, and he excluded from the analysis those who were considered radical surgery and were found to have microscopic residuals after surgery. Survival was shorter in those with severe preoperative symptoms, and tumor resection, lymphatic dissection, and splenectomy or not did not affect survival; whereas the quality of survival after surgery was significantly higher in the group with severe symptoms such as preoperative obstruction, perforation, and severe bleeding compared with the group with mild symptoms. Therefore, he believes that palliative surgery is necessary for patients with severe preoperative symptoms, while patients with mild preoperative symptoms should be carefully considered for surgery or not because they will not benefit from tumor resection, lymphatic dissection, or splenectomy. The proportion of patients with advanced gastric cancer is high in China, and there is currently a suspicion of overtreatment with surgery. We believe that patients with T4NxM0 and TxN3M0 should be treated with neoadjuvant chemotherapy as much as possible in order to achieve advancement of stage and obtain R0 resection. For those with preoperative bleeding, obstruction and other acute symptoms, palliative tumor resection or short-circuit surgery is necessary. It is still controversial whether postoperative chemotherapy is more favorable after tumor resection or volume reduction surgery, because studies have confirmed the effectiveness of chemotherapy alone for advanced tumors, while the blow to the patient from surgery is likely to be unfavorable to chemotherapy. Laparoscopic gastric cancer surgery With the development of minimally invasive surgery, laparoscopic gastric cancer surgery has been gradually carried out. At present, laparoscopic gastric cancer surgery mainly includes laparoscopic gastric mucosal resection, laparoscopic partial gastrectomy and laparoscopic assisted distal gastrectomy. They are mainly applied to mucosal cancer that is not suitable for endoscopic resection and early gastric cancer with good submucosal superficial differentiation, and D2 clearance for progressive gastric cancer is also being carried out experimentally. Kitano, the first to perform laparoscopic-assisted gastric cancer surgery, chose the indication for mucosal or submucosal early gastric cancer, and subsequently a certain number of reports have been published in Europe, America and Asia, even for stage II and III progressive gastric cancer. The advantages of laparoscopic-assisted gastric cancer surgery are less surgical bleeding, lower overall postoperative complication rate, faster recovery of gastrointestinal tract function, shorter average hospital stay, and less postoperative pain, but there are disadvantages such as longer average operative time, insufficient number of lymph node dissection, higher average cost, and certain learning curve required. The long-term results of laparoscopic gastric cancer surgery are still uncertain, and most of the reports are retrospective studies, with only three randomized studies on early gastric cancer and one on progressive gastric cancer, and the sample sizes of the studies are small. At present, laparoscopic gastric cancer surgery still cannot be used as a standard procedure for gastric cancer surgery because of the problems of operational level differences, inconsistent learning curves, differences in lymphatic clearance levels, non-blinded outcome assessment, and few randomized clinical trials, in addition to long-term outcome problems. in a Meta-analysis, Hosono et al. found that even if the learning curve of laparoscopic gastric cancer surgery was achieved, it was still difficult to reduce The average operation time and the number of lymph node dissection were difficult to increase, especially for lymphatic dissection on the side of the greater curvature of the stomach and the abdominal trunk and splenic artery, suggesting the complexity of laparoscopic surgery for gastric cancer. Currently, laparoscopic gastric cancer surgery has also been performed in China, but there are still many problems. First, many operators do not have a balanced grasp of the surgical oncology learning curve and laparoscopic learning curve. Secondly, laparoscopic gastric cancer surgery is currently mainly used for early gastric cancer, which requires us to establish a certain pathological and ultrasound endoscopic platform in order to strict the indications for surgery and reduce abuses. Laparoscopic gastric cancer surgery still needs a large sample of randomized controlled long-term studies to determine its long-term efficacy, and it cannot be used as the gold standard for gastric cancer surgery now, but can only be started experimentally under strict restrictions.