Improving lesion volume measurements on digital mammograms

Lesion volume is an important predictor for prognosis in breast cancer. However, it is currently impossible to compute lesion volumes accurately from digital mammography data, which is the most popular and readily available imaging modality for breast cancer. We make a step towards a more accurate lesion volume measurement on digital mammograms by developing a model that allows to estimate lesion volumes on processed mammogram. Processed mammograms are the images routinely used by radiologists in clinical practice as well as in breast cancer screening and are available in medical centers. Processed mammograms are obtained from raw mammograms, which are the X-ray data coming directly from the scanner, by applying certain vendor-specific non-linear transformations. At the core of our volume estimation method is a physics-based algorithm for measuring lesion volumes on raw mammograms. We subsequently extend this algorithm to processed mammograms via a deep learning image-to-image translation model that produces synthetic raw mammograms from processed mammograms in a multi-vendor setting. We assess the reliability and validity of our method using a dataset of 1778 mammograms with an annotated mass. Firstly, we investigate the correlations between lesion volumes computed from mediolateral oblique and craniocaudal views, with a resulting Pearson correlation of 0.93 [95% confidence interval (CI) 0.92 - 0.93]. Secondly, we compare the resulting lesion volumes from true and synthetic raw data, with a resulting Pearson correlation of 0.998 [95%CI 0.998 - 0.998] . Finally, for a subset of 100 mammograms with a malignant mass and concurrent MRI examination available, we analyze the agreement between lesion volume on mammography and MRI, resulting in an intraclass correlation coefficient of 0.81 [95%CI 0.73 - 0.87] for consistency and 0.78 [95%CI 0.66 - 0.86] for absolute agreement. In conclusion, we developed an algorithm to measure mammographic lesion volume that reached excellent reliability and good validity, when using MRI as ground truth. The algorithm may play a role in lesion characterization and breast cancer prognostication on mammograms.

Assessing Breast Cancer through Tumor Microenvironment Mapping of Collagen and Other Biomolecule Spectral Fingerprints─A Review

Breast cancer is a major challenge in the field of oncology, with around 2.3 million cases and around 670,000 deaths globally based on the GLOBOCAN 2022 data. Despite having advanced technologies, breast cancer remains the major type of cancer among women. This review highlights various collagen signatures and the role of different collagen types in breast tumor development, progression, and metastasis, along with the use of photoacoustic spectroscopy to offer insights into future cancer diagnostic applications without the need for surgery or other invasive techniques. Through mapping of the tumor microenvironment and spotlighting key components and their absorption wavelengths, we emphasize the need for extensive preclinical and clinical investigations.

Evaluation of an Italian Population-Based Programme for Risk Assessment and Genetic Counselling and Testing for BRCA1/2-Related Hereditary Breast and Ovarian Cancer after 10 Years of Operation: An Observational Study Protocol

Hereditary breast/ovarian cancer (HBOC) syndrome is caused by the inheritance of monoallelic germline BRCA1/2 gene mutations. If BRCA1/2 mutation carriers are identified before the disease develops, effective actions against HBOC can be taken, including intensive screening, risk-reducing mastectomy and salpingo-oophorectomy, and risk-reducing medications. The Italian National Prevention Plan mandates the creation of regional BRCA genetic testing programmes. So far, however, only informal data have been reported on their implementation. We have designed a study aimed at evaluating the results of a population-based programme for risk assessment and genetic counselling and testing for BRCA1/2-related HBOC that is underway in the Emilia-Romagna region (northern Italy). The programme-which is entirely free-includes basic screening with an estimate of the likelihood of carrying a BRCA1/2 mutation using a familial risk assessment tool, a closer examination of women with suspected risk increase, an assessment of the need for further genetic counselling and, if needed, genetic testing and risk-reducing interventions. In this paper, the design of the programme and the protocol of the study are presented. The study has an observational, historical cohort design. Eligible are the women found to be at an increased risk of HBOC (profile 3 women). The main objectives are (i) to determine the precision of the programme in measuring the level of risk of HBOC for profile 3 women; (ii) to determine the characteristics of profile 3 women and their association with the risk management strategy chosen; (iii) to compare the age at onset, histologic type, tumour stage, molecular subtype, and prognosis of breast/ovarian cancers observed in the cohort of profile 3 women with the features of sporadic cancers observed in the general female population; (iv) to determine the level and the determinants of adherence to recommendations; and (v) to determine the appropriateness and timing of risk-reducing surgery and medications. Investigating the quality and results of the programme is necessary because the best practices in risk assessment and genetic counselling and testing for BRCA1/2-related cancer and the challenges they encounter should be identified and shared. The study has the potential to provide sound empirical evidence for the factors affecting the effectiveness of this type of service.

The impact of preoperative breast MRI on the therapeutic management of breast cancer patients

BACKGROUND

The role of preoperative breast MRI to evaluate the extent of disease in breast cancer patients is considered controversial. We aimed at assessing the effect of breast MRI on the management of newly diagnosed breast cancer.

MATERIALS

A retrospective review of 202 consecutively seen patients who were newly diagnosed with breast cancer and who underwent preoperative breast MRIs at Assuta Ashdod between June 1, 2017, and June 1, 2020. Data included discovering suspicious lesions by conventional imaging, MRI findings, and surgical pathology results. This was analyzed to determine whether the MRI changed the management and whether it had a justified or unjustified effect on the treatment.

RESULTS

The mean age was 54.51 (standard deviation, 11.34 years). Breast MRI revealed additional findings in 56 % of patients and modified therapeutic management in 32 % of the cases evaluated, having a justified effect in 87.6 %. Patients with changed management had a statistically significantly higher mastectomy rate (36 %) than those who did not (14 %). No statistically significant association was found between independent variables such as breast density, tumor location on the breast, type of tumor, patient's demographic information, etc. And whether MRI findings changed the initial treatment plan.

CONCLUSIONS

MRI played an essential role in the preoperative staging of breast cancer in our study, modifying therapeutic planning in approximately one-third of the cases and having a justified effect on most of them. We, therefore, support preoperative breast MRI in newly diagnosed breast cancer patients.

Enabling AI-Generated Content for Gadolinium-Free Contrast-Enhanced Breast Magnetic Resonance Imaging

BACKGROUND

There is increasing interest in utilizing AI-generated content for gadolinium-free contrast-enhanced breast MRI.

PURPOSE

To develop a generative model for gadolinium-free contrast-enhanced breast MRI and evaluate the diagnostic utility of the generated scans.

STUDY TYPE

Retrospective.

POPULATION

Two hundred seventy-six women with 304 breast MRI examinations (49 ± 13 years, 243/61 for training/testing).

FIELD STRENGTH/SEQUENCE

ZOOMit diffusion-weighted imaging (DWI), T1-weighted volumetric interpolated breath-hold examination (T1W VIBE), and axial T2 3D SPACE at 3.0 T.

ASSESSMENT

A generative model was developed to generate contrast-enhanced scans using precontrast T1W VIBE and DWI images. The generated and real images were quantitatively compared using the structural similarity index (SSIM), mean absolute error (MAE), and Dice similarity coefficient. Three radiologists with 8, 5, and 5 years of experience independently rated the image quality and lesion visibility on AI-generated and real images within various subgroups using a five-point scale. Four breast radiologists, with 8, 8, 5, and 5 years of experience, independently and blindly interpreted four reading protocols: unenhanced MRI protocol alone and combined with AI-generated scans, abbreviated MRI protocol, and full-MRI protocol.

STATISTICAL ANALYSIS

Results were assessed using t-tests and McNemar tests. Using pathology diagnosis as reference standard, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each reading protocol. A P value <0.05 was considered significant.

RESULTS

In the test set, the generated images showed similarity to the real images (SSIM: 0.935 ± 0.047 [SD], MAE: 0.015 ± 0.012 [SD], and Dice coefficient: 0.726 ± 0.177 [SD]). No significant difference in lesion visibility was observed between real and AI-generated scans of the mass, non-mass, and benign lesion subgroups. Adding AI-generated scans to the unenhanced MRI protocol slightly improved breast cancer detection (sensitivity: 92.86% vs. 85.71%, NPV: 76.92% vs. 70.00%); achieved non-inferior diagnostic utility compared to the AB-MRI protocol and full-protocol (sensitivity: 92.86%, 95.24%; NPV: 75.00%, 81.82%).

