Results of MRI screening for breast cancer in high-risk patients with LCIS and atypical hyperplasia

Energy curve based enhanced smell agent optimizer for optimal multilevel threshold selection of thermographic breast image segmentation

Multilevel thresholding image segmentation will subdivide an image into several meaningful regions or objects, which makes the image more informative and easier to analyze. Optimal multilevel thresholding approaches are extensively used for segmentation because they are easy to implement and offer low computational cost. Multilevel thresholding image segmentation is frequently performed using popular methods such as Otsu's between-class variance and Kapur's entropy. Numerous researchers have used evolutionary algorithms to identify the best multilevel thresholds based on the above approaches using histogram. This paper uses the Energy Curve (EC) based thresholding method instead of the histogram. Chaotic Bidirectional Smell Agent Optimization with Adaptive Control Strategy (ChBSAOACS), a powerful evolutionary algorithm, is developed and employed in this paper to create and execute an effective method for multilevel thresholding segmentation of breast thermogram images based on energy curves. The proposed algorithm was tested for viability on standard breast thermogram images. All experimental data are examined quantitatively and qualitatively to verify the suggested method's efficacy.

Update on Lobular Neoplasia

Lobular neoplasia (LN) is a histopathologic entity that encompasses both lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia (ALH). Management of LN is known to be variable and institutionally dependent. The variability in approach after a diagnosis of LN at percutaneous breast biopsy derives in part from heterogeneity in the literature, resulting in a range of reported upgrade rates to malignancy after initial identification at percutaneous biopsy, and also from historical shifts in understanding of the natural history of LN. It has become increasingly recognized that not all LN is the same and that distinct variants of LN such as pleomorphic LCIS and florid LCIS have distinct natural histories and distinct likelihoods of upgrade to malignancy. In addition, it is also increasingly understood that appropriate management of LN relies on scrupulous radiologic-pathologic correlation. This review details the imaging features and histopathologic nature of ALH, classic-type LCIS, and the LCIS variants; addresses changes in the historical understanding of this entity contributing to confusion regarding its management; and discusses the importance of performing radiologic-pathologic correlation after percutaneous biopsy to help guide appropriate management steps when LN is encountered. In addition to the short-term implications of an LN diagnosis in terms of upgrade and surgical outcomes, the long-term implications of an LN diagnosis regarding risk of developing a later breast cancer are examined. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Prevalence, Impact, and Diagnostic Challenges of Benign Breast Disease: A Narrative Review

Benign breast diseases, which are commonly seen in clinical practice, have various clinical presentations and implications, as well as management strategies. This article describes common benign breast lesions, presentations of these lesions, and typical radiographic and histologic findings. Also included in this review are the most recent data and guideline-based recommendations for the management of benign breast diseases at diagnosis, including surgical referral, medical management, and ongoing surveillance.

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.

Screening MRI Does Not Increase Cancer Detection or Result in an Earlier Stage at Diagnosis for Patients with High-Risk Breast Lesions: A Propensity Score Analysis

BACKGROUND

Guidelines recommend consideration of screening MRI for patients with high-risk breast lesions (HRLs), acknowledging limited data for this moderate-risk population.

METHODS

This study identified patients with atypical ductal/lobular hyperplasia (ADH/ALH), lobular carcinoma in situ, (LCIS) or both evaluated at our high-risk clinic. Patients were categorized as having received screening mammography (MMG) alone vs. MMG and breast MRI (MMG+MRI). Inverse probability weighting based on propensity scores (PS) representing likelihood of MRI use was applied to Kaplan-Meier and Cox regression analyses to determine cancer detection and biopsy rates by screening group.

RESULTS

Among 908 eligible patients, 699 (77%) patients with available follow-up data were analyzed (542 with ADH/ALH and 157 with LCIS). Of the 699 patients, 540 (77%) received MMG alone, and 159 (23%) received MMG + MRI. The median follow-up period was 25 months, during which a median of two MRIs were performed. After PS-weighting, the characteristics of each screening group were well-balanced with respect to age, race, body mass index (BMI), menopausal status, breast density, family history, HRL type, and chemoprevention use. The 4 year breast cancer detection rate was 3.6% with both MMG alone and MMG+MRI (p = 0.89). The breast biopsy rates were significantly higher with MMG+MRI (30.5% vs12.6%; hazard ratio [HR], 2.67; p < 0.001). All breast cancers were clinically node-negative and pathologic stage 0 or 1. Among five cancers in the MMG+MRI group, two were MRI-detected, two were MMG-detected, and one was detected on clinical exam.

