Flat epithelial atypia and risk of breast cancer: A Mayo cohort study

Updates in the Surgical Management of Benign and High-Risk Breast Lesions

Benign breast disease (BBD) is a heterogenous group of lesions often classified as nonproliferative or proliferative, with the latter group further categorized based on the presence of atypia. Although nonproliferative lesions are more common, the risk of breast cancer is elevated in women with proliferative lesions. Historically, the majority of proliferative lesions were excised due to concern for future and/or concomitant breast cancer at the site of the index lesion. However, contemporary data suggest that the risk of cancer associated with various proliferative lesions may be lower than previously thought, and management of BBD has become more nuanced. In this review, we will focus on recent updates in the management of a select group of benign and high-risk lesions.

Increased risk of upstage when combinations of breast lesions of uncertain malignant potential are found on core needle biopsy: The need for surgical excision

BACKGROUND

Management of breast lesions of uncertain malignant potential diagnosed at core needle biopsy (CNB) is controversial due to variable upstage rate (UR) with surgical excision (SE).

METHODS

We performed an IRB-approved retrospective analysis of adult women who underwent CNB demonstrating atypical ductal hyperplasia (ADH), flat epithelial atypia, radial scar, or intraductal papilloma then SE between 2010 and 2022. We evaluated CNB pathology for combination diagnoses (CD), defined as multiple primary lesions or primary with lobular neoplasia (LN), and surgical pathology for upstage.

RESULTS

719 patients were included. UR was 12.2% (88/719). CD experienced higher UR than pure (17.7% (45/254) vs. 9.2% (43/465), p ​= ​0.001). ADH/LN had the highest UR of all CD (34.6% (9/26), p ​= ​0.001). Increased size (15.6 vs. 10.5 ​mm, p ​< ​0.001), distance from nipple (79 vs. 66 ​mm, p ​< ​0.001), and personal history of breast cancer (p ​= ​0.04) were associated with UR.

CONCLUSIONS

CD was associated with increased UR. ADH/LN had the highest UR.

The impact of nurse navigation on timeliness to treatment for benign high-risk breast pathology

PURPOSE

High-risk breast pathology is a breast cancer risk factor for which timely treatment is crucial. Nurse navigation programs have been implemented to minimize delays in patient care. This study evaluated nurse navigation in terms of timeliness to surgery for patients with high-risk breast pathology.

METHODS

This was a single-institution, retrospective review of patients with identified high-risk breast pathology undergoing lumpectomy between January 2017 and June 2019. Patients were stratified into cohorts based on periods with and without nurse navigation. Preoperative and postoperative time to care as well as demographic and tumor characteristics were compared using univariate and multivariate analysis.

RESULTS

100 patients had assigned nurse navigators and 29 patients did not. Nurse navigation was associated with reduced time from referral to date of surgery (DOS) by 16.9 days (p = 0.003). Patients > 75 years had a shorter time to first appointment (p = 0.03), and patients with Medicare insurance had a reduced time from referral to DOS (p = 0.005). 20% of all patients were upstaged to cancer on final surgical pathology.

CONCLUSION

Nurse navigation was significantly associated with decreased time to care for patients with high-risk breast pathology undergoing lumpectomy. We recommend nurse navigation programs as part of a comprehensive approach for patients with high-risk breast pathology.

Imaging Characteristics of and Multidisciplinary Management Considerations for Atypical Ductal Hyperplasia and Flat Epithelial Atypia: Review of Current Literature

High-risk lesions of the breast are frequently encountered in percutaneous biopsy specimens. While benign, these lesions have historically undergone surgical excision due to their potential to be upgraded to malignancy. However, there is emerging evidence that a tailored management approach should be considered to reduce overtreatment of these lesions. Flat epithelial atypia (FEA) and atypical ductal hyperplasia (ADH) are two of the most commonly encountered high-risk lesions. FEA has been shown to have a relatively low rate of progression to malignancy, and some guidelines are now recommending observation over routine excision in select cases. Selective observation may be reasonable in cases where the target lesion is small and completely removed at biopsy and when there are no underlying risk factors, such as a history of breast cancer or genetic mutation or concurrent ADH. ADH has the highest potential upgrade rate to malignancy of all the high-risk lesions. Most society guidelines continue to recommend surgical excision of this lesion. More recently, some literature suggests that ADH lesions that appear completely removed at biopsy, involve limited foci (less than two or three) with no necrosis or significant atypia, manifest as a small group of mammographic calcifications, or demonstrate no enhancement at MRI may be reasonable for observation. Ultimately, management of all high-risk lesions must be based on a multidisciplinary approach that considers all patient, radiologic, clinical, and histopathologic factors. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Isolated Flat Epithelial Atypia: Upgrade Outcomes After Multidisciplinary Review-Based Management Using Excision or Imaging Surveillance

Objective

To compare flat epithelial atypia (FEA) upgrade rates after excision versus surveillance and to identify variables associated with upgrade.

Methods

This single-institution retrospective study identified isolated FEA cases determined by percutaneous biopsy from April 2005 through July 2022 with excision or ≥2 years surveillance. All cases were recommended for excision or surveillance based on multidisciplinary discussion of clinical, imaging, and pathologic variables with emphasis on sampling adequacy and significant atypia. Truth was determined by pathology at excision or the absence of cancer on surveillance. Upgrade was defined as cancer occurring ≤2 cm from the biopsy site. Demographic, imaging, and biopsy variables were compared between those that did and did not upgrade.

Results

Among 112 cases of isolated FEA, imaging findings included calcifications in 81.3% (91/112), MRI lesions in 11.6% (13/112), and distortions or masses in 7.1% (8/112). Excision was recommended in 12.5% (14/112) and surveillance in 87.5% (98/112) of cases. Among those recommended for excision, 28.6% (4/14) of cases were upgraded, all to ductal carcinoma in situ. In those recommended for surveillance, 1.0% (1/98) were upgraded to invasive cancer. Overall, FEA had a 4.5% (5/112) upgrade rate, and 2.7% (3/112) also developed cancer >2 cm from the FEA. There were no significant differences in demographic, imaging, and biopsy variables between those that did and did not upgrade to cancer.