DATA CONCLUSION

AI-generated gadolinium-free contrast-enhanced breast MRI has potential to improve the sensitivity of unenhanced MRI in detecting breast cancer.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 3.

Addition of Contrast-enhanced Mammography to Tomosynthesis for Breast Cancer Detection in Women with a Personal History of Breast Cancer: Prospective TOCEM Trial Interim Analysis

Background Digital breast tomosynthesis (DBT) is often inadequate for screening women with a personal history of breast cancer (PHBC). The ongoing prospective Tomosynthesis or Contrast-Enhanced Mammography, or TOCEM, trial includes three annual screenings with both DBT and contrast-enhanced mammography (CEM). Purpose To perform interim assessment of cancer yield, stage, and recall rate when CEM is added to DBT in women with PHBC. Materials and Methods From October 2019 to December 2022, two radiologists interpreted both examinations: Observer 1 reviewed DBT first and then CEM, and observer 2 reviewed CEM first and then DBT. Effects of adding CEM to DBT on incremental cancer detection rate (ICDR), cancer type and node status, recall rate, and other performance characteristics of the primary radiologist decisions were assessed. Results Among the participants (mean age at entry, 63.6 years ± 9.6 [SD]), 1273, 819, and 227 women with PHBC completed year 1, 2, and 3 screening, respectively. For observer 1, year 1 cancer yield was 20 of 1273 (15.7 per 1000 screenings) for DBT and 29 of 1273 (22.8 per 1000 screenings; ICDR, 7.1 per 1000 screenings [95% CI: 3.2, 13.4]) for DBT plus CEM (P < .001). Year 2 plus 3 cancer yield was four of 1046 (3.8 per 1000 screenings) for DBT and eight of 1046 (7.6 per 1000 screenings; ICDR, 3.8 per 1000 screenings [95% CI: 1.0, 7.6]) for DBT plus CEM (P = .001). Year 1 recall rate for observer 1 was 103 of 1273 (8.1%) for (incidence) DBT alone and 187 of 1273 (14.7%) for DBT plus CEM (difference = 84 of 1273, 6.6% [95% CI: 5.3, 8.1]; P < .001). Year 2 plus 3 recall rate was 40 of 1046 (3.8%) for DBT and 92 of 1046 (8.8%) for DBT plus CEM (difference = 52 of 1046, 5.0% [95% CI: 3.7, 6.3]; P < .001). In 18 breasts with cancer detected only at CEM after integration of both observers, 13 (72%) cancers were invasive (median tumor size, 0.6 cm) and eight of nine (88%) with staging were N0. Among 1883 screenings with adequate reference standard, there were three interval cancers (one at the scar, two in axillae). Conclusion CEM added to DBT increased early breast cancer detection each year in women with PHBC, with an accompanying approximately 5.0%-6.6% recall rate increase. Clinical trial registration no. NCT04085510 © RSNA, 2024 Supplemental material is available for this article.

Clinical and Imaging Features of MRI Screen-Detected Breast Cancer

BACKGROUND

Supplemental screening with breast MRI is recommended annually for patients who have greater than 20% lifetime risk for breast cancer. While there is robust data regarding features of mammographic screen-detected breast cancers, there is limited data regarding MRI-screen-detected cancers.

PATIENTS AND METHODS

Screening breast MRIs performed between August 1, 2016 and July 30, 2022 identified 50 screen-detected breast cancers in 47 patients. Clinical and imaging features of all eligible cancers were recorded.

RESULTS

During the study period, 50 MRI-screen detected cancers were identified in 47 patients. The majority of MRI-screen detected cancers (32/50, 64%) were invasive. Pathology revealed ductal carcinoma in situ (DCIS) in 36% (18/50), invasive ductal carcinoma (IDC) in 52% (26/50), invasive lobular carcinoma in 10% (5/50), and angiosarcoma in 2% (1/50). The majority of patients (43/47, 91%) were stage 0 or 1 at diagnosis and there were no breast cancer-related deaths during the follow-up periods. Cancers presented as masses in 50% (25/50), nonmass enhancement in 48% (25/50), and a focus in 2% (1/50). DCIS was more likely to present as nonmass enhancement (94.4%, 17/18), whereas invasive cancers were more likely to present as masses (75%, 24/32) (P < .001). All cancers that were stage 2 at diagnosis were detected either on a baseline exam or more than 4 years since the prior MRI exam.

CONCLUSION

MRI screen-detected breast cancers were most often invasive cancers. Cancers detected by MRI screening had an excellent prognosis in our study population. Invasive cancers most commonly presented as a mass.

Revisiting Screening in Women With a Family History of Breast Cancer

Women with a family history (FH) of breast cancer and without known genetic susceptibility represent a unique population whose lifetime probability of developing breast cancer varies widely depending on familial factors, breast density, and the risk assessment tool used. Recently updated guidelines from the American College of Radiology recommend supplemental annual screening with contrast-enhanced MRI or contrast-enhanced mammography for women with an FH who are high risk (≥20% lifetime risk) or have dense breasts. To date, most screening studies addressing outcomes in women with FH have largely included those also with confirmed or suspected gene mutations, in whom the lifetime risk is highest, with limited data for women at average to intermediate risk who are not known to be genetically susceptible and may not benefit as much from the same screening approaches. Further research focusing specifically on women with FH as the only breast cancer risk factor is warranted to refine risk assessment and optimize a multimodality personalized screening approach.

Comparing the performance of full-field digital mammography and digital breast tomosynthesis in the post-treatment surveillance of patients with a history of breast cancer: A retrospective study

INTRODUCTION

The purpose of our study was to compare the performance of 2D (FFDM) against 3D (FFDM plus DBT) examinations in the post-treatment surveillance of asymptomatic breast cancer survivors.

METHODS

A list of women with a history of breast cancer who underwent screening mammography (2D or 3D) from 5/2017 to 5/2020 was retrieved. A total of 20,210 examinations were identified and performance metrics were compared.

RESULTS

There were no statistically significant difference in cancer detection rate (CDR) (p = 0.38), recall rate (RR) (p = 0.087), or positive predictive value (PPV) (p = 0.74) between 2D vs. 3D examinations. Stratification by breast tissue identified no statistically significant difference in CDR (p = 0.581 and p = 0.428), RR (p = 0.230 and p = 0.205), or PPV (p = 0.908 and p = 0.721) between fatty/scattered and heterogeneous/extremely dense breast tissue when comparing 2D vs 3D examinations. Stratification by age did not identify a significant difference in RR or PPV between the two groups. CDR was statistically increased with 2D vs. 3D examinations in the 60-69 years group (p = 0.021). Stratification by race did not identify a significant difference in RR or PPV between the two groups. CDR was statistically increased with 3D vs. 2D examinations in white women (p = 0.036). Stratification by laterality (bilateral vs. unilateral post mastectomy) did not identify a significant difference in RR or PPV between the two groups. CDR was statistically increased in 2D vs. 3D examinations in unilateral studies (p = 0.009).

CONCLUSION

For asymptomatic women with a history of breast cancer, there is no evidence that the addition of DBT to FFDM improves CDR, RR, or PPV.

IMPLICATIONS FOR PRACTICE

More studies are needed concerning screening methodologies supplementing FFDM in the screening regimens of breast cancer survivors.

