Risk Of Lymph Node Metastasis And Feasibility Of Endoscopic Treatment In Ulcerative Early Gastric Cancer

Objective:Early gastric cancer(EGC)is defined as carcinoma limited to the mucosa or submucosa,regardless of presence of lymph node metastasis(LNM).Patients with EGC generally have extremely good prognosis after radical resection,and the 5-year survival rate is reported to be approximately 90%.When LNM develops,this survival rate decreases to less than 70%.When the risk of LNM is considered minimal in patients with EGC,endoscopic submucosal dissection(ESD)is an effective alternative to radical resection.ESD is recommended for use in well-or moderately well-differentiated EGC confined to the mucosa without ulceration and with lesion size equal to or smaller than 20 mm.The absolute indications are so strict that few patients are eligible for ESD.In contrast with its use in non-ulcerative-type EGC,ESD is less commonly used in ulcerative-type EGC because of the higher risk of LNM in these tumors.This study aimed to estimate the feasibility of ESD for early gastric with ulceration.Methods:We reviewed the data from 691 patients who underwent gastrectomy for early gastric cancer with ulceration retrospectively.The data consisted of age,sex,body mass index,incidence of hypertension,alcohol consumption,smoking history,carcinoembryonic antigen(CEA)level,H.pylori infection status,tumor location,lesion size,macroscopic type,depth of invasion,number of tumors,tumor differentiation,Lauren type,presence of lymphovascular invasion,presence of perineural invasion,number of lymph nodes examined,surgical approach,and LNM.Subsequently,a stratification system for lesions in accordance with the expanded ESD criteria was created,and the associations between the subgroups and the rate of LNM were analyzed.Then,the 5-year overall survival(OS)and disease-free survival(DFS)rates of the subgroups were estimated.Results:LNM was confirmed in 16.5%(114/691)of the patients.Univariate analysis demonstrated that age,sex,tumor size,macroscopic features,depth of invasion,tumor differentiation,Lauren type,lymphovascular invasion(LVI)and perineural invasion were associated with LNM.Multivariate analysis showed that lymphovascular invasion and the depth of invasion were independent risk factors for LNM.Further stratification revealed that,when lesions sized < 30 mm,undifferentiated tumors with SM1 invasion had statistically higher rate of LNM and lower disease free survival rate than differentiated tumors with SM1 invasion and tumors limited in mucosal layer.Additionally,the incidence rate of LNM in patients with undifferentiated mucosal tumors with ulceration was 1.7% when the lesion was less than 20 mm and 2.7% when it was 20–30 mm,which was much lower than we had anticipated.The cumulative 5-year OS rate of the 346 patients was 91.4%,and the 5-year DFS rate of these patients was 93.1%.Furthermore,the 5-year OS rates of the differentiated mucosal lesions,undifferentiated mucosal lesions,differentiated lesions with SM1 invasion,and undifferentiated lesions with SM1 invasion were 89.6%,96.0%,94.7%,and 76.1%,respectively,and the 5-year DFS rates of the same groups were 91.4%,97.3%,100%,and76.1%,respectively.Conclusion:1.The depth of invasion and lymphovascular invasion were strongly associated with lymph node metastasis for ulcerative early gastric cancer.2.The lymph node metastasis rate of differentiated intramucosal carcinoma sized<30mm with ulceration was 3.3%.These lesions were not suitable for ESD guidelines(version 2020),which was consistent with the gastric cancer guidelines(version2014)as ESD expanded criteria.3.The lymph node metastasis rate of differentiated intramucosal carcinoma sized < 20 mm with ulceration was 1.7%.These lesions were suitable for ESD expanded criteria(version 2014).