Marked Background Parenchymal Enhancement Research Articles

Racial differences in background parenchymal enhancement, a novel marker of breast cancer.

10528 Background: Breast density is a risk factor for breast cancer that can guide eligibility for supplemental screening including MRI, but Black women are less likely to qualify for supplemental screening due to having less dense breasts on average despite higher rates of breast cancer mortality. Background parenchymal enhancement (BPE), the enhancement of fibroglandular breast tissue on contrast-enhanced MRI, is a novel biomarker that has been shown to be a superior breast cancer risk marker than breast density. Women with high BPE levels have up to a four-fold increased risk of breast cancer, even after adjusting for density, but no studies have examined BPE exclusively among Black women. Methods: We identified Black and white women ages 40-74 with no prior history of breast cancer who had a mammogram and subsequent MRI as part of a screening or diagnostic work-up from 2016-2022 at our institution. BPE was qualitatively defined according to BI-RADS (Breast Imaging Reporting and Data System), with four ordinal levels of increasing enhancement: minimal, mild, moderate, and marked. We conducted a cross-sectional study to perform a logistic regression with race as the exposure and moderate or marked BPE as the outcome, using minimal and mild BPE as the reference group, adjusted for age and BI-RADS density. Results: We included 1027 Black women and 4834 white women in our analysis. Fewer Black women had extremely dense breasts compared to white women (6% vs 13%, p= 0.04), however, there was a larger proportion of high BPE (moderate or marked) in Black women compared to white women (32% vs 28%, p = 0.03) (Table). There was an inverse association between age and BPE levels (p = 0.03), and a positive association between density and BPE levels regardless of race (p< 0.01) (not shown). Black women were 39% more likely to have high BPE levels (95% CI: 1.39 [1.19, 1.63]), adjusted for age and density. Conclusions: Black women have lower density but higher BPE than white women, suggesting that BPE may improve identification of breast cancer risk for Black women. Participants [Table: see text]

False-Positive and False-Negative Contrast-enhanced Mammograms: Pitfalls and Strategies to Improve Cancer Detection.

Contrast-enhanced mammography (CEM) is a relatively new breast imaging modality that uses intravenous contrast material to increase detection of breast cancer. CEM combines the structural information of conventional mammography with the functional information of tumor neovascularity. Initial studies have demonstrated that CEM and MRI perform with similar accuracies, with CEM having a slightly higher specificity (fewer false positives), although larger studies are needed. There are various reasons for false positives and false negatives at CEM. False positives at CEM can be caused by benign lesions with vascularity, including benign tumors, infection or inflammation, benign lesions in the skin, and imaging artifacts. False negatives at CEM can be attributed to incomplete or inadequate visualization of lesions, marked background parenchymal enhancement (BPE) obscuring cancer, lack of lesion contrast enhancement due to technical issues or less-vascular cancers, artifacts, and errors of lesion perception or characterization. When possible, real-time interpretation of CEM studies is ideal. If additional views are necessary, they may be obtained while contrast material is still in the breast parenchyma. Until recently, a limitation of CEM was the lack of CEM-guided biopsy capability. However, in 2020, the U.S. Food and Drug Administration cleared two devices to support CEM-guided biopsy using a stereotactic biopsy technique. The authors review various causes of false-positive and false-negative contrast-enhanced mammograms and discuss strategies to reduce these diagnostic errors to improve cancer detection while mitigating unnecessary additional imaging and procedures. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

A background parenchymal enhancement quantification framework of breast magnetic resonance imaging.

Background parenchymal enhancement (BPE) is defined as the enhanced proportion of normal fibroglandular tissue on enhanced magnetic resonance imaging. BPE shows promise as a quantitative imaging biomarker (QIB). However, the lack of consensus among radiologists in their semi-quantitative grading of BPE limits its clinical utility. The main objective of this study was to develop a BPE quantification model according to clinical expertise, with the BPE integral being used as a QIB to incorporate both the volume and intensity of the enhancement metrics. The model was applied to 2,786 cases to compare our quantitative results with radiologists' semi-quantitative BPE grading to evaluate the effectiveness of using the BPE integral as a QIB for analyzing BPE. Comparisons between multiple groups of nonnormally distributed BPE integrals were performed using the Kruskal-Wallis test. Our study found a considerable degree of concordance between our BPE quantitative integral and radiologists' semi-quantitative assessments. Specifically, our research results revealed significant variability in BPE integral attained through the BPE quantification framework among all semi-quantitative BPE grading groups labeled by experienced radiologists, including mild-moderate (P<0.001), mild-marked (P<0.001), and moderate-marked (P<0.001). Furthermore, there was an apparent correlation between BPE integral and BPE grades, with marked BPE displaying the highest BPE integral, followed by moderate BPE, with mild BPE exhibiting the lowest BPE integral value. The study developed and implemented a BPE quantification framework, which incorporated both the volume and intensity of enhancement and which could serve as a QIB for BPE.