Breast Cancer Screening for Women at Higher-Than-Average Risk: Updated Recommendations From the ACR

Early detection decreases breast cancer death. The ACR recommends annual screening beginning at age 40 for women of average risk and earlier and/or more intensive screening for women at higher-than-average risk. For most women at higher-than-average risk, the supplemental screening method of choice is breast MRI. Women with genetics-based increased risk, those with a calculated lifetime risk of 20% or more, and those exposed to chest radiation at young ages are recommended to undergo MRI surveillance starting at ages 25 to 30 and annual mammography (with a variable starting age between 25 and 40, depending on the type of risk). Mutation carriers can delay mammographic screening until age 40 if annual screening breast MRI is performed as recommended. Women diagnosed with breast cancer before age 50 or with personal histories of breast cancer and dense breasts should undergo annual supplemental breast MRI. Others with personal histories, and those with atypia at biopsy, should strongly consider MRI screening, especially if other risk factors are present. For women with dense breasts who desire supplemental screening, breast MRI is recommended. For those who qualify for but cannot undergo breast MRI, contrast-enhanced mammography or ultrasound could be considered. All women should undergo risk assessment by age 25, especially Black women and women of Ashkenazi Jewish heritage, so that those at higher-than-average risk can be identified and appropriate screening initiated.

Analytic Hierarchy Process Analysis of Patient Preferences for Contrast-Enhanced Mammography Versus MRI as Supplemental Screening Options for Breast Cancer

OBJECTIVE

To guide implementation of supplemental breast screening by assessing patient preferences for contrast-enhanced mammography (CEM) versus MRI using analytic hierarchy process (AHP) methodology.

METHODS

In an institutional review board-approved, HIPAA-compliant protocol, from March 23 to June 3, 2022, we contacted 579 women who had both CEM screening and MRI. Women were e-mailed an invitation to complete an online survey developed using an AHP-based model to elicit preferences for CEM or MRI. Methods for categorical data analysis were used to evaluate factors affecting preferences, under the Bonferroni correction for multiplicity.

RESULTS

Complete responses were received from 222 (38.3%) women; the 189 women with a personal history of breast cancer had a mean age 61.8 years, and the 34 women without a personal history of breast cancer had a mean age of 53.6 years. Of 222 respondents, 157 (70.7%, confidence interval [CI]: 64.7-76.7) were determined to prefer CEM to MRI. Breast positioning was the most important criterion for 74 of 222 (33.3%) respondents, with claustrophobia, intravenous line placement, and overall stress most important for 38, 37, and 39 women (17.1%, 16.7%, and 17.6%), respectively, and noise level, contrast injection, and indifference being emphasized least frequently (by 10 [4.5%], 11 [5.0%], and 13 [5.9%] women, respectively). CEM preference was most prevalent (MRI least prevalent) for respondents emphasizing claustrophobia (37 of 38 [97%], CI: 86.2-99.9); CEM preference was least prevalent (MRI most prevalent) for respondents emphasizing breast positioning (40 of 74 [54%], CI: 42.1-65.7).

CONCLUSIONS

AHP-based modeling reveals strong patient preferences for CEM over MRI, with claustrophobia favoring preference for CEM and breast positioning relatively favoring preference for MRI. Our results should help guide implementation of screening CEM and MRI.

An Unenhanced Breast MRI Protocol Based on Diffusion-Weighted Imaging: A Retrospective Single-Center Study on High-Risk Population for Breast Cancer

PURPOSE

This study aimed to investigate the use of contrast-free magnetic resonance imaging (MRI) as an innovative screening method for detecting breast cancer in high-risk asymptomatic women. Specifically, the researchers evaluated the diagnostic performance of diffusion-weighted imaging (DWI) in this population.

METHODS

MR images from asymptomatic women, carriers of a germline mutation in either the BRCA1 or BRCA2 gene, collected in a single center from January 2019 to December 2021 were retrospectively evaluated. A radiologist with experience in breast imaging (R1) and a radiology resident (R2) independently evaluated DWI/ADC maps and, in case of doubts, T2-WI. The standard of reference was the pathological diagnosis through biopsy or surgery, or ≥1 year of clinical and radiological follow-up. Diagnostic performances were calculated for both readers with a 95% confidence interval (CI). The agreement was assessed using Cohen's kappa (κ) statistics.

RESULTS

Out of 313 women, 145 women were included (49.5 ± 12 years), totaling 344 breast MRIs with DWI/ADC maps. The per-exam cancer prevalence was 11/344 (3.2%). The sensitivity was 8/11 (73%; 95% CI: 46-99%) for R1 and 7/11 (64%; 95% CI: 35-92%) for R2. The specificity was 301/333 (90%; 95% CI: 87-94%) for both readers. The diagnostic accuracy was 90% for both readers. R1 recalled 40/344 exams (11.6%) and R2 recalled 39/344 exams (11.3%). Inter-reader reproducibility between readers was in moderate agreement (κ = 0.43).

CONCLUSIONS

In female carriers of a BRCA1/2 mutation, breast DWI supplemented with T2-WI allowed breast cancer detection with high sensitivity and specificity by a radiologist with extensive experience in breast imaging, which is comparable to other screening tests. The findings suggest that DWI and T2-WI have the potential to serve as a stand-alone method for unenhanced breast MRI screening in a selected population, opening up new perspectives for prospective trials.

Challenges and Changes of the Breast Cancer Screening Paradigm

Since four decades mammography is used for early breast cancer detection in asymptomatic women and still remains the gold standard imaging modality. However, population screening programs can be personalized and women can be divided into different groups based on risk factors and personal preferences. The availability of new and evolving imaging modalities, for example, digital breast tomosynthesis, dynamic-contrast-enhanced magnetic resonance imaging (MRI), abbreviated MRI protocols, diffusion-weighted MRI, and contrast-enhanced mammography leads to new challenges and perspectives regarding the feasibility and potential harms of breast cancer screening. The aim of this review is to discuss the current guidelines for different risk groups, to analyze the recent published studies about the diagnostic performance of the imaging modalities and to discuss new developments and future perspectives. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 6.

Breast MRI: an illustration of benign findings

Despite its unparalleled sensitivity for aggressive breast cancer, breast MRI continually excites criticism for a specificity that lags behind that of modern mammographic techniques. Radiologists reporting breast MRI need to recognise the range of benign appearances on breast MRI to avoid unnecessary biopsy. This review summarises the reported diagnostic accuracy of breast MRI with particular attention to the technique's specificity, provides a referenced reporting strategy and discusses factors that compromise diagnostic confidence. We then present a pictorial review of benign findings on breast MRI. Enhancing radiological skills to discriminate malignant from benign findings will minimise false positive biopsies, enabling optimal use of multiparametric breast MRI for the benefit of screening clients and breast cancer patients.

The yield and effectiveness of breast cancer surveillance in women with PTEN Hamartoma Tumor Syndrome

BACKGROUND

Women with PTEN Hamartoma Tumor Syndrome (PHTS) are offered breast cancer (BC) surveillance because of an increased BC lifetime risk. Surveillance guidelines are, however, expert opinion-based because of a lack of data. We aimed to assess the yield and effectiveness of BC surveillance and the prevalence and type of breast disease in women with PHTS.

METHODS

Sixty-five women with PHTS who visited our center between 2001 and 2021 were included. Surveillance consisted of annual magnetic resonance imaging (MRI) and mammography from ages 25 and 30 years, respectively.

RESULTS

Thirty-nine women enrolled in the BC surveillance program (median age at first examination, 38 years [range, 24-70]) and underwent 156 surveillance rounds. Surveillance led to detection of BC in 7/39 women (cancer detection rate [CDR], 45/1000 rounds) and benign breast lesions (BBLs) in 11/39 women. Overall sensitivity₂ (which excludes prophylactic-mastectomy detected BCs) was 100%, whereas sensitivity₂ of mammography and MRI alone was 50% and 100%, respectively. Overall specificity was higher in follow-up rounds (86%) versus first rounds (71%). Regardless of surveillance, 21/65 women developed 35 distinct BCs (median age at first diagnosis, 40 years [range, 24-59]) and 23/65 developed 89 BBLs (median age at first diagnosis, 38 years [range, 15-61]). Surveillance-detected BCs were all T1 and N0, whereas outside surveillance-detected BCs were more often ≥T2 (60%) and N+ (45%) (p < .005).

CONCLUSIONS

The findings show that annual BC surveillance with MRI starting at age 25 years enables detection of early-stage BCs. Performance measures of surveillance and CDR were both high. BBLs were commonly present, underlining the importance of evaluation of all lesions independently.

LAY SUMMARY

Breast cancer surveillance leads to decreased tumor stage and improved survival. Breast cancer surveillance with breast magnetic resonance imaging from age 25 years onward is recommended.