Conclusion

Multidisciplinary management of isolated FEA distinguishes those at higher risk of upgrade to cancer (28.6%) in whom surgery is warranted from those at low risk of upgrade (1.0%) who can be managed non-operatively.

Are Columnar Cell Lesions the Earliest Non-Obligate Precursor in the Low-Grade Breast Neoplasia Pathway?

Columnar cell lesions (CCLs) of the breast comprise a spectrum of morphologic alterations of the terminal duct lobular unit involving variably dilated and enlarged acini lined by columnar epithelial cells. The World Health Organization currently classifies CCLs without atypia as columnar cell change (CCC) and columnar cell hyperplasia (CCH), whereas flat epithelial atypia (FEA) is a unifying term encompassing both CCC and CCH with cytologic atypia. CCLs have been increasingly recognized in stereotactic core needle biopsies (CNBs) performed for the assessment of calcifications. CCLs are believed to represent the earliest non-obligate precursor of low-grade invasive breast carcinomas as they share molecular alterations and often coexist with entities in the low-grade breast neoplasia pathway. Despite this association, however, the risk of progression of CCLs to invasive breast carcinoma appears low and may not exceed that of concurrent proliferative lesions. As the reported upgrade rates of pure CCL/FEA when identified as the most advanced high-risk lesion on CNB vary widely, the management of FEA diagnosed on CNB remains controversial. This review will include a historical overview of CCLs and will examine histologic diagnostic criteria, molecular alterations, prognosis and issues related to upgrade rates and clinical management.

Benign Breast Disease

Benign breast disease presents commonly in routine gynecologic care. Presenting symptoms such as breast mass, nipple discharge, or breast pain may raise concern for malignancy. Once breast cancer is ruled out, gynecologists must identify and appropriately treat benign breast disease. While most benign lesions can be managed conservatively, high-risk breast lesions can increase the future risk of breast cancer and may require additional screening imaging and surgical excision. Pharmacologic therapy may also have a role in certain conditions. Gynecologists should be proficient in the identification and management of benign breast disease.

Breast screening atypia and subsequent development of cancer: protocol for an observational analysis of the Sloane database in England (Sloane atypia cohort study)

INTRODUCTION

The National Health Service (NHS) Breast Screening Programme aims to detect cancer earlier when treatment is more effective but can harm women by over diagnosing and overtreating cancers which would never have become symptomatic. As well as breast cancer, a spectrum of atypical epithelial proliferations (atypia) can also be detected as part of screening. This spectrum of changes, while not cancer, may mean that a woman is more likely to develop breast cancer in the future. Follow-up of atypia is not evidence based. We currently do not know which atypia should be detected to avoid future cancer. This study will explore how atypia develops into breast cancer in terms of number of women, time of cancer development, cancer type and severity, and whether this varies for different types of atypia.

METHODS AND ANALYSIS

The Sloane cohort study began in April 2003 with ongoing data collection including atypia diagnosed through screening at screening units in the UK. The database for England has 3645 cases (24 September 2020) of epithelial atypia, with follow-up from 1 to 15 years. The outcomes include subsequent invasive breast cancer and the nature of subsequent cancer. Descriptive statistics will be produced. The observed rates of breast cancer at 1, 3 and 6 years for types of atypia will be reported with CIs, to enable comparison to women in the general population. Time to event methods will be used to describe the time to breast cancer diagnosis for the types of atypia, including flexible parametric modelling if appropriate. Patient representatives from Independent Cancer Patients' Voice are included at every stage of the research.

ETHICS AND DISSEMINATION

The study has received research ethics approval from the University of Warwick Biomedical and Scientific Research Ethics Committee (BSREC 10/20-21, 8 October 2020), Public Health England office for data release approvals (ODR1718_313) and approval from the English Breast Research Advisory Committee (BSPRAC_031). The findings will be disseminated to breast screening clinicians (via journal publication and conference presentation), to the NHS Breast Screening Programme to update their guidelines on how women with atypia should be followed up, and to the general public.

Intercepting Premalignant, Preinvasive Breast Lesions Through Vaccination

Breast cancer (BC) prevention remains the ultimate cost-effective method to reduce the global burden of invasive breast cancer (IBC). To date, surgery and chemoprevention remain the main risk-reducing modalities for those with hereditary cancer syndromes, as well as high-risk non-hereditary breast lesions such as ADH, ALH, or LCIS. Ductal carcinoma in situ (DCIS) is a preinvasive malignant lesion of the breast that closely mirrors IBC and, if left untreated, develops into IBC in up to 50% of lesions. Certain high-risk patients with DCIS may have a 25% risk of developing recurrent DCIS or IBC, even after surgical resection. The development of breast cancer elicits a strong immune response, which brings to prominence the numerous advantages associated with immune-based cancer prevention over drug-based chemoprevention, supported by the success of dendritic cell vaccines targeting HER2-expressing BC. Vaccination against BC to prevent or interrupt the process of BC development remains elusive but is a viable option. Vaccination to intercept preinvasive or premalignant breast conditions may be possible by interrupting the expression pattern of various oncodrivers. Growth factors may also function as potential immune targets to prevent breast cancer progression. Furthermore, neoantigens also serve as effective targets for interception by virtue of strong immunogenicity. It is noteworthy that the immune response also needs to be strong enough to result in target lesion elimination to avoid immunoediting as it may occur in IBC arising from DCIS. Overall, if the issue of vaccine targets can be solved by interrupting premalignant lesions, there is a potential to prevent the development of IBC.

