What is the incidence of upper gastric cancer among stomach cancers? Gastric cancer is one of the most common cancers in the world, and it should be ranked third in the world, and second in terms of both incidence and death. The incidence of gastric cancer in China is about 40 per 100,000 per year, and the incidence of gastric cancer in the world is about 900,000 per year, of which China accounts for 47%. The incidence of gastric cancer is increasing globally. Gastrointestinal tumor surgery accounts for 40%-45% of patients with upper gastric cancer, which means that the proportion of upper gastric cancer is getting higher and higher. Which part of the stomach is diseased in upper gastric cancer? From the point of view of anatomical structure of stomach, stomach can be divided into upper, middle and lower parts. Cancer that occurs in the lower part of stomach is usually called distal gastric cancer, while cancer that occurs in the upper part of stomach is called upper gastric cancer. What is the difference between upper gastric cancer and distal gastric cancer? Firstly, the lesion sites are different; secondly, the pathogenesis and pathological patterns are different, which determines the treatment options and prognosis of these two types of gastric cancer are also different. Generally speaking, due to the different lymph node metastasis patterns of upper gastric cancer and distal gastric cancer, distal gastric cancer can usually be treated by resection of most of the distal stomach, with a part of gastric tissues remaining; whereas the standard surgical treatment for upper gastric cancer is the resection of all gastric tissues. Meanwhile, the difference in surgical methods will make the patients’ quality of life different, for example, distal gastric cancer patients with residual gastric tissues after surgery are prone to gastroesophageal reflux and other surgical complications. Overall, the 5-year survival rate of gastric cancer patients who can be treated by surgery in China is 45%~50%. Among them, compared with distal gastric cancer, the average 5-year survival rate of patients with upper gastric cancer is 10-15% lower, which means that the treatment effect of upper gastric cancer is worse or the prognosis of upper gastric cancer is worse. Why total gastrectomy is needed for upper gastric cancer? Currently, the standard surgery for distal gastric cancer is radical lymph node dissection at the second station, i.e., in addition to removing part of the gastric tissue, the related lymph nodes at the first and second stations are also removed, that is to say, distal gastric cancer can be cleared of the lymph nodes at the second station while preserving part of the gastric tissue. For upper gastric cancer, the removal of second station lymph nodes also includes a part of lymph nodes of distal gastric tissue as well as the 6th and 10th lymph nodes, which are prone to recurrence and lymph node metastasis if they are not removed cleanly without total gastrectomy. From here, it can also be seen that the malignancy degree and metastatic recurrence rate of upper gastric cancer is higher than that of distal gastric cancer.