The prognosis of gastric cancer is related to these factors! What is the mainstream surgical method?

Author: Liang Bin, Chief Physician, Peking University People's Hospital

Reviewer: Yu Yanyan, Chief Physician, Peking University First Hospital

The stomach wall is divided into the mucosa, submucosa, muscularis, and serosa. Early gastric cancer refers to cancer tissue confined to the gastric mucosa and submucosa, regardless of its size and whether there is lymph node metastasis; mid-stage gastric cancer refers to cancer tissue that has infiltrated the muscularis or serosa, and may have lymph node metastasis, but no distant metastasis; advanced gastric cancer refers to the presence of abdominal or distant metastasis.

Figure 1 Original copyright image, no permission to reprint

The prognosis or treatment effect of gastric cancer is closely related to the stage. The 5-year survival rate of early gastric cancer is above 85%; the 5-year survival rate of mid-stage gastric cancer decreases; for late-stage gastric cancer, with other distant metastases such as the liver, peritoneum, and lungs, the 5-year survival rate may be less than 10%.

In addition, the prognosis of gastric cancer is related to the differentiation type of the tumor, that is, the degree of malignancy, and the tissue type of the tumor. According to the degree of differentiation, gastric cancer can be divided into well-differentiated adenocarcinoma, moderately differentiated adenocarcinoma, poorly differentiated adenocarcinoma, mucinous adenocarcinoma, signet ring cell carcinoma, etc. Among them, poorly differentiated adenocarcinoma, mucinous adenocarcinoma and signet ring cell carcinoma have relatively poor treatment effects due to their high degree of malignancy. As for the tissue typing of the tumor, if the invasiveness is high, the risk of metastasis is also greater, and the corresponding prognosis is also poor.

Generally speaking, the prognosis of gastric cancer is related to the tumor stage, differentiation, and classification, which is from the perspective of the tumor itself.

In addition, factors such as the choice of treatment method, the thoroughness of surgical resection, the individual patient's response to treatment, basic health status and age may affect the treatment effect.

The treatment strategies for gastric cancer include surgery, radiotherapy, chemotherapy, immunotherapy and traditional Chinese medicine treatment. Comprehensive treatment methods are required, and the choice of the main treatment method is closely related to the staging, aiming to achieve the best therapeutic effect, prolong survival and improve the quality of life.

When gastric cancer has not metastasized to distant sites and the cancerous tissue is still confined to the local part of the stomach, surgical treatment is generally the first choice. Taking early gastric cancer as an example, if the tumor is confined to the mucosal layer, does not protrude from the mucosal layer, and the long diameter does not exceed 2 cm, endoscopic resection can be selected, and a fiber gastroscope can be used to perform a complete resection along the bottom and periphery of the lesion. When the tumor breaks through the mucosal layer and invades the submucosal layer, but has not yet broken through the muscular layer, and the tumor is not large in size, and there is no enlargement of perigastric lymph nodes, resection surgery that preserves gastric function can be considered. This includes partial gastrectomy that preserves the cardia and pylorus, and radical gastrectomy that preserves the pylorus.

The cardia and pylorus are very important for the overall function of the stomach. Preserving the cardia and pylorus can improve the patient's quality of life. The pylorus can prevent the alkaline digestive juice in the duodenum from flowing back into the stomach and irritating the gastric mucosa; the cardia can prevent the acidic gastric juice from flowing back into the esophagus and causing reflux esophagitis.

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The mainstream surgical method for gastric cancer is radical surgery. Depending on the location and size of the tumor, partial gastrectomy or total gastrectomy, including peripheral lymph node dissection, can be performed. The standard for radical surgery is that no residual lesions can be seen under the naked eye or microscope. Radical surgery can be performed for early gastric cancer or locally advanced gastric cancer without distant metastasis.

If there are distant metastases such as liver metastasis, lung metastasis, and peritoneal metastasis, even if the stomach and surrounding lymph nodes are removed during surgery, it cannot be called a radical surgery, but a palliative surgery. Although the gastric cancer lesions and surrounding lymph nodes are removed, reducing the tumor burden, the metastatic lesions cannot be completely eliminated, and further treatment, such as chemotherapy, is required to control the metastatic lesions. Palliative surgery has little effect on prolonging the patient's survival. Therefore, unless there are complications that cannot be controlled by non-surgical means, such as massive gastrointestinal bleeding, gastric perforation, and pyloric obstruction, palliative surgery is generally not recommended for advanced gastric cancer.

In some cases, palliative resection is performed to control complications and save the patient's life, which is also called salvage surgery. For example, active gastrointestinal bleeding, gastric perforation, and pyloric obstruction occur. The tumor grows in the gastric antrum and blocks the pylorus. Food cannot be discharged from the stomach to the duodenum for digestion, which is called pyloric obstruction, which will cause vomiting, and the patient cannot eat or receive anti-tumor treatment. For patients with resectable pyloric obstruction, tumor resection can be considered first, and further anti-tumor treatment can be performed after the patient resumes eating. For patients with potentially resectable or unresectable pyloric obstruction, relieving the obstruction and establishing a nutritional treatment pathway are prerequisites for nutritional treatment and even anti-tumor treatment. Tube feeding or gastrojejunostomy can be used to solve the obstruction problem first, and chemotherapy can be performed after enteral nutrition or normal diet can be restored. If the patient has a good response to chemotherapy, the tumor has shrunk, and distant metastasis has been eliminated or controlled, surgery can be performed to remove the gastric cancer lesions, which can better prolong survival.

The operating procedures for radical surgery for gastric cancer are as follows: Regardless of whether open surgery or laparoscopic surgery is used, the first step is to carefully explore the surrounding organs in the abdominal cavity. This step is to confirm whether the actual stage of the tumor is accurate, evaluate the relationship between the tumor and adjacent organs, and check whether there is metastasis to other parts. Subsequently, the abdominal cavity is lavaged and the lavage fluid is collected for testing to determine whether there are detached tumor cells. After the exploration is completed, the primary lesion is resected and the lymph nodes are thoroughly cleared. After the resection is completed, necessary cleaning is performed, and then the digestive tract is reconstructed.

After radical surgery for gastric cancer, based on postoperative pathological staging, especially if there is lymph node metastasis, the probability of residual lesions increases and meets the chemotherapy criteria, so adjuvant chemotherapy is needed after surgery.