CONCLUSIONS

Screening MRI did not improve cancer detection, and cancer characteristics were favorable whether screened with MMG alone or MMG + MRI. These findings question the benefit of MRI for patients with HRL, although longer-term follow-up study is needed.

Accuracy of the Breast Cancer Surveillance Consortium Model Among Women with LCIS

PURPOSE

The Breast Cancer Surveillance Consortium (BCSC) model predicts risk of invasive breast cancer risk based on age, race, family history, breast density, and history of benign breast disease, including lobular carcinoma in situ (LCIS). However, validation studies for this model included few women with LCIS. We sought to evaluate the accuracy of the BCSC model among this cohort.

METHODS

Women with LCIS diagnosed between 1983 and 2017 were identified from a prospectively maintained database. The BCSC score was calculated; those with prior breast cancer, unknown breast density, age < 35 years or > 74 years, or with history of chemoprevention use were excluded. The Kaplan-Meier method was used to estimate incidence rates. Time-dependent receiver operating characteristic (ROC) analysis was used to analyze the discriminative capacity of the model.

RESULTS

1302 women with LCIS were included. At a median follow-up of 7 years, 152 women (12%) developed invasive cancer (6 with bilateral disease). Cumulative incidences of invasive breast cancer were 7.1% (95% CI 5.6-8.7) and 13.3% (95% CI 10.9-15.6), respectively, and the median BCSC risk scores were 4.9 and 10.4, respectively, at 5 and 10 years. The median 10-year BCSC score was significantly lower than the 10-year Tyrer-Cuzick score (10.4 vs 20.8, p < 0.001). The ROC curve scores (AUC) for BCSC at 5 and 10 years were 0.59 (95% CI 0.52-0.66) and 0.58 (95% CI 0.52-0.64), respectively.

CONCLUSION

The BCSC model has moderate accuracy in predicting invasive breast cancer risk among women with LCIS with fair discrimination for risk prediction between individuals.

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.

Current and Future Directions of Breast MRI

Magnetic resonance imaging (MRI) is the most sensitive exam for detecting breast cancer. The American College of Radiology recommends women with 20% or greater lifetime risk of developing breast cancer be screened annually with MRI. However, other high-risk populations would also benefit. Hartmann et al. reported women with atypical hyperplasia have nearly a 30% incidence of breast cancer at 25-year follow-up. Women with dense breast tissue have up to a 4-fold increased risk of breast cancer when compared to average-risk women; their cancers are more likely to be mammographically occult. Because multiple cohorts of women are at high risk for developing breast cancer, there has been a movement to develop an abbreviated MRI (abMRI) protocol to expand the availability of MRI screening. Studies on abMRI effectiveness have been promising, with Weinstein et al. demonstrating a cancer detection rate of 27.4/1000 in women with dense breasts after a negative digital breast tomosynthesis. Breast MRI is also used to evaluate the extent of disease as part of preoperative assessment in women with newly diagnosed breast cancer, and to assess a patient's response to neoadjuvant chemotherapy. This paper aims to explore the current uses of MRI and propose future indications and directions.

Contrast-Enhanced Digital Mammography Screening for Intermediate-Risk Women With a History of Lobular Neoplasia

OBJECTIVE. The objective of this study was to assess to the role of contrast-enhanced digital mammography (CEDM) as a screening tool in women at intermediate risk for developing breast cancer due to a personal history of lobular neoplasia without additional risk factors. MATERIALS AND METHODS. In this institutional review board-approved, observational, retrospective study, we reviewed our radiology department database to identify patients with a personal history of breast biopsy yielding lobular neoplasia who underwent screening CEDM at our institution between December 2012 and February 2019. A total of 132 women who underwent 306 CEDM examinations were included. All CEDM examinations were interpreted by dedicated breast imaging radiologists in conjunction with a review of the patient's clinical history and available prior breast imaging. In statistical analysis, sensitivity, specificity, NPV, positive likelihood ratio, and accuracy of CEDM in detecting cancer were determined, with pathology or 12-month imaging follow-up serving as the reference standard. RESULTS. CEDM detected cancer in six patients and showed an overall sensitivity of 100%, specificity of 88% (95% CI, 84-92%), NPV of 100%, and accuracy of 88% (95% CI, 84-92%). The positive likelihood ratio of 8.33 suggested that CEDM findings are 8.3 times more likely to be positive in an individual with breast cancer when compared with an individual without the disease. CONCLUSION. CEDM shows promise as a breast cancer screening examination in patients with a personal history of lobular neoplasia. Continued investigation with a larger patient population is needed to determine the true sensitivity and positive predictive value of CEDM for these patients.

