Axillary ultrasound for prediction of response to neoadjuvant therapy in the context of surgical strategies to axillary dissection in primary breast cancer: a systematic review of the current literature

Nomogram Based on US and Clinicopathologic Characteristics: Axillary Nodal Evaluation Following Neoadjuvant Chemotherapy in Patients With Node-Positive Breast Cancer

BACKGROUND

To develop a convenient modality to predict axillary response to neoadjuvant chemotherapy (NAC) in breast cancer patients.

MATERIALS AND METHODS

In this multi-center study, a total of 1019 breast cancer patients with biopsy-proven positive lymph node (LN) receiving NAC were randomly assigned to the training and validation groups at a ratio of 7:3. Clinicopathologic and ultrasound (US) characteristics of both primary tumors and LNs were used to develop corresponding prediction models, and a nomogram integrating clinicopathologic and US predictors was generated to predict the axillary response to NAC.

RESULTS

Axillary pathological complete response (pCR) was achieved in 47.79% of the patients. The expression of estrogen receptor, human epidermal growth factor receptor -2, Ki-67 score, and clinical nodal stage were independent predictors for nodal response to NAC. Location and radiological response of primary tumors, cortical thickness and shape of LNs on US were also significantly associated with nodal pCR. In the validation cohort, the discrimination of US model (area under the curve [AUC], 0.76) was superior to clinicopathologic model (AUC, 0.68); the combined model (AUC, 0.85) demonstrates strong discriminatory power in predicting nodal pCR. Calibration curves of the nomogram based on the combined model demonstrated that substantial agreement can be observed between the predictions and observations. This nomogram showed a false-negative rates of 16.67% in all patients and 10.53% in patients with triple negative breast cancer.

CONCLUSION

Nomogram incorporating routine clinicopathologic and US characteristics can predict nodal pCR and represents a tool to aid in treatment decisions for the axilla after NAC in breast cancer patients.

Controversies in axillary management of patients with breast cancer - updates for 2024

PURPOSE OF REVIEW

For some time now, the question of de-escalation in axillary staging in breast cancer patients has been raised. The aim is to improve the patients' quality of life and reduce morbidity by optimizing surgical strategies with a high level of oncological safety. This review offers a current overview of published evidence and clinical practice, aiming to guide the surgical community as they reassess and reshape their practices.

RECENT FINDINGS

Years after introducing sentinel lymph node biopsy (SLNB) in clinically node negative breast cancer patients several guidelines suggest completely omitting SLNB in older patients with low-risk tumors. It is worth noting that for patients with a metastatic sentinel lymph node in the upfront surgery setting, a de-escalation of axillary surgery may in fact lead to an escalation of radiation therapy. Currently, there is limited evidence on the axillary surgical approach for patients with initially positive node status achieving complete axillary response (ycN0), resulting in heterogenous guideline recommendations.

SUMMARY

Innovative trials are contributing to a growing evidence on de-escalation of axillary surgery with the aim of reducing arm morbidity and improving long-term health-related quality of life.

Axillary ultrasound for predicting response to neoadjuvant treatment in breast cancer patients-a single institution experience

BACKGROUND

In node-positive breast cancer patients at diagnosis (cN +) that render node-negative after neoadjuvant systemic treatment (NAST), axillary lymph node dissection (ALND) can be avoided in selected cases. Axillary ultrasound (AUS) is most often used for re-staging after NAST. We aimed to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of AUS after NAST for predicting nodal response at the Institute of Oncology, Ljubljana.

METHODS

Biopsy-confirmed cN + patients consecutively diagnosed at our institution between 2008 and 2021, who received NAST, followed by surgery were identified retrospectively. Only patients that underwent AUS after NAST were included. AUS results were compared to definite nodal histopathology results. We calculated sensitivity, specificity, PPV and NPV of AUS. We also calculated the proportion of patients with false-positive AUS that results in surgical overtreatment (unnecessary ALND).

RESULTS

We identified 437 cN + patients. In 244 (55.8%) AUS after NAST was performed. Among those, 42/244 (17.2%) were triple negative (TN), 78/244 (32.0%) Her-2 positive (Her-2 +), and 124/244 (50,8%) luminal Her-2 negative cancers. AUS was negative in 179/244 (73.4%), suspicious/positive in 65/244 (26.6%) (11/42 (26.2%) TN, 19/78 (24.4%) Her-2 + , and 35/124 (28.2%) luminal Her-2 negative cancers). On definite histopathology, nodal complete response (pCR) was observed in 89/244 (36.5%) (19/42 (45.2%) TN, 55/78 (70.5%) Her-2 + , and 15/124 (12.1%) luminal Her-2 negative cancers). Among patients with suspicious/positive AUS, pCR was observed in 20/65 (30.8%) (6/11 (54.5%) TN, 13/19 (68.4%) Her-2 + and 1/35 (2.9%) luminal Her-2 negative cancers). Sensitivity was 29.0%, specificity 77,5%, PPV 69.2%, NPV 38.5%. Specificity and PPV in TN was 68.4% and 45.4%, in Her-2 + 76.4% and 31.6%, in luminal Her-2 negative 93,3% and 97,1%, respectively.

