Atypical ductal hyperplasia and the risk of underestimation: tissue sampling method, multifocality, and associated calcification significantly influence the diagnostic upgrade rate based on subsequent surgical specimens

Atypical Ductal Hyperplasia and Lobular In Situ Neoplasm: High-Risk Lesions Challenging Breast Cancer Prevention

This retrospective study investigates the histopathological outcomes, upgrade rates, and disease-free survival (DFS) of high-risk breast lesions, including atypical ductal hyperplasia (ADH or DIN1b) and lobular in situ neoplasms (LIN), following Vacuum-Assisted Breast Biopsy (VABB) and surgical excision. The study addresses the challenge posed by these lesions due to their association with synchronous or adjacent Breast Cancer (BC) and increased future BC risk. The research, comprising 320 patients who underwent stereotactic VABB, focuses on 246 individuals with a diagnosis of ADH (120) or LIN (126) observed at follow-up. Pathological assessments, categorized by the UK B-coding system, were conducted, and biopsy samples were compared with corresponding excision specimens to determine upgrade rates for in situ or invasive carcinoma. Surgical excision was consistently performed for diagnosed ADH or LIN. Finally, patient follow-ups were assessed and compared between LIN and ADH groups to identify recurrence signs, defined as histologically confirmed breast lesions on either the same or opposite side. The results reveal that 176 (71.5%) patients showed no upgrade post-surgery, with ADH exhibiting a higher upgrade rate to in situ pathology than LIN1 (Atypical Lobular Hyperplasia, ALH)/LIN2 (Low-Grade Lobular in situ Carcinoma, LCIS) (38% vs. 20%, respectively, p-value = 0.002). Considering only patients without upgrade, DFS at 10 years was 77%, 64%, and 72% for ADH, LIN1, and LIN2 patients, respectively (p-value = 0.92). The study underscores the importance of a multidisciplinary approach, recognizing the evolving role of VABB. It emphasizes the need for careful follow-up, particularly for lobular lesions, offering valuable insights for clinicians navigating the complex landscape of high-risk breast lesions. The findings advocate for heightened awareness and vigilance in managing these lesions, contributing to the ongoing refinement of clinical strategies in BC care.

European guidelines for the diagnosis, treatment and follow-up of breast lesions with uncertain malignant potential (B3 lesions) developed jointly by EUSOMA, EUSOBI, ESP (BWG) and ESSO

INTRODUCTION

Breast lesions of uncertain malignant potential (B3) include atypical ductal and lobular hyperplasias, lobular carcinoma in situ, flat epithelial atypia, papillary lesions, radial scars and fibroepithelial lesions as well as other rare miscellaneous lesions. They are challenging to categorise histologically, requiring specialist training and multidisciplinary input. They may coexist with in situ or invasive breast cancer (BC) and increase the risk of subsequent BC development. Management should focus on adequate classification and management whilst avoiding overtreatment. The aim of these guidelines is to provide updated information regarding the diagnosis and management of B3 lesions, according to updated literature review evidence.

METHODS

These guidelines provide practical recommendations which can be applied in clinical practice which include recommendation grade and level of evidence. All sections were written according to an updated literature review and discussed at a consensus meeting. Critical appraisal by the expert writing committee adhered to the 23 items in the international Appraisal of Guidelines, Research and Evaluation (AGREE) tool.

RESULTS

Recommendations for further management after core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB) diagnosis of a B3 lesion reported in this guideline, vary depending on the presence of atypia, size of lesion, sampling size, and patient preferences. After CNB or VAB, the option of vacuum-assisted excision or surgical excision should be evaluated by a multidisciplinary team and shared decision-making with the patient is crucial for personalizing further treatment. De-escalation of surgical intervention for B3 breast lesions is ongoing, and the inclusion of vacuum-assisted excision (VAE) will decrease the need for surgical intervention in further approaches. Communication with patients may be different according to histological diagnosis, presence or absence of atypia, or risk of upgrade due to discordant imaging. Written information resources to help patients understand these issues alongside with verbal communication is recommended. Lifestyle interventions have a significant impact on BC incidence so lifestyle interventions need to be suggested to women at increased BC risk as a result of a diagnosis of a B3 lesion.