Management of women at increased risk for breast cancer secondary to high-risk proliferative lesions and family history of the disease

Women with breast biopsies showing high-risk proliferative lesions such as atypical hyperplasia (AH) and lobular carcinoma in situ (LCIS) have an increased risk of developing breast cancer. Other factors including age, family history of breast cancer, and extent of AH may play a role in increasing breast cancer risk. In addition to women with AH, there is a subset of women with a positive family history of breast cancer, without a known germline mutation, which places them also at an increased risk for breast cancer. Clinical management, screening, chemoprevention, and surgical risk-reduction are discussed in this review to inform the management of these high-risk women. Advanced imaging technology, pharmacologic research into different targets, and innovations in breast reconstruction are changing the way in which patients are counseled of their individual risk.

Executive Summary of the Early-Onset Breast Cancer Evidence Review Conference

The Centers for Disease Control and Prevention launched the Bring Your Brave campaign to increase knowledge about early-onset breast cancer, defined as breast cancer in women aged 18-45 years. The American College of Obstetricians and Gynecologists convened a panel of experts in breast disease from the Society for Academic Specialists in General Obstetrics and Gynecology to review relevant literature, validated tools, best practices, and practice guidelines as a first step toward developing educational materials for women's health care providers about early-onset breast cancer. Panel members conducted structured literature reviews, which were then reviewed by other panel members and discussed at an in-person meeting of stakeholder professional and patient advocacy organizations in April 2019. This article summarizes the relevant literature, existing guidance, and validated tools to guide health care providers in the prevention, early detection, and special considerations of early-onset breast cancer. Substantive knowledge gaps were noted and summarized to provide guidance for future research.

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.

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.

Highly Sensitive Fluorescence and Photoacoustic Detection of Metastatic Breast Cancer in Mice Using Dual-Modal Nanoprobes

The biomedical imaging of metastatic breast cancer, especially in lymphatic and lung metastasis, is highly significant in cancer staging as it helps assess disease prognosis and treatment. Using an albumin-indocyanine green dual-modal nanoprobe developed in our laboratory, in vivo fluorescence imaging and photoacoustic imaging of metastatic breast cancer tumors were performed separately. Fluorescence imaging at the near-infrared window features high imaging sensitivity but is generally limited by a low imaging depth. Thus, tumors can only be observed in situ whereas tumor cells in the lymph nodes and lung cannot be imaged in a precise manner. In contrast, photoacoustic imaging often helps overcome the limitations of imaging depth with high acoustic spatial resolution, which could provide complementary information for imaging cancer metastases. Ex vivo fluorescence and photoacoustic imaging were also performed to verify the tumor metastatic route. This study may not only provide insights into the design of dual-modal nanoprobes for breast cancer diagnosis but may also demonstrate the superiority of combined fluorescence imaging and photoacoustic imaging for guiding, monitoring, and evaluating lymphatic and lung metastatic stages of breast cancer with a high imaging specificity as well as sensitivity.

Role of Magnetic Resonance Imaging in the Preoperative Staging and Work-Up of Patients Affected by Invasive Lobular Carcinoma or Invasive Ductolobular Carcinoma

Purpose

The prevalence of invasive lobular carcinoma (ILC), the second most common type of breast cancer, accounts for 5%-15% of all invasive breast cancer cases. Its histological feature to spread in rows of single cell layers explains why it often fails to form a palpable lesion and the lack of sensitivity of mammography and ultrasound (US) to detect it. It also has a higher incidence of multifocal, multicentric, and contralateral disease when compared to the other histological subtypes. The clinicopathologic features and outcomes of Invasive Ductolobular Carcinoma (IDLC) are very similar to the ILC. The purpose of our study is to assess the importance of MRI in the preoperative management and staging of patients affected by ILC or IDLC.

Materials and Methods

We identified women diagnosed with ILC or IDLC. We selected the patients who had preoperative breast MRI. For each patient we identified the areas of multifocal, multicentric, or contralateral disease not visible to standard exams and detected by preoperative MRI. We analyzed the potential correlation between additional cancer areas and histological cancer markers.

Results

Of the 155 women who met our inclusion criteria, 93 (60%) had additional cancer areas detected by MRI. In 61 women, 39,4% of the overall population, the additional cancer areas were confirmed by US/tomosynthesis second look and biopsy. Presurgical MRI staging changed surgical management in the 37,4% of the patients. Only six patients of the overall population needed a reoperation after the initial surgery. No statistically significant correlation was found between MRI overestimation and the presence of histological peritumoral vascular/linfatic invasion. No statistically significant correlation was found between additional cancer areas and histological cancer markers.

