Simultaneous isolation of hormone receptor-positive breast cancer organoids and fibroblasts reveals stroma-mediated resistance mechanisms.

Recurrent hormone receptor-positive (HR+) breast cancer kills more than 600,000 women annually. Although HR+ breast cancers typically respond well to therapies, approximately 30% of patients relapse. At this stage, the tumors are usually metastatic and incurable. Resistance to therapy, particularly endocrine therapy is typically thought to be tumor intrinsic (e.g., estrogen receptor mutations). However, tumor-extrinsic factors also contribute to resistance. For example, stromal cells, such as cancer-associated fibroblasts (CAFs), residing in the tumor microenvironment, are known to stimulate resistance and disease recurrence. Recurrence in HR+ disease has been difficult to study due to the prolonged clinical course, complex nature of resistance, and lack of appropriate model systems. Existing HR+ models are limited to HR+ cell lines, a few HR+ organoid models, and xenograft models that all lack components of the human stroma. Therefore, there is an urgent need for more clinically relevant models to study the complex nature of recurrent HR+ breast cancer, and the factors contributing to treatment relapse. Here, we present an optimized protocol that allows a high take-rate, and simultaneous propagation of patient-derived organoids (PDOs) and matching CAFs, from primary and metastatic HR+ breast cancers. Our protocol allows for long-term culturing of HR+ PDOs that retain estrogen receptor expression and show responsiveness to hormone therapy. We further show the functional utility of this system by identifying CAF-secreted cytokines, such as growth-regulated oncogene α , as stroma-derived resistance drivers to endocrine therapy in HR+ PDOs.

Discrimination Between Benign and Malignant Lesions With Restriction Spectrum Imaging MRI in an Enriched Breast Cancer Screening Cohort.

BACKGROUND: Breast cancer screening with dynamic contrast-enhanced MRI (DCE-MRI) is recommended for high-risk women but has limitations, including variable specificity and difficulty in distinguishing cancerous (CL) and high-risk benign lesions (HRBL) from average-risk benign lesions (ARBL). Complementary non-invasive imaging techniques would be useful to improve specificity. PURPOSE: To evaluate the performance of a previously-developed breast-specific diffusion-weighted MRI (DW-MRI) model (BS-RSI3C) to improve discrimination between CL, HRBL, and ARBL in an enriched screening population. STUDY TYPE: Prospective. SUBJECTS: Exactly 187 women, either with mammography screening recommending additional imaging (N = 49) or high-risk individuals undergoing routine breast MRI (N = 138), before the biopsy. FIELD STRENGTH/SEQUENCE: Multishell DW-MRI echo planar imaging sequence with a reduced field of view at 3.0 T. ASSESSMENT: A total of 72 women had at least one biopsied lesion, with 89 lesions categorized into ARBL, HRBL, CL, and combined CLs and HRBLs (CHRLs). DW-MRI data were processed to produce apparent diffusion coefficient (ADC) maps, and estimate signal contributions (C1, C2, and C3-restricted, hindered, and free diffusion, respectively) from the BS-RSI3C model. Lesion regions of interest (ROIs) were delineated on DW images based on suspicious DCE-MRI findings by two radiologists; control ROIs were drawn in the contralateral breast. STATISTICAL TESTS: One-way ANOVA and two-sided t-tests were used to assess differences in signal contributions and ADC values among groups. P-values were adjusted using the Bonferroni method for multiple testing, P = 0.05 was used for the significance level. Receiver operating characteristics (ROC) curves and intra-class correlations (ICC) were also evaluated. RESULTS: C1, √C1C2, and log C 1 C 2 C 3 $$ \log \left(\frac{{\mathrm{C}}_1{\mathrm{C}}_2}{{\mathrm{C}}_3}\right) $$ were significantly different in HRBLs compared with ARBLs (P-values < 0.05). The log C 1 C 2 C 3 $$ \log \left(\frac{{\mathrm{C}}_1{\mathrm{C}}_2}{{\mathrm{C}}_3}\right) $$ had the highest AUC (0.821) in differentiating CHRLs from ARBLs, performing better than ADC (0.696), especially in non-mass enhancement (0.776 vs. 0.517). DATA CONCLUSION: This study demonstrated the BS-RSI3C could differentiate HRBLs from ARBLs in a screening population, and separate CHRLs from ARBLs better than ADC. TECHNICAL EFFICACY STAGE: 2.

