Elderly gastric cancer

　　How is elderly gastric cancer caused? Briefly described as follows:

　　The onset process of gastric cancer is long and complex. At present, no single factor has been proven to be the direct cause of human gastric cancer. Therefore, the occurrence of gastric cancer is related to many factors. Dietary factors are the focus of research, and some investigations have shown that high-salt, high-spice foods, polycyclic aromatic hydrocarbons produced during cooking, nitrosyl compounds, mycotoxins, some grains and food additives, etc., have carcinogenic effects.

　　Nitrosyl compounds Nitrosyl compounds

　　It is a large category of chemical carcinogens, among which non-volatile nitrosamine compounds such as N-methyl-N-nitro-N-nitrosoguanidine (MNNG), N-ethyl-N-nitrosoguanidine (ENNG) can induce gastric adenocarcinoma in rats and dogs, and precancerous lesions such as intestinal metaplasia and atypical hyperplasia of the gastric mucosa can be observed. Nitrosyl compounds that exist naturally are extremely微量. Their main source is the endogenous synthesis of nitrosyl compounds in the body. Nitrosyl compounds can also be synthesized under low pH conditions in gastric juice. When gastric mucosal lesions occur, such as atrophy of gastric glands, reduction of parietal cells, and increase in gastric juice pH value, bacteria in the stomach can accelerate the reduction of nitrates to nitrosyl compounds. It can be seen that the human gastric mucosa can be directly attacked by nitrosyl compounds under normal or damaged conditions.

　　2. Carcinogens of Polycyclic Aromatic Hydrocarbons

　　Can be contaminated food or formed during processing, such as Iceland, a high gastric cancer incidence country, where residents mainly live on fishing and pastoralism, and have the habit of eating smoked fish and smoked lamb. The analysis of the samples of smoked fish and smoked lamb found that these foods contain a large amount of carcinogens, including polycyclic aromatic hydrocarbons such as 3,4-benzo(a)pyrene. A large number of animal experiments have shown that experimental animals fed smoked food also obtained carcinogenic results.

　　3. Dietary Factors

　　The matched study of gastric cancer cases in China shows that high-salt diet, preserved food, fried food, irregular meal times, fast eating, overeating, liking to eat hot food, and other factors increase the risk of gastric cancer. The intake of high-concentration salt can damage the gastric mucosal barrier, causing edema of mucosal cells and loss of glands. At the same time, the intake of carcinogenic nitrosamines and high salt can increase the incidence of gastric cancer, with a shorter induction time and a promoting effect on the occurrence of gastric cancer.

　　4. Helicobacter pylori

　　Helicobacter pylori infection is related to gastric cancer, based on the following reasons: Helicobacter pylori is rarely isolated from normal gastric mucosa, and the infection rate increases with the aggravation of gastric mucosal lesions. Currently, it is believed that Helicobacter pylori is not a direct carcinogen for gastric cancer, but a condition factor that promotes the development of lesions through gastric mucosal injury, increasing the risk of gastric cancer. Helicobacter pylori can release various cytotoxic and inflammatory factors and participate in local immunity. The positive rate of Helicobacter pylori antibodies in the serum of gastric cancer patients before the disease is significantly higher than that of the control group, making it a risk factor for gastric cancer.

　　In addition, smoking, heredity, psychological factors, trace elements, some chronic gastric diseases such as chronic atrophic gastritis (CAG), gastric mucosal intestinal metaplasia (IM), and atypical hyperplasia (DYS), are also related to the occurrence of gastric cancer.

