Is Preoperative Axillary Imaging Beneficial in Identifying Clinically Node-Negative Patients Requiring Axillary Lymph Node Dissection?

Axillary nodal disease burden is not associated with an elevated 21-gene recurrence score in post-menopausal women presenting with a clinically negative axilla

BACKGROUND

The predictive and prognostic value of the recurrence score (RS) has emphasized the importance of tumor biology and has reduced the prognostic implications of limited nodal burden in post-menopausal women with HR+/HER2-invasive breast cancer (IBC). It is unclear whether routine axillary staging has a continued role in the management of small, clinically node negative (cN0) HR+/HER2- IBC. We sought to estimate the association of RS with pN stage.

METHODS

Patients >50yo diagnosed with cN0, HR+/HER2- IBC (2015-2019) with an available RS were identified from the National Cancer Database. The clinicopathologic characteristics and rates of pN-stage (pN0, pN1, pN2/3) were compared for RS of ≤25 vs. >25.

RESULTS

The median patient age was 64.1 (IQR 58-69) and the majority (75%) of tumors displayed ductal histology. Most (81.6%) were cT1 on presentation and pT1 (74.7%) on final pathology. There were 130,568 (86.2%) with a RS ​≤ ​25 and 20,879 (13.8%) with a RS ​> ​25. On final pathology, 128,995 (85.2%) were pN0 and 21,991 (14.5%) pN1. Of the pN1, 2699 (12.3%) yielded a RS ​> ​25. There were 461 (0.3%) patients with pN2-pN3 disease. Of those, 57 (12.4%) had RS ​> ​25.

CONCLUSION

In our analysis, pN0 and pN1 tumors are biologically similar by gene expression assay in postmenopausal patients with similar proportions of high RS. These data support the notion that tumor biology examined via RS may have more prognostic and predictive value than metastatic dissemination to limited lymph nodes. These findings support the ongoing evaluation of routine axillary staging in postmenopausal patients with HR+/HER2- IBC.

Recent Advances in the Upfront Surgical Management of the Axilla in Patients with Breast Cancer

Nodal status is an important prognostic indicator. Upfront axillary surgery for patients with breast cancer has historically been both diagnostic and therapeutic-serving to determine nodal status and inform adjuvant therapies, and to remove clinically significant disease. However, trials of de-escalation or omission of axillary surgery altogether consistently demonstrate noninferior oncologic outcomes in a wide variety of patient subsets. These strategies also reduce the morbidity associated with either sentinel lymphadenectomy or axillary lymph node dissection. Here we will briefly review landmark trials that have shaped upfront axillary surgery as well as recent advances, and discuss areas of ongoing investigation and future needs.

ACR Appropriateness Criteria® Imaging of Invasive Breast Cancer

As the proportion of women diagnosed with invasive breast cancer increases, the role of imaging for staging and surveillance purposes should be determined based on evidence-based guidelines. It is important to understand the indications for extent of disease evaluation and staging, as unnecessary imaging can delay care and even result in adverse outcomes. In asymptomatic patients that received treatment for curative intent, there is no role for imaging to screen for distant recurrence. Routine surveillance with an annual 2-D mammogram and/or tomosynthesis is recommended to detect an in-breast recurrence or a new primary breast cancer in women with a history of breast cancer, and MRI is increasingly used as an additional screening tool in this population, especially in women with dense breasts. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Axillary ultrasonography for early-stage invasive breast cancer

BACKGROUND

Among women with early invasive breast cancer and 1-2 positive sentinel nodes, sentinel lymph node biopsy (SLNB) is non-inferior to axillary lymph node dissection (ALND).1-3 However, preoperative axillary ultrasonography (AxUS) may not be sensitive enough to discriminate burden of nodal metastasis in these patients, potentially leading to overtreatment.4-6 This study compares axillary operation rates in patients who did and did not receive preoperative AxUS, assessing its utility and risks for overtreatment.

METHODS

This is a retrospective cohort study of patients with clinical T1/T2 breast tumors who were clinically node negative and underwent an axillary operation.

RESULTS

Patients who had preoperative AxUS received more ALND compared to patients who did not (5.6% vs. 1.4%, p ​< ​0.001). There was no significant difference in the number of additional axillary operations following SLNB (2.1% vs. 2.3%, p ​= ​0.77).

CONCLUSION

Eliminating preoperative AxUS is associated with fewer invasive ALND procedures, without increased rate of axillary reoperations.