CONCLUSIONS

These guidelines provide a state-of-the-art overview of the diagnosis, management and prognosis of B3 lesions in modern multidisciplinary breast practice.

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.

Estrogens and the risk of breast cancer: A narrative review of literature

In female mammals, the development and regulation of the reproductive system and non-reproductive system are significantly influenced by estrogens (oestrogens). In addition, lipid metabolism is another physiological role of estrogens. Estrogens act through different types of receptors to introduce signals to the target cell by affecting many estrogen response elements. Breast cancer is considered mostly a hormone-dependent disease. Approximately 70% of breast cancers express progesterone receptors and/or estrogen receptors, and they are a good marker for cancer prognosis. This review will discuss estrogen metabolism and the interaction of estrogen metabolites with breast cancer. The carcinogenic role of estrogen is discussed in light of both conventional and atypical cancers susceptible to hormones, such as prostate, endometrial, and lung cancer, as we examine how estrogen contributes to the formation and activation of breast cancer. In addition, this review will discuss other factors that can be associated with estrogen-driven breast cancer.

Active Surveillance for Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ

Atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) are relatively common breast lesions on the same spectrum of disease. Atypical ductal hyperblasia is a nonmalignant, high-risk lesion, and DCIS is a noninvasive malignancy. While a benefit of screening mammography is early cancer detection, it also leads to increased biopsy diagnosis of noninvasive lesions. Previously, treatment guidelines for both entities included surgical excision because of the risk of upgrade to invasive cancer after surgery and risk of progression to invasive cancer for DCIS. However, this universal management approach is not optimal for all patients because most lesions are not upgraded after surgery. Furthermore, some DCIS lesions do not progress to clinically significant invasive cancer. Overtreatment of high-risk lesions and DCIS is considered a burden on patients and clinicians and is a strain on the health care system. Extensive research has identified many potential histologic, clinical, and imaging factors that may predict ADH and DCIS upgrade and thereby help clinicians select which patients should undergo surgery and which may be appropriate for active surveillance (AS) with imaging. Additionally, multiple clinical trials are currently underway to evaluate whether AS for DCIS is feasible for a select group of patients. Recent advances in MRI, artificial intelligence, and molecular markers may also have an important role to play in stratifying patients and delineating best management guidelines. This review article discusses the available evidence regarding the feasibility and limitations of AS for ADH and DCIS, as well as recent advances in patient risk stratification.

Third International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

The heterogeneous group of B3 lesions in the breast harbors lesions with different malignant potential and progression risk. As several studies about B3 lesions have been published since the last Consensus in 2018, the 3rd International Consensus Conference discussed the six most relevant B3 lesions (atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), radial scar (RS), papillary lesions (PL) without atypia, and phyllodes tumors (PT)) and made recommendations for diagnostic and therapeutic approaches. Following a presentation of current data of each B3 lesion, the international and interdisciplinary panel of 33 specialists and key opinion leaders voted on the recommendations for further management after core-needle biopsy (CNB) and vacuum-assisted biopsy (VAB). In case of B3 lesion diagnosis on CNB, OE was recommended in ADH and PT, whereas in the other B3 lesions, vacuum-assisted excision was considered an equivalent alternative to OE. In ADH, most panelists (76%) recommended an open excision (OE) after diagnosis on VAB, whereas observation after a complete VAB-removal on imaging was accepted by 34%. In LN, the majority of the panel (90%) preferred observation following complete VAB-removal. Results were similar in RS (82%), PL (100%), and FEA (100%). In benign PT, a slim majority (55%) also recommended an observation after a complete VAB-removal. VAB with subsequent active surveillance can replace an open surgical intervention for most B3 lesions (RS, FEA, PL, PT, and LN). Compared to previous recommendations, there is an increasing trend to a de-escalating strategy in classical LN. Due to the higher risk of upgrade into malignancy, OE remains the preferred approach after the diagnosis of ADH.