Incidental Pathologic Findings in Young Adult Reduction Mammaplasty

BACKGROUND

This study aims to characterize incidental microscopic findings in this population to determine whether there is a benefit to routine histopathologic examination of breast tissue in young women.

METHODS

A retrospective review of young women who underwent reduction mammaplasty between June of 2010 and May of 2018 was performed at a single institution to identify demographics, age at the time of surgery, breast cancer risk factors, and pathologic data. Histologic reevaluation was performed when diagnostic clarification was needed. Descriptive, univariate, and multivariable statistical analyses were performed.

RESULTS

A total of 798 young women were included. At the time of surgery, the mean patient age was 17.5 ± 2.0 years, the mean body mass index was 28.7 ± 5.7 kg/m2, and the mean resection weight was 685 ± 339 g/breast. The majority of patients were reported to have pathologically normal tissue [n = 704 (88.2 percent)]. Of the 94 patients (11.8 percent) with abnormal findings, 21 (2.6 percent) had benign nonproliferative changes, 64 (8.0 percent) had proliferative lesions without atypia, nine (1.1 percent) had proliferative lesions with atypia, and a single patient (0.1 percent) had a borderline phyllodes tumor. Univariate and multivariate analyses revealed that age at menarche younger than 12 years was significantly associated with increased incidence of proliferative lesions.

CONCLUSIONS

Over 10 percent of young women with reduction mammaplasty have histopathologic findings. Although this study demonstrated an overall low incidence of atypical lesions, because early identification offers potential for improved surveillance, the authors continue to advocate for routine pathologic evaluation, particularly for women with early menarche.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

Managing patients with high-risk breast lesions, precursors on the breast neoplasia pathway

ABSTRACT

Breast cancer remains the most commonly diagnosed cancer among women. Imaging abnormalities may be noted on routine breast cancer screenings and require biopsy for further evaluation. Atypia and carcinoma in situ are nonmalignant lesions identified via breast biopsy and are associated with an increased risk of invasive carcinoma. Because of the lack of specialized breast cancer prevention and risk reduction programs, patients may not be able to access optimal management of the various subtypes of atypia and carcinoma in situ. By understanding the pathology of high-risk breast lesions and the resulting elevated cancer risk, healthcare providers, specifically primary care providers, can better counsel, manage, and treat patients to provide comprehensive quality care.

Risk factors for breast cancer development by tumor characteristics among women with benign breast disease

Background

Among women diagnosed with invasive breast cancer, 30% have a prior diagnosis of benign breast disease (BBD). Thus, it is important to identify factors among BBD patients that elevate invasive cancer risk. In the general population, risk factors differ in their associations by clinical pathologic features; however, whether women with BBD show etiologic heterogeneity in the types of breast cancers they develop remains unknown.

Methods

Using a nested case-control study of BBD and breast cancer risk conducted in a community healthcare plan (Kaiser Permanente Northwest), we assessed relationships of histologic features in BBD biopsies and patient characteristics with subsequent breast cancer risk and tested for heterogeneity of associations by estrogen receptor (ER) status, tumor grade, and size. The study included 514 invasive breast cancer cases (median follow-up of 9 years post-BBD diagnosis) and 514 matched controls, diagnosed with proliferative or non-proliferative BBD between 1971 and 2006, with follow-up through mid-2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using multivariable polytomous logistic regression models.

Results

Breast cancers were predominantly ER-positive (86%), well or moderately differentiated (73%), small (74% < 20 mm), and stage I/II (91%). Compared to patients with non-proliferative BBD, proliferative BBD with atypia conferred increased risk for ER-positive cancer (OR = 5.48, 95% CI = 2.14–14.01) with only one ER-negative case, P-heterogeneity = 0.45. The presence of columnar cell lesions (CCLs) at BBD diagnosis was associated with a 1.5-fold increase in the risk of both ER-positive and ER-negative tumors, with a 2-fold increase (95% CI = 1.21–3.58) observed among postmenopausal women (56%), independent of proliferative BBD status with and without atypia. We did not identify statistically significant differences in risk factor associations by tumor grade or size.

Conclusion

Most tumors that developed after a BBD diagnosis in this cohort were highly treatable low-stage ER-positive tumors. CCL in BBD biopsies may be associated with moderately increased risk, independent of BBD histology, and irrespective of ER status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01410-1.

Flat epithelial atypia: What the radiologist needs to know in 2021

The World Health Organization defines flat epithelial atypia (FEA), as a "presumably neoplastic intraductal alteration characterized by the replacement of native epithelial cells by a single layer or three to five layers of mildly atypical cells.". In this article, we will review FEA and compare its characteristics and differences with other atypical high-risk breast lesions. In addition, the imaging appearance of FEA will be described. Finally, we will discuss current outcomes and provide an update on its management based on the last recommendations.

Preneoplasia of the Breast and Molecular Landscape

The current model of human breast cancer progression proposes a linear multi-step process which initiates as flat epithelial atypia (FEA), progresses to atypical ductal hyperplasia (ADH), evolves into ductal carcinoma in situ (DCIS) and culminates in the potentially lethal stage of invasive ductal carcinoma. FEA commonly coexists with well-developed examples of ADH, low-grade DCIS, lobular neoplasia and tubular carcinoma. These findings and those of recent genetic studies suggest that FEA is a neoplastic lesion that may represent a precursor to or the earliest morphologic manifestation of ductal carcinoma in situ. At the same time, many of the genomic changes of ADH are also shared by common sporadic breast cancer, consistent with a high risk for future development of metachronous breast cancer.

Breast Cancer and Secondary Cancer Recurrences After Autologous Tissue Reconstruction

BACKGROUND

The medical literature defining breast cancer recurrence and secondary cancers after autologous tissue reconstruction for breast cancer is sparse. We sought to identify and analyze occurrences at our institution.

PATIENTS AND METHODS

A 20-year retrospective review of cancer recurrences and atypical breast neoplasms after autologous tissue breast reconstruction at Roswell Park Comprehensive Cancer Center was conducted after being granted a waiver from the institutional review board.