Is routine axillary lymph node dissection needed to tailor systemic treatments for breast cancer patients in the era of molecular oncology? A position paper of the Italian National Association of Breast Surgeons (ANISC)

BACKGROUND

De-escalation of axillary surgery in breast cancer (BC) management began when sentinel lymph node biopsy (SLNB) replaced axillary lymph node dissection (ALND) as standard of care in patients with node-negative BC. The second step consolidated ALND omission in selected subgroups of BC patients with up to two macrometastases and recognized BC molecular and genomic implication in predicting prognosis and planning adjuvant treatment. Outcomes from the recent RxPONDER and monarchE trials have come to challenge the previous cut-off of two SLN in order to inform decisions on systemic therapies for hormone receptor-positive (HR+), human epidermal growth factor receptor type-2 (HER2) negative BC, as the criteria included a cut-off of respectively three and four SLNs. In view of the controversy that this may lift in surgical practice, the Italian National Association of Breast Surgeons (Associazione Nazionale Italiana Senologi Chirurghi, ANISC) reviewed data regarding the latest trials on this topic and proposes an implementation in clinical practice.

MATERIAL AND METHODS

We reviewed the available literature offering data on the pathological nodal status of cN0 breast cancer patients.

RESULTS

The rates of pN2 status in cN0 patients ranges from 3.5 % to 16 %; pre-surgical diagnostic definition of axillary lymph node status in cN0 patients by ultrasound could be useful to inform about a possible involvement of ≥4 lymph nodes in this specific sub-groups of women.

CONCLUSIONS

The Italian National Association of Breast Surgeons (ANISC) considers that for HR + HER2-/cN0-pN1(sn) BC patients undergoing breast conserving treatment the preoperative workup should be optimized for a more detailed assessment of the axilla and the technique of SLNB should be optimized, if considered appropriate by the surgeon, not considering routine ALND always indicated to determine treatment recommendations according to criteria of eligibility to RxPONDER and monarch-E trials.

Can Axillary Ultrasound Identify Node Positive Patients Who can Avoid an Axillary Dissection After Neoadjuvant Chemotherapy?

INTRODUCTION

Axillary lymph node dissection (ALND) is recommended for patients with invasive breast cancer with axillary metastasis treated with neoadjuvant chemotherapy (NAC) who do not have a nodal pathologic complete response (n-pCR). We hypothesized that patients with a single, ultrasound-suspicious, nonpalpable lymph node (LN) at diagnosis, who do not achieve an n-pCR, will have ypN1 disease on surgical pathology.

METHODS

This retrospective study identified breast cancer patients in our institution from 2012 to 2020 with axillary metastasis treated with NAC who did not achieve an n-pCR and had an ALND. Patient's tumor characteristics, axillary ultrasound, and lymph node disease burden at the time of surgery were reviewed.

RESULTS

Fifty five patients met the criteria and 36% had one suspicious LN on ultrasound, 25% had 2, and 38% had >3. After chemotherapy, 64% had ypN1 disease, 29% had ypN2 disease, and 7% had ypN3 disease. Of the 20 patients with one abnormal LN on initial ultrasound, 17 (85%, 95% CI 61-96%) had ypN1 disease. Eleven patients with one abnormal LN on initial ultrasound also had no suspicious LNs on prechemotherapy physical exam; among these patients, 100% had ypN1 disease.

CONCLUSIONS

For breast cancer patients who do not achieve an n-pCR after NAC, pretreatment normal clinical axillary exam and prechemotherapy ultrasound showing only one abnormal LN is associated with ypN1 disease. It may be reasonable to consider omitting completion ALND in this subset of patients while awaiting the results of the Alliance A011202 trial.

Selecting Triple Negative Breast Cancer Patients for Immunotherapy

The approval of preoperative immunotherapy combined with chemotherapy is a practice-changing advance for patients with early-stage triple-negative breast cancer. The optimal patient selection requires careful attention to staging and balancing potential risks with expected benefits, particularly as it relates to immune-related adverse events.

De-escalation of axillary surgery in patients outside Z0011 criteria

Over the past 2 decades, axillary surgical management for breast cancer patients has been reshaped after several practice-changing randomized clinical trials provided evidence to support the de-escalation of axillary surgery, specifically the omission of axillary lymph node dissection, for patients with positive axillary lymph nodes. One such practice-changing trial was the American College of Surgeons Oncology Group Z0011 trial, which showed that patients with clinical T1-2 breast tumors and limited nodal disease (1-2 positive sentinel lymph nodes) who underwent upfront breast-conserving therapy could be safely spared the morbidity of axillary lymph node dissection. American College of Surgeons Oncology Group Z0011 has been criticized as several important groups were excluded, such as patients who underwent a mastectomy, patients with >2 positive sentinel lymph nodes, or patients with imaging-detected lymph node metastases. These exclusions have led to unclear guidelines and very difficult management decisions for many patients with breast cancer who are just outside the Z0011 criteria. Several subsequent trials that investigated sentinel lymph node biopsy alone or sentinel lymph node biopsy plus axillary radiation versus axillary lymph node dissection enrolled patients with higher volumes of disease than American College of Surgeons Oncology Group Z0011, such as mastectomy patients or patients with >2 positive sentinel lymph nodes. The goal of this review is to describe the findings of these trials and to discuss the current best practices regarding axillary management in patients who are candidates for upfront surgery but were excluded from American College of Surgeons Oncology Group Z0011, with a particular focus on patients undergoing mastectomy, patients with >2 positive sentinel lymph nodes, patients with large or multifocal tumors, and patients with imaging-detected biopsy-proven lymph node metastases.