Conclusions

Our study suggests that MRI is an important tool in the preoperative management and staging of patients affected by lobular or ductolobular invasive carcinoma.

Developments in Breast Imaging: Update on New and Evolving MR Imaging and Molecular Imaging Techniques

This article reviews new developments in breast imaging. There is growing interest in creating a shorter, less expensive MR protocol with broader applicability. There is an increasing focus on and consideration for the additive impact that functional analysis of breast pathology have on identifying and characterizing lesions. These developments apply to MR imaging and molecular imaging. This article reviews evolving breast imaging techniques with attention to strengths, weaknesses, and applications of these approaches. We aim to give the reader familiarity with the state of current developments in the field and to increase awareness of what to expect in breast imaging.

Utilization of breast cancer screening with magnetic resonance imaging in community practice

BACKGROUND

Breast cancer screening with magnetic resonance imaging (MRI) may be a useful adjunct to screening mammography in high-risk women, but MRI uptake may be increasing rapidly among low- and average-risk women for whom benefits are unestablished. Comparatively little is known about use of screening MRI in community practice.

OBJECTIVE

To assess relative utilization of MRI among women who do and do not meet professional society guidelines for supplemental screening, and describe utilization according to breast cancer risk indications.

DESIGN

Prospective cohort study conducted between 2007 and 2014.

PARTICIPANTS

In five regional imaging registries participating in the Breast Cancer Surveillance Consortium (BCSC), 348,955 women received a screening mammogram, of whom 1499 underwent screening MRI.

MAIN MEASURES

Lifetime breast cancer risk (< 20% or ≥ 20%) estimated by family history of two or more first-degree relatives, and Gail model risk estimates. Breast Imaging Reporting and Data System breast density and benign breast diseases also were assessed. Relative risks (RR) for undergoing screening MRI were estimated using Poisson regression.

KEY RESULTS

Among women with < 20% lifetime risk, which does not meet professional guidelines for supplementary MRI screening, and no first-degree breast cancer family history, screening MRI utilization was elevated among those with extremely dense breasts [RR 2.2; 95% confidence interval (CI) 1.7-2.8] relative to those with scattered fibroglandular densities and among women with atypia (RR 7.4; 95% CI 3.9-14.3.) or lobular carcinoma in situ (RR 33.1; 95% CI 18.0-60.9) relative to women with non-proliferative disease. Approximately 82.9% (95% CI 80.8%-84.7%) of screening MRIs occurred among women who did not meet professional guidelines and 35.5% (95% CI 33.1-37.9%) among women considered at low-to-average breast cancer risk.

CONCLUSION

Utilization of screening MRI in community settings is not consistent with current professional guidelines and the goal of delivery of high-value care.

Lobular Carcinoma in Situ: A 15-Year Single Institution Review

The optimal management of lobular carcinoma in situ (LCIS) has largely been debated. This study evaluated practice patterns and outcomes in women diagnosed with LCIS at a single institution from 2000 to 2014. Patient characteristics, histology, method of diagnosis, and management were examined in relation to disease-free survival, and overall survival (OS). A total of 209 patients were identified. Surgical management in the majority of patients was excisional biopsy or local excision. Patients diagnosed with LCIS by core biopsy were less likely to have mastectomy as compared with other methods of initial diagnosis (P = 0.01). A total of 108 (90.8%) patients received chemoprevention (CP) counseling, and 47 (43.5%) used chemoprevention. Estimated five-year disease-free survival rate was 96.3 per cent (95% confidence interval (CI): 92.0–98.3%) and OS rate was 98.6 per cent (95% CI: 94.6–99.7%). Older age was associated with a higher risk of subsequent breast cancer (hazard ratio (HR): 1.04; 95% CI: 1.01–1.07; P = 0.01). Older age (HR: 1.06; 95% CI: 1.02–1.11; P = 0.004) and diagnosis in the earlier years of the study period (HR: 0.65; 95% CI: 0.48–0.89; P = 0.007) were significantly associated with worse OS in multivariate analysis. LCIS has a favorable prognosis and is most commonly managed conservatively.

Imaging Management of Breast Density, a Controversial Risk Factor for Breast Cancer

BACKGROUND

Breast density is well recognized as an independent risk factor for the development of breast cancer. However, the magnitude of risk is controversial. As the public becomes increasingly aware of breast density as a risk factor, legislation and notification laws in relation to breast density have become common throughout the United States. Awareness of breast density as a risk factor for breast cancer presents new challenges for the clinician in the approach to the management and screening of women with dense breasts.