Safely reducing unnecessary benign breast biopsies by applying non-mass and DWI directional variance filters to ADC thresholding.

BACKGROUND: Thresholding apparent diffusion coefficient (ADC) maps obtained from Diffusion-Weighted-Imaging (DWI) has been proposed for identifying benign lesions that can safely avoid biopsy. The presence of malignancies with high ADC values leads to high thresholds, limiting numbers of avoidable biopsies. PURPOSE: We evaluate two previously reported methods for identifying avoidable biopsies: using case-set dependent ADC thresholds that assure 100% sensitivity and using negative likelihood ratio (LR-) with a fixed ADC threshold of 1.50 × 10-3 mm2/s. We evaluated improvements in efficacy obtained by excluding non-mass lesions and lesions with anisotropic intra-lesion morphologic characteristics. STUDY TYPE: Prospective. POPULATION: 55 adult females with dense breasts with 69 BI-RADS 4 or 5 lesions (38 malignant, 31 benign) identified on ultrasound and mammography and imaged with MRI prior to biopsy. FIELD STRENGTH/SEQUENCE: 1.5 T and 3.0 T. DWI. ASSESSMENT: Analysis of DWI, including directional images was done on an ROI basis. ROIs were drawn on DWI images acquired prior to biopsy, referencing all available images including DCE, and mean ADC was measured. Anisotropy was quantified via variation in ADC values in the lesion core across directional DWI images. STATISTICAL TESTS: Improvement in specificity at 100% sensitivity was evaluated with exact McNemar test with 1-sided p-value < 0.05 indicating statistical significance. RESULTS: Using ADC thresholding that assures 100% sensitivity, non-mass and directional variance filtering improved the percent of avoidable biopsies to 42% from baseline of 10% achieved with ADC thresholding alone. Using LR-, filtering improved outcome to 0.06 from baseline 0.25 with ADC thresholding alone. ADC thresholding showed a lower percentage of avoidable biopsies in our cohort than reported in prior studies. When ADC thresholding was supplemented with filtering, the percentage of avoidable biopsies exceeded those of prior studies. DATA CONCLUSION: Supplementing ADC thresholding with filters excluding non-mass lesions and lesions with anisotropic characteristics on DWI can result in an increased number of avoidable biopsies.

Factors Associated With Background Parenchymal Enhancement on Contrast-Enhanced Mammography.

OBJECTIVE. The purpose of this study was to determine the relationship between background parenchymal enhancement (BPE) on contrast-enhanced mammography (CEM) and breast tissue density, menstrual status, endocrine therapy, and risk factors for breast cancer and also to evaluate interreader agreement on classification of BPE on CEM. MATERIALS AND METHODS. Five subspecialty-trained breast radiologists independently and blindly graded tissue density (with fatty tissue and scattered fibroglandular tissue classified as nondense tissue and with heterogeneously dense and extremely dense classified as dense tissue) and BPE (with minimal or mild BPE categorized as low BPE and moderate or marked BPE categorized as high BPE) on CEM examinations performed from 2014 to 2018. Electronic medical charts were reviewed for information on menstrual status, endocrine therapy, history of breast surgery, and other risk factors for breast cancer. Comparisons were performed using the Kruskal-Wallis test, Mann-Whitney test, and Spearman rank correlation. Interreader agreement was estimated using the Fleiss kappa test. RESULTS. A total of 202 patients (mean [± SD] age, 54 ± 10 years; range, 25-84 years) underwent CEM. Tissue density was categorized as fatty in two patients (1%), scattered fibroglandular in 67 patients (33%), heterogeneously dense in 117 patients (58%), and extremely dense in 16 patients (8%). Among the 202 patients, BPE was minimal in 77 (38%), mild in 80 (40%), moderate in 31 (15%), and marked in 14 (7%). Dense breasts, younger age, premenopausal status, no history of endocrine therapy, and no history of breast cancer were significantly associated with high BPE. Among premenopausal patients, no association was found between BPE and time from last menstrual period to CEM. Overall interreader agreement on BPE was moderate (κ = 0.41; 95% CI, 0.40-0.42). Interreader agreement on tissue density was substantial (κ = 0.67; 95% CI, 0.66-0.69). CONCLUSION. Women with dense breasts, premenopausal status, and younger age are more likely to have greater BPE. Targeting CEM to the last menstrual period is not indicated.

