Indeterminate (B3) Breast Lesions and the Ongoing Role of Diagnostic Open Biopsy

Introduction. Due to their uncertain malignant potential, indeterminate breast lesions on core needle biopsy (CNB) require diagnostic open biopsy (DOB). This study evaluated DOB results given largely benign pathology. Lesions included are atypical papilloma, atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and radial scar/complex sclerosing lesions (RS/CSL). Methodology. A retrospective audit from 2010 to 2017 analysed patients with a screen-detected suspicious lesion and indeterminate (B3) CNB diagnosis. Primary outcome was the malignancy upgrade rate, with secondary evaluation of patient factors predictive of malignancy including age, symptoms, mammogram characteristics, lesion size, biopsy method, and past and family history. Results. 152 patients (median age 57 years) were included, with atypical papillomas being the largest subgroup (44.7%). On DOB histology, 99.34% were benign, resulting in a 0.66% malignancy upgrade rate. Patient characteristic analysis identified 86.84% of B3 lesions were in patients greater than 50 years old. 90.13% were asymptomatic, whilst 98.68% and 72.37% had a negative past and family history. Majority 46.71% of lesions had the mammogram characteristic of being a mass. However, with 57.89% of the lesion imaging size less than 4 mm, a corresponding 60.5% of core needle biopsies were performed stereotactically. The small malignant subgroup limited predictive factor evaluation. Conclusion. Albeit a low 0.66% malignancy upgrade rate in B3 lesions, no statistically significant patient predictive factors were identified. Until predictive factors and further assessment of vacuum-assisted excision (VAE) techniques evolve, DOB remains the standard of care.

Cost analysis of managing B3 breast lesions by vacuum excision at Leeds Breast Unit using a decision model

ObjectiveTo develop an economic model to evaluate the cost of using vacuum-assisted excision (VAE) for managing B3 breast lesions.DesignA decision tree of managing B3 breast lesions was developed to compare the costs of VAE with diagnostic excision (DE) from the perspective of the healthcare provider. Two different diagnostic pathways were compared which describe alternative approaches to the management of B3 lesions using inputs derived from a mix of primary and secondary data.SettingBased on a study conducted at Leeds Breast Unit, UK.Participants398 patients enter the model having undergone initial core needle biopsy, or vacuum-assisted biopsy, and diagnosed with B3 breast lesion.Main outcome measuresThe economic impact, in terms of cost, of various scenarios using analysis of extremes and probabilistic sensitivity analysis.ResultsVAE reduced the cost per patient by £1510.75. Analysis of extremes showed that managing B3 lesions using VAE was cost saving except the case where a combination of the highest cost associated with VAE and the lowest cost for DE were used. Probabilistic sensitivity analysis showed that using VAE for managing B3 lesions has a probability of 0.9 of being cost saving compared with using DE.ConclusionThis analysis shows the potential cost saving of using VAE as an alternative for managing B3 breast lesions compared with DE. Further research in this area and the effect of the VAE on patients’ quality of life is warranted.

B3 Lesions at Vacuum-Assisted Breast Biopsy under Ultrasound or Mammography Guidance: A Single-Center Experience on 3634 Consecutive Biopsies

The rate of upgrade to cancer for breast lesions with uncertain malignant potential (B3 lesions) diagnosed at needle biopsy is highly influenced by several factors, but large series are seldom available. We retrospectively assessed the upgrade rates of a consecutive series of B3 lesions diagnosed at ultrasound- or mammography-guided vacuum-assisted biopsy (VAB) at an EUSOMA-certified Breast Unit over a 7-year timeframe. The upgrade rate was defined as the number of ductal carcinoma in situ (DCIS) or invasive cancer at pathology after excision or during follow-up divided by the total number of B3 lesions. All lesions were reviewed by one of four pathologists with a second opinion for discordant assessments of borderline cases. Excision or surveillance were defined by the multidisciplinary tumor board, with 6- and 12-month follow-up. Out of 3634 VABs (63% ultrasound-guided), 604 (17%) yielded a B3 lesion. After excision, 17/604 B3 lesions were finally upgraded to malignancy (2.8%, 95% confidence interval [CI] 1.8–4.5%), 10/17 (59%) being upgraded to DCIS and 7/17 (41%) to invasive carcinoma. No cases were upgraded during follow-up. B3a lesions showed a significantly lower upgrade rate (0.4%, 95% CI 0.1–2.1%) than B3b lesions (4.7%, 95% CI 2.9–7.5%, p = 0.001), that had a 22.0 adjusted odds ratio for upgrade (95% CI 2.1–232.3). No significant difference was found in upgrade rates according to imaging guidance or needle caliper. Surveillance-oriented management can be considered for B3a lesions, while surgical excision should be pursued for B3b lesions.