The Role of Diffusion-Weighted Imaging Based on Maximum-Intensity Projection in Young Patients with Marked Background Parenchymal Enhancement on Contrast-Enhanced Breast MRI.

Diffusion-weighted imaging (DWI) utilizing maximum-intensity projection (MIP) was suggested as a cost-effective alternative tool without the risk of gadolinium-based contrast agents. The purpose of this study was to investigate whether DWI MIPs played a supportive role in young (≤60) patients with marked background parenchymal enhancement (BPE) on contrast-enhanced MRI (CE-MRI). The research included 1303 patients with varying degrees of BPE, and correlations between BPE on CE-MRI, the background diffusion signal (BDS) on DWI, and clinical parameters were analyzed. Lesion detection scores were compared between CE-MRI and DWI, with DWI showing higher scores. Among the 186 lesions in 181 patients with marked BPE on CE-MRI, the main lesion on MIPs of CE-MRI was partially or completely seen in 88.7% of cases, while it was not seen in 11.3% of cases. On the other hand, the main lesion on MIPs of DWI was seen in 91.4% of cases, with only 8.6% of cases showing no visibility. DWI achieved higher scores for lesion detection compared to CE-MRI. The presence of a marked BDS was significantly associated with a lower likelihood of a higher DWI score (p < 0.001), and non-mass lesions were associated with a decreased likelihood of a higher DWI score compared with mass lesions (p = 0.196). In conclusion, the inclusion of MIPs of DWI in the preoperative evaluation of breast cancer patients, particularly young women with marked BPE, proved highly beneficial in improving the overall diagnostic process.

Clinical and imaging modality factors impacting radiological interpretation of breast screening in young women with neurofibromatosis type 1.

Young women with Neurofibromatosis type 1 (NF1) have a high risk of developing breast cancer and poorer survival following breast cancer diagnosis. International guidelines recommend commencing breast screening between 30 and 35 years; however, the optimal screening modality is unestablished, and previous reports suggest that breast imaging may be complicated by the presence of intramammary and cutaneous neurofibromas (cNFs). The aim of this study was to explore potential barriers to implementation of breast screening for young women with NF1.Twenty-seven women (30-47 years) with NF1 completed breast screening with breast MRI, mammogram and breast ultrasound. Nineteen probably benign/suspicious lesions were detected across 14 women. Despite the presence of breast cNFs, initial biopsy rate for participants with NF1 (37%), were comparable to a BRCA pathogenic variant (PV) cohort (25%) (P = 0.311). No cancers or intramammary neurofibromas were identified. Most participants (89%) returned for second round screening.The presence of cNF did not affect clinician confidence in 3D mammogram interpretation, although increasing breast density, frequently seen in young women, impeded confidence for 2D and 3D mammogram. Moderate or marked background parenchymal enhancement on MRI was higher in the NF1 cohort (70.4%) than BRCA PV carriers (47.3%), which is an independent risk factor for breast cancer.Breast MRI was the preferred mode of screening over mammogram, as the majority (85%) with NF1 demonstrated breast density (BI-RADS 3C/4D), which hinders mammogram interpretation. For those with high breast density and high cNF breast coverage, 3D rather than 2D mammogram is preferred, if MRI is unavailable.

Qualitative assessments of density and background parenchymal enhancement on contrast-enhanced spectral mammography associated with breast cancer risk in high-risk women.

To investigate the correlation between the risk of breast cancer for high-risk females and the density and background parenchymal enhancement (BPE) on contrast-enhanced spectral mammography (CESM). Females at high-risk, without breast cancer history and received CESM from July 2016 to December 2017 were retrospectively enrolled. The longest follow-up time was 4.5 years, and patients who developed breast cancer with maximized follow-up time were classified as cancer cohort, while females who did not develop breast cancer were categorized as control cohort. These two cohorts were one-to-one matched in age, family and/or genetic history of breast cancer, menopausal status and BRCA status. The density and BPE at CESM imaging were assessed. Conditional logistic regression was applied to evaluate the relationship between imaging features and breast cancer risk. During the follow-up interval, 90 women at high-risk without history of breast cancer were newly diagnosed. Compared with minimal BPE, increasing BPE levels were associated with the risk of breast cancer among high-risk females in a time interval of 4.5 years (mild: odds ratio [OR]=3.2, p = 0.001; moderate: OR = 4.0, p = 0.002; marked: OR = 11.2, p < 0.001). In addition, females with mild, moderate or marked BPE were four times more likely to be diagnosed with breast cancer than females with minimal BPE in a time interval of 4.5 years (OR = 4.0, p < 0.001). Qualitative CESM BPE assessment may be useful in the prediction of breast cancer risk among high-risk females. • Qualitative CESM BPE assessment may be useful in the prediction of breast cancer risk among high-risk women during the follow-up period of 4.5 years. • The significance of breast density as an independent risk factor is not fully established for high-risk women during the follow-up period of 4.5 years.

