Risk Factors Influencing Lymph Node Around The Root Of Inferior Mesenteric Artery With Rectal Cancer

Objectives: To investigate the risk factors of inferior mesenteric artery root lymph node metastasis and establish nomogram model to predict the probability of inferior mesenteric artery root lymph node metastasis in patients with rectal cancer.Methods: In this study,we retrospectively analyzed the clinical and pathological data of patients with rectal cancer treated in our hospital from January 2012 to December 2020,including sex,age,preoperative CEA,preoperative CA199,tumor size,gross type,degree of differentiation,depth of invasion,number of regional lymph node metastasis,peripheral nerve invasion,vascular invasion,MMR protein,Ki67 antigen expression,RAS gene and BRAF gene type.Taking the occurrence of lymph node metastasis in the root of inferior mesenteric artery as the observation end point,univariate analysis and multivariate logistic regression analysis were used to analyze the risk factors of lymph node metastasis in the root of inferior mesenteric artery.Based on the risk factors,the predictive model and its ROC curve and correction curve were drawn.Results: A total of 1059 patients were included in this study.Univariate analysis showed that the preoperative CEA(P=0.006),preoperative CA199(P<0.001),gross type(P=0.006),degree of differentiation(P=0.007),infiltration depth(P=0.031),peripheral nerve infiltration(P=0.012),vascular invasion(P=0.001),number of lymph node metastasis at N1 station(P<0.001),number of lymph node metastasis at N2 station(P<0.001)were associated with lymph node metastases around the root of the inferior mesenteric artery.Multivariate logistic regression analysis showed that preoperative CA199>27U/ml(OR=3.213,P=0.012),gross type(infiltrative OR=17.413,ulcerative OR=2.345,P=0.007),lymph node metastasis at N2 station(OR=2.543,P<0.001)were independent risk factors for lymph node metastasis around the root of inferior mesenteric artery.The AUC of the line chart prediction model is 0.804.Conclusions: Preoperative CA199>27U/ml,gross type of infiltrative / ulcerative type and the number of lymph node metastasis at N2 station are independent risk factors for lymph node metastasis at the root of inferior mesenteric artery.Based on the drawn line chart prediction model,the risk of lymph node metastasis at the root of inferior mesenteric artery in patients with rectal cancer was evaluated,and more active treatment was recommended for high risk patients.