RESULTS

Eighteen locoregional recurrences among 337 cases were identified and analyzed. Overall recurrence rate was 5.3%. Four secondary cancers (1.2%) were radiation-induced angiosarcoma, undifferentiated pleomorphic sarcoma, and metaplastic carcinoma. One case of flat epithelial atypia was identified.

CONCLUSION

Our retrospective review found incidence and survival after treatment of breast cancer concordant with reports in the literature. We also identified and analyzed secondary neoplasms, including a unique case of undifferentiated pleomorphic sarcoma and metachronous recurrence of breast carcinoma. A case of recurrence as metaplastic carcinoma was identified.

Upgrade Rate of Flat Epithelial Atypia Diagnosed at Stereotactic Core Needle Biopsy of Microcalcifications: Is Excisional Biopsy Indicated?

OBJECTIVE

Whether the optimal management of pure flat epithelial atypia (FEA) found on core needle biopsy (CNB) specimens is surgical excision or imaging follow-up remains controversial. This study aimed to determine the upgrade rate to ductal carcinoma in situ (DCIS), invasive carcinoma or a high-risk lesion (atypical ductal hyperplasia, atypical lobular hyperplasia, or lobular carcinoma in situ), and it explored the relationship between a family history of breast cancer and the risk of upgrade.

METHODS

Cases with pure FEA found on stereotactic CNB of microcalcifications between March 2011 to December 2017 were followed by excisional biopsy or periodic imaging. The proportion of cases upgraded to a high-risk lesion and the odds of upgrade as related to a family history of breast cancer were determined with 95% confidence intervals (CIs).

RESULTS

We identified 622 cases of pure FEA; 101 (16.2%) underwent surgical excision and 269 (43.2%) had imaging follow-up of ≥ 24 months. There were no upgrades to DCIS or invasive cancer in any of these 370 individuals (0%), and 4.6% (17/370; 95% CI: 2.9%-7.2%) were upgraded to a high-risk lesion. There was a nonstatistically significant trend between family history and upgrade to high-risk lesion (odds ratio 1.72 [95% CI: 0.65%-4.57%]).

CONCLUSION

In our study, the upgrade rate of pure FEA to malignancy was 0%. We suggest that regular imaging follow-up is an appropriate alternative to surgery. Because of potential differences in biopsy techniques and pathologist interpretation of the primary biopsy, individual institutions should audit their own results prior to altering their management of FEA.

[Histological lesions of risk of breast carcinoma. Survival guide for the general pathologist]

Proliferative epithelial lesions are risk factors for breast cancer. They are a heterogeneous group of lesions in which the presence of atypia is related to varying degrees of risk. They should be considered in the differential diagnosis with benign lesions, in situ ductal carcinoma and infiltrating carcinoma. An accurate histopathological diagnosis is important in choosing the best therapeutic option, including vacuum assisted biopsy and surgery. We revise diagnostic criteria and the differential diagnosis of usual ductal hyperplasia, radial scar and complex sclerosing lesions, distinct types of adenosis, papillary lesions, atypical ductal hyperplasia, flat epithelial atypia and lobular neoplasia in situ. Furthermore, we summarize the degree of risk associated with the different conditions and management possibilities.

Flat Epithelial Atypia in Breast Core Needle Biopsies With Radiologic-Pathologic Concordance: Is Excision Necessary?

Flat epithelial atypia (FEA) is an alteration of terminal duct lobular units by a proliferation of ductal epithelium with low-grade atypia. No consensus exists on whether the diagnosis of FEA in core needle biopsy (CNB) requires excision (EXC). We retrospectively identified all in-house CNBs obtained between January 2012 and July 2018 with FEA. We reviewed all CNB slides and assessed radiologic-pathologic concordance. An upgrade was defined as invasive carcinoma (IC) and/or ductal carcinoma in situ in the EXC. The EXC slides of all upgraded cases were rereviewed. Out of ∼15,700 consecutive CNBs in the study period, 106 CNBs from 106 patients yielded FEA alone or with classic lobular neoplasia (LN). We excluded 52 CNBs (40 patients with prior/concurrent carcinoma and 12 without EXC). After rereview, we reclassified 14 cases (2 marked nuclear atypia, 10 focal atypical ductal hyperplasia, 2 benign). The final FEA study cohort consisted of 40 CNBs from 40 women. The CNB targeted mammographic calcifications in 36 (90%) cases, magnetic resonance imaging nonmass enhancement in 3 (8%), and 1 (2%) sonographic mass. All CNBs were deemed radiologic-pathologic concordant. FEA was present alone in 34 CNBs and with LN in 6. EXC yielded 2 low-grade IC, each spanning <2 mm, identified in tissue sections without biopsy site changes. The remaining 38 cases had no upgrade. Classic LN did not affect the upgrade. The upgrade rate of FEA was 5%; both minute, low-grade "incidental" IC. We conclude that nonsurgical management may be considered in patients without prior/concurrent carcinoma and radiologic-pathologic concordant CNB diagnosis of FEA.

Pitfalls and controversies in pathology impacting breast cancer management

Introduction: Breast cancer is a heterogeneous disease, at morphological, molecular, and clinical levels and this has significant implications for the diagnosis and management of the disease. The introduction of breast screening, and the use of small tissue sampling for diagnosis, the recognition of new morphological and molecular subtypes, and the increasing use of neoadjuvant therapies have created challenges in pathological diagnosis and classification.Areas covered: Areas of potential difficulty include columnar cell lesions, particularly flat epithelial atypia, atypical ductal hyperplasia, lobular neoplasia and its variants, and a range of papillary lesions. Fibroepithelial, sclerosing, mucinous, and apocrine lesions are also considered. Established and newer prognostic and predictive markers, such as immune infiltrates, PD-1 and PD-L1 and gene expression assays are evaluated. The unique challenges of pathology assessment post-neoadjuvant systemic therapy are also explored.Expert opinion: Controversies in clinical management arise due to incomplete and sometimes conflicting data on clinicopathological associations, prognosis, and outcome. The review will address some of these challenges.