Image-guided Microinvasive Percutaneous Treatment of Breast Lesions: Where Do We Stand?

Treatment of breast lesions has evolved toward the use of less-invasive or minimally invasive techniques. Minimally invasive treatments destroy focal groups of cells without surgery; hence, less anesthesia is required, better cosmetic outcomes are achieved because of minimal (if any) scarring, and recovery times are shorter. These techniques include cryoablation, radiofrequency ablation, microwave ablation, high-intensity focused US, laser therapy, vacuum-assisted excision, and irreversible electroporation. Each modality involves the use of different mechanisms and requires specific considerations for application. To date, only cryoablation and vacuum-assisted excision have received U.S. Food and Drug Administration approval for treatment of fibroadenomas and have been implemented as part of the treatment algorithm by the American Society of Breast Surgeons. Several clinical studies on this topic have been performed on outcomes in patients with breast cancer who were treated with these techniques. The results are promising, with more data for radiofrequency ablation and cryoablation available than for other minimally invasive methods for treatment of early-stage breast cancer. Clinical decisions should be made on a case-by-case basis, according to the availability of the technique. MRI is the most effective imaging modality for postprocedural follow-up, with the pattern of enhancement differentiating residual or recurrent disease from postprocedural changes. ©RSNA, 2021.

Implementing radar reflector-guided localization of nonpalpable breast lesions: Feasibility, challenges, outcomes, and lessons learned.

Reflector-guided localization uses a nonradioactive radar implant for wire-free presurgical breast lesion localization. A single-institution retrospective evaluation found lower rates of positive margins and of close margins for reflector-guided localizations compared with wire localizations, resulting in a statistically significant decrease in the re-excision rates (p = 0.015). The two approaches did not show statistically significant difference in localization time and OR time. Technical challenges included particulars inherent in reflector placement, while patient factors included special considerations for reflector placement in the postsurgical breast. Despite novel challenges, we found reflector-guided localization to be accurate and efficient.

Discrimination of benign from malignant breast lesions in dense breasts with model-based analysis of regions-of-interest using directional diffusion-weighted images.

BACKGROUND: There is an increasing interest in non-contrast-enhanced magnetic resonance imaging (MRI) for detecting and evaluating breast lesions. We present a methodology utilizing lesion core and periphery region of interest (ROI) features derived from directional diffusion-weighted imaging (DWI) data to evaluate performance in discriminating benign from malignant lesions in dense breasts. METHODS: We accrued 55 dense-breast cases with 69 lesions (31 benign; 38 cancer) at a single institution in a prospective study; cases with ROIs exceeding 7.50 cm2 were excluded, resulting in analysis of 50 cases with 63 lesions (29 benign, 34 cancers). Spin-echo echo-planar imaging DWI was acquired at 1.5 T and 3 T. Data from three diffusion encoding gradient directions were exported and processed independently. Lesion ROIs were hand-drawn on DWI images by two radiologists. A region growing algorithm generated 3D lesion models on augmented apparent-diffusion coefficient (ADC) maps and defined lesion core and lesion periphery sub-ROIs. A lesion-core and a lesion-periphery feature were defined and combined into an overall classifier whose performance was compared to that of mean ADC using receiver operating characteristic (ROC) analysis. Inter-observer variability in ROI definition was measured using Dice Similarity Coefficient (DSC). RESULTS: The region-growing algorithm for 3D lesion model generation improved inter-observer variability over hand drawn ROIs (DSC: 0.66 vs 0.56 (p < 0.001) with substantial agreement (DSC > 0.8) in 46% vs 13% of cases, respectively (p < 0.001)). The overall classifier improved discrimination over mean ADC, (ROC- area under the curve (AUC): 0.85 vs 0.75 and 0.83 vs 0.74 respectively for the two readers). CONCLUSIONS: A classifier generated from directional DWI information using lesion core and lesion periphery information separately can improve lesion discrimination in dense breasts over mean ADC and should be considered for inclusion in computer-aided diagnosis algorithms. Our model-based ROIs could facilitate standardization of breast MRI computer-aided diagnostics (CADx).

Contrast-Enhanced Mammography: A Systematic Guide to Interpretation and Reporting.