　　What diseases can elderly gastric cancer trigger? The following is a brief description:

　　1. Gastric Hemorrhage

　　Gastric hemorrhage after gastric cancer surgery is mostly due to anastomotic hemorrhage, and the reason is often that the blood vessels are not completely sealed during the suture of the gastric wall, especially in the case of shallow or not tight full-thickness suture. Sometimes, the bleeding of gastric wall blood vessels into the mucosa is not easy to detect. In recent years, some poor-quality staplers have closed or anastomosed the gastric wall during surgery, but delayed hemorrhage can still occur. In addition, stress ulcer is also a common cause of postoperative gastric hemorrhage. The hemorrhage caused by it can be diffuse, and the blood color is often coffee-colored or dark red, usually lasting for 3-5 days.

　　2. Anastomotic Fistula

　　Anastomotic fistula is a relatively serious complication after gastric cancer surgery, and its incidence has decreased due to the application of staplers and the improvement of surgical techniques in recent years. The reasons for the occurrence of anastomotic fistula after gastric cancer surgery are mostly tissue edema, malnutrition, and lack of anastomotic technique. Generally speaking, anastomotic fistula occurring 2-3 days after surgery is mostly due to surgical technique; while those occurring 7-9 days later are often due to other comprehensive factors.

　　3. Intestinal Obstruction

　　Intestinal obstruction occurring after gastric cancer surgery is relatively complex, including functional intestinal obstruction and mechanical intestinal obstruction. Most of the functional intestinal obstruction occurs around 10 days after gastric cancer surgery, but it is not absolute.

　　4. Gastric ileus

　　Gastric ileus is one of the more common complications after gastric cancer surgery, and it often occurs when the completeness of surgery is higher, which may be related to vagotomy and changes in gastric tone. It often occurs when the patient starts eating or the diet structure changes, with symptoms such as bloating, chest tightness, and discomfort in the upper abdomen.

　　5. Other

　　Other common complications after gastric cancer surgery include reflux esophagitis, dumping syndrome, and postoperative infection, etc., which should also be treated symptomatically.

　　What are the symptoms of elderly gastric cancer?

　　1. Symptoms of gastric cancer

　　1. Early gastric cancer

　　Early gastric cancer has no specific symptoms, even without any symptoms, and early gastric cancer without gastrointestinal symptoms can account for 1/4. Statistics of gastric cancer cases in China show that less than 1/3 of patients are diagnosed with gastric cancer within 3 months after the onset of symptoms. When the following atypical symptoms occur, the possibility of gastric cancer should be considered, and further examination should be carried out:

　　(1) Patients over the age of 40 with unexplained anorexia, epigastric discomfort, weight loss, and other symptoms.

　　(2) Patients with hematemesis, melena, or positive occult blood in stool of unknown etiology.

　　(3) Patients with a history of long-term chronic gastric disease, with a significant increase in symptoms in recent days.

　　(4) Patients with gastric ulcer, gastric polyps (especially adenomatous polyps), atrophic gastritis (especially with intestinal metaplasia, atypical epithelial hyperplasia, and other precancerous lesions), and residual stomach.

　　2. Advanced gastric cancer

　　As the patient's condition progresses, the development accelerates, and the symptoms gradually worsen over a period of several months. Generally, gastrointestinal symptoms include persistent epigastric pain, fullness, anorexia, nausea, vomiting, melena, and other symptoms. Symptoms related to the tumor site can also occur, such as gastric antrum cancer, which is often located on the lesser curvature, with early onset of upper abdominal pain of varying degrees. When cancer of the cardia appears, there may be discomfort under the xiphoid process or behind the sternum, with difficulty in eating, hidden pain, and progressive worsening, along with progressive dysphagia, vomiting, and regurgitation of mucus. If there is cancer near the pylorus or pyloric canal, due to tumor compression, the symptoms of pyloric obstruction may occur. Some patients may experience acute gastrointestinal bleeding and diagnosis is made only when there is a gastric perforation. As the condition further progresses, an abdominal mass can be palpated, ascites and jaundice can be found, as well as significant weight loss, weight loss, fatigue, edema, anemia, and cachexia, etc.