Outcomes and imaging features of microinvasive carcinoma and ductal carcinoma in situ: Matched cohort study

IntroductionThe purpose of this study is to investigate the differences in clinical outcomes between microinvasive carcinoma (mIC) and ductal carcinoma in situ (DCIS) and compare the imaging features of both using mammography, US and MRI. Materials and methodsThis retrospective study was approved by our institutional review board. Between January 2011 and December 2013, 516 women with mIC or DCIS confirmed by surgery were included. Patients were matched with propensity score matching to compare recurrence-free survival (RFS). RFS was compared using a Cox proportional hazards model. Imaging features were also compared between the two groups. ResultsAmong 516 women, 219 mIC and 297 DCIS tumors were identified. After matching, 132 women were allocated to each group. The mean follow-up duration was 80.2 months. In the matched cohort, no statistically significant association was observed between the DCIS and mIC groups in terms of total recurrence (hazard ratio [HR]: 1.7; 95% confidence interval [CI]: 0.8–4.0; P = 0.19), local-regional recurrence (HR: 3.4; 95% CI: 0.9–12.3, P = 0.07), or contralateral recurrence (HR: 0.9; 95% CI: 0.3–2.8, P = 0.89). Non-mass lesions at US (P = 0.004), moderate or marked background parenchymal enhancement (P = 0.04), and higher peak enhancement (P = 0.02) at MRI were more commonly seen in the mIC group than in the DCIS group. ConclusionMicroinvasive carcinomas are distinct from DCIS in terms of imaging features, but no statistically significant association in recurrence survival.

Abstract B015: MRI features can identify DCIS patients who can be managed with endocrine therapy alone

Abstract Background: Ductal carcinoma in situ (DCIS) represents almost a quarter of newly diagnosed breast cancers in the US. It is currently treated like a stage 1 cancer, with surgical excision, radiation, and endocrine therapy (ET). Not all cases will progress to invasive cancer and thus we may be overtreating some lesions. Using a cohort of women who participated in an Active Surveillance (AS) with neoadjuvant ET and serial MR imaging, we aimed to identify features on MRI that could stratify DCIS lesions with low- and high-risk of progressing to invasive cancer. Materials/Methods: This was an IRB-approved retrospective study of women with DCIS who chose AS for treatment and were enrolled in MR imaging studies between 2002 and 2020. All women in this study had at least 2 breast MRI scans, which consisted of normal sequences with two post-contrast timepoints. Two radiologists, who were blinded to outcomes, analyzed MRI sequences for each patient at each timepoint for features that may be indicative of risk. Baseline imaging features collected were utilized in an RPART recursive partitioning algorithm that created a classification tree based on a DCIS lesions likelihood to progress to invasive cancer. Our final cohort consisted of 63 cases of DCIS (62 women, 1 with bilateral disease) with a mean age of 58.3 years (range of 29.8-78.8 years). All 62 patients (63 cases, 100%, 63/63) agreed to take hormone therapy for their DCIS. Results: The RPART algorithm showed two baseline features that were important in predicting risk: 1) the presence of a lesion that is distinct from the surrounding tissue and 2) background parenchymal enhancement (BPE). It separated our cohort into three sub-groups based on risk of progression: A (n=32) with the lowest-risk, B (n=17) with the second lowest-risk, and C (n=14) with the highest-risk. In A and B, 6 cases of DCIS progressed to invasive cancer (12.2%, 6/49). These groups had an enrichment of mild, moderate, and marked BPE. Group A (12.5%, 4/32 progressed to IDC) did not have any lesions that were distinct above BPE. All cases in B (11.8%, 2/17 progressed to IDC) had lesions that were distinct above BPE initially but reduced in response to endocrine therapy. In C, 10 cases of DCIS progressed to invasive cancer (71.4%, 10/14). In this group, the combination of minimal BPE and a distinct lesion above BPE was enriched (78.6%, 11/14). Conclusion: Our results suggest that imaging features, such as BPE, lesion distinctness and change in BPE and lesion provide information about risk for invasive cancer. MRI features provide insight as to whether risk is diffuse or focal, and which women can safely undergo AS with hormone treatment and avoid surgery, and which women are at higher-risk and have focal lesions better treated with surgical excision. We plan to validate the use of these features to triage patients in an upcoming prospective multisite trial to stratify DCIS patients for active surveillance vs. surgical resection. Citation Format: Cristian K. Maldonado Rodas, Heather Greenwood, Rita Freimanis, Alexander D. Borowsky, Gillian Hirst, Nola Hylton, Laura Esserman, Amrita Basu. MRI features can identify DCIS patients who can be managed with endocrine therapy alone [abstract]. In: Proceedings of the AACR Special Conference on Rethinking DCIS: An Opportunity for Prevention?; 2022 Sep 8-11; Philadelphia, PA. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_1): Abstract nr B015.