OBJECTIVE: The purpose of this article is to discuss the essential steps involved in performing, interpreting, managing, and reporting findings on contrast-enhanced mammography for successful implementation into clinical practice. CONCLUSION: To successfully implement contrast-enhanced mammography into clinical practice, an understanding about the acquisition of images, image interpretation, and reporting of the spectrum of negative, benign, and malignant findings is essential.

Primary and Secondary Breast Lymphoma: Clinical, Pathologic, and Multimodality Imaging Review.

Breast lymphoma is a rare hematologic neoplasm that originates in the breast lymphoid tissue and includes primary breast lymphoma (PBL) and secondary breast lymphoma (SBL). PBL involves the breast lymphoid tissue in the absence of previously identified extramammary lymphoma and widespread disease. SBL is the most common metastasis to the breast, accounting for 17% of metastatic disease to the breast. PBL and SBL usually demonstrate imaging phenotypes that overlap with those of primary breast carcinoma, which makes a prospective diagnosis of breast lymphoma challenging. These nonspecific imaging features include an iso- to hyperdense oval mass or masses at mammography, a hypoechoic or mixed-echogenicity hypervascular mass at US, an enhancing mass with type II kinetics at MRI, and high fluorine 18-fluorodeoxyglucose avidity at PET. In cases of suspected lymphoma, reviewing the clinical history, using appropriate biopsy techniques, and evaluating for multiplicity, bilaterality, and distant disease are critical for diagnosis and management. A patient with PBL generally has an earlier clinical presentation with a palpable abnormality and a solitary imaging finding. In contrast, multiple masses in an older patient and an occult clinical presentation favor an SBL diagnosis. ©RSNA, 2019.

Breast MRI ordering practices in a large health care network.

The purpose of this study was to evaluate providers' ordering practices and perceptions of breast magnetic resonance imaging (MRI) in an academic network in order to better understand and educate a referral base. An online survey was distributed to primary care providers (PCPs) and specialists in our hospital and community practices. Questions included provider demographics, current ordering practices, challenges to ordering, and perceptions about breast MRI. Of 525 ordering providers, 134 responded (26% response rate). Of 134 providers, 57 (42%) order breast MRI in practice. Of those who do not, the most consistent reason was a lack of familiarity with the use of breast MRI (32/77 [42%] of cases). Of 57 cases, 45 (79%) order less than 10 exams annually. The most frequent indication is for high-risk screening (40/47 [84%]). PCPs order fewer breast MRI compared with specialists (P = 0.01). Both PCPs and specialists have mixed perceptions of the clinical utility of breast MRI. However, 30% of all providers are ordering more breast MRI since the enactment of breast density legislation in Massachusetts. Furthermore, 29% report they would order breast MRI more often to screen women with dense breasts if there was a low cost option. Referring provider surveys are useful tools for assessing a radiology practice. Our study suggests a growing clinical interest in breast MRI for screening; however, there is a need for provider education on the clinical utility of breast MRI. Increasing the radiologist's role in targeted educational interventions may help improve awareness and lead to more appropriate utilization of resources.

Potential role of abbreviated MRI for breast cancer screening in an academic medical center.

The purpose is to determine whether an abbreviated MRI protocol (ABMR) is ready to be used for breast cancer screening in an academic practice setting. Two hundred and fifty nine breast MRIs from 1/1/2012 to 6/30/2012 were retrospectively reviewed using ABMR (MIP, Pre-contrastT1, single dynamic post-contrastT1, and subtraction). Five breast radiologists (4-28 year-expr) participated in this reader study performed in two phases: Phase1 - radiologist's privy to clinical history but not to comparison imaging. Phase2 - radiologists provided comparison imaging. For phase1, studies were reviewed using three steps: (a) MIP only (positive/negative/intermediate); (b) ABMR (recall/no recall) and (c) With T2 (for changes in recommendations). Radiologist also recorded total time for interpretation. In Phase2 the MRIs coded as "recall" were re-reviewed with available comparison studies, noting changes in final recommendation. The abnormal interpretation rates (AIRs) were calculated for phase1 and phase2 results with comparison to the original full protocol. Of the 259 patients (avg. age-52 years; range 26-78), there were seven cancers (three invasive, three DCIS and one breast lymphoma). Acquisition time for ABMR was 3 minutes, ABMR + T2-8 minutes, and original full protocol 16 minutes. Average MIP was positive or indeterminate in 86% (6/7) and negative in 14% (1/7) cancers. The average AIR for MIP only was 20.8% (sens-77.1%; spec-80.8%. The AIR w/o comparisons was 25.6% (sens-91.4%; spec- 76.2%); however the average AIR decreased in phase 2 with comparisons to 13.7% (sens-91.4%; spec-88.5%). The AIR of the original full protocol read was 16.2% (sens-100%; spec-85.7%). Addition of T2 changed assessment in only 3% (1.2%-6.5%). Avg. read time for ABMR including T2 was 2.5 minutes (1.6-4.0 minutes). ABMR is reliable for breast cancer screening, with acceptable interpretation time and acceptable AIR.

