The Correlation Between Apparent Diffusion Coefficient(ADC) Value And Pathological Ki67 Index In Breast Cancer Receiving Neoadjuvant Chemotherapy

Objective: The objective of this study was to analyze correlations between the breast MRI(magnetic resonance imaging)ADC values before NAC(neoadjuvant chemotherapy)under different b values and the Ki67 indexes of biopsy pathology and correlations between the breast MRI ADC values after NAC under different b values and the postoperative pathological Ki67 indexes in breast cancer patients,and to analyze correlations between breast MRI Δ ADC values under different b values and pathological Δ Ki67 indexes before and after NAC further.In subgroups with different clinical and pathological characteristics,the correlations between the breast MRI ADC values before NAC and the Ki67 indexes of biopsy pathology,the correlations between the breast MRI ADC values after NAC and the postoperative pathological Ki67 indexes and the correlations between the breast MRIΔADC values and the pathological ΔKi67 indexes were analyzed under different b values.The research evaluated the accuracy of the prediction about the Ki67 indexes of postoperative breast cancer after NAC by ADC values under different b values of 3.0T breast MRI,it is expected that noninvasive means can be used to predict the proliferation activity of breast cancer cells,so as to provide a reliable basis for the the selection of chemotherapy regimen and surgical time to some extent.Methods: In preliminary research,the preoperative and postoperative pathological Ki67 indexes of breast cancer patients(n=184)who did not receive NAC at The Breast Disease Diagnosis and Treatment Center of Zhongda Hospital Affiliated to Southeast University from January 1,2017 to September 30,2019 were collected,as well as the relevant clinicopathological data.The biopsy and operation Ki67 indexes of breast cancer patients receiving NAC(n=48)at The Breast Disease Diagnosis and Treatment Center of Zhongda Hospital Affiliated to Southeast University from January 1,2017 to September 30,2019 were collected,as well as related clinicopathological characteristics,and the 3.0T breast MRI ADC values under different b values were measured before and after NAC.SPSS 23.0(IBM SPSS Statistics 23)was used for statistical analysis.Wilcoxon Sign Rank Test was used to compare the difference between preoperative and postoperative pathological Ki67 indexes in breast cancer patients without NAC.If the double variates conformed to the normal distribution,Pearson correlation analysis was adopted;if not,Spearman correlation analysis was adopted.The breast MRI Δ ADC values under different b values before and after chemotherapy in p CR and non-p CR groups were compared with Independent-Samples T Test(if variables conformed normal distribution)or Mann-Whitney U test(if variables did not conform to the normal distribution).R software(×64 3.6.1)was employed to draw the forest plots.Results: 1.There was a significant difference in pathological Ki67 index between biopsy and postoperation specimens(Z=-2.299,P=0.022),and the Ki67 index of biopsy pathology was significantly lower than that of postoperation pathology.2.There were no correlations between the breast MRI ADC values before NAC under different b values and the Ki67 indexes of biopsy pathology(n=48,P>0.05).If b=800 s/mm2 and b=1000 s/mm2 in Lumianl B(HER-2 positive)carcinomas(n=7),there were highly positive correlations between the breast MRI ADC values before NAC and the Ki67 indexes of biopsy pathology with the correlation coefficients being 0.852(P=0.015)and 0.927(P=0.003)respectively.3.There were no correlations between the breast MRI ADC values after NAC under different b values and postoperative pathological Ki67 indexes(n=38,P>0.05).In the subgroup analysis,for Luminal B(HER-2 negative)type carcinomas completing established NAC regimens(n=10),there were moderate correlations between the breast MRI ADC values after NAC under different b values and postoperative pathological Ki67 indexes,and the correlation coefficients were-0.711(b=400s/mm2,P=0.020),-0.723(b=800s/mm2,P=0.018)and-0.723(b=1000s/mm2,P=0.018).4.The correlations between breast MRIΔADC values under different b values and pathological ΔKi67 indexes before and after NAC were not significant(P > 0.05).5.There were no significant differences in the breast MRI ΔADC values under different b values before and after NAC between the p CR and non-p CR groups.6.The correlation between pathological ΔKi67 index and Miller-Payne system was moderate(r=0.670,P < 0.001).Conclusions: 1.In Luminal B(HER-2 negative)type carcinomas completing established NAC regimens,the breast MRI ADC value after NAC could be used to predict postoperative pathological Ki67 index partially,and the low ADC value of breast MRI after NAC was corresponding to the high postoperative pathological Ki67 index.2.There was no correlation between the breast MRI ADC value before NAC under different b values and the Ki67 index of biopsy pathology.3.It was not significant for the correlation between breast MRIΔADC value under different b value and pathological ΔKi67 index before and after NAC.