METHODS

The evidence and controversy surrounding breast density as a risk factor for the development of breast cancer are discussed. Common supplemental screening modalities for breast cancer are also discussed, including tomosynthesis, ultrasonography, and magnetic resonance imaging. A management strategy for screening women with dense breasts is also presented.

RESULTS

The American College of Radiology recognizes breast density as a controversial risk factor for breast cancer, whereas the American Congress of Obstetricians and Gynecologists recognizes breast density as a modest risk factor. Neither organization recommends the routine use of supplemental screening in women with dense breasts without considering additional patient-related risk factors.

CONCLUSIONS

Breast density is a poorly understood and controversial risk factor for the development of breast cancer. Mammography is a screening modality proven to reduce breast cancer-related mortality rates and is the single most appropriate tool for population-based screening. Use of supplemental screening modalities should be tailored to individual risk assessment.

Lobular carcinoma in situ of the breast - correlation between minimally invasive biopsy and final pathology

INTRODUCTION

Lobular carcinoma in situ (LCIS) is regarded as a non-obligate precursor of invasive breast cancer (IBC). Hence, the optimal management of LCIS found on minimally invasive breast biopsy remains a subject of debate. The aim of this study was to evaluate the correlation of biopsy findings with postoperative histology and to identify risk factors for upstaging to IBC.

MATERIAL AND METHODS

Twenty-seven patients with pure LCIS diagnosed on image-guided biopsy (vacuum-assisted or core-needle) underwent subsequent surgery. Clinical, radiological and histological features were compared to the final pathology after surgical excision.

RESULTS

Median age of patients was 56 years while median size of LCIS was 15 mm. Final examination demonstrated IBC foci in 29.6% of lesions. Upstaged patients were younger and had larger lesions but without statistical significance (p = 0.07 and p = 0.09, respectively). Palpable tumours (p = 0.0004), BIRADS 5 lesions (p = 0.0001), masses (p = 0.016) and pleomorphic LCIS (p = 0.0001) had a significantly increased rate of upstaging. Guidance of the procedure (ultrasound vs. stereotactic) was significantly associated with the upstaging risk (p = 0.016), while the importance of the biopsy technique (core-needle vs. vacuum-assisted) was not confirmed (p = 0.37). After excluding pleomorphic LCIS and mass-forming classic LCIS, there was no risk of upstaging for lesions with BIRADS 4 mammographic abnormalities.

CONCLUSIONS

Pleomorphic histology, mass formation and BIRADS 5 category reflect more aggressive behaviour of LCIS and identify patients who need subsequent surgery. For other patients, close follow-up could be a safe alternative.

The Changing World of Breast Cancer: A Radiologist's Perspective

Compared with other fields of medicine, there is hardly an area that has seen such fast development as the world of breast cancer. Indeed, the way we treat breast cancer has changed fundamentally over the past decades. Breast imaging has always been an integral part of this change, and it undergoes constant adjustment to new ways of thinking. This relates not only to the technical tools we use for diagnosing breast cancer but also to the way diagnostic information is used to guide treatment. There is a constant change of concepts for and attitudes toward breast cancer, and a constant flux of new ideas, new treatment approaches, and new insights into the molecular and biological behavior of this disease. Clinical breast radiologists and even more so, clinician scientists, interested in breast imaging need to keep abreast with this rapidly changing world. Diagnostic or treatment approaches that are considered useful today may be abandoned tomorrow. Approaches that seem irrelevant or far too extravagant today may prove clinically useful and adequate next year. Radiologists must constantly question what they do, and align their clinical aims and research objectives with the changing needs of contemporary breast oncology. Moreover, knowledge about the past helps better understand present debates and controversies. Accordingly, in this article, we provide an overview on the evolution of breast imaging and breast cancer treatment, describe current areas of research, and offer an outlook regarding the years to come.

Breast-Specific γ-Imaging for the Detection of Mammographically Occult Breast Cancer in Women at Increased Risk

Breast-specific γ-imaging (BSGI) is a physiologic imaging modality that can detect subcentimeter and mammographically occult breast cancer, with a sensitivity and specificity comparable to MRI. The purpose of this study was to determine the incremental increase in breast cancer detection when BSGI is used as an adjunct to mammography in women at increased risk for breast cancer.

METHODS

All patients undergoing BSGI from April 2010 through January 2014 were retrospectively reviewed. Eligible patients were identified as women at increased risk for breast cancer and whose most recent mammogram was benign. Examinations exhibiting focally increased radiotracer uptake were considered positive. Incremental increase in cancer detection was calculated as the percentage of mammographically occult BSGI-detected breast cancer and the number of mammographically occult breast cancers detected per 1,000 women screened.