Indications for biopsy of imaging-detected intramammary and axillary lymph nodes in the absence of concurrent breast cancer.

To evaluate the prevalence of malignancy in imaging-detected abnormal lymph nodes (LNs) in women without concurrent cancer and to identify imaging features predictive of malignancy in this population. This is an IRB-approved study with waived informed consent. We retrospectively reviewed medical records of all image-guided LN FNAs and CNBs performed at our institution from 1/1/08 through 12/31/10. LNs sampled in patients without concurrent breast cancer comprised our study group (SG; n = 77), and with concurrent breast cancer our reference group (RG; n = 124). Blinded to cytology/histology, imaging features of the LNs including size, loss of fatty hilum, and cortical thickness were reviewed. A low/high suspicion category was then assigned based on LN appearance. The prevalence of malignancy in LNs in SG was 6% (5/77) and in RG 52% (64/124; P < .0001). Complete loss of fatty hilum had 100% (5/5) sensitivity, and 100% (56/56) NPV for detecting cancer in SG, compared to 39% (25/64) sensitivity and 61% (60/99) NPV in RG. When a "high suspicion" imaging feature was used as a threshold to biopsy, the sensitivity (5/5) and NPV (45/45) in SG were 100%, and in RG 78% (50/64) and 77% (47/61), respectively. The prevalence of cancer in imaging-detected abnormal LNs in patients without concurrent breast cancer is low. In the absence of concurrent cancer, using highly suspicious features of loss of fatty hilum or cortical thickness ≥ 5 mm as a threshold to biopsy will maintain high sensitivity with lower false-positive biopsy rate.

Proposed biopsy performance benchmarks for MRI based on an audit of a large academic center.

Performance benchmarks exist for mammography (MG); however, performance benchmarks for magnetic resonance imaging (MRI) are not yet fully developed. The purpose of our study was to perform an MRI audit based on established MG and screening MRI benchmarks and to review whether these benchmarks can be applied to an MRI practice. An IRB approved retrospective review of breast MRIs was performed at our center from 1/1/2011 through 12/31/13. For patients with biopsy recommendation, core biopsy and surgical pathology results were reviewed. The data were used to derive mean performance parameter values, including abnormal interpretation rate (AIR), positive predictive value (PPV), cancer detection rate (CDR), percentage of minimal cancers and axillary node negative cancers and compared with MG and screening MRI benchmarks. MRIs were also divided by screening and diagnostic indications to assess for differences in performance benchmarks amongst these two groups. Of the 2455 MRIs performed over 3-years, 1563 were performed for screening indications and 892 for diagnostic indications. With the exception of PPV2 for screening breast MRIs from 2011 to 2013, PPVs were met for our screening and diagnostic populations when compared to the MRI screening benchmarks established by the Breast Imaging Reporting and Data System (BI-RADS) 5 Atlas® . AIR and CDR were lower for screening indications as compared to diagnostic indications. New MRI screening benchmarks can be used for screening MRI audits while the American College of Radiology (ACR) desirable goals for diagnostic MG can be used for diagnostic MRI audits. Our study corroborates established findings regarding differences in AIR and CDR amongst screening versus diagnostic indications.

Surgical upgrade rate of breast atypia to malignancy: An academic center's experience and validation of a predictive model.

Atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and lobular carcinoma in situ (LCIS) are commonly seen on breast core needle biopsy (CNB). Many institutions recommend excision of these lesions to exclude malignancy. A retrospective chart review was performed on patients who had ADH, ALH, or LCIS on breast CNB from 1/1/08 to 12/31/10 who subsequently had surgical excision of the biopsy site. Study objectives included determining upgrade to malignancy at surgical excision, identification of predictors of upgrade, and validation of a recently published predictive model. Clinical and demographic factors, pathology, characteristics of the biopsy procedure and visible residual lesion were recorded. T test and chi-squared test were used to identify predictors. Classification tree was used to predict upgrade. 151 patients had mean age of 53 years. The mean maximum lesion size on imaging was 11 mm. The primary atypia was ADH in 63.6%, ALH in 27.8%, and LCIS in 8.6%. 16.6% of patients had upgrade to malignancy, with 72% DCIS and 28% invasive carcinoma. Risk factors for upgrade included maximum lesion size (P = .002) and radiographic presence of residual lesion (P = .001). A predictive model based on these factors had sensitivity 78%, specificity 80% and AUC = 0.88. Validating a published nomogram with our data produced accuracy figures (AUC = 0.65) within published CI of 0.63-0.82. In CNB specimens containing ADH, ALH, or LCIS, initial lesion size and presence of residual lesion are predictors of upgrade to malignancy. A validated model may be helpful in developing patient management strategies.

Clinical Value of Mammography in the Evaluation of Palpable Breast Lumps in Women 30 Years Old and Older.

OBJECTIVE: The purpose of this study was to determine whether mammography adds clinical value in the diagnostic imaging workup of women 30 years old and older who present with palpable breast lumps. MATERIALS AND METHODS: We retrospectively identified the records of all women 30 years old and older who underwent imaging evaluation with mammography and ultrasound for a palpable lump between January 1, 2009, and December 31, 2010. Imaging reports were reviewed for findings related to the lump and for incidental nonpalpable findings. Benign versus malignant outcomes were determined by pathologic analysis or 24-month imaging or clinical follow-up. The contribution of mammography to final diagnosis was assessed on the basis of objective criteria to determine the clinical impact of mammographic findings. RESULTS: The study cohort included 861 patients presenting with 935 palpable lumps. Imaging correlates were reported for 568 of 935 (60.7%) lumps, and imaging findings were negative in 367 of 935 (39.3%). Of the 935 palpable lumps, 858 (91.8%) were benign and 77 (8.2%) were malignant. Mammography added clinical value in the evaluation of 27 of 77 (35.0%) malignant lumps by better delineating extent of disease and in the evaluation of 26 of 858 benign lumps (3.0%) by confirming benignity. Fifty-two of 861 (6.0%) patients had incidental findings that led to a recommendation for biopsy. Twenty-nine of the 52 findings were originally seen with mammography and 23 with ultrasound. Mammography also depicted seven incidental malignancies in nonpalpable areas, and ultrasound depicted one incidental malignancy. CONCLUSION: Adjunct mammography is warranted for evaluation of palpable breast lumps in women 30 years old and older because of the value added to clinical management. In all age cohorts, mammography contributed to delineation of disease extent, detection of incidental malignancies, and confirmation of benign diagnoses.

Apocrine Metaplasia Found at MR Biopsy: Is There Something to be Learned?

The purpose of this study was to determine (a) the frequency of apocrine metaplasia (ApoM) found on MR core biopsy of suspicious findings, and (b) to determine if there are specific MR imaging features that might obviate the need for biopsy. This HIPAA-compliant retrospective study was performed under IRB exemption for quality assurance studies. Patient demographics, MR imaging features, and pathology were reviewed. Breast lesions which underwent MR-guided biopsy, yielding ApoM on pathology analysis were included. Retrospective review of MR imaging features of these lesions was performed by two radiologists blinded to pathology results except for the presence of ApoM. Imaging features on MR assessed included location, size, morphology, T1 and T2 signals, and enhancement kinetics. Full pathology results were subsequently reviewed during data analysis. The pathology slides and imaging was subsequently reviewed by two fellowship trained radiologists and a breast pathologist to categorize the finding of ApoM into target lesion (imaging corresponds to size of lesion on pathology) versus incidental lesion. Target lesion characteristics were assessed to determine specific MRI features of ApoM. Between January 2011 to November 2012, 155 distinct breast lesions suspicious for malignancy successfully underwent MR-guided biopsy. Of the 155 lesions biopsied, 123 (79%) were benign and 32 (21%) were malignant. Of the 123 benign biopsies, ApoM was found in 57 (46%), of which 35 (61%) had no associated atypia and 22 (39%) had associated atypia. Of the 32 malignant biopsies, three (9%) had associated ApoM (DCIS in two cases and DCIS/LCIS in one case). Of the 60 cases with ApoM, only 11 (18.3%) were target lesions and 49 were incidental lesions (81.7%). Of the 60 cases with ApoM, 35 (58%) were masses (average size 0.8 cm for both with or without atypia) and 25 (42%) were nonmass enhancement (NME) (average size 2.1 cm with and 1.0 cm without atypia). Only five (14%) of 35 masses demonstrated spiculated margins, of which four were associated with atypia (80%). Of 22 lesions with atypia or other high-risk lesion, 14 (64%) were masses, most commonly with irregular margins (64%). Of the 12 T2 hyperintense lesions, only two (1.7)% had associated atypia or high-risk lesion, and none were associated with malignancy. Of the 11 target lesions, seven were T2 hyperintense. Enhancement kinetics were variable: 30 (50%) showed mixed persistent and plateau kinetics, eight (13%) persistent delayed enhancement, 10 (17%) plateau kinetics, four (7%) washout kinetics, and eight (13%) were below threshold for kinetic analysis. ApoM is a common benign pathologic result at MR-guided core biopsy for both masses and NME accounting for 39% of all biopsy results in this series. Although there is considerable variability in imaging characteristics on MR, our results suggest biopsy may be safely obviated for lesions that are subcentimeter T2 hyperintense areas of NME and short term follow-up imaging may be a reasonable alternative for these lesions.

