Treatment of different metastatic pathways of gastric cancer

If gastric cancer is not well controlled in the early stages, it will metastasize to varying degrees in the middle and late stages. There are four pathways of metastasis, usually the main one being lymph node metastasis, and in the late stages it can also metastasize through the blood.

1. Direct spread: This is when tumor cells grow and invade the stomach wall, develop in depth, break through the serosal layer, and directly invade adjacent organs and tissues, most commonly the greater omentum, liver, pancreas, and transverse colon, followed by the jejunum, diaphragm, and even the abdominal wall. Direct spread is related to the surgical method and whether radical resection is possible. Generally, when the spread to adjacent organs, such as the liver, is small and limited, it can be surgically removed. When the spread is large, it is difficult to completely remove it.

2. Lymph node metastasis: It is an important way for gastric cancer to spread, and it occurs relatively early. As the tumor grows, the deeper and wider it invades the stomach wall, the more chances it has to metastasize. It is divided into three stations or three groups according to the order of metastasis. And they are successively more serious. The third group of metastasis mostly occurs when the tumor invades the serosa. Generally speaking, when the third group of lymph node metastasis occurs, the chance of radical cure has been lost.

3. Hematogenous metastasis: Some patients may have gastric cancer cells or cancer thrombi that spread to other organs throughout the body through the blood circulation. They may metastasize to the liver, lungs, bones, kidneys, spleen, brain, meninges, skin, or to the ovaries, forming ovarian Krukenberg carcinoma or ovarian mucinous cell carcinoma. Hematogenous metastasis often occurs in the late stage of gastric cancer. In addition to treating the primary lesion, the metastatic lesion must also be treated.

4. Intraperitoneal implantation and metastasis of gastric cancer cells: In rare cases, the cancer breaks through the gastric wall serosa, and the cancerous tissue necrotizes and falls off, falling onto other organs and the peritoneum, which may cause implantation growth; in the late stage, cancerous peritonitis may occur, and there may be bloody ascites, and sometimes cancer cells can be found in the extracted ascites. Patients with implantation metastasis are all in the late stage, which makes treatment more difficult. Chemotherapy drugs are often injected into the abdominal cavity, but due to the extensive metastasis, they can only prolong life but cannot be cured.