Abbreviated Screening MRI for Women with a History of Breast Cancer: Comparison with Full-Protocol Breast MRI

Background Few studies have compared abbreviated breast MRI with full-protocol MRI in women with a personal history of breast cancer (PHBC), and they have not adjusted for confounding variables. Purpose To compare abbreviated breast MRI with full-protocol MRI in women with PHBC by using propensity score matching to adjust for confounding variables. Materials and Methods In this single-center retrospective study, women with PHBC who underwent full-protocol MRI (January 2008-August 2017) or abbreviated MRI (September 2017-April 2019) were identified. With use of a propensity score-matched cohort, screening performances were compared between the two MRI groups with the McNemar test or a propensity score-adjusted generalized estimating equation. The coprimary analyses were sensitivity and specificity. The secondary analyses were the cancer detection rate, interval cancer rate, positive predictive value for biopsies performed (PPV3), and Breast Imaging Reporting and Data System (BI-RADS) category 3 short-term follow-up rate. Results There were 726 women allocated to each MRI group (mean age ± SD, 50 years ± 8 for both groups). Abbreviated MRI and full-protocol MRI showed comparable sensitivity (15 of 15 cancers [100%; 95% CI: 78, 100] vs nine of 13 cancers [69%; 95% CI: 39, 91], respectively; P = .17). Abbreviated MRI showed higher specificity than full-protocol MRI (660 of 711 examinations [93%; 95% CI: 91, 95] vs 612 of 713 examinations [86%; 95% CI: 83, 88], respectively; P < .001). The cancer detection rate (21 vs 12 per 1000 examinations), interval cancer rate (0 vs five per 1000 examinations), and PPV3 (61% [14 of 23 examinations] vs 41% [nine of 22 examinations]) were comparable (all P < .05). The BI-RADS category 3 short-term follow-up rate of abbreviated MRI was less than half that of full-protocol MRI (5% [36 of 726 examinations] vs 12% [84 of 726 examinations], respectively; P < .001). Ninety-three percent (14 of 15) of cancers detected at abbreviated MRI were node-negative T1-invasive cancers (n = 6) or ductal carcinoma in situ (n = 8). Conclusion Abbreviated breast MRI showed comparable sensitivity and superior specificity to full-protocol MRI in breast cancer detection in women with a personal history of breast cancer. © RSNA, 2022 Online supplemental material is available for this article.

Screening MRI in Women at Intermediate Breast Cancer Risk: An Update of the Recent Literature

Guidelines issued by the American Cancer Society (ACS) in 2007 recommend neither for nor against screening MRI in women at intermediate breast cancer risk (15%-20%), including those with dense breast tissue, a history of lobular neoplasia or atypical ductal hyperplasia (ADH), or a prior breast cancer, because of scarce supporting evidence about the utility of MRI in these specific patient populations. However, since the issuance of the ACS guidelines in 2007, multiple investigations have found that women at intermediate risk may be suitable candidates for screening MRI, given the high detection rates of early-stage cancers and acceptable false-positive rates. For women with dense breast tissue, the Dense Tissue and Early Breast Neoplasm Screening trial reported that the incremental cancer detection rate (CDR) by MRI exceeded 16 cancers per 1000 examinations but decreased in the second round of screening; this decrease in CDR, however, occurred alongside a marked decrease in the false-positive rate. For women with lobular neoplasia or ADH, single-institution retrospective analyses have shown CDRs mostly ranging from 11 to 16 cancers per 1000 MRI examinations, with women with lobular carcinoma in situ benefitting more than women with atypical lobular hyperplasia or ADH. For patients with a prior breast cancer, the cancer yield by MRI varies widely but mostly ranges from 8 to 20 cancers per 1000 examinations, with certain subpopulations more likely to benefit, such as those with dense breasts. This article reviews and summarizes more recent studies on MRI screening of intermediate-risk women.

Automatic breast lesion detection in ultrafast DCE-MRI using deep learning

PURPOSE

We propose a deep learning-based computer-aided detection (CADe) method to detect breast lesions in ultrafast DCE-MRI sequences. This method uses both the 3D spatial information and temporal information obtained from the early-phase of the dynamic acquisition.

METHODS

The proposed CADe method, based on a modified 3D RetinaNet model, operates on ultrafast T1 weighted sequences, which are preprocessed for motion compensation, temporal normalization, and are cropped before passing into the model. The model is optimized to enable the detection of relatively small breast lesions in a screening setting, focusing on detection of lesions that are harder to differentiate from confounding structures inside the breast.

RESULTS

The method was developed based on a dataset consisting of 489 ultrafast MRI studies obtained from 462 patients containing a total of 572 lesions (365 malignant, 207 benign) and achieved a detection rate, sensitivity, and detection rate of benign lesions of 0.90 (0.876-0.934), 0.95 (0.934-0.980), and 0.81 (0.751-0.871) at four false positives per normal breast with 10-fold cross-testing, respectively.

CONCLUSIONS

The deep learning architecture used for the proposed CADe application can efficiently detect benign and malignant lesions on ultrafast DCE-MRI. Furthermore, utilizing the less visible hard-to-detect lesions in training improves the learning process and, subsequently, detection of malignant breast lesions.

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.

Supplemental Breast MRI for Women with Extremely Dense Breasts: Results of the Second Screening Round of the DENSE Trial

Background In the first (prevalent) supplemental MRI screening round of the Dense Tissue and Early Breast Neoplasm Screening (DENSE) trial, a considerable number of breast cancers were found at the cost of an increased false-positive rate (FPR). In incident screening rounds, a lower cancer detection rate (CDR) is expected due to a smaller pool of prevalent cancers, and a reduced FPR, due to the availability of prior MRI examinations. Purpose To investigate screening performance indicators of the second round (incidence round) of the DENSE trial. Materials and Methods The DENSE trial (ClinicalTrials.gov: NCT01315015) is embedded within the Dutch population-based biennial mammography screening program for women aged 50-75 years. MRI examinations were performed between December 2011 and January 2016. Women were eligible for the second round when they again had a negative screening mammogram 2 years after their first MRI. The recall rate, biopsy rate, CDR, FPR, positive predictive values, and distributions of tumor characteristics were calculated and compared with results of the first round using 95% CIs and χ² tests. Results A total of 3436 women (median age, 56 years; interquartile range, 48-64 years) underwent a second MRI screening. The CDR was 5.8 per 1000 screening examinations (95% CI: 3.8, 9.0) compared with 16.5 per 1000 screening examinations (95% CI: 13.3, 20.5) in the first round. The FPR was 26.3 per 1000 screening examinations (95% CI: 21.5, 32.3) in the second round versus 79.8 per 1000 screening examinations (95% CI: 72.4, 87.9) in the first round. The positive predictive value for recall was 18% (20 of 110 participants recalled; 95% CI: 12.1, 26.4), and the positive predictive value for biopsy was 24% (20 of 84 participants who underwent biopsy; 95% CI: 16.0, 33.9), both comparable to that of the first round. All tumors in the second round were stage 0-I and node negative. Conclusion The incremental cancer detection rate in the second round was 5.8 per 1000 screening examinations-compared with 16.5 per 1000 screening examinations in the first round. This was accompanied by a strong reduction in the number of false-positive results. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Moy and Gao in this issue.

Screening Algorithms in Dense Breasts: AJR Expert Panel Narrative Review

Screening mammography reduces breast cancer mortality; however, when used to examine women with dense breasts, its performance and resulting benefits are reduced. Increased breast density is an independent risk factor for breast cancer. Digital breast tomosynthesis (DBT), ultrasound (US), molecular breast imaging (MBI), MRI, and contrast-enhanced mammography (CEM) each have shown improved cancer detection in dense breasts when compared with 2D digital mammography (DM). DBT is the preferred mammographic technique for producing a simultaneous reduction in recalls (i.e., additional imaging). US further increases cancer detection after DM or DBT and reduces interval cancers (cancers detected in the interval between recommended screening examinations), but it also produces substantial additional false-positive findings. MBI improves cancer detection with an effective radiation dose that is approximately fourfold that of DM or DBT but is still within accepted limits. MRI provides the greatest increase in cancer detection and reduces interval cancers and late-stage disease; abbreviated techniques will reduce cost and improve availability. CEM appears to offer performance similar to that of MRI, but further validation is needed. Dense breast notification will soon be a national standard; therefore, understanding the performance of mammography and supplemental modalities is necessary to optimize screening for women with dense breasts.

