Analysis Of Extranodal Risk Factors For Lymph Node Metastasis In Rectal Carcinoma

Object:To evaluate the value of extranodal risk factors for lymph node metastasis in rectal carcinoma.Materials and Methods:108 patients with primary rectal cancer had been hospitalized in the radiology department of China-Japan Union Hospital of Jilin University from January 2016 to December 2017 were included in the study.All patients received electronic fibro-colonoscope examination before operation and were diagnosed as rectal carcinoma.All patients received surgery treatment in one week after MRI examination and the tumor specimen received postoperative pathological examination.Radical resection of rectal carcinoma was under the principle of total mesorectal excision.The collection data of imaging and pathology include the N stage,the location and size of the tumor,invasion depth of tumor,degree of differentiation,circumferential resection margin,intravascular tumor thrombus and nerve involvement.The data were statistically analyzed with spss22.0.Two variables Spearman rank coefficient method was used to analyze the factors that may influence the N staging of rectal cancer,and to explore the correlation between one by one factor and N stage.To further explore the factors that affecting the N staging of rectal cancer,on the basis of the independence of various factors(selecting the variables of P<0.05 in the analysis results),multiple logistic regression analysis was used to set the N staging(subdivided into N0,N1 a,N1b,N1 c,N2a,N2b)to be variable,and degree of differentiation,circumferential resection margin,intravascular tumor thrombus and nerve involvement were set as variables.Multiple logistic regression analysis was conducted to explore the relationship between these factors and N staging(subdivision)of rectal cancer.Using multiple logistic regression analysis to set the N staging(as N0,N1,N2)to be variable,and degree of differentiation,circumferential resection margin,intravascular tumor thrombus and nerve involvement were set as variables.Multiple Logistic regression analysis was conducted to explore the relationship between these factors and N staging(rough division)of rectal cancer.Using binary logistic regression analysis,N staging(N0,N1 a,N1b,N1 c were merged into N01,N2 a,N2b merged into N2)to be variable,and degree of differentiation,circumferential resection margin,intravascular tumor thrombus and nerve involvement were set as variables.Binary logistic regression analysis was conducted to explore the relationship between these factors and N staging(two value)of rectal cancer.Results:1.Both the location and size of the tumor are not related to N stage of rectal cancer,there are no statistic difference between them(P>0.05).There is a significant positive correlation between invasion depth of tumor and N stage of rectal cancer(sig=0.013<0.05,P=0.220);degree of differentiation is significantly negative correlated with N stage of rectal cancer(Sig=0.000<0.01,P=-0.396);circumferential resection margin is significantly positive correlated with N stage of rectal cancer(Sig=0.000<0.01,P=0.389);intravascular tumor thrombus is significantly positive correlated with N stage of rectal cancer(Sig=0.000<0.01,P=0.514),and nerve involvement is significantly positive correlated with N stage of rectal cancer(Sig=0.001<0.01,P=0.396).2.In multiple logistic regression analysis,the important factors that affect the N staging(subdivision)of rectal cancer are intravascular tumor thrombus and circumferential resection margin,but N1 a,N1b,N1 c and N2 a can not be well predicted by this regression model.After adjusting the model,we can see that in the multiple logistic regression analysis that affects the N staging(rough division)of rectal cancer,the important factors that affect the N staging of rectal cancer are still intravascular tumor thrombus and circumferential resection margin.In the binary logistic regression analysis model,the probability of N staging can be predicted by the intravascular tumor thrombus,nerve involvement and circumferential resection margin(judging as N0,N1 or N2 staging).Among them,intravascular tumor thrombus and ccircumferential resection margin are still important factors affecting N staging.Conclusions:1.Invasion depth of tumor,degree of differentiation,circumferential resection margin,intravascular tumor thrombus and nerve involvement are associated with lymph node metastasis of rectal carcinoma.2.Intravascular tumor thrombus and circumferential resection margin have significant influence an correlation in three different N-staging models.