Semi-quantitative MRI Findings Of Triple Negative Breast Cancer And Its Correlation With Ki-67 Labeling Index

Part Ⅰ.Semi-quantitative MRI findings of triple negative breast cancerObjective1.To investigate the findings of nuclear magnetic resonance imaging（MRI）in triple negative breast cancer（TNBC）and non-triple negative breast cancer（n TNBC）.2.To Semi-quantitative analysis the MRI signal values and hemodynamic characteristics.Materials and MethodsThis study retrospectively analyzed 108 cases of primary breast cancer confirmed by pathology in our hospital from January 2010 to December 2018.According to the molecular classification,the patients were divided into the TNBC group（33 cases）and the n TNBC group（75 cases）.All the patients received dynamic enhanced MRI（DCE-MRI）before treatment.Morphological features,signal values,and hemodynamic parameters of lesions were analyzed according to the ACR breast imaging report and data system（BI-RADS）.Morphological characteristics including:tumor size,margin,type of enhancement and internal enhancement mode;Tumor signal quantization values including:The signal intensity（SI）of the lesion and the chest wall muscle at the same slice were measured on the axial position T2-tirm-tra sequence imaging,and then the SIR value of the lesion was calculated.The apparent diffusion coefficient（ADC）of the lesion was measured on the axial DWI sequence imaging.Quantitative parameters of hemodynamics including time-intensity curve（TIC）,maximum of the enhancement ratio(E_max),and maximum of slope(Slope_max).The expression of estrogen receptor（ER）,progesterone receptor（PR）,human epidermal growth factor receptor 2（HER-2）in cancer cells were determined by immunohistochemical staining.Compared the differences of MRI parameters between TNBC group and n TNBC group.Results1.There were statistical differences in tumor size,margin,internal enhancement mode（P<0.01）.Compared with the n TNBC group,the TNBC group had larger tumor area,smooth margin,rim enhancement.2.Among all semi-quantitative parameters,only SIR and Slope_maxshowed statistical difference（P<0.01）.The SIR of TNBC group（5.5±0.3）was higher than that of n TNBC group（4.0±0.1）.Meanwhile,slope_maxin TNBC group（1.3±0.1）was significantly higher than that in n TNBC group（0.7±0.1）.Conclusion1.The highly invasive triple-negative breast cancer is easy to show relatively benign morphological features in MRI:smooth mass margin,rim enhancement.2.SIR and Slope_maxare helpful to identify TNBC and n TNBC.Part Ⅱ.Correlation between MRI findings of triple negative breast cancer and Ki-67 labeling indexObjectiveOur aim is to verify whether breast MRI could be considered as a useful tool to predict Ki-67 labeling index in TNBC at preoperational stage,thus resulting as a TNBC prognosis indicator.MethodsThis study retrospectively analyzed 108 cases of primary breast cancer confirmed by pathology in our hospital from January 2010 to December 2018.According to the molecular classification,the patients were divided into the TNBC group（33 cases）and the n TNBC group（75 cases）.All the patients received dynamic enhanced MRI（DCE-MRI）before treatment.Morphological features,signal values,and hemodynamic parameters of lesions were analyzed according to the ACR breast imaging report and data system（BI-RADS）.Morphological characteristics including:tumor size,margin,type of enhancement and internal enhancement mode;Tumor signal quantization values including:The signal intensity（SI）of the lesion and the chest wall muscle at the same slice were measured on the axial position T2-tirm-tra sequence,and then the SIR value of the lesion was calculated.The apparent diffusion coefficient（ADC）of the lesion was measured on the axial DWI sequence imaging.Quantitative parameters of hemodynamics including time-intensity curve（TIC）,maximum of the enhancement ratio(E_max),and maximum of slope(Slope_max).The expression of estrogen receptor（ER）,progesterone receptor（PR）,human epidermal growth factor receptor 2（HER-2）and Ki-67 labeling index in cancer cells were determined by immunohistochemical staining.Analyze the difference of the Ki-67labeling index between the TNBC group and the n TNBC group of DCE-MRI count parameters,and analyze the correlation between each parameters and the Ki-67labeling index.Results1.Compared with the n TNBC group,the Ki-67 labeling index is significantly different（p=0）.The Ki-67 labeling index（0.54±0.22）in the TNBC group was significantly higher than that in the n TNBC group（0.21±0.15）.2.There was no significant difference in Ki-67 labeling index among DCE-MRI count parameters in TNBC group（p>0.05）.3.The E_maxof the semi-quantitative parameters in the TNBC group was negatively correlated with the Ki-67 labeling index（r=-0.443,P=0.01）,and there was no correlation between other semi-quantitative parameters and the Ki-67 labeling index.ConclusionThe Ki-67 labeling index of triple-negative breast cancer is relatively high,and the early enhancement parameter E_maxof DCE-MRI can predict the expression of Ki-67labeling index of triple-negative breast cancer at preoperational stage.