EP.TH.803VAE for Breast Lesions of Uncertain Potential (B3) -A Quality Improvement Project

Aims Breast lesions of uncertain malignant potential (B3) account for 7% breast lesions biopsied. Management has been controversial and challenging for the MDT. Aim of the study was to compare current NHS BSP guidelines with our trust’s practice and the secondary outcome was a shorter patient pathway and cost effectiveness. Methods As per NHS BSP guidelines VAE should be performed for all B3 lesions diagnosed on 14g or vacuum assisted biopsy. We were referring them to other NHS trusts as there were no in-house facilities or doing an excisional biopsy if no resources for VAE available. From September 2019 VAEs started to be done by in-house consultant breast radiologist after getting the appropriate training and instruments. Data was collected from September 2019 to August 2020 for all patients. Results 22 VAEs were performed in one year. Out of those 6 (27.2%) were upgraded to malignancy and needed further surgery, 2 (9%) with atypia had 5 years mammographic surveillance and 14 (63%) were discharged including sclerosing lesions, radial scars, fibrosis and chronic inflammation. The cost of VAE in our hospital is £1330 vs. £2439 for Wire Guided wide local excision. This makes it cost effective. Conclusion We were following the VAE protocol as per NHS BSP guidelines. Despite added workload to radiology VAE is minimally invasive, safe and cost effective alternative to surgery providing thorough MDT discussion has taken place. Greater benefit was provided to patient as all VAEs were performed in radiology department avoiding general Anaesthesia and surgical trauma.

623 Completed Audit Cycle of Indications for Excision of Fibroadenomas At A University Hospital

Aim This audit looked at indications for excisions of fibroadenomas one year on from the first audit cycle and following intervention of presentation and teaching at local departmental meeting. This audit was motivated by a drive to reduce operations on benign breast conditions including fibroadenoma excisions. ABS (Association of Breast Surgery) guidelines advise excision for fibroepithelial lesions (B3) on biopsy, pain and increasing size. Local consensus is excision of fibroadenomas over 30mm on ultrasound. Method Patients who underwent surgical excisions of fibroadenomas over 6 months at one hospital were analysed for size on ultrasound, biopsy histology and reason for excision, and compared to previous audit results over 24 months. Results Over 6 months, 18 patients underwent excisions. Histology specimens showed 13/18 were fibroadenomas, 4/18 benign phyllodes and 1/18 other benign conditions. This was similar to the previous audit, although there was an increase in the rate of benign phyllodes. Pre-operatively, 11/18 of patients met the ABS criteria for excision (7/11 were B3 lesions, 3/11 for increasing size and 1/11 pain). 11/18 patients met the local criteria. 2/18 patients met neither criteria. This had improved compared to the first audit cycle. Conclusions 88.9% of patients met ABS or local criteria, compared to 83.7% previously, and so this had improved following intervention. One outcome from the first audit cycle was patients need greater reassurance about the benign nature of fibroadenomas to avoid unnecessary morbidity due to surgical procedures, and this appears to have improved on re-audit. Both patients not meeting criteria had histology showing fibroadenomas.

