The Outcome Of Low-Grade Gastric Intraepithelial Neoplasia And The Comparative Study Between Endoscopic Therapy And Surgical Resection For High-Grade Gastric Intraepithelial Neoplasia And Early Gastric Cancer

Background:Gastric cancer is the fourth most common cancer and the second leading cause of cancer associated death worldwide. Early diagnosis and treatment is the only effective way to improve its survival rate at present. In the past 20 years, it was reported in Japan that the diagnosis rate of early gastric cancer (ECG) rised from 5% to 30%, and the 5-year survival rate after treatment can reach 95% or higher and 100% for the gastric cancer limited to mucosa. In our country, the guideline for standard diagnosis and treatment of gastric cancer shows that the patients with ECG confined to the mucosa have a well prognosis, and the 5-year survival rate after treatment can reach 95% or more, but about 80% for the cancer invading to the submucosa.After the onset of symptoms of gastric cancer, more than 90% of the patients without treatment die within 1 year. Many studies have shown that about half of the patients with EGC are asymptomatic and the onset of symptoms always means the advanced gastric cancer. Therefore, the early diagnosis of gastric carcinoma becomes particularly important. A definite diagnosis of the gastric cancer by all means on its initial stage has profound meanings for improving the survival rate and the quality of life after therapy. The primary means for diagnosis of gastrointestinal diseases is endoscopy. Many new endoscopic technologies born in the past decade are greatly helpful to raise the detection rate of EGC. Gastric cancer usually lives through a long and continuous precancerous process instead of beginning from normal mucosa directly. The pattern accepted today is:chronic atrophic gastritis—intestinal metaplasia -dysplasia—gastric cancer. The gastric epithelial dysplasia is closely related to gastric cancer and considered as precancerous lesion.In 2000, the world health organization (WHO) introduced the concept of gastric intraepithelial neoplasia (GIN) into the new classification of tumors, which was based on the Vienna classification. In that classification, gastric intraepithelial neoplasia is explicitly divided into low grade intraepithelial neoplasia (LGIN) and high grade intraepithelial neoplasia (HGIN) according to cellular atypia and structural disorder. LGIN is equivalent to mild and moderate gastric epithelial dysplasia,and HGIN to severe gastric epithelial dysplasia and carcinoma in situ, which replaces the terms, such as dysplasia, atypical hyperplasia and carcinoma in situ. Given the highly malignant and bad outcomes of gastric cancer, the regularly endoscopic follow-up and effective therapy for the precancerous lesion are effective to improve the diagnosis and treatment of gastric cancer. The endoscopic treatment on EGC includes endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). The later one begins from Japan, and gains its popularity with the technologies to a mature stage. Some studies show that there is no significant difference between endoscopic treatment and surgery for intramucosal carcinoma, but the former can greatly reduce the complications and improve the quality of life after operation. However, minimally invasive endoscopic treatment on EGC is still in the initial stage in our country.This study aims at reviewing the 102193 patients out of 114650 ones undergoing endoscopy in our hospital from August 2000 to August 2010, and exploring endoscopic detection rate of GIN. In the 1144 cases of GIN diagnosed by endoscopy combined with pathology,346 patients with LGIN,taking regularly endoscopic examination,were selected to be followed up to study the outcome and the relationship between gastric cancer and its related factors. Meantime, a comparative study between endoscopic therapy and surgical resection for patients with HGIN and EGC from November 2006 to August 2010 were performed to preliminarily assess the clinical value of ESD in treating HGIN and EGC.This study includes the following two parts:Ⅰ. Clinical Pathology and Outcome of Low-Grade Gastric Intraepithelial NeoplasiaObjective:To study the detection of LGID by endoscopy together with pathology, and explore its pathological characteristics and outcome for the purpose of raising the early detection level of EGC.Methods:102193 patients undergoing routine endoscopy were studied retrospectively to explore the endoscopic detection and pathological results of GIN. And then 346 patients with LGIN diagnosed by endoscopy combined with pathology were followed up continually for 1 to 10 years to analyze the outcome and malignant changes.Results:The total endoscopic detection rate of GIN was 1.75%, in which that of LGIN was 1.1%. The grade of the lesion was unrelated to age (P>0.05). Compared to other parts of the stomach, the gastric angle had a higher positive rate of intestinal metaplasia in the lesion of LGIN (P<0.05). The malignant transformation rate of LGIN differs in different parts of gastric mucosa, and that is higher in the cardia than other parts (P<0.05).The total malignant transformation rate of LGIN in 346 patients was 4.6%, in which the rates of disappearance and malignant transformation in mild dysplasia were 78.7% and 0.45%, those in mild- -moderate dysplasia were 60.5% and 10.5%, and those in moderate dysplasia were 51.0% and 14.3% ,respectively, according to the classification of dysplasia in the old pathological diagnosis. Meantime, the rates were statistically different in mild, mild-moderate and moderate dysplasia (P<0.05). What's more, the analysis of factors influencing the malignant transformation showed that the malignant changes were associated with the coexistence of chronic atrophic gastritis and intestinal metaplasia, the infection of Helicobacter pylori (HP), the sites of lesions and age except for the pathological grade (P<0.05),but unrelated to gender(P>0.05).Conclusion:Different degrees of LGIN all have potential for malignant changes and the follow-up of patients with LGIN by endoscopy combined with pathology is helpful to detect gastric cancer early, especially for EGC.Ⅱ. The Comparative Study between Endoscopic Therapy and Surgical Resection for High-Grade Gastric Intraepithelial Neoplasia and Early Gastric CancerObjective:To compare the effect of ESD and surgical resection for HGIN and EGC. The primary indicators are the rate of complete resection, histological healing rate and survival rate. The second indicators are complications, recurrence rate and life quality after operation.Methods:316 patients with HGIN and EGC, who received treatment from November 2006 to Augest 2010 in our hospital were reviewed. Those subjects included 80 ones treated by ESD and 236 ones by surgery. Then the effects between the two therapeutic methods were compared.Results:The complete resection rate and histological healing rate by ESD were 93.8% and 98.8%, in which 100% and 100% for HGIN,92.3% and 100% for intramucosal carcinoma,92.3% and 100% for muscularis mucosal carcinoma,80.0% and 90.0% for submucosal cancer, respectively. As to the former four different pathological types, the rates of complete resection made no statistical differences (P>0.05), but histological healing rates differed statistically (P<0.05). The rates of obvious bleeding during the operation, perforation, delayed bleeding after operation were 0%,0% and 2.5%, respectively. The follow-up of 52 patients after ESD showed that the rate of recurrence and redidue was 1.9%. In addition, for the patients treated by ESD and the ones by surgery, the survival rates were not statistically different (P> 0.5) (52/52 VS 155/158), and the recurrence rates were not either (P>0.05) (1/52 VS 3/158).Conclusion:1.As to HGIN and EGC,the survival and recurrence rates after endoscopic therapy were not statistically different from that after surgery (P>0.05)2. The rates of histological healing and recurrence after ESD are associated with the pathological types and the invasive depth (P<0.05)3.The patients undergoing ESD have minor wound, quick recovery and high life quality after operation.