Columnar cell lesions of the breast: a practical review for the pathologist

Background

Columnar cell lesions (CCLs) of the breast are characterized by the substitution of regular layer of cuboid epithelial by columnar cells covering the terminal duct lobular units (TDLUs). It also comprises a spectrum of lesions characterized by enlarged TDLUs with variably dilated acini lined by columnar epithelial cells, ranging from one or two layers of benign epithelium to stratified epithelium with atypia. With the increasing use of mammography screening scans in the last 30 years, columnar cell lesions (CCLs) have been diagnosed more frequently, often associated with microcalcifications and abnormal calcifications, requiring breast biopsies. This literature review presents the historical development of this entity description, with many terminologies, the CCLs categories, differential diagnoses, immunohistochemical profile and genetic alterations, reproducibility and clinical implications. In addition it discusses the significance of flat epithelial atypia (FEA), a CCL with low-grade cytological atypia.

Practical considerations

FEA are a frequent finding in breast biopsies and should be a warning sign for other possible entities within the lesion area. Since CCLs are an increasingly recognized entity in the diagnostic spectrum of breast proliferative lesions, proper training or tutorials are advisable for general pathologists in order to teach them how to identify CCLs with confidence. Intraductal proliferations with architectural complexities such as cribriform patterns, rigid cellular bridges, and true micropapillary pattern should not fall into the FEA category and are best classified as atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS).

Conclusions

Among CCLs, FEA actually receives more attention due to atypia involved. FEA has been considered a non-obligate pre-neoplastic lesion and progression of these lesions to invasive cancer has been reported as increasingly low (2–7%). Therefore, controversy to the management of those lesions still remains and further intervention is restricted to cases with other premalignant lesions (ADH, DCIS) or in radiologic-pathologic disagreement.

Sonographic Features of Flat Epithelial Atypia Manifesting as a Non-Mass-Like Lesion: A Case Report

Patient: Female, 47

Final Diagnosis: Flat epithelial atypia of the breast

Symptoms: —

Medication: —

Clinical Procedure: —

Specialty: Radiology

Excision or Observation: The Dilemma of Managing High-Risk Breast Lesions

There is an enduring dilemma on the appropriate management of high-risk breast lesions; is surgical excision always warranted or can conservative management be utilized? We present cases of high-risk breast lesions diagnosed at core needle biopsy at our institution along with relevant factors to consider for appropriate management. We conclude that a nuanced approach is warranted over the broad stroke approach of surgical excision of all high-risk breast lesions.

Breast cancer risk in premalignant lesions: osteopontin splice variants indicate prognosis

BACKGROUND

Premalignant breast lesions pose variable risks for transformation, raising the question who should receive treatment to counteract the potential progression to breast cancer. Because the secreted metastasis mediator Osteopontin (OPN) is a marker for breast cancer aggressiveness, its presence in these lesions may reflect progression risk.

METHODS

By immunohistochemistry, we analyse the association of Osteopontin variant expression in healthy breasts, hyperplasias, papillomas, and carcinomas in situ from 434 women to assess a) staining for OPN exon 4 (present in OPN-a and OPN-b) or OPN-c in low-risk to high-risk lesions b) correlations between staining and progression (DCIS with invasion, invasive cancer) or survival.

RESULTS

The markers correlate with risk, and they are prognostic for ensuing invasive disease and survival. About 10% of OPN-c pathology score 0-1 (intensity), vs. 40% of score 3 experience cancer over 5 years. More than 90% of women, who progress, had pathology scores of 2-3 for OPN-c intensity at the time of initial diagnosis. When combining OPN-c and OPN exon 4 staining, all of the low intensity patients are alive after 5 years, whereas women in the high category have a close to 30% chance to die within 5 years. Of patients who succumb, close to 80% had a high combined score at the time of initial diagnosis.

CONCLUSION

The combined information of OPN splice variant immunohistochemistry can provide a foundation for very reliable prognostication and has the potential to aid decision making in the treatment of early breast lesions.

Flat epithelial atypia in directional vacuum-assisted biopsy of breast microcalcifications: surgical excision may not be necessary

The aim of this study was to analyze the clinicopathological features of patients with flat epithelial atypia, diagnosed in directional vacuum-assisted biopsy targeting microcalcifications, to identify upgrade rate to in situ ductal or invasive breast carcinoma, and determine factors predicting carcinoma in the subsequent excision. We retrospectively evaluated the histological, clinical, and mammographic features of 69 cases from 65 women, with directional vacuum-assisted biopsy-diagnosed flat epithelial atypia with or without atypical ductal hyperplasia or atypical lobular hyperplasia, which underwent subsequent surgical excision. The extent and percentage of microcalcifications sampled by directional vacuum-assisted biopsy were evaluated by mammography. All biopsy and surgical excision slides were reviewed. The age of the women ranged from 40 to 85 years (mean 57 years). All patients presented with mammographically detected microcalcifications only, except in one case that had associated architectural distortion. Extent of calcifications ranged from <1 cm (n = 47), 1-3 cm (n = 15) to > 3 cm (n = 6), and no measurement (n = 1). A mean of 11 cores (range 6-25) was obtained from each lesion. Post-biopsy mammogram revealed >90% removal of calcifications in 81% of cases. Pure flat epithelial atypia represented nearly two-thirds of directional vacuum-assisted biopsy specimens (n = 43, 62%), while flat epithelial atypia coexisted with atypical ductal hyperplasia (18 cases, 26%), or atypical lobular hyperplasia (8 cases, 12%). Upon excision, none of the cases were upgraded to in situ ductal or invasive breast cancer. In one case, however, an incidental, tubular carcinoma (4 mm) was found away from biopsy site. Excluding this case, the upgrade rate was 0%. Our study adds to the growing evidence that diagnosis of flat epithelial atypia on directional vacuum-assisted biopsy for microcalcifications as the only imaging finding is not associated with a significant upgrade to carcinoma on excision, and therefore, excision may not be necessary. Additionally, excision may not be necessary for flat epithelial atypia with atypical ductal hyperplasia limited to ≤2 terminal duct-lobular units, if at least 90% of calcifications have been removed on biopsy.