CONCLUSION

In approximately half of the patients, AUS falsely predicts nodal response after NAST and may lead to overtreatment in 30% of the cases (ALND). However, AUS has to be interpreted in context with tumor subtype. In luminal Her-2 negative cancers, it has a high PPV and is therefore useful.

Axillary staging in node-positive breast cancer converting to node negativity through neoadjuvant chemotherapy: Current evidence and perspectives

PURPOSE

Over the recent years, axillary staging of initially node-positive breast cancer patients converting to clinical node negativity after neoadjuvant chemotherapy has seen rapid changes. This narrative review aims to give a contemporary overview over published evidence and clinical practice, and thus provide some guidance to the surgical community in the process of re-evaluating and re-shaping surgical practice.

METHODS

The search strategy aimed at finding relevant studies. Only articles in English were considered.

RESULTS

The introduction of modern techniques offer more precise staging surgery and thus hopefully reduced arm morbidity. Clinical practice has however diverged both within countries and internationally. While some countries have adapted de-escalated axillary staging techniques such as targeted axillary dissection, targeted lymph node biopsy or sentinel lymph node biopsy, others continue to recommend a full axillary lymph node dissection. With the implementation of new techniques, many questions arise, regarding aspects of oncological safety, technical performance, budget and practicality, patient selection and indications for different levels of axillary staging procedures.

CONCLUSIONS

There is a growing body of evidence on de-escalation of axillary surgery in the setting of cN+ → ycN0 breast cancer treated with neoadjuvant chemotherapy. However, standards differ between countries and future studies are necessary to fully assess the optimal strategy for these patients.

Marking Techniques for Targeted Axillary Dissection Among Patients With Node-Positive Breast Cancer Treated With Neoadjuvant Chemotherapy

Invasive breast cancer with axillary lymph node (LN) invasion is a continuing problem worldwide. The morbidity associated with axillary LN dissection along with the high rate of nodal downstaging after neoadjuvant chemotherapy (NACT) made the standard treatment shift towards less invasive surgery. Sentinel lymph node biopsy (SLNB) after NACT is associated with high false-negative rates (13%-14%). To overcome this problem, it was concluded that the positive nodes should first be indicated with image-detectable markers and then removed together with SLNB: targeted axillary dissection (TAD). This review aims to describe and evaluate the different marking techniques for TAD in patients with node-positive breast cancer treated with NACT, namely: clip placement and guidewire localization; clip placement and 125I-labelled radioactive seed localization; clip placement and skin mark; clip placement and intraoperative ultrasound; tattooing with a sterile black carbon suspension; magnetic seeds; radar and infrared light technology localization. Targeted axillary dissection techniques have shown false-negative rates below 9% and identification rates above 95%. The most studied technique is guidewire localization, as it is also the oldest one. However, according to data gathered from this review, some newer techniques have shown to be very promising due to their statistical results and management factors.

Real de-escalation or escalation in disguise?

The past two decades have seen an unprecedented trend towards de-escalation of surgical therapy in the setting of early BC, the most prominent examples being the reduction of re-excision rates for close surgical margins after breast-conserving surgery and replacing axillary lymph node dissection by less radical procedures such as sentinel lymph node biopsy (SLNB). Numerous studies confirmed that reducing the extent of surgery in the upfront surgery setting does not impact locoregional recurrences and overall outcome. In the setting of primary systemic treatment, there is an increased use of less invasive staging strategies reaching from SLNB and targeted lymph node biopsy (TLNB) to targeted axillary dissection (TAD). Omission of any axillary surgery in the presence of pathological complete response in the breast is currently being investigated in clinical trials. On the other hand, concerns have been raised that surgical de-escalation might induce an escalation of other treatment modalities such as radiation therapy. Since most trials on surgical de-escalation did not include standardized protocols for adjuvant radiotherapy, it remains unclear, whether the effect of surgical de-escalation was valid in itself or if radiotherapy compensated for the decreased surgical extent. Uncertainties in scientific evidence may therefore lead to escalation of radiotherapy in some settings of surgical de-escalation. Further, the increasing rate of mastectomies including contralateral procedures in patients without genetic risk is alarming. Future studies of locoregional treatment strategies need to include an interdisciplinary approach to integrate de-escalation approaches combining surgery and radiotherapy in a way that promotes optimal quality of life and shared decision-making.

Localization Techniques for Non-Palpable Breast Lesions: Current Status, Knowledge Gaps, and Rationale for the MELODY Study (EUBREAST-4/iBRA-NET, NCT 05559411)

BACKGROUND

Surgical excision of a non-palpable breast lesion requires a localization step. Among available techniques, wire-guided localization (WGL) is most commonly used. Other techniques (radioactive, magnetic, radar or radiofrequency-based, and intraoperative ultrasound) have been developed in the last two decades with the aim of improving outcomes and logistics.

METHODS

We performed a systematic review on localization techniques for non-palpable breast cancer.