[B3 lesions of the breast: histological, clinical, and epidemiological aspects : Update]

B3 lesions of the breast are a heterogeneous group of lesions with uncertain malignant potential encompassing a broad spectrum of histologically distinct alterations that often pose challenging decisions if diagnosed on the preoperative core or vacuum biopsies. B3 lesions are mostly detected due to mammographic calcifications or mass lesions and, in most cases, encompass a spectrum of atypical lesions such as atypical ductal hyperplasia, classic lobular neoplasia, flat epithelial atypia, papillomas, fibroepithelial tumors, and rarely other lesions such as mucocele-like lesions, atypical apocrine lesions, and rare stromal proliferations. The use of immunohistochemical stains (estrogen receptors, basal cytokeratin, myoepithelial markers, and stromal marker panel) is useful in the differentiation of these lesions and allowing proper classification. Regarding clinical management of B3 lesions, the radiological-pathological correlation of the given entity plays the most important key element for the proper next diagnostic and therapeutic step.

Atypical Ductal Hyperplasia-Ductal Carcinoma In Situ Spectrum: Diagnostic Considerations and Treatment Impact in the Era of Deescalation

As the first node in treatment algorithms for breast disease, pathologists have the potential to play a critical role in refining appropriate therapy for lesions in the atypical ducal hyperplasia-ductal carcinoma in situ (ADH-DCIS) spectrum by conservatively approaching diagnosis of lesions limited in size on core needle biopsy. Appropriate efforts to downgrade the diagnosis of lesions at the borderline of ADH and DCIS will certainly lead to more breast conservation and avoid the common morbidities of mastectomy, sentinel node biopsy, and radiation therapy. Whether results of clinical trials of active surveillance will successfully identify a subset of women who may successfully forgo even limited breast-conserving surgery is eagerly anticipated. Given the increasing concern that a significant number of women with DCIS are overtreated, identification of patients at very low risk for progression who may forgo surgery and radiation therapy safely is of significant interest.

Atypical Ductal Hyperplasia: Risk Factors for Predicting Pathologic Upgrade on Excisional Biopsy

Purpose

To determine the incidence of atypical ductal hyperplasia (ADH) in needle biopsy and the upgrade rate to carcinoma, and to evaluate difference in findings between the upgrade and non-upgrade groups.

Materials and Methods

Among 9660 needle biopsies performed over 48 months, we reviewed the radiologic and histopathologic findings of ADH and compared the differences in imaging findings (mammography and breast US) and biopsy methods between the upgrade and non-upgrade groups.

Results

The incidence of ADH was 1.7% (169/9660). Of 112 resected cases and 30 cases followed-up for over 2 years, 35 were upgraded to carcinoma (24.6%, 35/142). The upgrade rates were significantly different according to biopsy methods: US-guided core needle biopsy (US-CNB) (40.7%, 22/54) vs. stereotactic-vacuum-assisted biopsy (S-VAB) (16.0%, 12/75) vs. US-guided VAB (US-VAB) (7.7%, 1/13) (p = 0.002). Multivariable analysis showed that only US-CNB (odds ratio = 5.19, 95% confidence interval: 2.16–13.95, p < 0.001) was an independent predictor for pathologic upgrade. There was no upgrade when a sonographic mass was biopsied by US-VAB (n = 7)

Conclusion

The incidence of ADH was relatively low (1.7%) and the upgrade rate was 24.6%. Surgical excision should be considered because of the considerable upgrade rate, except in the case of US-VAB.