Subtypes of Benign Breast Disease as a Risk Factor of Breast Cancer: A Systematic Review and Meta Analyses

BACKGROUND

Researchers suggest that benign breast disease (BBD) is a key risk factor for breast cancer. The present study aimed to determinate the risk level of breast cancer in terms of various BBD subgroups.

METHODS

A meta-analysis was performed to determinate the risk of breast cancer associated with BBD. Observational studies (traditional case-control studies, nested case-control studies, and cohort studies) published from January 2000 to June 2015 were assessed to evaluate the risk of developing breast cancer related to BBD. Various databases such as Medline (PubMed), Web of Science (ISI), Scopus, and Google Scholar were searched. The additional search included the Journal of Breast Cancer Research and Treatment and the Journal of Cancer Research.

RESULTS

Twenty studies out of 21 were used to estimate the risk of developing breast cancer related to proliferative disease without atypia versus non-proliferative disease and the reported risk ranged from 1.04 to 1.83. The reported risk of developing breast cancer related to proliferative disease with atypia versus non-proliferative disease in 21 studies ranged from 1.59 to 4.74. Based on 20 studies, the pooled risk estimates for developing breast cancer related to proliferative disease without atypia versus non-proliferative disease was 1.58 (95% CI: 1.51-1.66). Based on 21 studies, the pooled risk estimates for developing breast cancer related to proliferative disease with atypia versus non-proliferative disease was 3.49 (95% CI: 3.23-3.77).

CONCLUSION

The overall result of this review showed an elevated risk for breast cancer related to BBD subtypes. We propose better strategies for screening recommendations for such women.

Reviewing the Evidence to Guide Clinical Care: Proliferative Breast Lesions in Breast Reduction Specimens

The number of reduction mammoplasties performed in the United States continues to increase annually. Given the high incidence of breast cancer in women, it is routine practice for breast tissue excised during routine breast reductions procedures to be sent for pathology review. During pathology assessment, occult malignancy and on-occasion proliferative breast lesions of unknown and/or variable malignancy may also be present. We provide a review of commonly diagnosed atypical proliferative breast lesions in breast reduction specimens and a guide to plastic surgeons for further management.

Postoperative recurrence analysis of breast cancer patients based on clinical serum markers using discriminant methods

BACKGROUND

Breast cancer is a common gynecological malignant tumor and currently its clinical diagnosis mainly depends on methods of iconography and measurement of serum level.

OBJECTIVE

To analyze correlation between serum index levels and prognosis of patients with breast cancer in one week and six months after operation, and to establish support vector machine (SVM) model to evaluate its effectiveness.

METHODS

One hundred sixty eight patients diagnosed with breast cancer at Affiliated Cancer Hospital of Zhengzhou University were collected, 46 of which did palindromia while other 122 didn't six months after operation. Serum CA153, CA125 and CEA levels of different periods in two groups were analyzed from their differences. Through receiver operating characteristic (ROC) curve analysis, their diagnostic threshold values were calculated, at the same time, SVM model was built.

RESULTS

There was a significant difference between serum index levels of recurrence group and non-recurrence group in one week and six months after operation (P< 0.05); SVM model was established with an accuracy of 96.67% (29/30), a sensitivity of 90% (9/10) and a specificity of 100% (20/20).

CONCLUSIONS

Serum CAl53, CEA and CA125 levels after operation have certain instructional significance for prognosis of breast cancer patients, and the established SVM model has high clinical application value.

How Do We Approach Benign Proliferative Lesions?

PURPOSE OF REVIEW

The aim of this review is to summarize recently published literature addressing atypical ductal hyperplasia (ADH), lobular neoplasia (atypical lobular hyperplasia [ALH] and classic lobular carcinoma in situ [C-LCIS]), non-classic lobular carcinoma in situ (NC-LCIS), papillary lesions, and flat epithelial atypia (FEA).

RECENT FINDINGS

While ADH, ALN, and C-LCIS are well-established markers of an increased risk of future breast cancers, the risk implications are less clear for papillary lesions and FEA. NC-LCIS is the least well-characterized lesion, with scant published literature on its natural history and surgical management when encountered on needle biopsy. Recent data suggest that lobular neoplasia on core biopsy of a BI-RADS ≤ 4 concordant lesion does not require an excision, while ADH, atypical papillomas, and NC-LCIS should be excised. Evidence on FEA and papillomas without atypia suggests a low risk of upgrade on excision, and prospective studies on the upgrade of these lesions are ongoing.

Core Needle Biopsy of the Breast: An Evaluation of Contemporary Data

Benign and atypical lesions associated with breast cancer risk are often encountered in core needle biopsies (CNBs) of the breast. For these lesions, the rate of "upgrade" to carcinoma in excision specimens varies widely in the literature. Many CNB studies are limited by a lack of radiological-pathological correlation, consistent criteria for excision, and clinical follow-up for patients who forego excision. This article highlights contemporary diagnostic criteria and outcome data that would support an evidence-based approach to the management of these nonmalignant lesions of the breast diagnosed on CNB.

Flat epithelial atypia: conservative management of patients without residual microcalcifications post-vacuum-assisted breast biopsy

OBJECTIVE

To determine the malignancy rate (defined in this study as stability or absence of malignancy developed on close imaging follow-up post-biopsy) of conservative management in patients with a vacuum-assisted breast biopsy (VAB) diagnosis of flat epithelial atypia (FEA), performed on single group of microcalcifications, completely removed during procedure.