RESULTS

For most techniques, oncological outcomes such as lesion identification and clear margin rate seem either comparable with or better than for WGL, but evidence is limited to small cohort studies for some of the devices. Intraoperative ultrasound is associated with significantly higher negative margin rates in meta-analyses of randomized clinical trials (RCTs). Radioactive techniques were studied in several RCTs and are non-inferior to WGL. Smaller studies show higher patient preference towards wire-free localization, but little is known about surgeons' and radiologists' attitudes towards these techniques.

CONCLUSIONS

Large studies with an additional focus on patient, surgeon, and radiologist preference are necessary. This review aims to present the rationale for the MELODY (NCT05559411) study and to enable standardization of outcome measures for future studies.

Surgical Management of the Axilla for Breast Cancer

This review discusses the contemporary surgical management of the axilla in patients with breast cancer. Surgical paradigms are highlighted by clinical nodal status at presentation and treatment approach, including upfront surgery and neoadjuvant systemic therapy settings. This review focuses on the increasing opportunities for de-escalating the extent of axillary surgery in the era of sentinel lymph node biopsy, while also reviewing the remaining indications for axillary clearance with axillary lymph node dissection.

Lymph node microcalcifications after neoadjuvant chemotherapy: A therapeutic response marker

Lymph node microcalcifications are rare events, and when they are accompanied by neoplasia, they usually seem to be associated with a metastatic condition. We present a case of a patient with breast cancer and lymph node microcalcifications undergoing neoadjuvant chemotherapy (NCT). A change in the calcification pattern towards becoming coarse was observed. Calcification represented a marker of axillary disease, and it was resected after NCT. This is the first report of a patient with lymph node microcalcification undergoing NCT. We observed a change in the calcification format, which facilitated lymph node sentinel identification. Pathological evaluation indicated metastatic disease.

Axillary staging and management of cN + breast cancer patients treated with neoadjuvant chemotherapy: results of a survey among breast cancer surgeons in Spain

INTRODUCTION

Given the high rate of complete nodal response, the role of axillary lymph node dissection on staging the axilla has been questioned. This survey, addressed to breast cancer surgeons in Spain, has the objective of assessing current clinical trends on axillary staging of cN + patients treated with NAC.

METHODS

An online survey was conducted among breast surgeons from the Spanish Society of Surgery (AEC), Spanish Surgical Oncology Society (SEOQ), Spanish Breast Cancer Surgeons Society (AECIMA) and Spanish Gynecology and Obstetrics Society (SEGO). It was structured in 5 sections: general information and clinical practice, knowledge of clinical trials, diagnosis work-up and nodal marking, axillary staging, and axillary treatment.

RESULTS

150 breast cancer surgeons completed the full survey (96.7%). 81.8% of respondents performed SLNB or targeted axillary dissection in cN1 patients treated with NAC. Radiological axillary response was the preferred parameter guiding the surgical strategy. The excision of the clipped node (92.0%), use of dual tracer (73.2%), and axillary US (65.9%) after treatment were the most important variables considered by respondents, to increase the accuracy of SLNB in cN + patients.

CONCLUSION

This survey confirms a trend toward a less invasive approach for axillary staging in cN + patients treated with NAC among breast cancer surgeons in Spain. While there is widespread agreement in less invasive approaches to axillary staging, there is, however, a lack of consensus around treatment strategy. Further, it shows a wide heterogeneity in their clinical practice. This study highlights the need for clear evidence concerning less invasive staging procedures and their oncological safety, to ensure consistent recommendations in surgical practice.

Current trends in diagnostic and therapeutic management of the axilla in breast cancer patients receiving neoadjuvant therapy: results of the German-wide NOGGO MONITOR 24 survey

PURPOSE

In the last 2 decades, the optimal management of the axilla in breast cancer patients receiving neoadjuvant chemotherapy (NACT) has been one of the most frequently discussed topics. Little is known about the attitudes of surgeons/radiologists towards new developments such as targeted axillary dissection. Therefore, the NOGGO conducted a survey to evaluate the current approach to axillary management.

METHODS

A standardized digital questionnaire was sent out to > 200 departments in Germany between 7/2021 and 5/2022. The survey was supported by EUBREAST.

RESULTS

In total, 116 physicians completed the survey. In cN0 patients scheduled to receive NACT, 89% of respondents recommended sentinel lymph node biopsy (SLNB) after NACT. In case of ypN1mi(sn), 44% advised no further therapy, while 31% proposed ALND and 25% axillary irradiation. 64% of respondents recommended a minimally invasive axillary biopsy to cN + patients. TAD was used at the departments of 82% of respondents and was offered to all cN + patients converting to ycN0 by 57% and only to selected patients, usually based on the number of suspicious nodes at time of presentation, by 43%. The most common marking technique was a clip/coil. 67% estimated that the detection rate of their marker was very good or good.

CONCLUSION

This survey shows a heterogenous approach towards axillary management in the neoadjuvant setting in Germany. Most respondents follow current guidelines. Since only two-thirds of respondents experienced the detection rate of the marker used at their department as (very) good, future studies should focus on the comparative evaluation of different marking techniques.

