Analysis The Risk Factors Of No.253 Lymph Nodes Metastasis In Rectal Cancer And Establishment Of Preoperative Prediction Model

Objective: At present,there is still controversy regarding the risk of No.253 lymph node metastasis in rectal cancer patients and whether routine dissection is required.This study summarized the relevant data of rectal cancer patients who accepted NO.253 lymph node dissection in our hospital,and analyzed the risk factors of NO.253 lymph node metastasis for rectal cancer patients.Establish the preoperative evaluation model,explore the effect of preserving the left colon artery on the quality of NO.253 lymph nodes dissection,provide a basis for the development of individualized,accurate and rational surgical plans for patients who with rectal cancer,and minimize the risks and complications of surgery.Methods: Collected clinical and pathological data of 163 patients who underwent rectal cancer surgery in our department from August 2018 to December 2020,all patients were underwent D3 radical resection of rectal cancer and preserved the left colon artery(LCA)as much as possible,marked No.253 lymph nodes area during the operation,and separated the lymph nodes in this area for examination after the operation.Analysis the risk factors of No.253 lymph nodes metastasis in rectal cancer include: gender,age,body mass index(BMI),distance from the lower end of the tumor to the anus,whether there is liver metastasis before surgery,serum carcinoembryonic antigen(CEA)value,Tumor location(upper and lower peritoneum),inferior mesenteric artery(IMA)type,tumor occupies the circumference of the bowel,tumor long diameter,gross morphology of tumor,histological types,differentiation degree,depth of invasion,perineural invasion,vascular tumor thrombus,lymph node status,microsatellite status,expression of p53 and Ki-67.Data processing uses SPSS 20.0 software to classify data,Fisher exact probability method is used to test count data;normality test is performed on measurement data,and continuous numerical variables that meet the normal distribution are expressed as ? x ±s,independent samples t test is used for comparison between two groups,Mann-Whitney U test is used for comparison of two groups of numerical variables with non-normal distribution,data information is expressed by M(Q1,Q3);Mann Whitney U test was used to compare the two groups,incorporate meaningful single factors into binary logistic regression analysis of independent risk factors;Using R software package to draw Nomogram diagram,draw the prediction model receiver operator characteristic(ROC)curve,calculate the area under the receiver operating characteristics curve(AUC),95% CI,sensitivity,specificity.P<0.05 means the difference is statistically significant.Results: Included in this study,9 of the 163 patients had NO.253 lymph nodes metastasis,and the metastasis rate was 5.52%.2658 lymph nodes were detected after surgery in total,the average number of lymph nodes was 16.31,334 lymph nodes were detected in No.253 lymph nodes area,the average number of lymph nodes detected in each patient was 2.04(1-6),there were 21 lymph nodes with metastasis,and the metastasis rate was 6.29%.The total number of lymph nodes dissections in the 61 patients who unreserved LCA group(including one without LCA)was 1001,with a median of 16 pieces/case,and the number of NO.253 lymph nodes dissections was 129,with a median of2 pieces/case(1 to 5 pieces/case);The total number of lymph nodes dissections in the 102 patients who keep the LCA group was 1657,with a median of 15pieces/case,and the number of NO.253 lymph nodes dissections was 205,with a median of 2 pieces/case(1 to 6 pieces/case),There was no significant difference in the total number of lymph nodes between the two groups and the number of NO.253 lymph nodes(P>0.05).Univariate analysis showed that:preoperative liver metastasis(P<0.001),CEA value(P<0.001),tumor location(upper peritoneum)(P=0.035),tumor differentiation(P=0.013),postoperative T staging(P=0.025),postoperative N staging(P=0.039),vascular tumor thrombus(P=0.005)are risk factors of No.253 lymph nodes metastasis in rectal cancer;Multivariate analysis showed that: tumor location(upper peritoneum)(P=0.020,OR=4.724,95%CI 1.754-7.515),preoperative liver metastasis(P=0.018,OR=5.928,95%CI 1.735-7.015),vascular tumor thrombus(P=0.047,OR=6.66,95%CI 1.043-11.141),CEA value(P=0.018,OR=2.421,95%CI 1.160-5.051)are independent risk factors of No.253 lymph nodes metastasis.Take the tumor location,preoperative liver metastasis,and CEA value,draw Nomogram through R software,draw the ROC curve of the prediction model,calculate the area under the curve AUC=0.935(95%CI0.854-1.00),sensitivity It was 77.8%,and the specificity was 99.35%.Conclusion: 1.Univariate analysis suggests that preoperative liver metastasis,CEA value,tumor differentiation,tumor location(upper peritoneum),vascular tumor thrombus,pathological T stage,and pathological N stage are risk factors of No.253 lymph nodes metastasis in rectal cancer.2.Multivariate analysis indicated that preoperative liver metastasis,tumor location(upper peritoneum),CEA value,and vascular tumor thrombus were independent risk factors of No.253 lymph nodes metastasis.3.Preserving the left colon artery will not affect the quality of NO.253 lymph nodes dissection.4.In this study,a preoperative assessment model was established based on the factors of liver metastasis,tumor location,and CEA values.The sensitivity was77.8% and the specificity was 99.35%.However,since this study is a single-center,small-sample study,the results need to be carefully considered.