METHODS

This is a retrospective, monocentric, observational study, approved by IRB. Inclusion criteria were: VAB performed on a single group of microcalcifications; the absence of residual calcifications post-VAB; diagnosis of isolated FEA as the most advanced proliferative lesion; radiological follow-up at least of 12 months. The personal history of breast cancer or other high-risk lesions was an exclusion criteria. The patients enrolled were conservatively managed, without surgical excision, through close follow-up: the first two mammographies performed with an interval of 6 months after biopsy, followed by annual mammographic and clinical checks.

RESULTS

48 consecutive patients were enrolled in the study, all females, with age range of 39-76 years (mean 53,3 years) and radiological follow-up range of 13-75 months (mean 41.5 months). All the lesions were classified as BI-RADS 4b. The diameter range of the group of calcifications was 3-10 mm (mean 5, 6 mm). In each patient, 7 to 15 samples (mean 11) were obtained. Among all the patients, there was only one case (2%) of new microcalcifications, developed in the same breast, 26 months after and 8 mm from the site of previous VAB, and interpreted as ADH at surgical excision. All the checks of the other patients were negative.

CONCLUSION

Even with a limited follow-up, we found a malignancy rate lower than 2%, through a defined population. Further studies with bigger number of patients and extended follow-up are needed to reinforce this hypothesis. Advances in knowledge: Surgical excision may not be necessary in patients with VAB diagnosis of isolated FEA, without residual microcalcifications post-procedure and considered concordant with the mammographic presentation, considering the low rate of malignancy at subsequent follow-ups.

Association between mammographic breast density and histologic features of benign breast disease

BACKGROUND

Over 40% of women undergoing breast screening have mammographically dense breasts. Elevated mammographic breast density (MBD) is an established breast cancer risk factor and is known to mask tumors within the dense tissue. However, the association of MBD with high risk benign breast disease (BBD) is unknown.

METHOD

We analyzed data for 3400 women diagnosed with pathologically confirmed BBD in the Mayo Clinic BBD cohort from 1985-2001, with a clinical MBD measure (either parenchymal pattern (PP) or Breast Imaging Reporting and Data Systems (BI-RADS) density) and expert pathology review. Risk factor information was collected from medical records and questionnaires. MBD was dichotomized as dense (PP classification P2 or DY, or BI-RADS classification c or d) or non-dense (PP classification N1 or P1, or BI-RADS classification a or b). Associations of clinical and histologic characteristics with MBD were examined using logistic regression analysis to estimate odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Of 3400 women in the study, 2163 (64%) had dense breasts. Adjusting for age and body mass index (BMI), there were positive associations of dense breasts with use of hormone therapy (HT), lack of lobular involution, presence of atypical lobular hyperplasia (ALH), histologic fibrosis, columnar cell hyperplasia/flat epithelia atypia (CCH/FEA), sclerosing adenosis (SA), cyst, usual ductal hyperplasia, and calcifications. In fully adjusted multivariate models, HT (1.3, 95% CI 1.1-1.5), ALH (1.5, 95% CI 1.0-2.2), lack of lobular involution (OR 1.6, 95% CI 1.2-2.1, compared to complete involution), fibrosis (OR 2.2, 95% CI 1.9-2.6) and CCH/FEA (OR 1.3, 95% CI 1.0-1.6) remained significantly associated with high MBD.

CONCLUSION

Our findings support an association between high risk BBD and high MBD, suggesting that risks associated with the latter may act early in breast carcinogenesis.

Precursor Lesions of the Low-Grade Breast Neoplasia Pathway

The nonobligate precursor lesions columnar cell change/hyperplasia and flat epithelial atypia, atypical ductal hyperplasia and atypical lobular hyperplasia, lobular carcinoma in situ, and low-grade ductal carcinoma in situ share morphologic, immunophenotypic, and molecular features supporting the existence of a low-grade breast neoplasia pathway. The practical implication for pathologists is that the identification of one of these lesions should prompt careful search for others. From a clinical management perspective, however, their designation as "precursor lesions" should not be overemphasized, as the risk of progression among the earliest lesions is exceedingly low. Factors determining which lesions will progress remain unknown.

Flat Epithelial Atypia on Core Biopsy and Upgrade to Cancer: a Systematic Review and Meta-Analysis

BACKGROUND

No consensus exists on whether flat epithelial atypia (FEA) diagnosed percutaneously should be surgically excised. A systematic review and meta-analysis of the frequency of upgrade to cancer or an atypical ductal hyperplasia (ADH) at surgical excision of FEA was performed.

METHODS

Embase, MEDLINE, Scopus, and Web of Science databases from January 2003 to November 2015 were searched. The inclusion criteria required a manuscript in English with original data on FEA diagnosed percutaneously, data including the presence or absence of other concurrent high-risk lesions, and data including outcome of cancer at surgical excision. Studies were assessed for quality, and two reviewers extracted data. Random-effects meta-analysis was used to pool estimates. The impact of study-level characteristics was assessed by stratified meta-analysis and meta-regression.

RESULTS

The inclusion criteria was met by 32 studies. A total of 1966 core needle biopsies showed pure FEA, and 1517 (77%) showed surgical excision. The proportions of patients with upgrade to cancer varied from 0 to 42%, with an overall pooled estimate of 11.1%. Heterogeneity was observed, with the greatest impact based on whether a study included cases of FEA diagnosed before 2003. With restriction of the investigation to 16 higher-quality studies, the cancer upgrade pooled estimate was 7.5% (95% confidence interval [CI], 5.4-10.4%), and the rate of invasive cancer was 3% (95% CI 1.9-4.5%). For upgrade to ADH, data from 22 studies including 937 patients were analyzed. The proportion of patients upgraded to ADH ranged from 0 to 60%, with a pooled estimate of 17.9% overall and 18.6% among high-quality studies.