AGO Recommendations for the Surgical Therapy of Breast Cancer: Update 2022

The recommendations of the AGO Breast Committee on the surgical therapy of breast cancer were last updated in March 2022 (www.ago-online.de). Since surgical therapy is one of several partial steps in the treatment of breast cancer, extensive diagnostic and oncological expertise of a breast surgeon and good interdisciplinary cooperation with diagnostic radiologists is of great importance. The most important changes concern localization techniques, resection margins, axillary management in the neoadjuvant setting and the evaluation of the meshes in reconstructive surgery. Based on meta-analyses of randomized studies, the level of recommendation of an intraoperative breast ultrasound for the localization of non-palpable lesions was elevated to "++". Thus, the technique is considered to be equivalent to wire localization, provided that it is a lesion which can be well represented by sonography, the surgeon has extensive experience in breast ultrasound and has access to a suitable ultrasound device during the operation. In invasive breast cancer, the aim is to reach negative resection margins ("no tumor on ink"), regardless of whether an extensive intraductal component is present or not. Oncoplastic operations can also replace a mastectomy in selected cases due to the large number of existing techniques, and are equivalent to segmental resection in terms of oncological safety at comparable rates of complications. Sentinel node excision is recommended for patients with cN0 status receiving neoadjuvant chemotherapy after completion of chemotherapy. Minimally invasive biopsy is recommended for initially suspect lymph nodes. After neoadjuvant chemotherapy, patients with initially 1 - 3 suspicious lymph nodes and a good response (ycN0) can receive the targeted axillary dissection and the axillary dissection as equivalent options.

Axillary Staging after Neoadjuvant Chemotherapy for Initially Node-Positive Breast Carcinoma in Germany: Initial Data from the AXSANA study

Introduction To date, the optimal axillary staging procedure for initially node-positive breast carcinoma patients after neoadjuvant chemotherapy (NACT) has been unclear. The aim of the AXSANA study is to prospectively compare different surgical staging techniques with respect to the oncological outcome and quality of life for the patients. Little is known about current clinical practice in Germany. Material and Methods In this paper we analyzed data from patients enrolled in the AXSANA study at German study sites from June 2020 to March 2022. Results During the period under investigation, 1135 patients were recruited at 143 study sites. More than three suspicious lymph nodes were initially found in 22% of patients. The target lymph node (TLN) was marked in 64% of cases. This was done with clips/coils in 83% of patients, with magnetic seeds or carbon suspension in 8% each, and with a radar marker in 1% of patients. After NACT, targeted axillary dissection (TAD) or axillary lymphadenectomy (ALND) were each planned in 48% of patients, and sentinel lymph node biopsy alone (SLNB) in 2%. Clinically, the nodal status after NACT was found to be unremarkable in 65% of cases. Histological lymph node status was correctly assessed by palpation in 65% of patients and by sonography in 69% of patients. Conclusion At the German AXSANA study sites, TAD and ALND are currently used as the most common surgical staging procedures after NACT in initially node-positive breast cancer patients. The TLN is marked with various markers prior to NACT. Given the inadequate accuracy of clinical assessment of axillary lymph node status after NACT, it should be questioned whether axillary dissection after NACT should be performed based on clinical assessment of nodal status alone.

ACR Appropriateness Criteria® Imaging of the Axilla

This publication reviews the current evidence supporting the imaging approach of the axilla in various scenarios with broad differential diagnosis ranging from inflammatory to malignant etiologies. Controversies on the management of axillary adenopathy results in disagreement on the appropriate axillary imaging tests. Ultrasound is often the appropriate initial imaging test in several clinical scenarios. Clinical information (such as age, physical examinations, risk factors) and concurrent complete breast evaluation with mammogram, tomosynthesis, or MRI impact the type of initial imaging test for the axilla. Several impactful clinical trials demonstrated that selected patient's population can received sentinel lymph node biopsy instead of axillary lymph node dissection with similar overall survival, and axillary lymph node dissection is a safe alternative as the nodal staging procedure for clinically node negative patients or even for some node positive patients with limited nodal tumor burden. This approach is not universally accepted, which adversely affect the type of imaging tests considered appropriate for axilla. This document is focused on the initial imaging of the axilla in various scenarios, with the understanding that concurrent or subsequent additional tests may also be performed for the breast. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Combining conventional ultrasound and sonoelastography to predict axillary status after neoadjuvant chemotherapy for breast cancer

OBJECTIVE

To determine the ability of conventional ultrasound (US) combined with shear wave elastography (SWE) to reveal axillary status after neoadjuvant chemotherapy (NAC) in breast cancer patients.

METHODS

From September 2016 to December 2021, 201 patients with node-positive breast cancer who underwent NAC were enrolled in this prospective study. Conventional US features of axillary lymph nodes and SWE characteristics of breast lesions after NAC were analyzed. The diagnostic performances of US, SWE, and their combination were assessed using multivariate logistic regression and receiver operator characteristic curve (ROC) analyses.