[High-risk screening using magnetic resonance imaging]

BACKGROUND

Specialized breast cancer early detection programs with magnetic resonance imaging (MRI) in high-risk patients are by now well established in several countries. In Germany, such a program has been running as part of routine care since 2005.

OBJECTIVES

This review article will summarize current developments in high-risk screening with MRI.

MATERIALS AND METHODS

Experiences with the high-risk screening program in Germany over now more than 10 years as well as a review of the current literature will form the basis for this article.

RESULTS

The MRI of the breast is by far the most sensitive imaging modality for the detection of breast cancer and represents the back bone of high-risk screening. More than 90% of cancers detected at high-risk screening are visible on the MRI and more than 30% of cancers are detected primarily by MRI alone. However, a prerequisite for effective screening with MRI is a sufficiently high breast cancer incidence in the screened population. This is demonstrated by the fact that the positive predictive value of screening with MRI in women without a BRCA1/2 mutation in the age group between 30 and 39 years is unacceptably low with 2.9%.

CONCLUSIONS

In high-risk screening, MRI is the primary imaging tool with mammography and/or ultrasound added as adjunct if necessary. In women with a strong family history of breast cancer but no proven pathogenic mutation in one of the known risk genes in the index patient in the family, the high-risk screening should not routinely start at age 30, but should be postponed until the 10-year breast cancer risk passes a threshold of 5%.

Magnetic Resonance Imaging in Screening of Breast Cancer

Magnetic Resonance (MR) imaging is the most sensitive modality for breast cancer detection but is currently limited to screening women at high risk due to limited specificity and test accessibility. However, specificity of MR imaging improves with successive rounds of screening, and abbreviated approaches have the potential to increase access and decrease cost. There is growing evidence to support supplemental MR imaging in moderate-risk women, and current guidelines continue to evolve. Functional imaging has the potential to maximize survival benefit of screening. Leveraging MR imaging as a possible primary screening tool is therefore also being investigated in average-risk women.

Ex Vivo Study of Artifacts Caused by Breast Tissue Markers with Different 1.5 Tesla and 3 Tesla MRI Scanners - A Bicentric Study

RATIONALE AND OBJECTIVES

The purpose of our study was to evaluate magnetic resonance (MR) artifacts related to breast tissue markers in breast imaging procedures.

MATERIALS AND METHODS

In this bicentric prospective ex vivo study 10 different commercially available markers were measured in self-made breast phantoms. Breast tissue markers varying in marker size, composition, and shape were evaluated. MR imaging (MRI) scans were performed on 1.5 Tesla (T) and 3 T scanners from 2 different vendors, using dedicated breast coils. Three different sequences (T1-weighted images with and without fat saturation, T2-weighted images) were acquired in axial and coronal view. Three blinded readers electronically measured the artifact length.

RESULTS

All markers caused artifacts in MRI. The largest median artifact length was 10.4 mm, interquartile range (IQR 9.4-11.0 mm), the smallest 4.8 mm (IQR 4.5-5.2 mm). Relative artifact length (quotient artifact length in mm/real physical length of the marker) ranged between 0.9 (IQR 0.9-1.2) and 3.0 (IQR 2.8-3.4). Mean artifact length was higher for metallic markers (10.2 mm; IQR 8.7-11.5 mm) compared to metallic markers with nonmetallic coating (7.7 mm; IQR 6.3-10.2 mm) and nonmetallic marker (7.6 mm; IQR 5.9-10.0 mm); all p < 0.0001. Artifact size was higher in coronal in comparison to axial view; p < 0.05. The results were comparable between the different field strengths, the sites and sequences; p > 0.05. Interobserver agreement was excellent (ntraclass correlation coefficient = 0.83).

CONCLUSION

Artifacts are necessary in the detection and localization of breast tissue markers, but could also limit the interpretation of MRI due to the possibility of masking the residual tumor after biopsy. This artifact size varies among the different clips evaluated. It depends on marker composition and scan direction but is not influenced by image sequence, field strength or scanner type.

Breast Magnetic Resonance Imaging Audit: Pitfalls, Challenges, and Future Considerations

Breast magnetic resonance (MR) imaging is the most sensitive imaging modality for breast cancer detection and guidelines recommend its use, in addition to screening mammography, for high-risk women. The most recent American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) manual coordinated cross-modality BI-RADS terminology and established an outcome monitoring section that helps guide a medical imaging outcomes audit. This article provides a framework for performing a breast MR imaging audit in clinical practice, incorporating ACR BI-RADS guidance and more recently published data, clarifies common pitfalls, and discusses audit challenges related to evolving clinical practice.

Abbreviated Screening Breast MRI in Women at Higher-than-Average Risk for Breast Cancer with Prior Normal Full Protocol MRI

OBJECTIVE

To compare the performance of abbreviated screening breast MRI (ABMR) versus full protocol MRI (FPMR) in women at higher-than-average risk for breast cancer with a prior normal FPMR.

METHODS

ABMR was performed on higher-than-average-risk women who had a prior normal FPMR. ABMR protocol consisted of short inversion time inversion recovery imaging, precontrast, and two early postcontrast sequences acquired in under 10 minutes. Retrospective review of ABMR examinations performed from July 2016 to July 2018 was compared with a control group who underwent routine screening with FPMR who had a prior normal FPMR performed from July 2014 to June 2016. Screening outcome metrics were calculated and compared, adjusting for differences in patient demographics.

RESULTS

The study cohort included 481 ABMR examinations, while the control group included 440 FPMR studies. There was no significant difference in the abnormal interpretation rate (AIR) or cancer detection rate (CDR) for the ABMR versus the FPMR group (AIR 6.0% vs 6.8% respectively, odds ratio (OR) 0.91, 95% confidence interval (CI): 0.53-1.5, P = 0.73; CDR 8.3 vs 11 cancers detected per 1000 examinations respectively, OR 0.73, 95% CI: 0.20-2.7, P = 0.64). The PPV2 and PPV3 for the ABMR group was 19% and 21% versus 16% and 16% for the FPMR group, with no statistical difference. Sensitivity was 100% in each group with no interval cancers. There was no difference in specificity between the ABMR and FPMR groups, 93% versus 94%, respectively (P = 0.73).

CONCLUSION

ABMR may be used to screen higher-than-average-risk women with a prior normal FPMR as outcome metrics are equivalent to FPMR.

Current status of breast cancer screening in high-risk women in Japan

Overseas, the importance for breast MRI screening for high-risk groups has been shown. However, the evidence among Japanese population was lacking. Therefore, we collaborated with the "Study on clinical and genetic characterization of hereditary breast and ovarian cancer and improvement in prognosis using genetic information in Japan" group, as part of the Comprehensive Research Project on the Promotion of Cancer Control, Health and Labour Sciences Research, and have been conducting the study entitled, "Study of the usefulness of MRI surveillance of BRCA1/2 mutation carriers" since 2014. In addition, we found that in the Japanese population also, the pathological and imaging characteristics differ between BRCA1 and BRCA2 mutation carriers, like in non-Japanese populations by the several reports. In high-risk females, risk categories such as BRCA1 or BRCA2 mutation carriers are very important. Furthermore, in the future, the optimal surveillance modalities and examination intervals would also vary according to the age, thinness of the breast (constitution), breast density (individual differences on mammography), etc.; this would be "personalized surveillance", and quality-assured MRI examination is of the essence. This review will present clinical trial data of prospective MRI surveillance in Japan, and summarize the current status of breast cancer screening in high-risk Japanese women.

