The Value Of Preoperative DCE-MRI Features Of Primary Lesion For Predicting Axillary Lymph Node Metastasis In Breast Cancer

Objective:To investigate the value of preoperative DCE-MRI features of breast cancer primary lesion in predicting axillary lymph node metastasis.Methods:Retrospective analysis of 231 cases of breast cancer who were operated radical mastectomy from June 2014 to June 2017,According to the postoperative pathological status of lymph nodes,there were 91 cases in the lymph node metastasis group and 140 cases in the non-lymph node metastasis group.The lymph node metastasis group was divided into N1,N2,and N3 stages according to the number of lymph node metastasis and TNM stage,which were 61 cases,20 cases,and 10 cases,respectively.The clinicopathological features of the two groups were collected including menopausal status,pathological type,mass size,pathological grade and immunohistochemistry.All patients underwent GE’s 1.5T EXCITE HD MR scanning to observe MRI morphological features including long diameter of lesion,enhanced statement,internal enhancement mode,lymph node short diameter,and time-signal intensity curve;dynamic parameters of lesions were measured by Omni-Kinetics software including volume transfer constant(K^trans),rate constant(K_ep),plasma volume fraction（V_p）,time to peak（TTP）,Max Concentration（Max Conc）,area under the time signal curve（AUC）and time signal curve maximum slope（Max Slope）.The clinicopathological features and DCE-MRI features of the axillary lymph node metastasis group and the non-lymph node metastasis group were compared.The chi-square test/Fisher exact probability method was used for the count data,and the rank sum test was used for the quantitative data.ROC curves were used to evaluate the efficacy of predicting axillary lymph node metastasis,and logistic regression was used to calculate the efficacy of combination of each characteristics of lesions in prediction of axillary lymph node metastasis.Results:1.Clinicopathological features of axillary lymph node metastasis group and non-lymph node metastasis groupTumor size,pathological grade,HER-2 status and Ki-67 proliferation index were statistically different between the axillary lymph node metastasis group and the non-lymph node metastasis group（P<0.05）.The larger the mass,the higher the pathological grade,the more easily Lymph nodes metastasized.The HER-2 positive（32.97%,30/91）and Ki-67≥14%（87.91%,80/91）were higher in the lymph node metastasis group than those in non-lymph node metastasis group（20.71%,29/140,77.14%,108/140）.2.DCE-MRI features of axillary lymph node metastasis group and non-lymph node metastasis groupThe long diameter of the primary tumor and the short diameter of the lymph nodes were statistically different between the axillary lymph node metastasis group and the non-lymph node metastasis group（P<0.05）.Compared with non-lymph node metastasis group（38.57%,54/140）,long diameter of the primary lesion>2 cm（72.53%,66/91）in the lymph node metastasis group were higher.It suggested that the long diameter of the primary lesion was>2 cm,the more easily Lymph nodes metastasized.The shorter diameter of lymph node<10mm（97.14%,136/140）of the non-lymph node metastasis group was higher than that of the lymph node metastasis group.The smaller the shorter diameter of the lymph node,the lower the lymph node metastasis rate.The remaining features（type of lesion enhancement,enhancement mode and TIC curve type）were not statistically different between the two groups（P<0.05）.AUC value,Max Conc value,TTP value,Max Slope value,K^transrans value,and K_epp value of primary lesion had statistical differences in axillary lymph node metastasis group and non-lymph node metastasis group（P<0.05）.In the axillary lymph node metastasis group,the interquartile range of AUC value,Max Conc value,TTP value,Max Slope value,K^transrans value and K_epp value were0.19（0.09-0.34）,0.07（0.03-0.12）,4.25（4.12-4.25）,0.07（0.04-0.14）,0.46（0.26-0.92）and 0.25（0.13-0.41）,respectively.That were higher than interquartile range of the axillary lymph node metastasis group0.11（0.05-0.21）,0.04（0.02-0.07）,4.13（4.12-4.25）,0.05（0.03 0.09）,0.28（0.13-0.51）and 0.08（0.01-0.21）.However,there was no significant difference in V_p value between the axillary lymph node metastasis group and the non-lymph node metastasis group,the interquartile range of two groups were 2.42（1.48-4.35）and 2.16（1.53-3.08）,respectively（P>0.05）.3.DCE-MRI characteristics of axillary lymph node metastasis in different stagesThere were no statistically significant differences in the long diameter of the primary lesion,types of lesion enhancement,ways of enhancement,TIC curves type and dynamic parameters in lymph node metastasis stages（P>0.05）.4.ROC curve analysis of DCE-MRI in predicting axillary lymph node metastasisROC curve was drawn to predict axillary lymph node metastasis.The area under the curve that long diameter predicted metastasis of axillary lymph node was 0.670（95%CI,0.608-0.731）.The area under the curve that short diameter of lymph node predicted axillary lymph node metastasis was 0.645（95%CI,0.595-0.695）.The area under the curve predicted by K^trans,K_ep,AUC,Max Conc,TTP and Max Slope for axillary lymph node metastasis was 0.669（95%CI,0.598-0.739）,0.737（95%CI,0.672-0.801）,0.658（95%CI,0.585-0.730）,0.666（95%CI,0.594-0.739）,0.586（95%CI,0.515-0.658）,and 0.661（95%CI,0.595-0.658）,respectively;The area under the curve that combination of dynamic parameters predicted axillary lymph node metastasis was 0.744（95%CI,0.681-0.807）,and the sensitivity and specificity were 72.53%、and 65.00%,respectively.The area under the curve that the long diameter of the lesion and the short diameter of the lymph node combined with the dynamic parameters predicted the axillary lymph node metastasis was0.770（95%CI,0.709-0.831）.which was higher than that of single variable prediction and the joint prediction of dynamic parameters.The specificity was 74.29%and the sensitivity was 65.93%.Conclusion:1.The long diameter of the primary lesion,the short diameter of the lymph node and the dynamic parameters of DCE-MRI can predict axillary lymph node metastasis.2.DCE-MRI features could not predict the staging of axillary lymph node metastasis.3.The efficacy of DCE-MRI dynamic parameters combined with long diameter of primary lesion and short diameter of lymph node in predicting axillary lymph node metastasis was higher than that of short diameter of lymph node,long diameter of primary lesion and combination of dynamic parameters.4.Comprehensive analysis of DCE-MRI features of the primary lesion is of great significance for the prediction of preoperative breast cancer lymph node metastasis,as well as for guiding the selection and design of clinical treatment programs.