Clinical management of atypical ductal hyperplasia on vacuum-assisted biopsy of microcalcifications: External validation study of a decision tree selecting patients eligible for surveillance

BACKGROUND

Atypical lesions found on percutaneous breast biopsy raise specific management issues. The aim of this study was to validate the previous performance of a decision tree defined by Forgeard et al to select a subset of patients at low-risk of surgical diagnostic upgrade that would be eligible for surveillance.

METHODS

A consecutive series of 211 patients diagnosed with ADH on vacuum-assisted biopsy (VAB) of clustered microcalcifications alone, then operated in our institution, was reviewed. Histological findings on percutaneous cores were compared with definitive diagnoses on surgical specimens. The rate of cancer underestimation on VAB was analyzed in the four arms and two management attitudes defined in the scheme, using size and quality of microcalcification removal and the number of ADH foci.

RESULTS

Ninety-eight women with ADH met the inclusion criteria. Overall, 20 cancers were diagnosed at surgery, showing a malignancy rate of 44% (17/39 patients) in the surgery group and of 5% (3/59 patients) in the surveillance group, which was not significantly different from the 2% rate in the monitored reference group (p > 0.64). The malignancy rate increased significantly with the size of clustered microcalcifications (0% when < 6mm, 17% when between 6mm and 21 mm, 48% when > 21 mm, p < 0001) and the number of ADH foci on VAB (14% when ≤ 2, 45% when > 2, p < 0.005).

CONCLUSION

Our results corroborate - within the limits of large confidence intervals - those obtained with the reference decision tree. Due to statistical uncertainty, however, they need to be prospectively validated in a broader series.

Prospective Multicenter Study Validate a Prediction Model for Surgery Uptake Among Women with Atypical Breast Lesions

BACKGROUND

Diagnosis of atypical breast lesions (ABLs) leads to unnecessary surgery in 75-90% of women. We have previously developed a model including age, complete radiological target excision after biopsy, and focus size that predicts the probability of cancer at surgery. The present study aimed to validate this model in a prospective multicenter setting.

- METHODS

Women with a recently diagnosed ABL on image-guided biopsy were recruited in 18 centers, before wire-guided localized excisional lumpectomy. Primary outcome was the negative predictive value (NPV) of the model.

RESULTS

The NOMAT model could be used in 287 of the 300 patients included (195 with ADH). At surgery, 12 invasive (all grade 1), and 43 in situ carcinomas were identified (all ABL: 55/287, 19%; ADH only: 49/195, 25%). The area under the receiving operating characteristics curve of the model was 0.64 (95% CI 0.58-0.69) for all ABL, and 0.63 for ADH only (95% CI 0.56-0.70). For the pre-specified threshold of 20% predicted probability of cancer, NPV was 82% (77-87%) for all ABL, and 77% (95% CI 71-83%) for patients with ADH. At a 10% threshold, NPV was 89% (84-94%) for all ABL, and 85% (95% CI 78--92%) for the ADH. At this threshold, 58% of the whole ABL population (and 54% of ADH patients) could have avoided surgery with only 2 missed invasive cancers.

CONCLUSION

The NOMAT model could be useful to avoid unnecessary surgery among women with ABL, including for patients with ADH.

CLINICAL TRIAL REGISTRATION

NCT02523612.

Role of vacuum assisted excision in minimising overtreatment of ductal atypias

PURPOSE

B3 lesions are indeterminate lesions of uncertain malignant potential. They include lesions with and without epithelial atypia. Those with atypia include atypical intraductal epithelial proliferation (AIDEP)/atypical ductal hyperplasia (ADH) and flat epithelial atypia (FEA). They are traditionally managed with surgery. Vacuum assisted excision (VAE) allows larger samples to be obtained using a vacuum assisted biopsy (VAB) device, which equates to a surgical biopsy. We propose that VAE and mammographic surveillance is a safe alternative to surgery in managing the ductal atypias; (AIDEP/ADH and FEA).