　　2. Signs

　　Early gastric cancer does not show positive signs during abdominal examination, so physical examination is not helpful for early diagnosis. When entering the advanced stage (middle and late stage), there may be epigastric tenderness, fullness, or nodular mass in the gastric area, with hard texture and relatively fixed, and the surface is uneven and nodular. When cancer in the pyloric area causes obstruction, an expanded gastric shape can be seen, with a splash sound, and the upper abdomen is prominent and full. Invasion into the pancreas, especially the head of the pancreas, and the ligamentum hepatoduodenale, can lead to compression of the common bile duct by the retroperitoneal lymph nodes of the pancreas and duodenum, resulting in obstructive jaundice. When there is intrahepatic metastasis, the liver is large with uneven surface nodules, hard texture, and can also be accompanied by jaundice. Peritoneal implantation can produce ascites, which is mostly hemorrhagic. Metastasis to the small intestine, colon, and mesentery can cause intestinal obstruction, with peristaltic waves in the intestinal shape. In female patients, metastasis to the ovary is known as Krukenberg tumor. Distant lymph node metastasis can cause enlargement of the left supraclavicular or both supraclavicular lymph nodes, and the presence of these signs indicates that the patient has entered the middle and late stages, and most have lost the opportunity for radical surgery.

　　How to prevent the occurrence of gastric cancer in the elderly? Briefly described as follows:

　　Third-level prevention

　　Efforts should be made to control and exclude known suspected carcinogenic factors, eliminate the causes to reduce the incidence, which is also known as level I prevention.

　　Level I Prevention

　　(1) Paying attention to dietary hygiene: It should be avoided to eat刺激性饮食 excessively, to moderate alcohol consumption, to have regular meals, and to prevent overeating to reduce the occurrence of gastritis and gastric ulcers.

　　(2) Frozen preservation: After changing the food preservation methods from traditional salt curing or smoking (which contains carcinogenic benzopyrene compounds) to frozen preservation storage, the incidence of gastric cancer has continued to decline.

　　(3) Avoiding high-salt diets: High-salt diets can destroy the mucus protective layer of the gastric mucosa, making the gastric mucosa exposed and easily damaged, and more likely to come into contact with carcinogens. Therefore, the intake of salt in the diet should be reduced. Therefore, the daily salt intake should be controlled below 10g, with about 6g being appropriate.

　　(4) Regularly consuming fresh vegetables and fruits: It is known that nitrosamine compounds can be synthesized in the stomach under the action of low acid and bacteria. The nitrates or nitrites entering the stomach through food can combine with amines to form carcinogenic nitrosamines, while vitamin C can break this synthesis process, thereby helping to prevent gastric cancer.

　　(5) Consuming more milk and dairy products: In recent years, the Japan Cancer Research Society has found that the incidence of gastric cancer is negatively correlated with the consumption of milk and dairy products. The reason is that milk contains vitamin A, which helps in the repair of mucosal epithelium.

　　(6) Increasing the intake of protein in food: The protein content in meats, fish, beans, and other foods is high. Studies have shown that insufficient protein intake and malnutrition are prone to gastric cancer.

　　(7) Quitting smoking: A long-term prospective study by Takashi Hashimoto in Japan believes that smoking is a strong carcinogenic risk factor, and its risk is related to the age of starting smoking and the amount of smoking.

　　Level II Prevention

　　Through censuses in the natural population or regular follow-up checks of susceptible individuals, early detection, timely treatment, and reduction of mortality rate, i.e., level II prevention, can be achieved. It is necessary to clearly identify high-risk populations for gastric cancer. When establishing high-risk individuals, it should be closely related to local living habits and environmental conditions, such as whether they have a low-protein diet, a history of consuming unfresh food or moldy food rich in nitrosamines, a preference for fried, smoked, or preserved food, a lack of fresh vegetables and fruits, and the quality of drinking water. In addition, the family history of gastric cancer is also an essential factor to consider. Individuals with clinical symptoms should be paid special attention, especially when symptoms are prominent or there are signs such as vomiting blood, black stools, or masses in the upper abdomen, regular checks should be carried out. Gastric ulcers that do not heal for a long time or have severe scar tissue, atrophic gastritis with intestinal metaplasia and severe atypical hyperplasia, and multiple polyps or solitary polyps with a diameter greater than 2cm should all be listed as objects for regular clinical follow-up checks.

