About the occurrence of gastric cancer
Gastric cancer refers to malignant lesions of the epithelial cells of the gastric mucosa. The occurrence of gastric cancer is related to genetic, environmental or dietary factors, among which food factors and Helicobacter pylori infection (Hp) are more important. High salt intake, pickled and smoked foods, low intake of fresh fruits and green vegetables and lack of antioxidant vitamins in food are all related to the occurrence of gastric cancer. It is generally believed that gastric carcinogenesis is not a leap from normal cells to cancer cells, but a gradual process, and before developing into cancer, it often undergoes years of continuous precancerous changes. Pre-cancerous diseases (refers to benign gastric diseases associated with gastric cancer with the risk of cancer) and pre-cancerous lesions (refers to pathological changes that are more likely to transform into cancerous tissues) of gastric cancer mainly include chronic atrophic gastritis, gastric adenoma, gastric ulcer, remnant stomach, pernicious anemia and giant gastric mucosal crepitus, etc.
About the diagnosis of gastric cancer
Early stage cancer can be asymptomatic or detected when patients visit the doctor for indigestion symptoms such as epigastric discomfort, poor appetite and fatigue. The common symptoms of gastric cancer are epigastric pain, epigastric fullness and discomfort, nausea, vomiting, vomiting blood, black stool and malignant mass. If a lump, ascites or enlarged lymph nodes are found in the abdomen, the disease is already in advanced stage and the treatment effect is poor. In recent years, due to the application of powerful acid-suppressing drugs such as PPI, patients with gastric cancer can also get a certain degree of symptomatic relief and have been mistaken for gastritis, which delays the diagnosis.
Early gastric cancer refers to cancer involving only the mucosal layer or submucosal layer of the stomach wall (superficial gastric cancer).
Gastroscopy and pathological biopsy can diagnose gastric cancer but cannot determine whether it is early stage cancer.
The following points are more important in the diagnosis of gastric cancer.
1. Because most of the early gastric cancers can be completely cured, so special attention should be paid to the detection of early cancers.
2. those who have symptoms of gastritis but never had gastroscopy must have gastroscopy if early cancer cannot be detected by B-ultrasound or CT
3.Gastric ulcer or atrophic gastritis found by gastroscopy must be pathologically biopsied to assess the degree of its cellular heterogeneous hyperplasia, and those with severe heterogeneous hyperplasia need to be treated as early stage cancer.
4.Gastric ulcer or tumor lesion found under gastroscopy, pathological biopsy is clearly identified as gastric cancer, ultrasound endoscopy and CT examination are needed to determine whether it is early or progressive stage, simple gastroscopy cannot distinguish early or late stage of gastric cancer.
Gastric cancer suspected under gastroscopy but not confirmed by pathological biopsy can be judged by ultrasound endoscopy without repeated gastroscopy biopsy of the patient.
(EUS can be used to confirm the diagnosis of gastric cancer if repeated gastroscopy cannot determine it)
About the treatment of gastric cancer
For early stage gastric cancer, if it is intra-mucosal cancer, endoscopic peeling and resection is feasible, while those with sub-mucosal infiltration or lymph node metastasis can be treated with chemotherapy and additional surgery. For progressive stage cancer, we emphasize comprehensive treatment based on surgery and advocate 1-2 courses of chemotherapy before surgery to prevent the spread of cancer cells that may be induced by fasting, panic, surgical trauma, low resistance and surgical extrusion during the perioperative period. It has been proved that the use of preoperative chemotherapy followed by surgery combined with postoperative chemotherapy can reduce the recurrence of cancer after surgery, improve the intraoperative tumor surgical staging and increase the surgical resection rate of patients. For those who cannot undergo surgical resection for advanced gastric cancer, chemotherapy and nutritional support therapy are the main treatments to improve the quality of survival.
For whether chemotherapy should be administered after surgery, generally according to the following principles.
1.For endoscopic resection of early stage cancer, if there is cancer residue in the cut edge or tumor cells infiltrate into the submucosa, chemotherapy or additional surgical operation is required.
2.If the surgically resected gastric cancer is T1-N0M0 stage, chemotherapy is not needed.
3.Stage T2-N0M0 gastric cancer can be treated without chemotherapy; however, if the cancer cells are hypodifferentiated, lymphatic vessels, blood vessels and nerves are invaded, and the age is less than 50 years old, postoperative chemotherapy is required.
4.Metastasis in lymph nodes (N) or metastasis in other organs (M) need chemotherapy.
5.Post-operative chemotherapy time: usually starts about four weeks after surgery.
6.Number of times of postoperative chemotherapy: if the surgery can completely remove the tumor, postoperative chemotherapy should be adhered to 4-5 courses; if the surgery cannot remove the tumor or cut cleanly, postoperative chemotherapy should be mastered according to the patient’s condition and status, with the main focus on improving the quality of life.
Pre-cancerous lesions or part of early cancer can be removed endoscopically without surgical incision.