The value of imaging combined with clinicopathological features in the diagnosis of high-risk breast lesions.

BackgroundThe upgrade of high-risk breast lesions (HRLs) is closely related to subsequent treatment, but the current predictors for upgrade are limited to intratumoral features of single imaging mode.MethodsWe retrospectively reviewed 230 HRLs detected by mammography, ultrasound, and magnetic resonance imaging (MRI) before biopsy at the Fudan University Cancer Hospital from January 2017 to March 2018. The clinical features, imaging data according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon, and tumor upgrade situation were received. Based on the different risks of upgrade reported, the lesions were classified into high-risk I [HR-I, with atypical hyperplasia (AH)] and high-risk II (HR-II, without AH). We analyzed the association between clinicopathological and imaging factors and upgrade. We used the receiver operating characteristic (ROC) curve to compare the efficacy of three imaging modes for predicting upgrade.ResultsWe included 230 HRLs in 230 women in the study, and the overall upgrade rate was 20.4% (47/230). The upgrade rate was higher in HR-I compared to HR-II (38.5% vs. 4.1%, P<0.01). In patients with AH, estrogen receptor-positive (ER+) patients accounted for 81.0% (64/79). For all HRLs and HR-I, in clinical characteristics, age, maximum size of lesion, and menopausal status were significantly associated with upgrade (P<0.05). In imaging factors, MRI background parenchymal enhancement (BPE), signs of MRI and ultrasound were significantly correlated with upgrade (P<0.05). Patients with negative MRI or ultrasound manifestations had lower upgrade rates (P<0.01). For HR-II, only BPE showed a significant difference between groups (P=0.001). Multifactorial analysis of all HRLs showed that age and BPE were independent predictors of upgrade (P<0.01). The areas under the ROC cure (AUCs) for predicting upgrade in mammography, ultrasound, and MRI were 0.606, 0.590, and 0.913, respectively, indicating that MRI diagnosis was significantly better than mammography and ultrasound (P<0.001).ConclusionsHRLs with AH had a higher rate of upgrade and increased ER expression. Among three imaging modes, MRI was more effective than ultrasound and mammography in diagnosing the upgrade of HRLs. Older age and moderate to marked BPE can indicate malignant upgrade. MRI can provide a certain value for the diagnosis and follow-up of HRLs.

Ultrafast Dynamic Contrast-enhanced MRI of the Breast: How Is It Used?

Ultrafast dynamic contrast-enhanced (UF-DCE) MRI is a new approach to capture kinetic information in the very early post-contrast period with high temporal resolution while keeping reasonable spatial resolution. The detailed timing and shape of the upslope in the time–intensity curve are analyzed. New kinetic parameters obtained from UF-DCE MRI are useful in differentiating malignant from benign lesions and in evaluating prognostic markers of the breast cancers. Clinically, UF-DCE MRI contributes in identifying hypervascular lesions when the background parenchymal enhancement (BPE) is marked on conventional dynamic MRI. This review starts with the technical aspect of accelerated acquisition. Practical aspects of UF-DCE MRI include identification of target hypervascular lesions from marked BPE and diagnosis of malignant and benign lesions based on new kinetic parameters derived from UF-DCE MRI: maximum slope (MS), time to enhance (TTE), bolus arrival time (BAT), time interval between arterial and venous visualization (AVI), and empirical mathematical model (EMM). The parameters derived from UF-DCE MRI are compared in terms of their diagnostic performance and association with prognostic markers. Pitfalls of UF-DCE MRI in the clinical situation are also covered. Since UF-DCE MRI is an evolving technique, future prospects of UF-DCE MRI are discussed in detail by citing recent evidence. The topic covers prediction of treatment response, multiparametric approach using DWI-derived parameters, evaluation of tumor-related vessels, and application of artificial intelligence for UF-DCE MRI. Along with comprehensive literature review, illustrative clinical cases are used to understand the value of UF-DCE MRI.