RESULTS

Included in this study were 849 patients in whom 14 BSGI examinations detected mammographically occult breast cancer. Patients ranged in age from 26 to 83 y, with a mean age of 57 y. Eleven of 14 cancers were detected in women with dense breasts. The addition of BSGI to the annual breast screen of asymptomatic women at increased risk for breast cancer yields 16.5 cancers per 1,000 women screened. When high-risk lesions and cancers were combined, BSGI detected 33.0 high-risk lesions and cancers per 1,000 women screened.

CONCLUSION

BSGI is a reliable adjunct modality to screening mammography that increases breast cancer detection by 1.7% (14/849) in women at increased risk for breast cancer, comparable to results reported for breast MRI. BSGI is beneficial in breast cancer detection in women at increased risk, particularly in those with dense breasts.

The role of dynamic contrast-enhanced screening breast MRI in populations at increased risk for breast cancer

Breast MRI is more sensitive than mammography in detecting breast cancer. However, MRI as a screening tool is limited to high-risk patients due to cost, low specificity and insufficient evidence for its use in intermediate-risk populations. Nonetheless, in the past decade, there has been a dramatic increase in the use of breast-screening MRI in the community setting. In this review, we set to describe the current literature on the use of screening MRI in high- and intermediate-risk populations. We will also describe novel applications of breast MRI including abbreviated breast MRI protocols, background parenchymal enhancement and diffusion-weighted imaging.

Lesions of uncertain malignant potential in the breast (B3): what do we know?

Breast lesions classified as of uncertain malignant potential (B3) on biopsy form a diverse group of abnormalities, which pose a diagnostic and management challenge. In this paper, we discuss the imaging and pathology features as well as the management of the most controversial B3 lesions, consisting of papillary lesions, complex sclerosing lesions/radial scars, lobular intraepithelial neoplasia, and atypical epithelial proliferation of ductal type. As there is an association with malignancy at the time of diagnosis, as well as an increase in the risk of subsequent development of cancer, a multidisciplinary discussion is almost always required to tailor treatment.

UK national survey of management of breast lobular carcinoma in situ

INTRODUCTION

There is no national standard treatment for patients with breast lobular carcinoma in situ (LCIS). Association of Breast Surgery guidelines for the management of breast cancer suggest that lesions containing LCIS should be excised for definitive diagnosis and recommend close surveillance after excision biopsy. The aim of this study was to form a picture of the current management of LCIS by UK breast surgeons.

METHODS

A questionnaire about the management of LCIS was sent to 490 UK breast surgeons.

RESULTS

Of 490 questionnaires sent out, 173 (35%) were returned. When LCIS is present in a core biopsy, 61% of breast surgeons perform surgical excision, 22% would not excise but would continue follow-up and the remainder perform neither or set no clear management plan. Over half (54%) follow patients up with five years of annual mammography. If classic LCIS were found at the margins of wide local excision, 92% would not re-excise. Conversely, if pleomorphic LCIS were found, 71% would achieve clear margins. Respondents were split evenly regarding management of classic LCIS with a family history as 54% would not alter management whereas 43% would treat the disease more aggressively.

CONCLUSIONS

Our survey has shown that in cases where LCIS is found at core biopsy, most surgeons follow Association of Breast Surgery guidance, obtaining further histological samples to exclude pleomorphic LCIS, ductal carcinoma in situ or invasive cancer, whereas others opt for annual surveillance and some discharge the patient. This study highlighted the huge variability in LCIS management, and the need for randomised controlled trials and input into national audits such as the Sloane Project to establish evidence-based national standard guidelines.

Screening magnetic resonance imaging recommendations and outcomes in patients at high risk for breast cancer

The purpose of this study was to determine magnetic resonance imaging (MRI) screening recommendations and the subsequent outcomes in women with increased risk for breast cancer evaluated by oncology subspecialists at an academic center. Patients evaluated between 1/1/2007 and 3/1/2011 under diagnosis codes for family history of breast or ovarian cancer, genetic syndromes, lobular carcinoma in situ or atypical hyperplasia were included. Patients with a history of breast cancer were excluded. Retrospective review of prospectively acquired demographics, lifetime risk of breast cancer, and screening recommendations were obtained from the medical record. Retrospective review of the results of prospectively interpreted breast imaging examinations and image-guided biopsies were analyzed. 282 women were included. The majority of patients were premenopausal with a median age of 43. Most (69%) were referred due to a family history of breast or ovarian cancers. MRI was recommended for 84% of patients based on a documented lifetime risk >20%. Most women referred for MRI screening (88%) were compliant with this recommendation. A total of 299 breast MRI examinations were performed in 146 patients. Biopsy was performed for 32 (11%) exams and 10 cancers were detected for a positive predictive value (PPV) of 31% (based on biopsy performed) and an overall per exam cancer yield of 3.3%. Three cancers were detected in patients who did not undergo screening MRI. The 13 cancers were Stage 0-II; all patients were without evidence of disease with a median follow-up of 22 months. In a cohort of women seen by breast subspecialty providers, screening breast MRI was recommended according to guidelines, and used primarily in premenopausal women with a family history or genetic predisposition to breast cancer. Adherence to MRI screening recommendations was high and cancer yield from breast MRI was similar to that in clinical trials.