CONCLUSIONS

With patient management change potential for approximately 25% of patients, this analysis supports a general recommendation for surgical excision of FEA diagnosed by core biopsy.

Biomarkers expression in benign breast diseases and risk of subsequent breast cancer: a case-control study

Women with benign breast diseases (BBD) have a high risk of breast cancer. However, no biomarkers have been clearly established to predict cancer in these women. Our aim was to explore whether estrogen receptor (ER), progesterone receptor (PR), and Ki67 expression stratify risk of breast cancer in screened women with BBD. We conducted a nested case-control study. Women with breast cancer and prior BBDs (86 cases) were matched to women with prior BBDs who were free from breast cancer (172 controls). The matching factors were age at BBD diagnosis, type of BBD, and follow-up time since BBD diagnosis. ER, PR, and Ki67 expression were obtained from BBDs' specimens. Conditional logistic regression was used to estimate odds ratios (ORs), and 95% confidence intervals (CIs) of breast cancer risk according to ER, PR, and Ki67 expression. Women with >90% of ER expression had a higher risk of breast cancer (OR = 2.63; 95% CI: 1.26-5.51) than women with ≤70% of ER expression. Similarly, women with >80% of PR expression had a higher risk of breast cancer (OR = 2.22; 95% CI: 1.15-4.27) than women with ≤40% of PR expression. Women with proliferative disease and ≥1% of Ki67 expression had a nonsignificantly increased risk of breast cancer (OR = 1.16; 95% CI: 0.46-2.90) than women with <1% of Ki67 expression. A high expression of ER and PR in BBD is associated with an increased risk of subsequent breast cancer. In proliferative disease, high Ki67 expression may also have an increased risk. This information is helpful to better characterize BBD and is one more step toward personalizing the clinical management of these women.

Surgical implications and variability in the use of the flat epithelial atypia diagnosis on breast biopsy specimens

OBJECTIVES

Flat epithelial atypia (FEA) is a relatively new diagnostic term with uncertain clinical significance for surgical management. Any implied risk of invasive breast cancer associated with FEA is contingent upon diagnostic reproducibility, yet little is known regarding its use.

MATERIALS AND METHODS

Pathologists in the Breast Pathology Study interpreted one of four 60-case test sets, one slide per case, constructed from 240 breast biopsy specimens. An electronic data form with standardized diagnostic categories was used; participants were instructed to indicate all diagnoses present. We assessed participants' use of FEA as a diagnostic term within: 1) each test set; 2) 72 cases classified by reference as benign without FEA; and 3) six cases classified by reference as FEA. 115 pathologists participated, providing 6900 total independent assessments.

RESULTS

Notation of FEA ranged from 0% to 35% of the cases interpreted, with most pathologists noting FEA on 4 or more test cases. At least one participant noted FEA in 34 of the 72 benign non-FEA cases. For the 6 reference FEA cases, participant agreement with the case reference FEA diagnosis ranged from 17% to 52%; diagnoses noted by participating pathologists for these FEA cases included columnar cell hyperplasia, usual ductal hyperplasia, atypical lobular hyperplasia, and atypical ductal hyperplasia.

CONCLUSIONS

We observed wide variation in the diagnosis of FEA among U.S. pathologists. This suggests that perceptions of diagnostic criteria and any implied risk associated with FEA may also vary. Surgical excision following a core biopsy diagnosis of FEA should be reconsidered and studied further.

Responsiveness of Brca1 and Trp53 Deficiency-Induced Mammary Preneoplasia to Selective Estrogen Modulators versus an Aromatase Inhibitor in Mus musculus

An intervention study initiated at age 4 months compared the impact of tamoxifen (25 mg), raloxifene (22.5 mg), and letrozole (2.5 mg) administered by 60-day release subcutaneous pellet on mammary preneoplasia prevalence at age 6 months in conditional genetically engineered mouse models with different Breast cancer 1 (Brca1) gene dosages targeted to mammary epithelial cells and germline Tumor protein P53 (Trp53) haploinsufficiency (10-16/cohort). The proportion of unexposed control mice demonstrating mammary preneoplasia at age 6 months was highest in Brca1^{fl11/fl11/Cre/p53-/+} (54%) mice followed by Brca1^{WT/fl11/Cre/p53-/+} mice (30%). By age 12 months, invasive mammary cancers appeared in 80% of Brca1^{fl11/fl11/Cre/p53-/+} and 42% of Brca1^{WT/fl11/Cre/p53-/+} control unexposed mice. The spectrum of cancer histology was similar in both models without somatic mutation of the nongenetically engineered Brca1, Trp53, Brca2, or Death-associated protein kinase 3 (Dapk3) alleles. Two-month exposure to tamoxifen, raloxifene, and letrozole significantly reduced estrogen-mediated tertiary branching by 65%, 71%, and 78%, respectively, in Brca1^{fl11/fl11/Cre/p53-/+} mice at age 6 months. However, only letrozole significantly reduced hyperplastic alveolar nodules (HAN) prevalence (by 52%) and number (by 30%) and invasive cancer appeared despite tamoxifen exposure. In contrast, tamoxifen significantly reduced HAN number by 95% in Brca1^{WT/fl11/Cre/p53-/+} mice. Control mice with varying combinations of the different genetically modified alleles and MMTV-Cre transgene demonstrated that the combination of Brca1 insufficiency and Trp53 haploinsufficiency was required for appearance of preneoplasia and no individual genetic alteration confounded the response to tamoxifen. In summary, although specific antihormonal approaches showed effectiveness, with Brca1 gene dosage implicated as a possible modifying variable, more effective chemopreventive approaches for Brca1 mutation-induced cancer may require alternative and/or additional agents. Cancer Prev Res; 10(4); 244-54. ©2017 AACR.