Comparative Accuracy of Preoperative Tumor Size Assessment on Ultrasonography and Magnetic Resonance Imaging in Ductal Carcinoma In Situ

Purpose: The purpose of this study was to compare the accuracy of preoperative breast tumor size measured by ultrasonography (US) and magnetic resonance imaging (MRI) in patients with ductal carcinoma in situ (DCIS).Methods: Medical records of 74 patients postoperatively diagnosed with DCIS were retrospectively analyzed. Tumor size measurements obtained using the two imaging modalities were compared for accuracy with those obtained during the final pathologic examination. Patients with only microcalcification on imaging were excluded.Results: For all patients, Lin’s concordance correlation coefficient (CCC) of MRI was 0.725, which was more accurate than 0.670 of US. In subgroup analysis, CCC of US was 0.757, more accurate than 0.697 of MRI in premenopausal DCIS patients. Background parenchymal enhancement (BPE) was the only risk factor deteriorating the accuracy of US and MRI examinations. Moderate and marked BPE was associated with the inaccurate tumor size estimations in both US and MRI (odds ratio [OR]:2.23, 95% confidence interval [CI]=1.12−3.52, p=0.001 in US, OR:8.16, 95% CI=1.17−15.2, p=0.031 in MRI).Conclusion: MRI was more accurate for measuring tumor size in patients with DCIS. Moderate and marked BPE was a risk factor that prevented accurate measurement of preoperative tumor size. In premenopausal patients, US would help measure tumor size accurately.

Interval Cancers after Negative Supplemental Screening Breast MRI Results in Women with a Personal History of Breast Cancer.

Background There are few interval cancer studies of incident screening MRI for women with a personal history of breast cancer (PHBC). Purpose To evaluate the performance measures of screening breast MRI in women with a PHBC across multiple rounds and to identify subgroups who might be more at risk for interval cancer. Materials and Methods Between January 2008 and March 2019, consecutive screening breast MRI studies for women who had undergone breast-conserving surgery because of breast cancer were retrospectively identified. Inclusion criteria were negative or benign findings at mammography with US, availability of at least 1 year of follow-up data, and examinations having been performed within 12 months after the initial cancer surgery. Performance measures were calculated for each round. Multivariable logistic regression analysis was performed to determine factors associated with the risk of interval cancer. Results Among the 6603 MRI examinations for 2809 women (median age, 47 years; interquartile range, 42-53 years), the cancer detection rate was 8.3 per 1000 screening examinations (55 of 6603 examinations) and the interval cancer rate was 1.5 per 1000 screening examinations (10 of 6603 examinations). The sensitivity and specificity were 85% (55 of 65 examinations; 95% CI: 76, 93) and 88.3% (5775 of 6538 examinations; 95% CI: 87.6, 89.1), respectively. At multivariable analysis, interval cancers were associated with a first-degree family history of breast cancer (odds ratio [OR], 5.4; 95% CI: 1.3, 22.5; P = .02), estrogen receptor- and progesterone receptor-negative primary cancers (OR, 3.6; 95% CI: 1.1, 12.2; P = .04), and moderate or marked background parenchymal enhancement (OR, 10.8; 95% CI: 3.3, 35.7; P < .001). Conclusion Performance of screening breast MRI in women with a personal history of breast cancer was sustained across multiple rounds, and a first-degree family history of breast cancer, estrogen receptor- and progesterone receptor-negative primary cancers, and moderate or marked background parenchymal enhancement at MRI were independently associated with the risk of developing interval cancers. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Slanetz in this issue.

Metabolic changes in breast cancer on dual-time-point 18F-FDG PET/CT imaging according to primary tumor uptake and background parenchymal enhancement.

This study was aimed at investigating metabolic changes in breast cancer on dual-time-point 18F-FDG PET/CT imaging (DTPI) according to primary tumor uptake and determining whether this technique is affected by background parenchymal enhancement (BPE). A total of 189 patients with newly diagnosed breast cancer who underwent DTPI examination were retrospectively evaluated. DTPI was performed using a standard FDG/PET protocol followed by delayed image acquisition at 120min after injection. Patients were divided into two groups according to primary tumor uptake as breast cancer with low maximum standard uptake value (SUVmax) (< 2.5) and high SUVmax (≥ 2.5). The maximal SUV of the primary breast tumor (T-SUVmax), contralateral breast parenchyma uptake (B-SUVmax) according to different BPE grades, tumor to background ratio (T/B-SUVmax), and their percentage changes between early and delayed images (retention index, RI) were calculated. For primary tumor uptake, tumors with high SUV had a significant increase in mean T-SUVmax between early and delayed images (8.17 vs. 9.16, P < 0.001), and %RI T-SUVmax was 10.52%. Conversely, mean T-SUVmax did not change between early and delayed images for tumors with low SUV (1.96 vs. 1.94, P = 0.610), and %RI T-SUVmax was -1.41%. The mean %RI B-SUVmax was -12.43% for minimal BPE, -14.19% for mild BPE, -19.49% for moderate BPE, and -21.25% for marked BPE grade, indicating that higher BPE grades undergo better washouts on delayed imaging (β = -3.220, P < 0.001 for trend). The %RI T/B-SUVmax of both breast cancer groups with low SUV and high SUV was 18.86% and 32.47%, respectively. Breast cancer with low SUV undergoes no significant change in SUV on DTPI; however, washing of background parenchymal activity was evident over time, resulting in significantly increased tumor contrast in delayed images, which leads to increased sensitivity. Breast parenchymal washout was more significant with increased BPE level. Therefore, DTPI is expected to be more useful for evaluating breast lesions in regions with marked BPE on MRI.