Accuracy of screening mammography in women with a history of lobular carcinoma in situ or atypical hyperplasia of the breast

Women with lobular carcinoma in situ (LCIS), atypical lobular hyperplasia (ALH), atypical ductal hyperplasia (ADH), or atypical hyperplasia (AH) are at increased breast cancer (BC) risk. We investigated the accuracy and outcomes of mammography screening in women with histology-proven LCIS, ALH, ADH, or AH history who had screening through Breast Cancer Surveillance Consortium-affiliated mammography facilities. Screens from two cohorts, defined by LCIS/ALH or ADH/AH history, were compared to two cohorts without such history mammogram-matched for age-group, breast density, family history, screen-year, and mammography registry. Overall 359 BCs (277 invasive BC) occurred within 1 year from screening among 52,380 screens. In the LCIS/ALH cohort [versus comparator screens] cancer incidence rates, cancer detection rates (CDR), and interval cancer rates (ICR) were significantly higher (all P < 0.001); although ICR was 4.4/1,000 screens [versus 0.9/1,000; P < 0.001] the proportion that were interval cancers did not differ between compared cohorts (P = 0.43); screening sensitivity was 76.1 % [versus 82.3 %; P = 0.43], however, specificity was significantly lower at 85.1 % [versus 90.7 %; P < 0.0001]. In the ADH/AH cohort [versus comparator] cancer rates and CDR were significantly higher (P < 0.001); although ICR was 2.6/1,000 screens [versus 0.9/1,000; P = 0.002] the proportion that were interval cancers did not differ between cohorts (P = 0.74); screening sensitivity was 81.0 % [versus 82.6 %; P = 0.74] and specificity was lower at 86.2 % [versus 90.2 %; P < 0.0001]. Mammography screening sensitivity in LCIS/ALH and ADH/AH cohorts did not significantly differ from that of matched screens, however, specificity was lower, and ICRs were higher (reflecting underlying cancer rates). Adjunct screening may be of value in these women if it reduces ICR without substantially reducing specificity.

Impact of preoperative breast MRI on surgical decision making and clinical outcomes: a systematic review

BACKGROUND

Preoperative magnetic resonance imaging (MRI) is increasingly used in the workup of breast cancer patients and could lead to changes in surgical management. It is unclear how the information gained from MRI studies affects surgical decision making and influences clinical outcomes. These issues are addressed in this review.

METHODS

PubMed database searches were performed to retrieve and analyze respective original research and review articles on preoperative MRI in the evaluation of breast cancer patients.

RESULTS

Preoperative MRI is a highly sensitive but nonspecific method that leads to changes in surgical management with increased numbers of more extended surgical interventions. It appears that a relatively large proportion of MRI-driven changes in surgical management result in overtreatment without conclusively proven beneficial effects on such clinical outcomes as decrease in reoperation rates or improved patient survival.

CONCLUSIONS

Thus, routine use of supplementary preoperative breast MRI should be discouraged until compelling evidence of its effectiveness is available.

Rapid increase in breast magnetic resonance imaging use: trends from 2000 to 2011

IMPORTANCE

Breast magnetic resonance imaging (MRI) is highly sensitive for detecting breast cancer. Low specificity, cost, and little evidence regarding mortality benefits, however, limit recommendations for its use to high-risk women. How breast MRI is actually used in community settings is unknown.

OBJECTIVE

To describe breast MRI trends and indications in a community setting.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study at a not-for-profit health plan and multispecialty group medical practice in New England of 10,518 women aged 20 years and older enrolled in the health plan for at least 1 year who had at least 1 breast MRI between January 1, 2000, and December 31, 2011.