RESULTS

The area under the ROC curve (AUC) for the ability of conventional US features to determine axillary status after NAC was 0.82, with a sensitivity of 85.23%, a specificity of 67.39%, and an accuracy of 76.11%. Shear wave velocity (SWV) displayed moderate performance for predicting axilla status after NAC with SWV_mean demonstrating an AUC of 0.85. Cortical thickness and shape of axillary nodes and SWV_mean of breast tumors were independently associated with axillary nodal metastasis after NAC. Compared to conventional US, the combination of conventional US of axillary lymph nodes with SWE of breast lesions achieved a significantly higher AUC (0.90 vs 0.82, p < 0.01, Delong's test) with a sensitivity of 87.50%, improved specificity of 82.61% and accuracy of 85.00%.

CONCLUSIONS

Breast SWE was independently associated with residual metastasis of axillary node after NAC in patients with initially diagnosed positive axilla. Combining SWE with conventional US showed good diagnostic performance for axillary node disease after NAC.

KEY POINTS

• Breast SWE can serve as a supplement to axilla US for the evaluation of the axilla after NAC. • The combination of axilla US with breast SWE may be a promising method to facilitate less-invasive treatment in patients receiving NAC.

A Canadian national guideline on the neoadjuvant treatment of invasive breast cancer, including patient assessment, systemic therapy, and local management principles

Purpose

The neoadjuvant treatment of breast cancer (NABC) is a rapidly changing area that benefits from guidelines integrating evidence with expert consensus to help direct practice. This can optimize patient outcomes by ensuring the appropriate use of evolving neoadjuvant principles.

Methods

An expert panel formulated evidence-based practice recommendations spanning the entire neoadjuvant breast cancer treatment journey. These were sent for practice-based consensus across Canada using the modified Delphi methodology, through a secure online survey. Final recommendations were graded using the GRADE criteria for guidelines. The evidence was reviewed over the course of guideline development to ensure recommendations remained aligned with current relevant data.

Results

Response rate to the online survey was almost 30%; representation was achieved from various medical specialties from both community and academic centres in various Canadian provinces. Two rounds of consensus were required to achieve 80% or higher consensus on 59 final statements. Five additional statements were added to reflect updated evidence but not sent for consensus.

Conclusions

Key highlights of this comprehensive Canadian guideline on NABC include the use of neoadjuvant therapy for early stage triple negative and HER2 positive breast cancer, with subsequent adjuvant treatments for patients with residual disease. The use of molecular signatures, other targeted adjuvant therapies, and optimal response-based local regional management remain actively evolving areas. Many statements had evolving or limited data but still achieved high consensus, demonstrating the utility of such a guideline in helping to unify practice while further evidence evolves in this important area of breast cancer management.

Axillary ultrasonography combined with pre-operative wire localisation of clipped node in nodal restaging after neoadjuvant chemotherapy in node positive breast cancer patients: a pilot study

OBJECTIVE

To evaluate the role of axillary ultrasonography (axUS) and ultrasound-guided pre-operative wire localisation of pre-treatment positive clipped node (CN) for prediction of nodal response to neoadjuvant chemotherapy (NACT) in node positive breast carcinoma patients.

METHODS AND MATERIALS

A prospective study was conducted between June 2018 and August 2020 after Ethics Committee approval. Breast carcinoma patients (cT1-cT4b) with palpable axillary nodes (cN1-cN3) and suitable for NACT were recruited after written informed consent. Single, most suspicious node was biopsied and clipped. Nodal response to NACT was assessed on axUS. Wire localisation of CN was performed prior to axillary lymph node dissection (ALND). Diagnostic performances of axUS and CN excision were assessed.

RESULTS

Of the 69 patients evaluated, 32 patients (mean age, 43.5 ± 11.8 years; females, 31/32 [97%]; pre-menopausal, 18/32 [56.3%]) with metastatic nodes who received NACT were included. Nodal pathological complete response rate was 34.4% (11/32) overall and 70% (7/10) in patients with ≤2 suspicious nodes on pre-NACT axUS. False-negative rates (FNRs) of axUS and CN excision were 4.8% and 28.6% respectively. Combination of post-NACT axUS and CN excision had an FNR of 4.8% overall and 0% in patients with ≤2 suspicious nodes on pre-NACT axUS.

CONCLUSION

Combination of AxUS and ultrasound-guided wire localisation of pre-treatment positive CN has high diagnostic accuracy for nodal restaging after NACT in node positive breast cancer patients.

ADVANCES IN KNOWLEDGE

Addition of axUS assessment to wire localisation of CN reduces its FNR for detecting residual metastasis after NACT.