Screening in patients with increased risk of breast cancer (part 2). Where are we now? Actual MRI screening controversies

For women with a high risk of breast cancer, early detection plays an important role. Due to the high incidence of breast cancer, and at a younger age than in the general population, screening begins earlier, and there is considerable evidence that magnetic resonance is the most sensitive diagnostic tool, and the principal American and European guidelines agree on the recommendation to perform annual magnetic resonance (with supplemental annual mammography) as an optimal mode of screening. In addition to the absence of current consensus on which patients should be included in the recommendation for magnetic resonance screening (widely discussed in the introduction of part 1 of this work), there are other aspects that are different between guidelines, that are not specified, or that are susceptible to change based on the evidence of several years of experience, that we have called «controversies», such as the age to begin screening, the possible advisability of using a different strategy in different subgroups, performing alternate versus synchronous magnetic resonance and mammography, the age at which to terminate the two techniques, or how to follow up after risk reduction surgery.The aim of the second part of the paper is, by reviewing the literature, to provide an update in relation to some of the main «controversies» in high risk screening with magnetic resonance. And finally, based on all this, to propose a possible model of optimal and updated screening protocol.

The supplemental value of mammographic screening over breast MRI alone in BRCA2 mutation carriers

Purpose

BRCA2 mutation carriers are offered annual breast screening with MRI and mammography. The aim of this study was to investigate the supplemental value of mammographic screening over MRI screening alone.

Methods

In this multicenter study, proven BRCA2 mutation carriers, who developed breast cancer during screening using both digital mammography and state-of-art breast MRI, were identified. Clinical data were reviewed to classify cases in screen-detected and interval cancers. Imaging was reviewed to assess the diagnostic value of mammography and MRI, using the Breast Imaging and Data System (BI-RADS) classification allocated at the time of diagnosis.

Results

From January 2003 till March 2019, 62 invasive breast cancers and 23 ductal carcinomas in situ were diagnosed in 83 BRCA2 mutation carriers under surveillance. Overall screening sensitivity was 95.2% (81/85). Four interval cancers occurred (4.7% (4/85)). MRI detected 73 of 85 breast cancers (sensitivity 85.8%) and 42 mammography (sensitivity 49.9%) (p < 0.001).

Eight mammography-only lesions occurred. In 1 of 17 women younger than 40 years, a 6-mm grade 3 DCIS, retrospectively visible on MRI, was detected with mammography only in a 38-year-old woman. The other 7 mammography-only breast cancers were diagnosed in women aged 50 years and older, increasing sensitivity in this subgroup from 79.5% (35/44) to 95.5% (42/44) (p ≤ 0.001).

Conclusions

In BRCA2 mutation carriers younger than 40 years, the benefit of mammographic screening over MRI was very small. In carriers of 50 years and older, mammographic screening contributed significantly. Hence, we propose to postpone mammographic screening in BRCA2 mutation carriers to at least age 40.

Screening in patients with increased risk of breast cancer (part 1): pros and cons of MRI screening

Screening plays an important role in women with a high risk of breast cancer. Given this population's high incidence of breast cancer and younger age of onset compared to the general population, it is recommended that screening starts earlier. There is ample evidence that magnetic resonance imaging (MRI) is the most sensitive diagnostic tool, and American and the European guidelines both recommend annual MRI screening (with supplementary annual mammography) as the optimum screening modality. Nevertheless, the current guidelines do not totally agree about the recommendations for MRI screening in some subgroups of patients. The first part of this article on screening in women with increased risk of breast cancer reviews the literature to explain and evaluate the advantages of MRI screening compared to screening with mammography alone: increased detection of smaller cancers with less associated lymph node involvement and a reduction in the rate of interval cancers, which can have an impact on survival and mortality (with comparable effects to other preventative measures). At the same time, however, we would like to reflect on the drawbacks of MRI screening that affect its applicability.

Feasibility of abbreviated magnetic resonance imaging (AB-MRI) screening in women with a personal history (PH) of breast cancer

PURPOSE

To investigate the feasibility of abbreviated magnetic resonance imaging (AB-MRI) in women with a personal history (PH) of breast cancer as a screening tool.

MATERIALS AND METHODS

We retrospectively reviewed 1880 screening AB-MRIs in 763 women with a PH of breast cancer (median age, 55 years; range, 23-89 years) between October 2015 and October 2016. The total acquisition times of AB-MRI were 8.3 min and 2.8 min with and without T2-weighted imaging, respectively. The tissue diagnosis or one-year follow-up status was used as the reference standard. The characteristics of tumor recurrences detected on AB-MRI screenings were analyzed. The cancer detection rates (CDRs) and additional CDRs for the 1st round and overall rounds of AB-MRI screening were calculated. The recall rate, sensitivity, specificity, positive predictive values for recall (PPV1) and biopsy (PPV3) for the 1st round of AB-MRI screening were calculated. The diagnostic performance of the combination of mammography and ultrasonography was compared with that of AB-MRI by receiver operating characteristic (ROC) curve analysis.

RESULTS

Fifteen of a total of 21 recurrences were detected on the 1st round of AB-MRI screening: 93.3% were node-negative T1 tumors (median tumor size, 1.02 cm; range, 0.1-2 cm) or Tis; 66.7% were high-grade tumors; 8 of these 15 were mammographically and ultrasonographically occult. The CDR and additional CDR for the 1st round of AB-MRI screening were 0.019 and 0.010 per woman, respectively. The sensitivity, specificity, recall rate, PPV1 and PPV3 for the 1st round of AB-MRI screening were 100%, 96.0%, 14.3%, 13.8% and 58.3%, respectively. For detecting secondary cancer, AB-MRI showed a higher sensitivity and PPV than the combination of mammography and ultrasonography (95.2%, 57.1% vs 47.6%, 38.5%). The area under the ROC curve was higher for AB-MRI (0.966; 95% CI: 0.951-0.978) than the combination of mammography and ultrasonography (0.727; 95% CI: 0.694-0.759) (P<0.0001).

CONCLUSION

AB-MRI improved cancer detection with a high specificity, sensitivity and PPV in women with a PH of breast cancer. AB-MRI could be a useful screening tool for detecting secondary cancer considering its high diagnostic performance and short examination time.

Comparison of Abbreviated Breast MRI vs Digital Breast Tomosynthesis for Breast Cancer Detection Among Women With Dense Breasts Undergoing Screening

IMPORTANCE

Improved screening methods for women with dense breasts are needed because of their increased risk of breast cancer and of failed early diagnosis by screening mammography.

OBJECTIVE

To compare the screening performance of abbreviated breast magnetic resonance imaging (MRI) and digital breast tomosynthesis (DBT) in women with dense breasts.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study with longitudinal follow-up at 48 academic, community hospital, and private practice sites in the United States and Germany, conducted between December 2016 and November 2017 among average-risk women aged 40 to 75 years with heterogeneously dense or extremely dense breasts undergoing routine screening. Follow-up ascertainment of cancer diagnoses was complete through September 12, 2019.

EXPOSURES

All women underwent screening by both DBT and abbreviated breast MRI, performed in randomized order and read independently to avoid interpretation bias.

MAIN OUTCOMES AND MEASURES

The primary end point was the invasive cancer detection rate. Secondary outcomes included sensitivity, specificity, additional imaging recommendation rate, and positive predictive value (PPV) of biopsy, using invasive cancer and ductal carcinoma in situ (DCIS) to define a positive reference standard. All outcomes are reported at the participant level. Pathology of core or surgical biopsy was the reference standard for cancer detection rate and PPV; interval cancers reported until the next annual screen were included in the reference standard for sensitivity and specificity.