Malignancy Rate and Malignancy Risk Assessment in Different Lesions of Uncertain Malignant Potential in the Breast (B3 Lesions): An Analysis of 192 Cases from a Single Institution

<b><i>Background:</i></b> The question of how to deal with B3 lesions is of emerging interest. <b><i>Methods:</i></b> In the breast diagnostics of 192 patients between 2009 and 2016, a minimally invasive biopsy revealed a B3 lesion with subsequent resection. This study investigates the malignancy rate of different B3 subgroups and the risk factors that play a role in obtaining a malignant finding. <b><i>Results:</i></b> The distribution of B3 lesions after minimally invasive biopsy was as follows: atypical ductal hyperplasia (ADH), 7.3%; flat epithelial atypia (FEA), 7.8%; lobular neoplasia (LN), 7.8%; papilloma (Pa), 49.5%; phylloidal tumour (PT), 8.9%; radial sclerosing scar (RS), 3.1%; mixed findings, 10.4%; and other B3 lesions, 5.2%. Most B3 lesions were detected by stereotactic vacuum-assisted biopsy (44.3%), 36.5% by ultrasound-assisted biopsy, and 19.3% by magnetic resonance imaging-assisted biopsy. Most B3 lesions (55.2%) were verified by surgical resection, whereas 30.7% were downgraded to a benign lesion. About 14.1% of the cases were upgraded to malignant lesions, 9.4% to ductal carcinoma in situ and 4.7% to invasive carcinoma. In relation to individual B3 lesions, the following malignancy rates were found: 28.6% (ADH), 13.3% (FEA), 33.3% (LN), 12.6% (Pa), 5.9% (PT), and 0% (RS). The most important risk factor was increasing age. Postmenopausal status was considered an increased risk for an upgrade (<i>p =</i> 0.015). A known malignancy in the ipsilateral breast was a significant risk factor for a malignant upgrade (<i>p =</i> 0.003). <b><i>Conclusion:</i></b> Increasing knowledge about B3 lesions allows us to develop a “lesion-specific” therapy approach in the heterogeneous group of B3 lesions, with follow-up imaging for some lesions with less malignant potential and concordance with imaging or further surgical resection in cases of disconcordance with imaging or higher malignant potential.

Breast lesions excised via vacuum-assisted system: could we get any clues for B3 lesions before excision biopsy?

Background The purpose of this study was to determine the validity of the ultrasound features as well as patient characteristics assigned to B3 (uncertain malignant potential) breast lesions before vacuum-assisted excision biopsy (VAEB). Methods This study population consisted of 2245 women with breast-nodular abnormalities, which were conducted ultrasound-guided VAEB (US-VAEB). Patient’s clinical and anamnestic data and lesion-related ultrasonic feature variables of B3 captured before US-VAEB were compared with those of benign or malignant cases, using histopathological results as a benchmark. Results The proportions of benign, B3 and malignant breast lesions diagnosed post-US-VAEB were 88.5, 8.2 and 3.4% respectively. B3 high frequent occurred in BI-RADS-US grade 3 (7.7%), grade 4a (11.0%) and grade 4b (9.1%). The overall malignancy underestimation rate of B3 was 4.4% (8/183). Malignant lesions were found mostly in the range of BI-RADS grade 4b (27.3%), grade 4c (33.3%) and grade 5 (100%). Multivariate binary logistic regression analyses (B3 vs benign) showed that non-menopausal patients (95% CI 1.628–8.616, P = 0.002), single (95% CI 1.370–2.650, P = 0.000) or vascularity (95% CI 1.745–4.150, P = 0.000) nodules in ultrasonic features were significant risk factors for B3 occurrences. In addition, patients elder than 50 years (95% CI 3.178–19.816, P = 0.000), unclear margin (95% CI 3.571–14.119, P = 0.000) or suspicious calcification (95% CI 4.010–30.733, P = 0.000) lesions were significantly associated with higher risks of malignant potentials for B3 cases (malignant vs B3). Conclusion The results of this study indicate that ultrasound findings and patients’ characteristics might provide valuable information for distinguishing B3 lesions from benign breast abnormalities before VAEB, and help to reduce malignancy underestimation of B3.

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).