AGO Recommendations for the Surgical Therapy of the Axilla After Neoadjuvant Chemotherapy: 2021 Update

For many decades, the standard procedure to treat breast cancer included complete dissection of the axillary lymph nodes. The aim was to determine histological node status, which was then used as the basis for adjuvant therapy, and to ensure locoregional tumour control. In addition to the debate on how to optimise the therapeutic strategies of systemic treatment and radiotherapy, the current discussion focuses on improving surgical procedures to treat breast cancer. As neoadjuvant chemotherapy is becoming increasingly important, the surgical procedures used to treat breast cancer, whether they are breast surgery or axillary dissection, are changing. Based on the currently available data, carrying out SLNE prior to neoadjuvant chemotherapy is not recommended. In contrast, surgical axillary management after neoadjuvant chemotherapy is considered the procedure of choice for axillary staging and can range from SLNE to TAD and ALND. To reduce the rate of false negatives during surgical staging of the axilla in pN+ _CNB stage before NACT and ycN0 after NACT, targeted axillary dissection (TAD), the removal of > 2 SLNs (SLNE, no untargeted axillary sampling), immunohistochemistry to detect isolated tumour cells and micro-metastases, and marking positive lymph nodes before NACT should be the standard approach. This most recent update on surgical axillary management describes the significance of isolated tumour cells and micro-metastasis after neoadjuvant chemotherapy and the clinical consequences of low volume residual disease diagnosed using SLNE and TAD and provides an overview of this yearʼs AGO recommendations for surgical management of the axilla during primary surgery and in relation to neoadjuvant chemotherapy.

Targeted Removal of Axillary Lymph Nodes After Carbon Marking in Patients with Breast Cancer Treated with Primary Chemotherapy

In breast cancer patients who have received primary chemotherapy and then no longer have any suspicious lymph nodes clinically and/or on imaging, marking of initially suspicious axillary lymph nodes with targeted removal has recently been discussed and practised both in Germany and internationally as an alternative to complete axillary lymph node dissection. Tattooing of the suspicious lymph nodes with a highly purified carbon suspension is currently being investigated in clinical studies. Compared with other techniques, the advantages of this method are the high rate of intraoperative lymph node detection, avoidance of an immediately preoperative localisation procedure and the low costs. The practical aspects of lymph node tattooing and the current data regarding this method will be described.

Breast cancer subtypes affect the ultrasound performance for axillary lymph node status evaluation after neoadjuvant chemotherapy: a retrospective analysis

PURPOSE

The aim of our study was to investigate the effect of breast cancer subtypes on the diagnostic value of axillary ultrasound for node status evaluation after neoadjuvant chemotherapy.

PATIENTS AND METHODS

Pathologic node-positive breast cancer patients underwent axillary ultrasound imaging after neoadjuvant chemotherapy were retrospectively reviewed. The enrolled patients were classified into four subtypes: Luminal A, Luminal B, human epidermal growth factor receptor 2-enriched and triple-negative. Ultrasound images of axillary nodes were reviewed and were evaluated as normal or abnormal and were associated with final pathologic results. Diagnostic value of axillary ultrasound was assessed in four subtypes based on sensitivity, specificity, positive predictive value and negative predictive value. The diagnostic value of axillary ultrasound as well as clinical and pathological characteristics was compared between four breast cancer subtypes using chi-square test or fisher's exact test.

RESULT

Luminal A subtype had highest positive predictive value (92.1%), lowest sensitivity (43.8%) and lowest negative predictive value (11.8%). Triple-negative subtype had lowest positive predictive value (73.2%), highest sensitivity (76.9%) and highest negative predictive value (59.1%) (P < 0.05). Luminal B and human epidermal growth factor receptor 2-enriched subtypes had medium sensitivity, positive predictive value and negative predictive value.

CONCLUSION

The diagnostic value of axillary ultrasound for node residue disease assessment after neoadjuvant chemotherapy is different between four breast cancer subtypes.

Evaluation of sonographic detectability of different markers within an in vitro simulation model of the axilla

PURPOSE

Clip-marking of axillary lymph nodes with initial biopsy-confirmed metastasis is required for targeted axillary dissection (TAD), which includes sentinel lymph node dissection (SLND) and selective localization and removal of the clipped targeted lymph node. There have been several studies which examined the feasibility of TAD in routine clinical use. In this context, the optimal clip visualisation was noted as one of the crucial limiting factors. We, therefore, evaluated the sonographic detectability of 10 different commercially available markers within an in vitro model simulating the anatomical composition of the axilla.

METHODS

In this standardised model consisting of porcine fat with 30 mm thickness, the visibility of a total of ten markers was analysed in all 3 planes (parallel, diagonal, orthograde) with wire guidance and then classified into either "visibility good", "visibility moderate" or "visibility poor" with regard to the alignment of the transducer. Additionally, "real-life conditions" were simulated, in which the markers were searched without any wires guidance.

RESULTS

It was observed that, while not all markers are detectable in fatty tissue, markers with spherical shape (non-embedded Inconel or Nitinol) or rectangular-shaped Titanium markers with embedded material have a clear advantage. 3D-shaped markers can always be detected in all three axes, which is of particular importance in the axilla with its pyramid shape and fatty tissue.

CONCLUSION

The shape and the embedding of the material play a crucial role for visibility and efficacy of the marker, as reliable marking of suspicious and pathological axillary lymph nodes is essential for TAD.

