Investigation On Correlation Between MRI Features Of Breast Cancers And Molecular Classification,and Correlation Between IVIM Parameters And Immunohistochemical Index

PART ONECORRELATION BETWEEN MRI FEATURES OF BREASTCANCERS AND MOLECULAR CLASSIFICATIONObjective:The aim of this study is to determine whether Magnetic Resonance Imaging(MRI)features of breast cancer are associated with its molecular subtypes,histologic grades,and lymph node involvement.Materials and Methods:We analyzed Data obtained from 142 patients with invasive breast cancer treated at our institution between January 2015 and December 2015,2 patients had bilateral breast cancers.All those patients had preoperative breast MRI,a total of 144 tumors were classified into five molecular subtypes based on the expression of ER,PR,HER-land Ki-67.All the patients were reviewed for MRI features,molecular subtypes,histologic grades and lymph node involvement.The differences among molecular subtypes were examined with χ2 test and Fisher exact probability test by SPSS 19.0.Results:The distribution of subtypes was luminal A,33(22.%);luminal B(HER-2-),55(38.2%);luminal B(HER-2+),19(13.2%);HER-2,14(9.7%)and Basal-like,23(16.0%).Significant differences in multicentric/multifocal disease,shape and margin of masses,enhancement pattern,histologic grades and lymph node involvement were observed among subtypes(P<0.05).(1)For the Luminal group(inclube Luminal A and Luminal B),96 of 107 cancers(89.7%)appeared as masses,irregular shape was seen in the majority of the masses(79.2%)and spiculated/irregular(94.8%)margin were most common.(2)When compared with other subtypes,non-mass/mixed enhancement lesions and multifocality were most common in HER2-positive tumors,which were found in 35.7%of the 14 leisions and 55.6%of the 9 masses respectively.Lymph node involvement was significantly more commonly observed in HER-2(57.1%,8 of 14)and luminal B(44.6%,33 of 74)subtypes.(3)Triple-negative tumors were more often high-grade tumors(87.0%,20 of 23).At MRI,mass enhancement occurred in 87.0%of the triple-negative cancers,round/oval and irregular shape were equally identical in frequency in triple-negative subtype,smooth margin was more common(40%).At dynamic evaluation,triple-negative tumors display rim enhancement most characteristically(40%),high signal intensity was often seen in the mass on STIR(40%),reflecting tumoral necrosis in these high-grade tumors.Conclusion:MRI features are associated with molecular subtype to some extent,preoperative breast MRI is significantly more likely to help guide treatment and estimate the prognosis.PART TWOCORRELATION BETWEEN IVIM PARAMETERS OF BREAST CANCER AND IMMUNOHISTOCHEMICAL INDEXObjective:The aim of this study was to correlate apparent diffusion coefficient(ADC)and intravoxel incoherent motion(IVIM)parameters(D,D*,f)of breast cancer with immunohistochemical index(ER,PR,HER-2 and Ki-67)expression State.Materials and Methods:Patients who were diagnosed with breast cancer and underwent breast MRI with Intravoxel Incoherent Motion Diffusion-Weighted Imaging preoperatively between November 2015 and February 2016 in our institution were included in this study.All MR imaging examinations were performed on a 3.0 T MRI scanner(Philips,Ingenia).The ADC value were calculated from the DW images at all b-values,assuming monoexponential signal shape,IVIM parameters(D,D*,f)value were obtained using multi-b-value DWI with a biexponential curve fitting.All three measurements were averaged.Those measurements were proceeded by two radiologists specializing in breast imaging.T test were used to explore the correlation between ADC or IVIM parameters(D,D*,f)of breast cancer and immunohistochemical index(ER,PR,HER-2,and Ki-67)expression State performed by SPSS 19.0.A P value of less than 0.05 was considered indicative of a significant difference.Results:Finally,55 breast cancer lesions with positive pathologic results in 51 patients(2 patients with bilateral breast cancer and 2 patients with multiple malignant lesions in the ipsilateral breast)were included in our study.Patients ranged in age from 29 to 85 years,with a mean age of 55 years.Of the 55 lesions,the amount of estrogen receptor,progesterone receptor,HER-2 positive and Ki-67 high-expression lesions were 45,40,14 and 36 respectively.(1)No statistically significant correlations were observed between mean ADC value and estrogen receptor,progesterone receptor,HER-2 positive and negative groups,as well as Ki-67 high and low expression groups(P>0.05).(2)There were no significant differences among IVIM parameters(D,D*,f)in estrogen receptor,progesterone receptor,HER-2 positive and negative groups(P>0.05).(3)We used a cutoff value of 14%to divide Ki-67 into low-expression and high-expression groups,mean D value in the Ki-67 high-expression groups were significantly lower than those in the Ki-67 low-expression groups(0.80±0.16 vs 0.88±0.14;P=0.046),while no significant differences in D*and f value between Ki-67 high and low expression groups were showedConclusion:IVIM-DWI separation of perfusion and diffusion,using multi-b-value DWI with a biexponential curve fitting.Such analysis from IVIM can result in perfusion-related incoherent microcirculation(D*)and microvascular volume fraction(f),along with pure diffusion coefficient(D).IVIM parameter was relative to Ki-67 expression in breast carcinoma,this may indicate the potential to provide a surrogate measure of Ki-67 expression through noninvasive imaging tools.