METHOD

Retrospective analysis of prospectively collected data on B3 lesions (April 2009 - March 2016) from consecutive breast screening patients diagnosed with AIDEP/ADH or FEA on initial diagnostic core biopsy. Mammographic abnormality, breast density, size, management pathway and upgrade to cancer and types of cancer were also collected during the treatment pathway and 5 year surveillance period (April 2009 - April 2019).

RESULTS

273 cases of ductal atypia were identified. 187/273 (68.5 %) cases were managed with VAE only as no upgrade to malignancy and then 5 year mammographic surveillance. 34/273 (12.5 %) cases had a VAE diagnosing malignancy. 24/273 (8.8 %) cases had a VAE and then a surgical biopsy due to radiological or pathological concern, 8/24 upgraded to malignancy. 22/273 (8%) cases had a surgical diagnostic biopsy, 9/22 (41 %) cases were upgraded to malignancy. In total 51/273 (19 %) cases were diagnosed with cancer on the new pathway (13 invasive (all ER positive and Her2 negative) and 38 non-invasive, (34 ductal carcinoma in situ (DCIS) and 4 cases of lobular carcinoma in situ (LCIS)). While 17/273 (6.2 %) cases developed malignancy (12 invasive (all HER2 negative) and 4 DCIS and 1 LCIS) during the 5 year surveillance period.

CONCLUSIONS

VAE is a safe alternative to surgery in managing ductal atypias. 187/273 (68.5 %) women avoided surgery. While 34/51 cancers (66.7 %) were diagnosed preoperatively using VAE, allowing the women to have a single therapeutic procedure.

Positive predictive value for malignancy of uncertain malignant potential (B3) breast lesions diagnosed on vacuum-assisted biopsy (VAB): is surgical excision still recommended?

PURPOSE

Breast lesions classified as of "uncertain malignant potential" represent a heterogeneous group of abnormalities with an increased risk of associated malignancy. Clinical management of B3 lesions diagnosed on vacuum-assisted breast biopsy (VABB) is still challenging: surgical excision is no longer the only available treatment and VABB may be sufficient for therapeutic excision. The aim of the present study is to evaluate the positive predictive value (PPV) for malignancy in B3 lesions that underwent surgical excision, identifying possible upgrading predictive factors and characterizing the malignant lesions eventually diagnosed. These results are compared with a subset of patients with B3 lesions who underwent follow-up.

METHODS

A total of 1250 VABBs were performed between January 2006 and December 2017 at our center. In total, 150 B3 cases were diagnosed and 68 of them underwent surgical excision. VABB findings were correlated with excision histology. A PPV for malignancy for each B3 subtype was derived.

RESULTS

The overall PPV rate was 28%, with the highest upgrade rate for atypical ductal hyperplasia (41%), followed by classical lobular neoplasia (29%) and flat epithelial atypia (11%). Only two cases of carcinoma were detected in the follow-up cohort, both associated with atypical ductal hyperplasia at VABB.

CONCLUSION

Open surgery is recommended in case of atypical ductal hyperplasia while, for other B3 lesions, excision with VABB only may be an acceptable alternative if radio-pathological correlation is assessed, if all microcalcifications have been removed by VABB, and if the lesion lacks high-risk cytological features.

KEY POINTS

• Surgical treatment is strongly recommended in case of ADH, while the upgrade rate in case of pure FEA, especially following complete microcalcification removal by VABB, may be sufficiently low to advice surveillance as a management strategy. • The use of 11-G- or 8-G-needle VABB, resulting in possible complete diagnostic excision of the lesion, can be an acceptable alternative in case of RS, considering open surgery only for selected high-risk patients. • LN management is more controversial: surgical excision may be recommended following classical LN diagnosis on breast biopsy if an additional B3 lesion is concurrently detected while in the presence of isolated LN with adequate radiological-pathological correlation follow-up alone could be an acceptable option.