RESULTS

Among 1516 enrolled women, 1444 (median age, 54 [range, 40-75] years) completed both examinations and were included in the analysis. The reference standard was positive for invasive cancer with or without DCIS in 17 women and for DCIS alone in another 6. No interval cancers were observed during follow-up. Abbreviated breast MRI detected all 17 women with invasive cancer and 5 of 6 women with DCIS. Digital breast tomosynthesis detected 7 of 17 women with invasive cancer and 2 of 6 women with DCIS. The invasive cancer detection rate was 11.8 (95% CI, 7.4-18.8) per 1000 women for abbreviated breast MRI vs 4.8 (95% CI, 2.4-10.0) per 1000 women for DBT, a difference of 7 (95% CI, 2.2-11.6) per 1000 women (exact McNemar P = .002). For detection of invasive cancer and DCIS, sensitivity was 95.7% (95% CI, 79.0%-99.2%) with abbreviated breast MRI vs 39.1% (95% CI, 22.2%-59.2%) with DBT (P = .001) and specificity was 86.7% (95% CI, 84.8%-88.4%) vs 97.4% (95% CI, 96.5%-98.1%), respectively (P < .001). The additional imaging recommendation rate was 7.5% (95% CI, 6.2%-9.0%) with abbreviated breast MRI vs 10.1% (95% CI, 8.7%-11.8%) with DBT (P = .02) and the PPV was 19.6% (95% CI, 13.2%-28.2%) vs 31.0% (95% CI, 17.0%-49.7%), respectively (P = .15).

CONCLUSIONS AND RELEVANCE

Among women with dense breasts undergoing screening, abbreviated breast MRI, compared with DBT, was associated with a significantly higher rate of invasive breast cancer detection. Further research is needed to better understand the relationship between screening methods and clinical outcome.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02933489.

The Effect of Prior Comparison MRI on Interpretive Performance of Screening Breast MRI

OBJECTIVE

To evaluate the effect of prior comparison MRI on interpretive performance of screening breast MRI.

METHODS

After institutional review board approval, all screening breast MRI examinations performed from January 2011 through December 2014 were retrospectively reviewed. Screening performance metrics were estimated and compared for exams with and without a prior comparison MRI, using logistic regression models to adjust for age and screening indication (BRCA mutation or thoracic radiation versus breast cancer history versus high-risk lesion history versus breast cancer family history).

RESULTS

Most exams, 4509 (87%), had a prior comparison MRI (incidence round), while 661 (13%) did not (prevalence round). Abnormal interpretation rate (6% vs 20%, P < 0.01), biopsy rate (3% vs 9%, P < 0.01), and false-positive biopsy recommendation rate per 1000 exams (21 vs 71, P < 0.01) were significantly lower in the incidence rounds compared to the prevalence rounds, while specificity was significantly higher (95% vs 81%, P < 0.01). There was no difference in cancer detection rate (CDR) per 1000 exams (12 vs 20, P = 0.1), positive predictive value of biopsies performed (PPV3) (35% vs 23%, P = 0.1), or sensitivity (86% vs 76%, P = 0.4).

CONCLUSION

Presence of a prior comparison significantly improves incidence round screening breast MRI examination performance compared with prevalence round screening. Consideration should be given to updating the BI-RADS breast MRI screening benchmarks and auditing prevalence and incidence round examinations separately.

Abbreviated Magnetic Resonance Imaging for Breast Cancer Screening: Concept, Early Results, and Considerations

Breast magnetic resonance imaging (MRI) has been increasingly utilized, especially in screening for high-risk cases, because of its high sensitivity and superior ability to detect cancers as compared with mammography and ultrasound. Several limitations such as higher cost, longer examination time, longer interpretation time, and low availability have hindered the wider application of MRI, especially for screening of average-risk women. To overcome some of these limitations and increase access to MRI screening, an abbreviated breast MRI protocol has been introduced. Abbreviated breast MRI is becoming popular and challenges the status quo. This review aims to present an overview of abbreviated MRI, discuss the current findings, and introduce ongoing prospective trials.

Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer in Women: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Pathogenic mutations in breast cancer susceptibility genes BRCA1 and BRCA2 increase risks for breast, ovarian, fallopian tube, and peritoneal cancer in women; interventions reduce risk in mutation carriers.

OBJECTIVE

To update the 2013 US Preventive Services Task Force review on benefits and harms of risk assessment, genetic counseling, and genetic testing for BRCA1/2-related cancer in women.

DATA SOURCES

Cochrane libraries; MEDLINE, PsycINFO, EMBASE (January 1, 2013, to March 6, 2019, for updates; January 1, 1994, to March 6, 2019, for new key questions and populations); reference lists.

STUDY SELECTION

Discriminatory accuracy studies, randomized clinical trials (RCTs), and observational studies of women without recently diagnosed BRCA1/2-related cancer.

DATA EXTRACTION AND SYNTHESIS

Data on study methods, setting, population characteristics, eligibility criteria, interventions, numbers enrolled and lost to follow-up, outcome ascertainment, and results were abstracted. Two reviewers independently assessed study quality.

MAIN OUTCOMES AND MEASURES

Cancer incidence and mortality; discriminatory accuracy of risk assessment tools for BRCA1/2 mutations; benefits and harms of risk assessment, genetic counseling, genetic testing, and risk-reducing interventions.

RESULTS

For this review, 103 studies (110 articles; N = 92 712) were included. No studies evaluated the effectiveness of risk assessment, genetic counseling, and genetic testing in reducing incidence and mortality of BRCA1/2-related cancer. Fourteen studies (n = 43 813) of 8 risk assessment tools to guide referrals to genetic counseling demonstrated moderate to high accuracy (area under the receiver operating characteristic curve, 0.68-0.96). Twenty-eight studies (n = 8060) indicated that genetic counseling was associated with reduced breast cancer worry, anxiety, and depression; increased understanding of risk; and decreased intention for testing. Twenty studies (n = 4322) showed that breast cancer worry and anxiety were higher after testing for women with positive results and lower for others; understanding of risk was higher after testing. In 8 RCTs (n = 54 651), tamoxifen (relative risk [RR], 0.69 [95% CI, 0.59-0.84]; 4 trials), raloxifene (RR, 0.44 [95% CI, 0.24-0.80]; 2 trials), and aromatase inhibitors (RR, 0.45 [95% CI, 0.26-0.70]; 2 trials) were associated with lower risks of invasive breast cancer compared with placebo; results were not specific to mutation carriers. Mastectomy was associated with 90% to 100% reduction in breast cancer incidence (6 studies; n = 2546) and 81% to 100% reduction in breast cancer mortality (1 study; n = 639); oophorectomy was associated with 69% to 100% reduction in ovarian cancer (2 studies; n = 2108); complications were common with mastectomy.

CONCLUSIONS AND RELEVANCE

Among women without recently diagnosed BRCA1/2-related cancer, the benefits and harms of risk assessment, genetic counseling, and genetic testing to reduce cancer incidence and mortality have not been directly evaluated by current research.

A Microsimulation Model for Evaluating the Effectiveness of Cancer Risk Management for BRCA Pathogenic Variant Carriers: miBRovaCAre

OBJECTIVES

To develop a validated model for evaluating the real-world effectiveness of long-term clinical management strategies for women with germline BRCA1 or BRCA2 pathogenic variants.

METHODS

A microsimulation model was developed that included a BRCA-specific natural history for breast and ovarian cancer, a clinical framework for carrier follow-up, and cancer risk management strategies (breast screening, risk-reducing mastectomy, and bilateral salpingo-oophorectomy). Adherence rates and outcomes for breast screening and risk-reducing surgery were obtained from BRCA carriers seen through a familial cancer service in Melbourne, Australia. The model was assessed for internal and external validity. The model was used to compare women perfectly adhering to screening recommendations versus actual adherence of the clinical cohort.

RESULTS

The model accurately predicted cancer incidence, pathology, and mortality. Using actual adherence for breast screening resulted in additional breast cancer deaths (per 1000 women: BRCA1, 2.7; BRCA2, 1.6) compared with perfect screening adherence. This decreased average life expectancy by 0.30 life-years for BRCA1 and 0.07 life-years for BRCA2. When carriers had access to risk-reducing mastectomy, the benefit from improved screening adherence was not significant.

CONCLUSIONS

The developed model is a good descriptor of BRCA carriers' lifetime trajectory and its modification by use of risk management strategies alone or in combination. Evaluations of breast screening in BRCA carriers may overestimate the benefits of screening programs unless adherence is considered. By incorporating real-world clinical practice and patient behavior, this model can assist in developing clinical services and improving clinical outcomes for carriers.

The clinical impact of MRI screening for BRCA mutation carriers: the first report in Japan

BACKGROUND

There is no consensus on the appropriate surveillance for high-risk women with breast cancer in Japan. We investigated their imaging features and pathological characteristics to build a proper surveillance system for asymptomatic high-risk individuals in the future.

