Effect Of Gender Factor On Lymph Node Metastasis For Early Gastric Cancer

Background and Aim Early gastric cancer(EGC)is defined as tumor localized to the mucosa(M)or submucosa(SM),irrespective of lymph node metastasis(LNM).With increasing incidence rate of EGC,patients require endoscopic submucosal dissection(ESD)or endoscopic mucosal resection(EMR).According to the guidelines of Japan Gastroenterological Endoscopy Society,endoscopic resection should be carried out when the likelihood of LNM is extremely low,and lesion size and site are amenable to resection en bloc.So,it is important to give a accurate preoperative assessment,EGC has a better prognosis,for which LNM is an independent prognostic risk factor,Nevertheless,there are still no effective methods for determining whether LNM occurs before surgery,so it is of great significance to find the risk factors for LNM.According to previous research,tumor size,depth of invasion,pathological type,with ulcer or not were the risk factors of lymph node metastasis in early gastric cancer.Japan Gastroenterological Endoscopy Society make a classification of ESD indications according to tumor-related factors mentioned above,(include absolutely indication lesion,expanded indication lesion and out of indication lesion).Some research report that estrogen receptor α 36(ER-α 36)is expressed in human gastric cancer and is highly correlated with lymph node metastasis,another previous research show overexpression of ERa inhibits proliferation and invasion of gastric cancer cells.Both previous article and tne guideline did not mention the impact of gender factor on lymph node metastasis,therefore,we performed a sex-control analysis and meta analysis to clarify the effect of gender factor on LNM.Methods Collect 426 cases clinicopathological data of radical gastrectomy for early gastric cancer in General Surgery Department of Drum Tower Hospital,medical school of Nanjing University,from June 2010 to June 2016,those data(include gender,age,tumor location,tumor size,macroscopic type,pathological type,Lauren classification,degree of differentiation,depth of invasion and location of metastasized lymph node)make a retrospective analysis include Univariate analysis(Chi-square test or T test)and multivariate analysis(Binary logistic regression analysis)to identify the risk factors of lymph node metastasis in early gastric cancer,then,we performed a sex-control analysis to clarify the effect of gender factor on lymph node metastasis.Results 426 cases of early gastric cancer patients enrolled in this study,male 292 cases,female 134 cases,male to female ratio was 2.18:1.There were 48(12.91%)patients with lymph node metastasis.Univariate analysis show:gender,age,tumor location,tumor size,Lauren type,depth of invasion have a significant difference.multivariate analysis show:gender(P=0.008,OR=2.328,95%CI:1.148-4.721),age(P=0.014,0R=1.923,95%CI:1.143-3.235),depth of invasion(P=0.000,OR=4.208,95%CI:2.043-8.668)were the risk factor of lymph node metastasis.sex-control analysis show:among all the patients with early gastric cancer,male account for 72.3%,female account for 27.7%,the rate of lymph node metastasis in male and female group were 8.90%and 21.64%respectively(P=0.000).Then,the patients were divided into three groups(premenopausal female,menopausal female and male groups).The proportion of premenopausal female,menopausal female and male groups were 40(9.39%),94(22.07%)and 292(68.54%)respectively,and the LNM rates were 11(27.50%),18(19.15%)and 26(8.90%)respectively,it show a significant difference.lymph node metastasis rate is relate to age,the mean age of male and female patients with lymph node metastasis were 59.65+8.09,and 53.48±12.50 respectively,the median ages of males and females with LNM were 62 and 54 years respectively,suggesting that LNM occurred in females 6.17±2.88 years earlier than in males.Frequency distribution analysis show there were two peaks of age in total early gastric cancer with lymph node metastasis,it was 50 and 60 in male but 45 and 55 in female.All the risk factors(gender,age,tumor size,pathological type and depth of invasion)had significant gender differences.Although the subgroups of risk factors including tumor location,macroscopic type and Lauren classification had no significant gender differences,the LNM rate of females was still higher than that of males.Conclusions The rate of LNM in EGC was 12.91%.Gender,age and depth of invasion were the risk factors for LNM.All the risk factors had significant gender differences,females had a higher rate of LNM than that of males.