　　3. Tier 3 Prevention

　　Active treatment of various precancerous lesions is recommended. It is now known that patients with atrophic gastritis, gastric polyps, gastric ulcers, and those who have undergone subtotal gastrectomy have a higher incidence of gastric cancer. Therefore, for patients with a long history and a clear diagnosis of the above conditions, regular follow-up examinations should be conducted. If symptoms do not improve after systematic internal medicine treatment for 3 months, early fiberoptic endoscopic examination should be performed to clarify the pathological diagnosis, and surgical resection may be necessary if indicated.

　　2. Risk Factors and Intervention Measures

　　High-salt diet and Helicobacter pylori infection are the main factors causing initial lesions of the gastric mucosa. Gastric cancer is a chronic disease with a long onset process. Therefore, preventive work at all stages can reduce the risk of gastric cancer or delay its onset. It is recommended to promote low-salt diet, combat Helicobacter pylori infection, improve nutritional levels, block the synthesis of nitrosamines, enhance the repair capacity of gastric mucosal damage, and treat precancerous lesions including chronic atrophic gastritis, gastric polyps, gastric ulcers, and residual stomach, which are important measures for preventing gastric cancer. There should be planned follow-up and regular re-examinations. Endoscopic examination should be conducted every six months. In population screening, it has been reported that occult blood in stool is used as one of the initial screening methods. The diagnosis of gastric cancer is a key link in prevention and treatment. Early detection is not easy, as early gastric cancer has no typical symptoms, and population screening is not easy to implement on a large scale. Monitoring and follow-up of precancerous disease patients are effective measures for early diagnosis. Rational selection of examination methods and prompt pathological diagnosis are essential. Where conditions permit, population screening can be conducted using endoscopy as a means of detailed examination. Endoscopy helps determine the depth of cancer infiltration and the presence of metastasis, providing a basis for surgery. Imaging diagnosis, including ultrasound, CT, and magnetic resonance, is of great value in determining the presence of metastasis. Tumor markers such as CEA, CA19-9, and CA72.4 have certain value in the diagnosis of gastric cancer and are even more valuable in prognosis monitoring and recurrence detection.

　　3. Community Intervention

　　The community should promote health and hygiene in food consumption in various forms, avoid or reduce the intake of possible carcinogenic substances, store food for freezing and preservation, and eat more vegetables and fruits rich in vitamin C. Close follow-up should be conducted on high-risk populations with precancerous changes in gastric cancer and genetic factors, with regular checks to detect changes early and receive timely treatment.

　　What should be done for the examination of elderly gastric cancer? Briefly described as follows:

　　One, Laboratory examination

　　Routine laboratory tests are not important for early diagnosis and confirmation. In order to understand the condition of the disease and decide the treatment plan, observe and detect the toxic effects of chemotherapy, regular examination of blood routine including total white blood cell count, hemoglobin, and platelet count, urine routine, and occult blood in feces, as well as the normality of liver and kidney function is necessary.

　　Two, Serum enzyme tests

　　In clinical practice, it can be used for early diagnosis, therapeutic effect observation, and prognosis monitoring, and has auxiliary value. Pepsinogen (pepsinogen, PG) is a digestive enzyme precursor secreted by the gastric mucosa and can be divided into PCⅠ and PGⅡ two subtypes. The normal gastric mucosa is 1:1 for PGⅠ/PGⅡ. In atrophic gastritis, it decreases, and when PGⅠ decreases significantly, it indicates an increased risk of intestinal-type gastric cancer. The activity of alkaline phosphatase (ALP) increases in patients with gastric cancer and is divided into 5 isoenzymes, of which AIP2 comes from the liver, and an increase may indicate the possibility of liver metastasis.

