Analysis Of Related Clinical Biological Indicators For Predicting Pathological Complete Response After Neoadjuvant Chemotherapy In Breast Cancer

Objective:Neoadjuvant chemotherapy can reduce tumor burden or even make tumor disappear,and achieve pathological complete response（PCR）.But not all tumors shrink after chemotherapy,and their efficacy may be stable or increase,thus delaying treatment.Objective of this study:To analyze the clinicopathological characteristics of breast cancer patients before treatment and the relationship between the efficacy of NAC2 after 2 cycles（NAC₂ for short）and PCR,so as to provide the basis for correctly judging the efficacy of neoadjuvant as soon as possible and guiding the clinical treatment.Methods:Patients admitted to the Fourth Hospital of Hebei Medical University from July 2018 to September 2020 who were diagnosed with invasive breast cancer and had received at least 4 cycles of NAC,and had received imaging evaluation（including breast MRI,breast ultrasound and mammography）before and after 2 cycles of NAC,respectively。Clinical features,pathological features,and imaging evaluation before and after 2 cycles of NAC were retrospectively analyzed.SPSS software was used for statistical analysis,andχ2test was used for univariate analysis of the correlation between each influencing factor and PCR.Mann-Whitney U rank-sum test was used to compare the changes of the lesion maximum diameter and apparent diffusion coefficient（ADC）before and after NAC 2 cycles.Based on the analysis of Receiver operator characteristic curve（ROC curve）,the Area under curve（AUC）was calculated to obtain and compare the diagnostic value of various indicators.The maximum Youden index（sensitivity+specificity-1）was used to determine the optimal critical value;Multivariate analysis was performed using binary logistic regression.Results:Of the 258 patients,61 patients achieved pCR,with a pCR rate of 25.8%.1.Compared with the non-pCR group,there were statistically significant differences in the maximum diameter of the lesions before NAC,the maximum diameter of the lesions after the NAC 2 cycle and the reduction rate of the maximum diameter of the lesions after the NAC 2 cycle in breast ultrasound and MRI evaluation,and statistically significant differences in the ADC value and the change rate of the ADC value after the NAC 2 cycle（P<0.05）.ROC curve was drawn based on the above indicators.The higher diagnostic value was the rate of reduction of the maximum diameter of lesions（AUC=0.913）and the rate of change of ADC value（AUC=0.917）of breast MRI.Based on the maximum Youden index,the optimal cut-off value of the maximum diameter reduction rate of breast MRI lesions was 38.56%,the sensitivity was 88.5%,and the specificity was 88.8%;the optimal cut-off value of the ADC value change rate was 24.53%,the sensitivity was 93.4%,and the specificity was 81.7%.2.Univariate analysis showed that molecular typing,c T stage,pre-NAC ER,PR,HER-2,Ki-67 expression status were the influencing factors of pCR（P<0.05）.3.Multivariate analysis showed that the pre-NAC HER-expression status,the maximum diameter reduction rate of lesions after NAC 2 cycle and the change rate of ADC value after NAC 2 cycle were independent predictors of pCR（P<0.05）.Conclusions:1.Breast MRI was better than breast ultrasound in predicting the accuracy of pCR after NAC 2 cycles;2.The maximal diameter decrease rate of lesions and ADC value change rate of breast MRI after NAC 2 cycles had higher predictive value for pCR,with the optimal cut-off values of 38.56%and 24.53%,respectively.3.The expression status of HER-2,the reduction rate of the maximum diameter of lesions and the change rate of ADC value of breast MRI after NAC 2 cycle were independent predictors of pCR.