The stomach is located in the upper abdomen of the body, in the shape of a “J”, and is an important digestive organ for food. Stomach cancer can develop in any part of the stomach and the development process may take many years. The symptoms of gastric cancer and precancerous lesions are insidious and non-specific, so early gastric cancer is difficult to be detected. In fact, only 5-10% of gastric cancers in China can be diagnosed early. The main pathological type of gastric cancer is adenocarcinoma. Other types of gastric cancer include squamous cell carcinoma, adenosquamous carcinoma, carcinoid carcinoma, small cell carcinoma, etc. The latter types are less common, and there are differences in treatment options for different types of gastric cancer. The following factors may increase the risk of gastric cancer: 1. infection with Helicobacter pylori (HP), HP can cause chronic inflammation of the superficial layer of the stomach wall and may cause precancerous lesions, recent studies have shown that eradication treatment given in people infected with Hp can reduce the risk of developing gastric cancer. 2. High intake of cured and smoked foods, such as smoked fish, bacon and kimchi. In contrast, a high intake of fruits and vegetables (especially foods rich in chlorophyll and vitamin C) can reduce the risk of stomach cancer. 3.Smoking and alcohol abuse. 4.History of stomach surgery, such as major gastrectomy for ulcer patients. 5.Familial cancer syndrome, such as familial adenomatous polyposis, can increase the risk of colorectal cancer and mildly increase the risk of gastric cancer. 6.Family history of gastric cancer. 7, polyps in the stomach especially multiple polyps (small benign growths can sometimes develop into gastric cancer). Prevention and early detection The symptoms of stomach cancer are not specific and may include: indigestion and stomach discomfort, feeling of fullness after meals, mild nausea, loss of appetite, and heartburn. When gastric cancer progresses to a more malignant stage, patients may experience: black stools, vomiting, unexplained weight loss, and stomach pain, which may also be caused by benign conditions such as simple indigestion or ulcers. However, if these symptoms persist for a long time or get progressively worse, one should visit a hospital for detailed examination. Diagnosis and Staging Although gastric cancer has the highest incidence and mortality rate in China, it is still difficult to carry out extensive routine screening due to the limitation of medical resources. However, if there are factors of high incidence of gastric cancer or symptoms mentioned above, you should seek medical consultation in time. If you have any questions about your symptoms and test results, please consult with a specialist. Doctors will first take a detailed medical history, conduct a physical examination and make an appointment to draw blood, but some tests must be used to really confirm the diagnosis. These include upper gastrointestinal imaging, gastroscopy, ultrasound/CT of the abdomen and pelvis, chest radiographs, and, if necessary, other tests such as cranial examinations and bone scans to understand the extent of the lesion. Upper gastrointestinal imaging is often abbreviated as “barium meal”, in which the patient drinks a liquid containing barium and the doctor observes the structure and contour of the stomach under X-ray, which is performed in the radiology department of the hospital. Gastroscopy is an essential test for gastric cancer. Gastroscopy is a thin and light tube that enters the stomach through the mouth and captures images through a camera at the end, allowing the doctor to clearly observe the stomach mucosa and, if necessary, take a small piece of tissue to look for cancer cells. Abdominal ultrasound and CT are mainly to observe the spread of gastric cancer in the abdominal cavity and determine the severity of the disease. Pelvic ultrasound and CT are especially important for female patients to observe whether there is ovarian metastasis. If patients have symptoms such as dizziness, blurred vision and bone pain, head CT/MRI and bone scan will also be performed to exclude metastasis in these two areas. If necessary, laparoscopic exploration is also performed, which is a minimally invasive procedure that requires general anesthesia to explore the abdominal cavity through a tube with a camera at the end, mainly to observe the surface of the lymph nodes around the stomach and other abdominal organs to determine whether the cancer has invaded these areas. The effectiveness of treatment for gastric cancer depends on the stage of the disease, i.e. the size of the tumor growth, the degree of infiltration of the stomach wall and whether it invades surrounding organs, lymph nodes and other parts of the body. So far, surgery is the only treatment that may achieve a cure. Doctors will decide the overall treatment plan according to the stage of the disease: radical surgery alone, adjuvant chemotherapy after radical surgery, chemotherapy-surgery-re-chemotherapy, systemic chemotherapy, combined radiotherapy or intervention, and symptomatic support. Surgery Surgery is the common treatment for gastric cancer patients. If the results of staging tests suggest that surgery is appropriate, the surgeon may perform the following procedures: subtotal gastrectomy: removal of the part of the stomach containing the tumor and parts of the tissues and organs adjacent to the tumor (such as part of the small intestine or esophagus, depending on the location of the tumor). Total gastrectomy: Removal of all the stomach tissue and part of the small intestine, esophagus and adjacent tissues, after which the esophagus is anastomosed to the small intestine. During the operation, the surgeon removes the adjacent lymph nodes to check for cancer metastases. In special cases, parts of the organs surrounding the stomach may also be removed. Chemotherapy Chemotherapy is another means of treating gastric cancer, which is to give anti-tumor drugs and is mainly used in the following three cases: adjuvant treatment after surgery, hoping that this will reduce local recurrence and distant metastasis after surgery; chemotherapy is given to gastric cancer with more extensive local growth before surgery to shrink the tumor, reduce the stage and improve the success rate of surgery; recurrent and metastatic gastric cancer that cannot be operated should be treated with systemic chemotherapy to control symptoms and To improve the quality of life and prolong the survival period. Among the chemotherapy drugs for gastric cancer, 5-fluorouracil has the longest history and is still the most widely used drug, and its oral formulation is capecitabine (Siroda). Epiaminomycin and cisplatin are also traditional drugs with clear efficacy. The newly developed oxaliplatin, paclitaxel-like drugs, and irinotecan have also shown good results. These drugs can be given in combination regimens, but to date there is no fully accepted standard chemotherapy regimen for gastric cancer. There are also times when drugs are injected directly into the abdominal cavity in the hope that this will reduce ascites. Molecularly targeted drugs such as cetuximab are just beginning to be investigated in the treatment of gastric cancer. Radiation therapy Radiation therapy is most often used in combination with chemotherapy to treat gastric cancer. New research shows that postoperative chemotherapy plus radiation therapy prolongs survival for many gastric cancer patients compared to surgery alone. Pre-surgical radiation therapy or radiotherapy is still being studied. If you have had surgery on your stomach, your doctor will advise you to eat smaller and more frequent meals. Your doctor will also give you vitamin supplements because the stomach does a great job of absorbing vitamins. After your treatment, your doctor will perform some follow-up examinations to monitor your health or to detect any recurrence or metastasis of the tumor. If you feel that you have any new symptoms, please see your doctor immediately. The survival period of stomach cancer depends on how advanced the disease is at the time of initial diagnosis. The earlier it is detected, the longer the survival period. Supportive adjuvant therapy Supportive adjuvant therapy plays a big role in improving the function and quality of life of patients with gastric cancer. Various symptoms and adverse effects such as anemia, fever and GI symptoms should be actively managed during any treatment. Doctors and nurses will inform patients and families about what to look for during treatment and are always available to answer questions. Every patient should be screened for nutritional risk and given nutritional support if necessary. Gastric cancer is a weakly immunogenic tumor, and various immunotherapies have no clear efficacy against gastric cancer.