Correlation Of Background Parenchymal Enhancement With Menstruation,Diagnostic Efficacy And Biomarkers Of Breast Cancer On Breast MRI

Objective: To evaluate the correlation of women menopausal status, menstrual cycle and the background parenchymal enhancement(BPE) of breast in different phases of dynamic magnetic resonance(MR) imaging. To investigate the effect of background parenchymal enhancement in the diagnostic efficacy of breast cancer and the correlation between background parenchymal enhancement with biomarkers of breast cancer.Materials and Methods: This retrospective study evaluated the dynamic contrast-enhanced breast MR images of 279 women from May 2013 to February 2014 who had completed a questionnaire survey about menstrual status(menopausal status and menstrual cycle), the information of MRI and the immunohistochemical results. The qualitative and quantitative BPE were analyzed. We qualitatively evaluated BPE of the whole breast and categorized enhancement as minimal, mild, moderate, or marked according to breast imaging reporting and data system(BI-RADS) established by American college of radiology(ACR) in 2013; and calculated the rate at which signal intensity increased((SIpost?SIpre)/ SIpre×100%) in regions of interest in from the different phases to the before contrast administration phase to assess BPE quantitatively. Pathologic diagnosis as the gold standard, through analyzing the morphologic type of breast cancer and the difference between the enhancement of breast cancer and ipsilateral BPE(SILesion-BPE), to compare the difference of SILesion-BPE between not only mass and non-mass lesions, but also invasive carcinoma of no special type and ductal carcinoma in situ. At last, to analyze the correlation of BPE and biomarkers. SPSS 19.0 software was used to make the following statistic analysis, Mann-Whitney U-test was used for comparing the difference of BPE between premenopausal and postmenopausal women. For the difference of the BPE between the menstrual cycle weeks in premenopausal women, Kruskal-Wzllis H-test was used. Mann-Whitney U-test was used for comparing the difference of SILesion-BPE between mass and non-mass lesions, and IDC-NOS and DCIS. At breast MRI BPE were analysed using Spearman's rank correlation coefficient.Results: Of all the 279 cases, including 189(68.9%) premenopausal women and 90(31.1%) postmenopausal women. 204 cases(73.1%) were malignant lesions. The 75 patients(26.9%) were confirmed benignant after surgery or clinical follow-up for more than 1 year to ensure benign case.In the different phases(Phase1, 2, 8), premenopausal women showed significantly higher BPE than the postmenopausal women(P<0.001). According 189 premenopausal women, the BPE was lowest in the 2nd week in menstrual cycle, but statistical analysis showed no significant difference in Phase1, 2, 8 of the 1st, 2nd, 3rd, and 4th week(P>0.05).Of all the 204 malignant cases, mass lesions are 156(76.5%) and non-mass lesions are 48(23.5%), including invasive ductal carcinoma, not otherwise specified,(IDC-NOS) in 169, ductal carcinoma in situ(DCIS) in 18. At early dynamic phase, mass group that the SILesion-BPE is significant higher than non-mass group(Phase1:P=0.001; Phase2:P=0.016). Whether early or late dynamic phase, the SILesion-BPE is significant different between IDC-NOS and DCIS group(Phase1:P=0.000; Phase2:P=0.000; Phase8:P=0.003). At late dynamic phase, the proportion of moderate and marked background enhancement in DCIS group is significant higher than IDC-NOS(72.2% vs. 21.9%).At early dynamic phase of DCE-MRI, breast BPE of triple-negative breast cancer(TNBC) group is significant higher than non-TNBC group in postmenopausal women. Breast BPE was positively correlated with HER2 expression in premenopausal women.Conclusion: Premenopausal women showed significantly higher BPE than the postmenopausal women. The BPE was lowest in the 2nd week in menstrual cycle, then it showed a rising trend in 3rd and 4th week that has consistent trend with different levels of hormone. Breast MRI should be performed appropriately in the 2nd week in menstrual cycle for premenopausal women. BPE influence obviously non-mass lesions in observation at early dynamic phase. DCIS cases have more moderate and marked background enhancement at late dynamic phase and may influence assessment of DCIS. At early dynamic phase, there is a certain correlation between BPE and HER2 expression. BPE in premenopausal women was more obvious, HER2 expression was higher. BPE of TNBC in postmenopausal women may be obvious. BPE may serve as additional predictors of breast cancer biomarkers.