METHODS

We retrospectively reviewed 93 female (median age 43 years) BRCA1 and BRCA2 mutation carriers from our institutional clinical database from 2011 to 2017. The study population was composed of 112 breast cancers. Mammography and MRI were reviewed by examiners blinded to patients' clinical history. Final surgical or biopsy histopathology served as the reference standard in all the patients.

RESULTS

Fifty-nine breast cancers met selection criteria; of these, 30 were BRCA1-associated tumors, and 29 were BRCA2-associated tumors. Invasive ductal carcinoma was the most prevalent type in both BRCA1 and BRCA2. There were statistically significant differences in phenotype, nuclear grade, and Ki-67 labeling index between BRCA1 and BRCA2 mutation carriers. Additionally, imaging findings on mammography and MRI were statistically different. Tumors in BRCA2 carriers demonstrated mammographic calcifications more frequently, while those in BRCA1 carriers demonstrated a mass or architectural distortion (P < 0.001). Enhancement pattern on MRI also significantly differed between the two subgroups (P = 0.006). The size of MRI-detected lesions was statistically smaller than the size of those detected by other modalities (P = 0.004).

CONCLUSIONS

The imaging and histological characteristics of BRCA1/2 mutation carriers were consistent with other countries' studies. MRI-detected lesions were significantly smaller than lesions detected by non-MRI modality. All lesions in BRCA1 mutation carriers could be detected by MRI.

Amount of fibroglandular tissue FGT and background parenchymal enhancement BPE in relation to breast cancer risk and false positives in a breast MRI screening program : A retrospective cohort study

Objectives

The purpose of this study is to evaluate the predictive value of the amount of fibroglandular tissue (FGT) and background parenchymal enhancement (BPE), measured at baseline on breast MRI, for breast cancer development and risk of false-positive findings in women at increased risk for breast cancer.

Methods

Negative baseline MRI scans of 1533 women participating in a screening program for women at increased risk for breast cancer between January 1, 2003, and January 1, 2014, were selected. Automated tools based on deep learning were used to obtain quantitative measures of FGT and BPE. Logistic regression using forward selection was used to assess relationships between FGT, BPE, cancer detection, false-positive recall, and false-positive biopsy.

Results

Sixty cancers were detected in follow-up. FGT was only associated to short-term cancer risk; BPE was not associated with cancer risk. High FGT and BPE did lead to more false-positive recalls at baseline (OR 1.259, p = 0.050, and OR 1.475, p = 0.003) and to more frequent false-positive biopsies at baseline (OR 1.315, p = 0.049, and OR 1.807, p = 0.002), but were not predictive for false-positive findings in subsequent screening rounds.

Conclusions

FGT and BPE, measured on baseline MRI, are not predictive for overall breast cancer development in women at increased risk. High FGT and BPE lead to more false-positive findings at baseline.

Key Points

• Amount of fibroglandular tissue is only predictive for short-term breast cancer risk in women at increased risk.

• Background parenchymal enhancement measured on baseline MRI is not predictive for breast cancer development in women at increased risk.

• High amount of fibroglandular tissue and background parenchymal enhancement lead to more false-positive findings at baseline MRI.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06020-2) contains supplementary material, which is available to authorized users.

Contrast-enhanced MRI for breast cancer screening

Multiple studies in the first decade of the 21^st century have established contrast-enhanced breast MRI as a screening modality for women with a hereditary or familial increased risk for the development of breast cancer. In recent studies, in women with various risk profiles, the sensitivity ranges between 81% and 100%, which is approximately twice as high as the sensitivity of mammography. The specificity increases in follow-up rounds to around 97%, with positive predictive values for biopsy in the same range as for mammography. MRI preferentially detects the more aggressive/invasive types of breast cancer, but has a higher sensitivity than mammography for any type of cancer. This performance implies that in women screened with breast MRI, all other examinations must be regarded as supplemental. Mammography may yield ~5% additional cancers, mostly ductal carcinoma in situ, while slightly decreasing specificity and increasing the costs. Ultrasound has no supplemental value when MRI is used. Evidence is mounting that in other groups of women the performance of MRI is likewise superior to more conventional screening techniques. Particularly in women with a personal history of breast cancer, the gain seems to be high, but also in women with a biopsy history of lobular carcinoma in situ and even women at average risk, similar results are reported. Initial outcome studies show that breast MRI detects cancer earlier, which induces a stage-shift increasing the survival benefit of screening. Cost-effectiveness is still an issue, particularly for women at lower risk. Since costs of the MRI scan itself are a driving factor, efforts to reduce these costs are essential. The use of abbreviated MRI protocols may enable more widespread use of breast MRI for screening. Level of Evidence: 1 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:377-390.

The added value of mammography in different age-groups of women with and without BRCA mutation screened with breast MRI

Background

Breast magnetic resonance imaging (MRI) is the most sensitive imaging method for breast cancer detection and is therefore offered as a screening technique to women at increased risk of developing breast cancer. However, mammography is currently added from the age of 30 without proven benefits. The purpose of this study is to investigate the added cancer detection of mammography when breast MRI is available, focusing on the value in women with and without BRCA mutation, and in the age groups above and below 50 years.

Methods

This retrospective single-center study evaluated 6553 screening rounds in 2026 women at increased risk of breast cancer (1 January 2003 to 1 January 2014). Risk category (BRCA mutation versus others at increased risk of breast cancer), age at examination, recall, biopsy, and histopathological diagnosis were recorded. Cancer yield, false positive recall rate (FPR), and false positive biopsy rate (FPB) were calculated using generalized estimating equations for separate age categories (< 40, 40–50, 50–60, ≥ 60 years). Numbers of screens needed to detect an additional breast cancer with mammography (NSN) were calculated for the subgroups.

Results

Of a total of 125 screen-detected breast cancers, 112 were detected by MRI and 66 by mammography: 13 cancers were solely detected by mammography, including 8 cases of ductal carcinoma in situ. In BRCA mutation carriers, 3 of 61 cancers were detected only on mammography, while in other women 10 of 64 cases were detected with mammography alone. While 77% of mammography-detected-only cancers were detected in women ≥ 50 years of age, mammography also added more to the FPR in these women. Below 50 years the number of mammographic examinations needed to find an MRI-occult cancer was 1427.

Conclusions

Mammography is of limited added value in terms of cancer detection when breast MRI is available for women of all ages who are at increased risk. While the benefit appears slightly larger in women over 50 years of age without BRCA mutation, there is also a substantial increase in false positive findings in these women.

The frequency of missed breast cancers in women participating in a high-risk MRI screening program

Purpose

To evaluate the frequency of missed cancers on breast MRI in women participating in a high-risk screening program.

Methods

Patient files from women who participated in an increased risk mammography and MRI screening program (2003–2014) were coupled to the Dutch National Cancer Registry. For each cancer detected, we determined whether an MRI scan was available (0–24 months before cancer detection), which was reported to be negative. These negative MRI scans were in consensus re-evaluated by two dedicated breast radiologists, with knowledge of the cancer location. Cancers were scored as invisible, minimal sign, or visible. Additionally, BI-RADS scores, background parenchymal enhancement, and image quality (IQ; perfect, sufficient, bad) were determined. Results were stratified by detection mode (mammography, MRI, interval cancers, or cancers in prophylactic mastectomies) and patient characteristics (presence of BRCA mutation, age, menopausal state).

Results

Negative prior MRI scans were available for 131 breast cancers. Overall 31% of cancers were visible at the initially negative MRI scan and 34% of cancers showed a minimal sign. The presence of a BRCA mutation strongly reduced the likelihood of visible findings in the last negative MRI (19 vs. 46%, P < 0.001). Less than perfect IQ increased the likelihood of visible findings and minimal signs in the negative MRI (P = 0.021).

Conclusion

This study shows that almost one-third of cancers detected in a high-risk screening program are already visible at the last negative MRI scan, and even more in women without BRCA mutations. Regular auditing and double reading for breast MRI screening is warranted.