Abstract PD9-01: Prospect trial MRI findings: High incidence of occult cancers in apparently low risk cases

Abstract Background and Aim The role of staging breast magnetic resonance imaging (MRI) of apparently localised breast cancer is controversial. Some recommend MRI in selected ‘high risk’ situations, while others suggest it has little or no role. Few studies demonstrate improved outcomes associated with MRI. ANZ 1002 : Post-operative Radiotherapy Omission in Selected Patients with Early breast Cancer Trial (PROSPECT) is a prospective single-arm study using preoperative MRI to identify a group of patients with early breast cancer in whom radiotherapy might be safely omitted. Inclusion criteria include nil/minimal or mild Background Parenchymal Enhancement (BPE), unifocal pT1N0 invasive cancer, not TNBC, no LVI. Since September 2011, 443 patients have undergone MRI and 201 have had radiotherapy omitted. Primary analysis of ipsilateral local recurrence is due in May 2021. Here we report imaging, subsequent biopsy findings for occult lesions and mastectomy rates. Methods All patients who underwent PROSPECT MRI in addition to mammogram (MMG) and ultrasound (US) were included. Imaging findings on MMG, US and MRI were documented. Breast Imaging-Reporting and Data System (BIRADS) 4 or higher lesions on MRI were subject to biopsy under US if possible, or MRI or surgical biopsy if not. Pathologic results of lesions identified by MRI were described and the extent of surgery was documented. Results: Over 8 years, 443 patients were identified; mean age 63 years (range: 50 to 84), median index tumour size 13mm (range: 2 to 111), grade 1 (188), grade 2 (212) or grade 3 (38). MRI showed nil/minimal or mild BPE in 336 patients and moderate or marked BPE in 107. A total of 189 occult BIRADS&amp;gt;3 lesions were identified in 140 (32%) patients; 135 (71%) were ipsilateral; 36 (19%) could be identified and biopsied with MRI-directed, US-guided biopsy, while 63 (33%) underwent MRI-guided biopsy, 82 (43%) surgical biopsy after MRI-guided hook needle localisation, 1 underwent a stereotactic biopsy and 7 were not biopsied due to proximity to the index lesion. A total of 51 occult malignant lesions were identified in 40 patients (9% of the total patient cohort). 36 were invasive cancer and 15 were DCIS. There were 17 invasive and 14 DCIS ipsilateral occult lesions in 26 patients (6% of total cohort) and 19 invasive and 1 DCIS contralateral lesions in 18 patients (4% of total cohort) An additional 16 lesions in 9 patients were malignant but considered part of the primary cancer. There were 3 ‘at risk’ lesions: 1 LCIS and 2 ADH. There were a total of 112 benign biopsies in 95 patients. 9 patients in the cohort (2%) underwent total mastectomy due to pathological extent of disease of the index cancer (4), multicentric cancer (3) or patient choice (2). A higher proportion of patients with moderate/marked BPE had occult lesions (29% vs. 39%, p=0.09) and occult malignant lesions (8% vs. 13%, p=0.09) compared to those with less BPE. Conclusion Breast MRI in selected, low risk patients over 50 years old with low risk apparently unifocal cancer identified an occult breast cancer in 9% of patients. Only 2% underwent total mastectomy. Primary analysis of PROSPECT in 2021 will help define the clinical utility of these findings. Background Parenchymal EnhancementNil/Mild (n=336)Mod/Marked (n=107)p-valueNo occult lesions237 (71%)66 (62%)0.09Occult lesions99 (29%)41 (38%)No occult malignant lesions310 (92%)93 (87%)0.09Occult malignant lesions26 (8%)14 (13%)Age &amp;lt;65192 (57%)65 (61%)0.51Age &amp;gt;65144 (43%)42 (39%) Citation Format: Allison Rose, Arlene Mou, John Collins, Anita Skandarajah, Janemary Hughes, Heath Badger, Helen Braggett, Nicholas Zdenkowski, Rebecca Asher, Andrew Spillane, Boon Chua, Gregory Bruce Mann. Prospect trial MRI findings: High incidence of occult cancers in apparently low risk cases [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD9-01.

The Utility of Short-Interval Follow-Up for Baseline High-Risk Screening Breast MRI.

