The Relationship Of Milky Spots And Micro-metastasis Of Gastric Cancer

Objective:Gastric cancer is a common malignant tumor with high incidence and mortality rate,and peritoneal metastasis is a key channel for metastasis.The transcoelomic dissemination of tumor was reckoned as a result of the gravity of tumor cells that falls on serous membrane of low viscera and forms the new secondary tumor. The current study shows that milky spots play an important role in the process of tumor peritoneal dissemination. The main channel of peritoneal metastasis is transcoelomic metastasis, and 73.9% of patients who suffered from gastric cancer with biological activity cancer cell in abdominal cavity will have peritoneal metastasis. Their deaths are mostly caused by metastasis or relapse, and micro metastasis is the main source of metastasis and relapse. Milky spots are formed by macrophages gathering with few lymphocytes and mast cells around the vascular network, which is mainly at great omentum of abdominal cavity.This experiment is to discuss the role of milky spots in peritoneal metastasis of gastric cancer and features of formation focus caused by micro-metastasis of gastric cancer milky spots, through the establishment of peritoneal metastasis model and dynamic observation of features of peritoneal free cells' peritoneal milky spots metastasis, which lay the foundation for further features and mechanism understanding of peritoneal metastasis.Method:30 615 mice were divided into 3 groups and 104 gastric cancer cell line MFC which is the source of proximal gastric cancer of 615 mice marked by Di fluorescent chemical dye, and 3 groups of mice were killed in 24,48 and 72 hours respectively and their greater omentum were taken out. The macrophages in omentum milky spots were directly stained with FITC to observe gastric cancer cell changes under immune fluorescence microscope in milky spot area.Result: 1. Under transmission electron microscope observation, it can be found that the milky spots mainly consist of macrophages, with a variety of sizes and shapes and many microvilli. There are a few round or ovalymphocytes in the middle of macrophages, with a small amount of short microvilli on cell surface. The cell nucleus is relative large, which occupied the most of the cell in a round or oval shape and shallow depression. Also, there is a small amount of neutrophil in milky spots.2. Under immunofluorescence microscope observation of omentum in mice that were killed in 24 hours, there were tumor cells Dil-MFC in area where a large number of macrophages gathered and tumor cell debris was found in other areas. The gastric cancer cells ratio of milky spots and non-milky spots area was 168:1(p<0.01).After 48 hours of intraperitoneal injection, the Dil-MFC cells decreased in macrophage gathering area under the action of macrophages, and the majority of cancer cells were eliminated with only a few cells survived by scattering around the milky spots. Gastric cancer cells ratio of milky spots and non-milky spots was 60:1(p<0.01).After 72 hours, Dil-MFC cells further decreased, and the proliferation of cell clusters and the formation of the proliferation of tumor micrometastase could be seen. The gastric cancer cells ratio of milky spots and non-milky spots was(p<0.05).3. The gastric cancer cells variation in the three time points of 24 hours,48 hours,and 72 hours in milky spot area has statistical significance (p<0.05).Conclusion:1. Through electron microscope observation, it reveals that milky spots are mainly composed of with a few lymphocytes and neutrophils.2. The cells selectively violate milky spots in the early stages of peritoneal metastasis. In 72h after intraperitoneal injection, the Dil-MFC cells that survive in the milky spots begin to proliferate and form micrometastasis proliferation.