　　Three, Imaging examination

　　1. X-ray examination

　　(1) Barium meal gastroscopy: This is a traditional method of gastric examination that utilizes the contrast shadow produced by barium sulfate against the gastric wall for diagnosis. The main X-ray signs of gastric cancer in barium meal gastroscopy include ulcer shadows, filling defects, changes in mucosal folds, abnormal motility, and obstructive changes. This ancient traditional method of gastric examination has now been gradually replaced by double-contrast gastroscopy.

　　(2) Double-contrast gastroscopy: Double-contrast gastroscopy is a method of examination that simultaneously injects two different types of contrast agents, low viscosity high concentration barium sulfate and gas (air or CO2), into the stomach for透视 and photography.

　　(3) X-ray diagnosis of other gastric malignant tumors:

　　A. Malignant lymphoma generally has a larger range, with明显 thickened and irregular gastric mucosa, sometimes with ulcer shadows, and the mucosal interruption and destruction at the edge of the ulcer shadows.

　　B. Smooth muscle sarcoma (Leiomyosarcoma) Smooth muscle sarcoma is a submucosal tumor, which can be seen as a relatively smooth filling defect in the stomach, often with a mucosal bridge above, and local gastric villi can still be seen. When the lesion progresses to the gastric mucosa, local ulcer shadows can be observed.

　　2. CT examination

　　Early gastric cancer with localized thickening over 5mm can be detected, and when it exceeds 1cm, it can be clearly displayed. CT can observe the 3-layer structure of the gastric wall, which is equivalent to the mucosal layer, submucosal layer, and serosal muscle layer. Most scholars adopt Moss's CT staging; stage I intraluminal mass, 1cm thickening of the gastric wall, no extragastric invasion, stage I and II are estimated to be surgically resectable, stage III thickening of the gastric wall with extragastric invasion, no distant metastasis, and stage IV with distant metastasis.

　　3. Ultrasound examination of gastric cancer

　　4. Gastroscopy

　　In the mid-1980s, the research on electronic gastroscopy was successful. The imaging adopts a micro camera system, which is directly displayed on the screen and can be recorded, printed, and photographed. It can directly visualize the gastric mucosal lesions and take living tissue samples, which can accurately make the final pathological diagnosis and is irreplaceable by any other examination method in the diagnosis of gastric cancer.

　　4. Radioisotope examination

　　The following is a brief description of the dietary principles for elderly gastric cancer patients:

　　1. Do not eat salted, smoked, roasted, and fried foods, especially charred and carbonized foods.

　　2. Adhere to a low-fat diet, often eat some lean meat, eggs, and yogurt.

　　3. Foods should be kept fresh, and do not eat moldy and deteriorated foods.

　　4. Resolve to quit harmful smoking and drinking habits, keep the bowels通畅, and constipated patients should eat fiber-rich foods and drink some honey every day.

　　5. Eat more coarse grains and杂粮, such as brown rice, corn, whole wheat bread, and eat less refined rice and flour.

　　6. Often eat nutritious dry fruits and seeds, such as sunflower seeds, sesame seeds, pumpkin seeds, watermelon seeds, peanuts, walnuts, dried apricots, almonds, raisins, etc. These foods are all very good.

　　The following is a brief description of the treatment methods for elderly gastric cancer:

　　1. Treatment

　　1. Routine treatment

　　(1) Surgical treatment: Surgical operation is the main means of treating gastric cancer and the only method that can cure gastric cancer at present. For a long time, due to the late stage of gastric cancer patients admitted to the hospital, the efficacy of gastric cancer surgical treatment has not been satisfactory. According to the statistics of Chinese Gastric Cancer Research Association on Chinese data since 1987, the average 5-year survival rate after radical resection of gastric cancer has increased to 37%.