MAIN OUTCOMES AND MEASURES

Breast MRI counts were obtained from claims data. Clinical indication (screening, diagnostic evaluation, staging or treatment, or surveillance) was determined using a prediction model developed from electronic medical records on a subset of participants. Breast cancer risk status was assessed using claims data and, for the subset, also through electronic medical record review. RESULTS; Breast MRI use increased more than 20-fold from 6.5 per 10,000 women in 2000 to 130.7 per 10,000 in 2009. Use then declined and stabilized to 104.8 per 10,000 by 2011. Screening and surveillance, rare indications in 2000, together accounted for 57.6% of MRI use by 2011; 30.1% had a claims-documented personal history and 51.7% a family history of breast cancer, whereas 3.5% of women had a documented genetic mutation. In the subset of women with electronic medical records who received screening or surveillance MRIs, only 21.0% had evidence of meeting American Cancer Society (ACS) criteria for breast MRI. Conversely, only 48.4% of women with documented deleterious genetic mutations received breast MRI screening.

CONCLUSIONS AND RELEVANCE

Breast MRI use increased steeply over 10 years and then stabilized, especially for screening and surveillance among women with family or personal history of breast cancer; most women receiving screening and surveillance breast MRIs lacked documented evidence of meeting ACS criteria, and many women with mutations were not screened. Efforts are needed to ensure that breast MRI use and documentation are focused on those women who will benefit most.

Germline CDH1 mutations in bilateral lobular carcinoma in situ

BACKGROUND

Invasive lobular breast cancer (ILC) and lobular carcinoma in situ (LCIS) are characterised by loss of E-cadherin expression. However germline CDH1 mutations are rare in cases of ILC with no family history of hereditary diffuse gastric cancer (HDGC) and have not been described in women with LCIS.

METHODS

We screened the CDH1 gene in 50 cases of bilateral LCIS/ILC using Sanger sequencing and MLPA.

RESULTS

Sanger sequencing revealed four pathogenic germline mutations, including a novel splicing mutation (c.48+1G>A). The remaining three (c.1465insC, c.1942G>T, c.2398delC) have been previously described. All four cases had bilateral LCIS +/- ILC and no family history of gastric cancer.

CONCLUSION

CDH1 germline mutations have not been previously described in women with LCIS. We have shown that germline CDH1 mutations are associated with early onset of bilateral LCIS with or without ILC in women without a family history of gastric cancer. CDH1 mutation screening should be considered in women with early onset of bilateral LCIS/ILC with no family history of HDGC.

Is there a role for routine screening MRI in women with LCIS?

Women with lobular carcinoma in situ (LCIS) have an elevated breast cancer risk, yet the benefit of MRI screening is unclear. We examined cancer detection rates with mammography alone versus mammography plus MRI in this high-risk population. From a prospectively maintained, single-institution database, we identified 776 patients diagnosed with LCIS after the adoption of screening MRI in April 1999. In addition to annual mammography and breast exam, MRI was used at the discretion of the physician and patient. Kaplan-Meier methods and landmark analyses at 1, 2, and 3 years following LCIS diagnosis were performed to compare rates of cancer detection with or without MRI. MRI screening was performed in 455 (59 %) patients (median, 3/patient). Median time from LCIS diagnosis to first MRI was 9 months (range 0.3-137 months). Patients undergoing MRI were younger (p < 0.0001), premenopausal (p < 0.0001), and more likely to have ≥1 first-degree relative with breast cancer (p = 0.009). At a median follow-up of 58 months, 98/776 (13 %) patients developed cancer. The crude cancer detection rate in both screening groups was 13 %. MRI was not associated with earlier stage, smaller size, or node negativity. Landmark analyses at 1, 2, and 3 years after LCIS diagnosis failed to demonstrate increased cancer detection rates among women having MRI (p = 0.23, 0.26, and 0.13, respectively). Although a diagnosis of LCIS remains a significant risk factor for breast cancer, the routine use of MRI does not result in increased cancer detection rates (short-term), nor does it result in earlier stage at diagnosis, illustrating the importance of defining optimal screening strategies for high-risk patients based on tumor biology rather than numerical risk.

Screening MR imaging versus screening ultrasound: pros and cons

Data support greater sensitivity of MR imaging compared with mammography and ultrasound in high-risk populations, in particular BRCA 1 and BRCA 2 carriers. Screening ultrasound improves cancer yield versus mammography alone in high-risk patients and in patients with dense breasts and is less expensive. Drawbacks include low positive predictive value, operator dependence, and significant physician time expenditure. Advances, such as refinement of automated whole-breast ultrasound, new outcomes data from ultrasound-detected masses in BI-RADS 3 and 4a categories, and development of new MR imaging sequences that allow rapid screening, potentially without use of contrast, will likely reveal the most appropriate tool over time.