Prediction of Low versus High Recurrence Scores in Estrogen Receptor-Positive, Lymph Node-Negative Invasive Breast Cancer on the Basis of Radiologic-Pathologic Features: Comparison with Oncotype DX Test Recurrence Scores.

Purpose To review mammographic, ultrasonographic (US), and magnetic resonance (MR) imaging features and pathologic characteristics of estrogen receptor (ER)-positive, lymph node-negative invasive breast cancer and to determine the relationship of these characteristics to Oncotype DX (Genomic Health, Redwood City, Calif) test recurrence scores (ODRS) for breast cancer recurrence. Materials and Methods This institutional review board-approved retrospective study was performed in a single large academic medical center. The study population included patients with ER-positive, lymph node-negative invasive breast cancer who underwent genomic testing from January 1, 2009, to December 31, 2013. Imaging features of the tumor were classified according to the Breast Imaging Reporting and Data System lexicon by breast imagers who were blinded to the ODRS. Mammography was performed in 86% of patients, US was performed in 84%, and MR imaging was performed in 33%, including morphologic and kinetic evaluation. Images from each imaging modality were evaluated. Each imaging finding, progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status, and tumor grade were then individually correlated with ODRS. Analysis of variance was used to determine differences for each imaging feature. Regression analysis was used to calculate prediction of recurrence on the basis of imaging features combined with histopathologic features. Results The 319 patients had a mean age ± standard deviation of 55 years ± 8.7 (range, 31-82 years). Imaging features with a positive correlation with ODRS included a well-circumscribed oval mass (P = .024) at mammography, vascularity (P = .047) and posterior enhancement (P = .004) at US, and lobulated mass (P = .002) at MR imaging. Recurrence scores were predicted by using these features in combination with PR and HER2 status and tumor grade by using the threshold of more than 30 as a high recurrence score. With a regression tree, there was correlation (r = 0.79) with 89% sensitivity and 83% specificity. Conclusion On the basis of preliminary data, information obtained routinely for breast cancer diagnosis can reliably be used to predict the ODRS with high sensitivity and specificity. (©) RSNA, 2016.

Increased Cancer Detection Rate and Variations in the Recall Rate Resulting from Implementation of 3D Digital Breast Tomosynthesis into a Population-based Screening Program.