Formosanin C promotes the curative efficacy of ultrasound-guided radiofrequency ablation in a mouse model of breast cancer

Breast cancer is the leading cause of tumor-associated death among women worldwide, and new therapeutic strategies are required to improve the post-surgery prognosis and quality of life of patients. Radiofrequency ablation (RFA) is a less invasive approach compared with traditional surgical resection to treat malignancies, and the combination of RFA and chemotherapeutic agents, including formosanin C (FC), can synergistically improve the curative effects against breast carcinoma. However, the detailed mechanisms remain unclear. In the present study, nude mice were used to identify the influence of FC on the therapeutic efficacy of RFA for breast cancer. Flow cytometry was performed to demonstrate the proportional alteration of CD8⁺ and CD45⁺ T cells with different biomarkers, including CD107a, IFNγ and TNFα. It was demonstrated that FC enhanced the therapeutic efficacy of RFA in breast cancer, while RFA combined with FC improved the proportion of IFNγ⁺ and TNFα⁺ CD8⁺ T cells and CD107a⁺ CD8⁺ T cells in tumor-infiltrating lymphocytes, thus increasing the immune responses caused by surgery and chemotherapy. The present study indicated that FC may promote the curative efficacy of ultrasound-guided RFA against breast tumor by regulating adaptive immune responses.

Staging of the Axilla in Breast Cancer and the Evolving Role of Axillary Ultrasound

Axillary lymph nodes have long been recognized as a route for breast cancer to spread systemically. As a result, staging of the axilla has always played a central role in the treatment of breast cancer. Anatomic staging was believed to be important for two reasons: 1) it predicts prognosis and guides medical therapy, and 2) it is a potential therapy for removal of disease in the axilla. This paradigm has now been called into question. Prognostic information is driven increasingly by tumor biology, and trials such as the ACOSOG Z0011 demonstrates removal of axillary disease is not therapeutic. Staging of the axilla has undergone a dramatic de-escalation; however, sentinel lymph node biopsy (SLNB) is still an invasive surgery and represents a large economic burden on the healthcare system. In this review, we outline the changing paradigms of axillary staging in breast cancer from emphasis on anatomic staging to tumor biology, and the evolving role of axillary ultrasound, bringing patients less invasive and more personalized therapy.

Lost clips after targeted lymph node biopsy in breast cancer patients: Follow-up of the CLIP-study

INTRODUCTION

Clipping and selective removal of axillary lymph nodes in breast cancer patients presenting with initially node-positive disease and achieving a nodal downstaging after primary systemic therapy is a less invasive method for axillary staging. An imaging guided localization and successful extirpation of these clipped lymph nodes is not possible in all patients. To date no follow-up data regarding patients with lost clips are available.

MATERIAL AND METHODS

The oncological outcome of all participants of the CLIP-study and the results of postoperative axillary imaging in those patients with unproven clip resection are presented.

RESULTS

A total of thirty patients were included into the pilot study. In ten of these patients (33%) the removal of the clipped axillary lymph node could not be verified by intraoperative radiograph. Postoperative imaging did not find lost clips in eight of these ten patients (80%). The lost clip was detected in two patients after surgery (20%), by mammography in one patient during routine follow-up and by computed tomography scan in one patient before radiotherapy. After a median follow-up of 40 months, 26 (87%) patients were still alive. Seven patients (23%) developed distant recurrent disease. No local or axillary recurrences were observed.

CONCLUSION

Lost clips were detected by postoperative imaging only in a minority of patients. The impact of lost clips on axillary recurrences in breast cancer patients is still unclear and should be further clarified in larger, multicentric trials.

Surgical Management of the Axilla in Clinically Node-Positive Breast Cancer Patients Converting to Clinical Node Negativity through Neoadjuvant Chemotherapy: Current Status, Knowledge Gaps, and Rationale for the EUBREAST-03 AXSANA Study

In the last two decades, surgical methods for axillary staging in breast cancer patients have become less extensive, and full axillary lymph node dissection (ALND) is confined to selected patients. In initially node-positive patients undergoing neoadjuvant chemotherapy, however, the optimal management remains unclear. Current guidelines vary widely, endorsing different strategies. We performed a literature review on axillary staging strategies and their place in international recommendations. This overview defines knowledge gaps associated with specific procedures, summarizes currently ongoing clinical trials that address these unsolved issues, and provides the rationale for further research. While some guidelines have already implemented surgical de-escalation, replacing ALND with, e.g., sentinel lymph node biopsy (SLNB) or targeted axillary dissection (TAD) in cN+ patients converting to clinical node negativity, others recommend ALND. Numerous techniques are in use for tagging lymph node metastasis, but many questions regarding the marking technique, i.e., the optimal time for marker placement and the number of marked nodes, remain unanswered. The optimal number of SLNs to be excised also remains a matter of debate. Data on oncological safety and quality of life following different staging procedures are lacking. These results provide the rationale for the multinational prospective cohort study AXSANA initiated by EUBREAST, which started enrollment in June 2020 and aims at recruiting 3000 patients in 20 countries (NCT04373655; Funded by AGO-B, Claudia von Schilling Foundation for Breast Cancer Research, AWOgyn, EndoMag, Mammotome, and MeritMedical).