　　① For early gastric cancer without lymph node metastasis in stages I and II, and for intermediate gastric cancer not invaded the serosal layer (T2), R1 surgery can be performed (complete resection of N1 station lymph nodes), with a margin of at least 3-4 cm from the visible tumor margin to prevent residual disease.

　　② For stage I and II gastric cancer with N1 lymph node metastasis, R2 surgery can be performed (complete resection of N1 and N2 stations of lymph nodes).

　　③ For stage III gastric cancer with serosal invasion and N2 lymph node metastasis, or N2, N3 lymph node metastasis, expanded R2+ or R3 surgery can be performed (complete resection of N1, N2, N3 lymph nodes).

　　④ For stage IV gastric cancer that invades surrounding organs (pancreas, transverse colon, liver) with N3 lymph node metastasis and is estimated to be resectable, perform R3 combined resection with the invaded organs. When widely invaded surrounding organs, and invaded N3 lymph nodes and distant lymph nodes, extensive peritoneal and obvious liver metastasis, only palliative resection, conversion surgery, or only exploratory surgery can be performed.

　　⑤ Resection of the primary tumor: In recent years, there has been a consensus on the extent of gastric resection. The gastric transection line should be at least 5 cm away from the visible tumor margin, and the distal part of the cancer should be resected about 3-4 cm of the first part of the duodenum, while the proximal part of the cancer should be resected about 3-4 cm of the lower end of the esophagus.

　　(2) Radiotherapy: Gastric cancer is insensitive to radiation, while the adjacent organs of the stomach, such as the liver, pancreas, and kidneys, are relatively sensitive to radiation, which limits the application of radiotherapy. In comprehensive treatment, it has certain value as an adjuvant treatment measure. Preoperative radiotherapy can improve the resection rate of surgery, and intraoperative radiotherapy can help eliminate subclinical cancer foci remaining in the surgical field. Radiotherapy can also be used for localized cancer foci or localized residual lymph node metastases after palliative resection.

　　(3) Medical treatment

　　① Auxiliary chemotherapy for gastric cancer: According to the biological characteristics of cancer cells, surgery cannot completely remove the subclinical metastatic foci and cancer cells that exist after surgery. The subclinical metastatic foci that cannot be detected by surgery are the main sources of postoperative recurrence. Therefore, adjuvant chemotherapy before, during, and after surgery is necessary. The purpose of preoperative chemotherapy (neo-adjuvant chemotherapy) is to localize the tumor so as to facilitate complete resection. Inhibition of the biological activity of cancer cells is conducive to reducing the spread during surgery, eliminating subclinical cancer foci, and reducing the recurrence rate after surgery. The purpose of intraoperative chemotherapy is to eliminate residual cancer foci, while postoperative adjuvant chemotherapy is to prevent recurrence and metastasis and improve the 5-year survival rate.

　　② Immunotherapy: According to the view of modern immunology and the fact that tumor chemotherapy cannot completely eliminate tumor cells, biological therapy should help to deal with postoperative subclinical metastasis. There have been no successful reports on the active immunotherapy of gastric cancer. Recently, it has been introduced that patients are pre-treated with doxorubicin 30mg, then immunized with autologous gastric cancer cells, supplemented with FT-207 and BRM. In 20 patients with stage IV gastric cancer who underwent non-radical surgery, the survival period was prolonged. Passive immunotherapy of gastric cancer such as LAK, TIL cells, etc., has been used in the treatment of gastric cancer, and it is hoped that positive results can be achieved.

　　③ Endoscopic treatment

　　A, Local drug injection: It is a palliative treatment method, which can directly inject anticancer drugs, immunomodulatory drugs, and sclerosing agents into the tumor site to kill the tumor. If there is a cancerous stricture, the injection method can also be used to relieve symptoms. Commonly used drugs include mitomycin (MMC), fluorouracil, and bleomycin. Complications include the formation of local ulcers, with perforation being rare.

