The Predictive Value Of MRI Multi-parameter Combinates With Ki67 For Locally Advanced Breast Cancer On Pathological Response After Neoadjuvant Chemotherapy

Objective:To analyze the predictive value of MRI multiple-parameter combinates with Ki67 for locally advanced breast cancer on pathological response after neoadjuvant chemotherapy（NAC）.Methods:50 cases of locally advanced breast cancer confirmed by pathological puncture in our hospital from January 2013 to December 2018 were retrospectively collected.DCE-MRI and DWI examination was performed before NAC and 6 cycles later.According to Miller&Payne modified pathological grading,the patients were divided into the major histological response（MHR）group（n=19）and non-major histological response（NMHR）group（n=31）.The largest diameter（LD）,ADC value,the expression of Ki67,early enhancement rate（E）and maximum enhancement rate(E_max)was measured before and after NAC in two groups,the change rate of which was calculated.t test and non-parametric test was used to analyze whether there was statistical difference in parameters between the two groups before and after NAC.The ROC curves were drawn for the variables with statistical difference in the change percentange of each parameter between the MHR group and NMHR after NAC,with which to explore the diagnostic ability of its on pathological response.Binary Logistic regression was used to select the variables related to pathological response.The model was established to obtain joint predictive factor and evaluate the diagnostic ability on pathological response.The Hosmer-Lemeshow test was performed to test the goodness of model fitness.Results:1Before NAC,there was no statistically significant in tumor maximum diameter,ADC value,the expression of Ki67,the early enhancement rate and the maximum enhancement rate between the MHR group and NMHR（P>0.05）.2 After NAC,there was statistically significant between the two groups in the change percentage of maximum diameter change,ADC value,the early enhancement rate and the maximum enhancement rate（P<0.05）,while there was no statistically significant difference in the change percentage of the expression of Ki67 between the two groups（P>0.05）.3 The area under the ROC curve of the change percentage of maximum diameter,ADC value,the early enhancement rate and the maximum enhancement rate for pathological response was0.776,0.873,0.733 and 0.820.The AUC of the joint factor fitted by Logistic regression was 0.944,which was better than the diagnostic ability of a single parameter.The Hosmer-Lemeshow test results showed that the P value of the model was larger than0.10（0.137）.Conclusion:The change of morphological and functional MRI parameters have certain diagnostic value in predicting the pathological response after NAC in locally advanced breast cancer.The combined diagnostic ability of the two parameters is better than that of a single MRI parameter.The decrease of expression of Ki67 can indicate the decrease of residual tumor load after NAC,but it can not predict pathological response.