Accuracy of breast MRI in evaluating nodal status after neoadjuvant therapy in invasive lobular carcinoma

Neoadjuvant therapy in breast cancer can downstage axillary lymph nodes and reduce extent of axillary surgery. As such, accurate determination of nodal status after neoadjuvant therapy and before surgery impacts surgical management. There are scarce data on the diagnostic accuracy of breast magnetic resonance imaging (MRI) for nodal evaluation after neoadjuvant therapy in patients with invasive lobular carcinoma (ILC), a diffusely growing tumor type. We retrospectively analyzed patients with stage 1–3 ILC who underwent pre-operative breast MRI after either neoadjuvant chemotherapy or endocrine therapy at our institution between 2006 and 2019. Two breast radiologists reviewed MRIs and evaluated axillary nodes for suspicious features. All patients underwent either sentinel node biopsy or axillary dissection. We evaluated sensitivity, specificity, negative and positive predictive values, and overall accuracy of the post-treatment breast MRI in predicting pathologic nodal status. Of 79 patients, 58.2% received neoadjuvant chemotherapy and 41.8% neoadjuvant endocrine therapy. The sensitivity and negative predictive value of MRI were significantly higher in the neoadjuvant endocrine therapy cohort than in the neoadjuvant chemotherapy cohort (66.7 vs. 37.9%, p = 0.012 and 70.6 vs. 40%, p = 0.007, respectively), while overall accuracy was similar. Upstaging from clinically node negative to pathologically node positive occurred in 28.0 and 41.7%, respectively. In clinically node positive patients, those with an abnormal post-treatment MRI had a significantly higher proportion of patients with ≥4 positive nodes on pathology compared to those with a normal MRI (61.1 versus 16.7%, p = 0.034). Overall, accuracy of breast MRI for predicting nodal status after neoadjuvant therapy in ILC was low in both chemotherapy and endocrine therapy cohorts. However, post-treatment breast MRI may help identify patients with a high burden of nodal disease (≥4 positive nodes), which could impact pre-operative systemic therapy decisions. Further studies are needed to assess other imaging modalities to evaluate for nodal disease following neoadjuvant therapy and to improve clinical staging in patients with ILC.

Carbon tattooing for targeted lymph node biopsy after primary systemic therapy in breast cancer: prospective multicentre TATTOO trial

Background

Several techniques for targeted lymph node biopsy in patients with node-positive breast cancer receiving primary systemic therapy are in use, each with their inherent advantages and disadvantages. The aim of the TATTOO trial was to evaluate the feasibility and accuracy of carbon tattooing of positive lymph nodes as a method for targeted lymph node biopsy avoiding radiation exposure, high costs, and preoperative localization procedures.

Methods

Patients with initially cT1–4c cN1–3 cM0 invasive breast cancer were included in this prospective multicentre trial. Before initiation of primary systemic therapy, a carbon suspension was injected into the most suspicious axillary lymph node. Targeted lymph node biopsy was performed in all patients after completion of primary systemic therapy. Additional sentinel lymph node biopsy was done in those with axillary downstaging, and completion axillary lymph node dissection in patients still presenting with suspicious lymph nodes.

Results

A total of 118 patients were included and 110 were eligible for data analysis. The detection rate for the targeted lymph node was 93.6 per cent (103 of 110), and the sentinel lymph node was identical to the targeted lymph node in 60 per cent. The false-negative rate for the combination of targeted and sentinel node lymph node biopsy (targeted axillary dissection) was 9 per cent.

Conclusion

Targeted axillary dissection after carbon tattooing is associated with a high detection rate, an acceptable false-negative rate, and appears feasible for clinical use even in healthcare settings with limited resources.

Can we avoid axillary lymph node dissection in N2 breast cancer patients with chemo-sensitive tumours such as HER2 and TNBC?

PURPOSE

To find a group of cN2 patients or patients with high axillary burden who become ypN0 after neoadjuvant chemotherapy (NACT) and who may benefit from avoiding a lymphadenectomy.

METHODS

A retrospective observational cohort study was conducted with 221 clinically staged N2 patients or patients with at least 3 suspicious lymph nodes found by ultrasound at diagnosis. The predictive factors for ypN0 analysed were age, MRI-determined tumour size, histological subtype, the Nottingham histologic grade, surrogate molecular subtype, ki-67 and vascular invasion when present. Clinical and radiological responses after NACT were also evaluated. Univariate and multivariate analyses by logistic regression were performed. Distant disease-free survival (DDFS) was calculated in relation to the status of the axillary lymph nodes after NACT.

RESULTS

After NACT, 89 patients (40.3%) had axillary pathologic complete response (pCR) (ypN0) and 132 (59.7%) had residual axillary disease (ypN+). Molecular surrogate subtype, Ki-67 expression, and the clinical and radiological responses to NACT were the only independent factors associated with ypN0. Axillary pCR was observed more often in HER2-positive and triple-negative tumours than in luminal ones (OR 7.5 and 3.6, respectively). DDFS was 88.7% (95% CI 80.7-96.7%) for ypN0 and 56.2% (95% CI 32.1-80.3%) for ypN+ (p = 0.09).

CONCLUSIONS

In HER2-positive and triple-negative breast cancer patients staged as cN2 or with high axillary burden before NACT, a sentinel lymph node biopsy after NACT could be recommended if there is a clinical and radiological response.