PURPOSE: To compare the recall and cancer detection rates (CDRs) at screening with digital breast tomosynthesis (DBT) with those at screening with two-dimensional (2D) mammography and to evaluate variations in the recall rate (RR) according to patient age, risk factors, and breast density and among individual radiologists at a single U.S. academic medical center. MATERIALS AND METHODS: This institutional review board-approved, HIPAA-compliant prospective study with a retrospective cohort included 85 852 asymptomatic women who presented for breast cancer screening over a 3-year period beginning in 2011. A DBT unit was introduced into the existing 2D mammography screening program, and patients were assigned to the first available machine. Ten breast-subspecialized radiologists interpreted approximately 90% of the examinations. RRs were calculated overall and according to patient age, breast density, and individual radiologist. CDRs were calculated. Single and multiple mixed-effect logistic regression analyses, χ(2) tests, and Bonferroni correction were utilized, as appropriate. RESULTS: The study included 5703 (6.6%) DBT examinations and 80 149 (93.4%) 2D mammography examinations. The DBT subgroup contained a higher proportion of patients with risk factors for breast cancer and baseline examinations. DBT was used to detect 54.3% more carcinomas (+1.9 per 1000, P < .0018) than 2D mammography. The RR was 7.51% for 2D mammography and 6.10% for DBT (absolute change, 1.41%; relative change, -18.8%; P < .0001). The DBT subgroup demonstrated a significantly lower RR for patients with extremely or heterogeneously dense breasts and for patients in their 5th and 7th decades. CONCLUSION: Implementing DBT into a U.S. breast cancer screening program significantly decreased the screening RR overall and for certain patient subgroups, while significantly increasing the CDR. These findings may encourage more widespread adoption and reimbursement of DBT and facilitate improved patient selection.

Improving Patient Care by Incorporation of Multidisciplinary Breast Radiology-Pathology Correlation Conference.

PURPOSE: It is well known that radiologic-pathologic correlation is critical in managing patients with breast disease. Although regular multidisciplinary conferences addressing radiologic-pathologic correlation are common at most major academic institutions, this approach is not universal in community-based settings or even some of the smaller academic practices. This study was performed to assess the impact of a weekly multidisciplinary conference on patient care to determine whether all breast practices should adopt this approach as a means to streamline and improve the quality of patient care. METHODS: We reviewed cases of percutaneous breast core biopsies presented at our weekly breast radiology-pathology correlation conference from July 1, 2008, to June 30, 2012. Each reviewed case was assigned to 1 of 4 categories (concordant → concordant, concordant → discordant, discordant → discordant, and discordant → concordant) based on the "initial" and "final" impressions of concordance between radiology and pathology. Changes in concordance, histopathological diagnosis, or management that occurred during the conference were recorded prospectively and analysed. Changes in management that were considered significant included changes in recommendations for surgery, repeat core biopsy, or follow-up imaging. RESULTS: Of 1387 presented at the conference, 1313 (94.7%) had no change during the meeting, confirming 1279 (92.2%) concordant and 34 (2.4%) discordant cases. A total of 74 (5.3%) cases had a change during the conference: 22 of 74 (29.7%) were changed from discordant to concordant, avoiding surgical excision in 15 and short interval imaging in 7; 23 of 74 (31.1%) were changed from concordant to discordant; on excision 3 were cancer, 3 atypia, 10 benign, 2 stable on follow-up imaging, and 5 lost to follow-up; the remaining 29 of 74 (39.2%) stayed concordant after review, but had a change in management, avoiding surgery in 14 and short interval imaging in 15. Overall, as a result of this conference, repeat biopsy or excision was recommended in 23, surgery was avoided in 29, short interval imaging avoided in 22, and cancer detected in 3 cases. CONCLUSIONS: Our weekly breast radiology-pathology correlation conference impacted patient management in up to 5.3% of cases. These results support the need to incorporate a weekly multidisciplinary case review of breast core biopsies into all breast care practices. Such a conference maximizes cancer detection, identifies discordant cases in a timely manner, decreases follow-up imaging, and avoids unnecessary surgical intervention.

Role of imaging in neoadjuvant therapy for breast cancer.

Neoadjuvant chemotherapy (NAC) involves administration of chemotherapeutic agents to patients with newly diagnosed breast cancer prior to definitive surgical treatment. Assessment of disease response to chemotherapeutic agents in vivo prior to any surgical intervention is necessary as medical oncologists are commonly tailoring or changing therapy during NAC based on response. It can also maximize the pathologic complete response (pCR) rate, resulting in more women undergoing breast conservation rather than mastectomy. Although some studies show a pCR to NAC in only 13-26 % of women, recent studies have shown higher pCR rates, especially for HER2-positive disease treated with targeted anti-HER2 therapy. Thus, accurate imaging tools for quantifying disease response are critical in the evaluation and management of patients undergoing NAC. There is currently no standard imaging method for monitoring response to therapy. Response to therapy tends to vary by tumor subtype and can be accurately assessed on imaging. We review the role of imaging before and after neoadjuvant therapy and discuss the advantages and limitations of currently available modalities, including mammography, ultrasonography, magnetic resonance imaging, and nuclear imaging.