3.0T Magnetic Resonance Imaging Application Of Triple-negative Breast Cancer

Objective:To invstigate the MRI manifestations of triple-negative breast cancer(TNBC)on dynamic contrast-enhanced MRI and DWI and to increase the understanding of the TNBC and to provide the basis for clinical preoperative evaluation.Materials and Methods:281 patients(all females, mean age 51.7y) with breast cancer who underwent 3T MRI scan from Augest,2012 to Augest,2014 were included of which three negative breast cancer as the study group, Luminal breast cancer and HER-2 + breast cancer as a control group.All the patients were without any puncture, operation, neoadjuvant chemotherapy and endocrine therapy before examination.And all the patients underwent dynamic enhanced MRI scanning(DCE-MRI) and diffusion weighted imaging scan in order to obtain the feature of morphology(Tumor size, tumor type, tumor shapes, mass margin,enhancement pattern), hemodynamic parameters(time signal curve, early enhancement rate,outflow rate) and ADC value.The above indexes were assessed by two deputy director of professional image doctors in a double blind method respectively and the inconsistent results need to discuss and reach to a agreement.281 patients underwent pathologically and Immunohistochemical examination to obtain tumor pathological type, lymph node metastasis, histological grade and estrogen receptor/progesterone receptor and the expression of Her-2.Comparing the MRI findings and the performance of clinical pathology of these two subtypes and TNBC. Statistical comparisons were performed using SPSS software version21.0.The ANOVA was used to the measurement data, the Chi-square test(X2) was used to count data, LSD of Variance analysis was used to comparison of the two index of the measurement data. The ANOVA was used to breast cancer age, tumor size, early enhancement rate, rate of flowand ADC value. Comparsion of MRI imaging features and pathological characteristics among the three groups of breast cancer was used Chi-square test(X2) analysis and there was no statistical significance. Fisher’s exact probability was used to comparison of TIC curve and strengthening type. Logistic regression was used to determine the three-negative breast cancer diagnostic factor analysis, using Multiple linear regression analysis of factors affecting the ADC value of TNBC.The signifi cance level for these statistical analyses was defined as P<0.05.Results:The study included 281 cases of invasive breast cancer, the 62 cases(22.1%) is TNBC, 149 cases(53%) is Luminal type and 70 cases is HER-2+ type.Compared to theLuminal and HER-2+,the TNBC was larger(P=0.001),shape(irregular,P=0.002), margin(smooth,P=0.001),T2WI(hyperintensity,P<0.001),enhancement(rim,P=0.005). On DWI, the mean ADC value of TNBC(0.93±0.21×10-3mm2/s) is higher than Luminal and HER-2+(0.87±0.29×10-3mm2/s, 0.90±0.19×10-3mm2/s,respectively;P=0.061).Logistic regression analysis showed the tumor size(P=0.044), enhancement pattern(rim enhancement, P=0.033)and grading of tissue(grade III, P =0.000) is diagnosis factors of TNBC(P < 0.05). Multiple linear regression analysis showed that the T2 WI signal intensity of TNBC(high signal)and histological grading(Class III) was the influence factors of ADC value, indicating that T2 WI signal intensity, tumor histological grade were significantly correlated with ADC value(P<0.05).Age and axillary lymph node of three groups has no statistically significance(P=0.862、P=0.873).Tissue grade between the three groups of breast cancer grading was significantly different(P < 0.001).The proportion of TNBC III(39/62 cases, 62.9%) was significantly higher than that of Luminaltype(5/149 cases, 3.4%) and type HER-2+(13/70 cases, 18.6%).Grade difference between TNBC and Luminal type has statistical significance(P <0.001),but has not statistically significant with HER-2+ type(P=0.196).Conclusion:MRI Characteristics of the three negative breast cancer showed larger tumors size, irregular, smooth margins and high signal on T2 WI and rim enhancement. DCE-MRI rim enhancement has high diagnostic value on the three negative breast cancer.High signal on T2 WI was correlated with ADC value of negative breast cancer and to predict the risk of cancer.