I. Treatment principles of gastric cancer 1. Early gastric cancer with no evidence of lymph node metastasis can be treated by endoscopic treatment or surgery according to the depth of tumor invasion, without adjuvant radiotherapy or chemotherapy after surgery. 2. Early gastric cancer with localized progressive stage or lymph node metastasis should be treated mainly by surgery. Depending on the depth of tumor invasion and whether it is accompanied by lymph node metastasis, direct radical surgery or preoperative neoadjuvant chemotherapy can be considered before radical surgery. Adjuvant treatment plan (adjuvant chemotherapy and, if necessary, adjuvant chemoradiotherapy) should be decided according to the postoperative pathological stage for locally progressive gastric cancer that has been successfully performed radical surgery. 3. Recurrent/metastatic gastric cancer should be treated with a comprehensive treatment based on drug therapy, and local treatment such as palliative surgery, radiotherapy, interventional therapy, radiofrequency therapy should be given at the appropriate time, and the best supportive treatment such as pain relief, stent placement and nutritional support should also be actively given. Common types of gastric cancer surgery Surgery is an important part of gastric cancer treatment. There are many surgical procedures for gastric cancer, which are summarized as follows: 1. Endoscopic mucosal resection and endoscopic submucosal resection: its main indications are highly differentiated or moderately differentiated, non-ulcerated, less than 2 cm in diameter, and intra-mucosal cancer without lymph node metastasis.
According to the current situation in China, it is difficult to carry out this treatment in clinical application. The main reasons are: ① ultrasonic gastroscopy is not yet popular in China, so the depth of tumor infiltration and lymph node metastasis around the stomach are difficult to be accurately evaluated before surgery; ② even intramucosal cancer has a lymph node metastasis rate of 3%-8%, which is a potential risk; ③ the medical standard in China varies. Gastric D1 resection: It is suitable for intramucosal cancer with diameter over 2cm and gastric cancer invading the submucosa. Once lymph node metastasis appears, D2 resection should be performed. Therefore, for early gastric cancer, the intraoperative judgment of whether there is lymph node metastasis becomes an important basis for choosing a reasonable surgical method. 2. Standard surgery: D2 radical surgery is the standard surgery for gastric cancer, and the standard surgery (D2 radical surgery) should be performed if the depth of tumor infiltration exceeds the submucosa layer (muscle layer or above), or if there is lymph node metastasis but it has not yet invaded the adjacent organs. D2 radical surgery for gastric cancer not only fully resects the lesion, but also completely contours the perigastric lymph nodes at stations 1 and 2, and performs extra-retinal bursal resection of large and small omentum and stomach, etc. The whole procedure is performed according to the principle of tumor resection, and lymph node dissection and gastric tumor resection are completed simultaneously. The whole procedure is done according to the principle of tumor resection, and lymph node dissection and gastric tumor resection are completed simultaneously. If the tumor directly invades the perigastric organs, expanded combined organ resection is feasible. 3.Expanded surgery: If the primary gastric cancer or metastasis directly invades the perigastric organs (T4) or lymph node metastasis reaches far away from N2, radical resection is still possible; the scope of resection is combined organ resection and/or D2 plus (or) D3 lymph node dissection, and the stage of disease is IIIa, IIIb and part of IV. 4.Palliative surgery: It is only applicable to those who have distant metastasis or tumor invading important organs that cannot be removed and combined with bleeding, perforation, obstruction and other conditions. Palliative surgery is aimed at relieving symptoms and improving quality of life.