Lymph node metastasis in early gastric cancer with submucosal invasion:Feasibility of minimally invasive surgery

AIM:To explore the feasibility of pertorming minimallyinvasive surgery(MIS)on subsets of submucosal gastriccancers that are unlikely to have regional lymph nodemetastasis.METHODS:A total of 105 patients underwent radicalgastrectomy with lymph node dissection for submucosalgastric cancer at our hospital from January 1995 to December1995.Besides investigating many clinicopathological featuressuch as tumor size,gross appearance,and differentiation,we measured the depth of invasion into submucosa minutelyand analyzed the clinicopathologic features of these patientsregarding lymph node metastasis.RESULTS:The rate of lymph node metastasis in caseswhere the depth of invasion was<500 μm,500-2 000 μm,or>2 000 μm was 9%(2/23),19%(7136),and 33%(15/46),respectively(P<0.05).In univariate analysis,no significantcorrelation was found between lymph node metastasis andclinicopathological characteristics such as age,sex,tumorlocation,gross appearance,tumor differentiation,Lauren’sclassification,and lymphatic invasion.In multivariateanalysis, tumor size(>4 cm vs≤2 cm,odds ratio=4.80,P=0.04)and depth of invasion(>2 000 μm vs ≤500 μm,odds ratio=6.81,P=0.02)were significantly correlatedwith lymph node metastasis.Combining the depth and sizein cases where the depth of invasion was less than 500 μm,we found that lymph node metastasis occurred where thetumor size was greater than 4 cm.In cases where thetumor size was less than 2 cm,lymph node metastasiswas found only where the depth of tumor invasion wasmore than 2 000 μm.CONCLUSION:MIS can be applied to submucosal gastriccancer that is less than 2 cm in size and 500 μm in depth.