Patients with a high lifetime risk of developing breast cancer undergo annual screening magnetic resonance imaging (MRI) starting at age 30. A proportion of these patients are subsequently required to undergo short-interval follow-up MRI 6 months after their baseline examination. The purpose of this study was to evaluate the utility and outcome of these short-interval follow-up examinations in this population. A retrospective review was performed of 523 patients who received their baseline high-risk breast screening MRI at our institution between 2013 and 2017. The proportion of patients who received a short-interval follow-up MRI at 6 months was recorded. The findings at baseline and follow-up MRI were recorded, as well as the outcomes and results of any interventions performed. Ninety-six (17.6%) patients (age range: 25-67, mean age: 41) received a short-interval follow-up MRI following their baseline screening examination. Indications for follow-up included moderate to marked background parenchymal enhancement, nonmass enhancement, and likely benign enhancing mass. Of the 92 patients, 5 (5.4%) went on to have a biopsy, with none revealing a malignant pathology. The remainder either returned to routine screening (91.3%) or received further imaging in the form of ultrasound or additional follow-up MRI (3.3%). Short-interval follow-up breast MRI in high-risk patients after a baseline screening study with likely benign findings is unlikely to yield clinically significant findings. This retrospective study can be considered a starting point for additional future work looking at the rate, indications, and yield of short-interval follow-up following baseline high-risk screening breast MRI studies.

Ultrafast Dynamic Contrast-Enhanced Breast MRI: Lesion Conspicuity and Size Assessment according to Background Parenchymal Enhancement.

ObjectiveTo evaluate the clinical utility of ultrafast dynamic contrast-enhanced (DCE)-MRI compared to conventional DCE-MRI by studying lesion conspicuity and size according to the level of background parenchymal enhancement (BPE).Materials and MethodsThis study included 360 women (median age, 54 years; range, 26–82 years) with 361 who had undergone breast MRI, including both ultrafast and conventional DCE-MRI before surgery, between January and December 2017. Conspicuity was evaluated using a five-point score. Size was measured as the single maximal diameter. The Wilcoxon signed-rank test was used to compare median conspicuity score. To identify factors associated with conspicuity, multivariable logistic regression was performed. Absolute agreement between size at MRI and histopathologic examination was assessed using the intraclass correlation coefficient (ICC).ResultsThe median conspicuity scores were 5 at both scans, but the interquartile ranges were significantly different (5-5 at ultrafast vs. 4-5 at conventional, p < 0.001). Premenopausal status (odds ratio [OR] = 2.2, p = 0.048), non-mass enhancement (OR = 4.1, p = 0.001), moderate to marked BPE (OR = 7.5, p < 0.001), and shorter time to enhancement (OR = 0.9, p = 0.043) were independently associated with better conspicuity at ultrafast scans. Tumor size agreement between MRI and histopathologic examination was similar for both scans (ICC = 0.66 for ultrafast vs. 0.63 for conventional).ConclusionUltrafast DCE-MRI could improve lesion conspicuity compared to conventional DCE-MRI, especially in women with premenopausal status, non-mass enhancement, moderate to marked BPE or short time to enhancement.

Effect of Background Parenchymal Enhancement on Cancer Risk Across Different High-Risk Patient Populations Undergoing Screening Breast MRI.

The purpose of this study is to evaluate the effect of background parenchymal enhancement (BPE) on breast cancer risk across different high-risk patient populations undergoing screening breast MRI. Consecutive screening breast MRI examinations performed between 2011 and 2014 were reviewed. Multivariate logistic regression using generalized estimating equations was used to assess the association of the following variables with cancer risk: age, qualitative BPE prospective clinical assessment (minimal or mild vs moderate or marked), mammographic breast density (dense vs not dense), and screening indication (prioritized in the following order: BRCA carrier or history of thoracic radiation, breast cancer personal history, high-risk lesion, and breast cancer family history). Cancer diagnosis was defined as a tissue diagnosis of invasive or in situ carcinoma within 12 months of the screening MRI. The study cohort included 4686 screening MRI examinations performed in 2446 women, grouped by BPE as minimal or mild (3975/4686; 85%) versus moderate or marked (711/4686; 15%) and by screening indication as BRCA carrier or history of thoracic radiation (548/4686; 12%), breast cancer personal history (2541/4686; 54%), high-risk lesion (362/4686; 8%), and breast cancer family history (1235/4686; 26%). After adjustment for confounding variables, only BPE and screening indication were independent predictors of cancer diagnosis (p = 0.02 and p < 0.01, respectively). The odds ratio for developing cancer in the moderate or marked BPE group compared with the minimal or mild group was 2.1 (95% CI, 1.1-4.0), after adjusting for age, breast density, and screening indication. Increased BPE level is an independent predictor of breast cancer in women undergoing screening MRI for different high-risk indications.