　　B, Peritoneal perfusion chemotherapy: In advanced gastric cancer, peritoneal implantation metastasis can cause ascites. The local concentration of anticancer drugs injected into the peritoneum is greater than the plasma concentration, reaching more than 20 times, thereby causing mild systemic reactions and strong local antitumor effects. Anticancer drugs can be directly administered to the tumor cells to kill them, and at the same time, it thickens the peritoneum, inhibits adhesion, and suppresses the production of ascites. However, complications such as intestinal adhesion and intestinal obstruction can occur.

　　C, Endoscopic resection and microwave coagulation therapy: Suitable for early gastric cancer with early lesions, no lymph node metastasis, and can achieve radical cure by local resection; or early gastric cancer in elderly patients, those with surgical contraindications, or those who refuse surgery, with tumor size less than 2cm in the elevated type and less than 1cm in the concave type. Under endoscopy, high-frequency electrocoagulation resection is used, with methods such as saline injection sheath resection, traction sheath resection, and negative pressure aspiration resection. After surgery, local ulcers form, which heal after 4 to 6 weeks. This method is safe, with few severe complications, and bleeding and perforation are rare. The cure rate of resection can reach 95%. Microwave coagulation therapy uses multiple-point radiation on the lesion. The indications for early cancer are the same as for resection. The microwave is emitted at the tip of the wire, and the local cancer tissue absorbs energy and converts it into heat to produce tissue coagulation.

　　2. Rehabilitation Treatment

　　The prognosis of stomach cancer depends on clinical staging and pathological type. For the malabsorption syndrome in patients after stomach cancer surgery, high-calorie, easily digestible nutrients should be provided, and attention should be paid to the supplementation of B vitamins. Encourage patients to eat more, and patients with difficulty in eating and obstruction can be given parenteral nutrition support treatment. For mixed anemia caused by poor absorption of iron and vitamin B12 or folic acid deficiency, supplementation should be given through extraintestinal routes.

　　Second, Prognosis

　　Many factors affect the prognosis of stomach cancer, including age, gender, disease stage, pathological type, and treatment type. Generally speaking, the efficacy of elderly patients is better than that of young patients; female patients seem to have a longer survival time than male patients; if stomach cancer is staged according to TNM: the 5-year survival rate of stage I is >79%, stage II is 50%, stage III is 10%, and stage IV has a very low 5-year survival rate; the prognosis of intestinal-type stomach cancer is better than that of diffuse-type, and intestinal-type stomach cancer is prone to liver metastasis, while diffuse-type is prone to peritoneal metastasis and lymph node metastasis. When using other classifications, the prognosis is good in the order of differentiated adenocarcinoma, mucinous adenocarcinoma, poorly differentiated adenocarcinoma, undifferentiated adenocarcinoma, and the worst mucinous cancer. The location, macroscopic morphology, and size of the tumor also have something to do with the prognosis. The best prognosis is in the corpus of the stomach, followed by the antrum, the proximal part, and extensive cancer. The prognosis of a tumor with clear boundaries is better than that of a diffuse tumor. The possibility of lymph node metastasis in polypoid gastric cancer and ulcerous gastric cancer is less than that in ulcerative infiltrative and diffuse infiltrative types, and the prognosis is also better. From the size of the tumor, a smaller tumor has a better prognosis than a larger tumor, and the worst prognosis is for tumors >4cm. Treatment type and prognosis: If stomach cancer patients do not receive treatment, their survival time is about 11 months. A study shows that 84% of patients die within 6 months after diagnosis, and 96% of patients die within 1 year after diagnosis. The survival time of patients who undergo radical surgery is 28 months, and some reported that the 5-year survival rate of this group of patients is about 40%. The survival time of patients who undergo palliative surgery is 4-14 months, and there are very few patients who survive for 5 years.