The Clinical Study On The Relationship Between Lymph Nodes Metastasis And Pathological Factors In Early Gastric Cancer

Background: Early gastric cancer (EGC) is defined as invasive gastric cancer thatinvades no more deeply than the submucosa by Japanese Research Society forGastric Cancer published in1962, irrespective of lymph node metastasis. EGC hasbeen named superficial gastric cancer, and the Japanese standard is commonly usedby international society. Global incidence rate of gastric cancer is17.6/100,000,taking up first place of malignant tumor (10.5%). The retrospective investigationresult of malignant tumor from1973to1975showed that adjusted death rate ofgastric cancer was5.41/100,000, about160,000to200,000died in gastric cancer,took up23.03%of malignant tumor and its death rate of gastric cancer lied in the firstposition. Although a few regions decrease, and the total trend still go up. In the recenthalf century, research of gastric cancer has got much development. Because of thedevelopment of census and monitoring work, and the generalization use of fiberopticgastroscope, electronic gastroscope, ultrasound gastroscope and X-ray double contrastradiography diagnostic methods, detection rate and diagnosis rate of EGC obviouslyincrease, and treatment level significantly raises. WHO points out that longdevelopment time of EGC makes the possibility of the discovery and diagnosis ofEGC.In the transfer process of gastric cancer, lymphaden metastasis is an overridingmetastasis style, also it is one of evaluation standards. Capillary network of gastricmucosa has affluent lymphatic capillary net, linking with lymphatic capillary ofbathypelagic lamina propria, then goes into submucosa, once again coincide aslymphatic vessel strainer in vascular plexus. Lymphatic vessel of lamina propriabegins to show up valves. Lymphatic vessel strainer of submucosa again assemblelymphatic vessel, go through muscular layer, meanwhile accept small lymphaticvessel of muscular layer, at last assemble lymphatic vessel of subserosa, then reach toplacenta percreta, go along with artery after leave gastric wall, and gather to regionalnodes of circumambient stomach. In the strainer of different lymphatic vessel ofgastric wall, lymphatic vessel anastomosis is extensive in submucosa, to form intoglomerate clumps. Therefore, limited tumor of mucomembranous could extend towhole stomach through lymph network of this layer. Lymphatic vessel of cardiac endof stomach and Esophageal submucosa and muscular layer have affluent anastomosis,so it is one way of gastric mucosa tumor transferring to esophagus and mediastinum.Because lack of anastomosis in lymphatic vessel network of duodenal submucosa,few goes through lymphatic vessel network of submucosa to duodenum, it diffusestowards duodenum through lymphatic vessel anastomosis network of stomach andduodenal serosa.At present, EGC treatment mainly adopts surgery modus operandi, and the overriding lymphaden scavenge way is by means of radical cure I and radical cureII(D1, D2). Domestic research reports that survival rate of5years may reach to95%,and the main reasons:①modus operandi improving and surgical technic raising;②grasping biology behavior and carrying out reasonable radical excision;③gastriccancer patients of early and metaphase stage increasing. Use of therapeutic endoscopyand laparoscope aid radically treating a few EGC patients is an importantdevelopment in recent years treatment research.Endoscopic excision including in endoscopic mucosal resection (EMR) andendoscopic submucosal dissection (ESD), has many superiorities such as littletraumatic occlusion, small complication, light ache, effectively shorteninghospitalization cycle, and raising life quality after operation. It is more and more usedin the treatment of EGC. However, departed researches has given absolute indicationof endoscopic excision, but expanding indication of ESD treatment EGC still lies inclinical test stage because of lack of clinical correlated evidence of long-termprognosis. At present, it doesn’t exist accurate evaluation method of lymphadenmetastasis condition of EGC, but it determines treatment way and prognosis judgmentof EGC according to lymphaden metastases or not.This study retrospectively analyzed the relation between clinical pathologycharacteristic and lymphaden metastasis of EGC patients in our department, exploredmore reasonable diagnose and treat flow-sheet. Most of early gastric cancer didn’thave sings and symptoms, but there was individual case of sings and symptomsdisproportionate with staging, some sings and symptoms easily confused with otherstomach disease or precancerosis, so it required to further examine and identificate. Itwas a very important concept for patients and doctors. Therefore, through reasonablediagnose and treat flow-sheet of hospital admission, we choose suitable treatmentstyle according to different patients, finally make EGC patients profit from it.Objective: Through retrospective analysis of clinical pathology characteristic data ofEGC in our department, explore the correlation between lymphaden metastasis ofEGC and clinical pathology factors, discover regularity of lymphaden metastasis ofEGC. It can formulate flow-sheet for diagnose and treat of EGC patients, and providereference for choosing rational therapeutic regimen.Method:271cases of EGC patients accepted in our section office during2005.10to2011.10were conducted as samples. The index investigated includes sex, age, tumorposition, tumor size (cm), general types, pathological classification and depth ofinvasion. The data was dealt with SPSS15.0. The univariate analysis of therelationship between lymph node metastasis and every clinical pathological featureswas carried out with chi square test and multivariate analysis was done withdichotomic unconditional Logistic regression analysis (P<0.05). Correlative factorsgot with statistical significance were further used for statistical analysis combined with the lymph node metastasis.Result: The rate of lymph node metastasis of those tumor with size≥3cm is42.2%,obviously higher than other groups (P<0.01); the rate of lymph node metastasis ofundifferentiated tumor is21.6%, obviously higher than10.2%of differentiatedtumor(P<0.05); that of infiltrating submucosal is32.7%, obviously higher than4.3%of infiltrating mucous layer（P<0.01）. Multivariate Logistic regression analysisreveals that the factors affecting lymph node metastasis include tumor size,pathological classification and depth of invasion. The risk of lymph node metastasis is4.392times as great as previous for each additional level of tumor size (95%CI:2.438～7.911). In pathological classification’s respect, the risk of lymph nodemetastasis in undifferentiated tumor is4.708times as great as in differentiated tumor(95%CI:1.915～11.572); in the aspect of the depth of invasion, the risk of lymphnode metastasis when tumor invades submucous layer is11.310times as great as thatwhen tumor invades mucous layer(95%CI:4.377～29.227). The further analysis ofthe rate of lymph node metastasis shows that lymph node metastasis can not be foundin the patients with differentiated tumor of which the size is below3.0cm when tumorinvades mucous layer; at the same time, lymph node metastasis can not be found inthe patients with undifferentiated tumor whose size is below2.0cm as well. However,lymph node metastasis occurs in all the sorts when tumor invades submucous layer.Conclusion: Patients with early gastric cancer are recommended to have apreoperative endoscopic ultrasonographic (EUS) scan as well as pathologicalscreenings for deciding the most appropriate type of surgery. The indications forendoscopic resection should be strictly followed:1) For mucosal tumor with a sizeless than2cm, regardless of its pathological classification, EMR or ESD isappropriate,;2) For pathologically diffuse-typed mucosal tumor with a size from2-3cm, ESD is recommendable;3) For pathologically intestinal-typed mucosal tumorwith a size not less than2cm, or mucosal tumor that with a size not less than3cmregardless of its pathological classification, or all the sub-mucosal tumor, eitherlaparoscopic or laparotomic lymph node dissection should be performed, in order toavoid lymph node metastases to a large extend.