Prediction of Residual Malignancy After Excisional Biopsy for Breast Cancer With Suspicious Microcalcifications: Comparison of Mammography and Magnetic Resonance Imaging

BackgroundWhether surgery should be performed after excisional biopsy based on mammography or magnetic resonance imaging (MRI) findings has not been evaluated for breast cancer with suspicious microcalcifications on mammography. This study investigated the ability of mammography and MRI to predict residual malignancy after excisional biopsy for suspicious microcalcifications and whether background parenchymal enhancement (BPE) influences the diagnostic performance of MRI. Patients and MethodsFifty-one patients with breast cancer who underwent excisional biopsy for suspicious microcalcifications between January 2009 and February 2019 were enrolled in this single-center retrospective study. Two expert readers independently evaluated the ability of mammography and MRI to predict residual malignancy at the surgical site. The diagnostic value of mammography and MRI was evaluated using histopathology as the standard. ResultsThirty-two patients had residual malignancy. The average overall sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve for residual malignancy were 78.1%, 42.1%, 69.4%, 42.1%, 62.7%, and 0.601 for mammography and 81.2%, 57.8%, 76.4%, 57.8%, 73.5%, and 0.696 for MRI; the respective values for residual malignancy were 88.8%, 57.1%, 72.7%, 57.4%, 76.5%, and 0.73 in the low BPE group and 71.4%, 60%, 83.3%, 57.4%, 65.7%, and 0.657 in the high BPE group. ConclusionsMRI is more accurate than mammography for prediction of residual malignancy after excisional biopsy for breast cancer with suspicious microcalcifications. However, the BPE of MRI influences diagnostic performance, so careful assessment is needed in patients with moderate or marked BPE.

Population-Based Assessment of the Association Between Magnetic Resonance Imaging Background Parenchymal Enhancement and Future Primary Breast Cancer Risk.

To evaluate comparative associations of breast magnetic resonance imaging (MRI) background parenchymal enhancement (BPE) and mammographic breast density with subsequent breast cancer risk. We examined women undergoing breast MRI in the Breast Cancer Surveillance Consortium from 2005 to 2015 (with one exam in 2000) using qualitative BPE assessments of minimal, mild, moderate, or marked. Breast density was assessed on mammography performed within 5 years of MRI. Among women diagnosed with breast cancer, the first BPE assessment was included if it was more than 3 months before their first diagnosis. Breast cancer risk associated with BPE was estimated using Cox proportional hazards regression. Among 4,247 women, 176 developed breast cancer (invasive, n = 129; ductal carcinoma in situ,n = 47) over a median follow-up time of 2.8 years. More women with cancer had mild, moderate, or marked BPE than women without cancer (80% v 66%, respectively). Compared with minimal BPE, increasing BPE levels were associated with significantly increased cancer risk (mild: hazard ratio [HR], 1.80; 95% CI, 1.12 to 2.87; moderate: HR, 2.42; 95% CI, 1.51 to 3.86; and marked: HR, 3.41; 95% CI, 2.05 to 5.66). Compared with women with minimal BPE and almost entirely fatty or scattered fibroglandular breast density, women with mild, moderate, or marked BPE demonstrated elevated cancer risk if they had almost entirely fatty or scattered fibroglandular breast density (HR, 2.30; 95% CI, 1.19 to 4.46) or heterogeneous or extremely dense breasts (HR, 2.61; 95% CI, 1.44 to 4.72), with no significant interaction (P = .82). Combined mild, moderate, and marked BPE demonstrated significantly increased risk of invasive cancer (HR, 2.73; 95% CI, 1.66 to 4.49) but not ductal carcinoma in situ (HR, 1.48; 95% CI, 0.72 to 3.05). BPE is associated with future invasive breast cancer risk independent of breast density. BPE should be considered for risk prediction models for women undergoing breast MRI.

Background parenchymal enhancement in breast magnetic resonance imaging: A review of current evidences and future trends.

Background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) is a dynamic process, which varies among women and within the same woman over time due to different factors. BPE has profound implications for women with or at risk of breast cancer. Breast radiologist should be aware of factors that could potentially influence BPE and have to be familiar with its typical appearance. Marked BPE could indeed affect the diagnostic accuracy of breast MRI, but this shortcoming can be minimized through evaluation by dedicated radiologists, in order to correctly interpret and properly manage the additional findings. BPE shows promise as an imaging biomarker but many issues need to be addressed before it can be used either to determine screening strategy or the value of risk-reducing interventions. This review analyzes the clinical influence of BPE on breast MRI interpretation, breast cancer staging and surgical outcome and discusses current available evidences about BPE as an imaging biomarker.