A novel nomogram for the preoperative prediction of sentinel lymph node metastasis in breast cancer

BACKGROUND OR PURPOSE

A practical noninvasive method to identify sentinel lymph node (SLN) status in breast cancer patients, who had a suspicious axillary lymph node (ALN) at ultrasound (US), but a negative clinical physical examination is needed. To predict SLN metastasis using a nomogram based on US and biopsy-based pathological features, this retrospective study investigated associations between clinicopathological features and SLN status.

METHODS

Patients treated with SLN dissection at four centers were apportioned to training, internal, or external validation sets (n = 472, 175, and 81). Lymph node ultrasound and pathological characteristics were compared using chi-squared and t-tests. A nomogram predicting SLN metastasis was constructed using multivariate logistic regression models.

RESULTS

In the training set, statistically significant factors associated with SLN+ were as follows: histology type (p < 0.001); progesterone receptor (PR: p = 0.003); Her-2 status (p = 0.049); and ALN-US shape (p = 0.034), corticomedullary demarcation (CMD: p < 0.001), and blood flow (p = 0.001). With multivariate analysis, five independent variables (histological type, PR status, ALN-US shape, CMD, and blood flow) were integrated into the nomogram (C-statistic 0.714 [95% CI: 0.688-0.740]) and validated internally (0.816 [95% CI: 0.784-0.849]) and externally (0.942 [95% CI: 0.918-0.966]), with good predictive accuracy and clinical applicability.

CONCLUSION

This nomogram could be a direct and reliable tool for individual preoperative evaluation of SLN status, and therefore aids decisions concerning ALN dissection and adjuvant treatment.

Conservative axillary surgery is emerging in the surgical management of breast cancer

Axillary lymph node dissection (ALND) has been the standard axillary treatment for breast cancer for a long time. However, ALND is associated with postoperative morbidities, including local sensory dysfunction, reduced shoulder mobility and most notably arm lymphedema. Recently, ALND can be avoided not only in clinically node-negative (cN0) patients with negative sentinel lymph nodes (SLNs), but also in patients with less than 3 positive SLNs receiving breast radiation, axillary radiation, or a combination of the two. Moreover, SLN biopsy has been adopted for use in clinically node-positive (cN +) patients presenting as cN0 after neoadjuvant chemotherapy (NAC); ALND may be avoided in cN + patients who convert to SLN-negative following NAC. Patients who undergo SLN biopsy alone have less postsurgical morbidities than those who undergo ALND. Nevertheless, ALND is still required in a select group of patients. A variety of conservative approaches to ALND have been developed to spare arm lymphatics to minimize arm lymphedema. These conservative procedures seem to decrease the incidence of lymphedema without increasing axillary recurrence. In the era of effective multimodality therapy, full conventional ALND removing all microscopic axillary disease may now be unnecessary in both cN0 patients and cN + patients. Regardless, emerging procedures for ALND should still be considered as investigational approaches, as further studies with longer follow-up are necessary to determine the safety of conservative ALND to spare arm lymphatics.

Beyond N Staging in Breast Cancer: Importance of MRI and Ultrasound-based Imaging

The correct N-staging in breast cancer is crucial to tailor treatment and stratify the prognosis. N-staging is based on the number and the localization of suspicious regional nodes on physical examination and/or imaging. Since clinical examination of the axillary cavity is associated with a high false negative rate, imaging modalities play a central role. In the presence of a T1 or T2 tumor and 0–2 suspicious nodes, on imaging at the axillary level I or II, a patient should undergo sentinel lymph node biopsy (SLNB), whereas in the presence of three or more suspicious nodes at the axillary level I or II confirmed by biopsy, they should undergo axillary lymph node dissection (ALND) or neoadjuvant chemotherapy according to a multidisciplinary approach, as well as in the case of internal mammary, supraclavicular, or level III axillary involved lymph nodes. In this scenario, radiological assessment of lymph nodes at the time of diagnosis must be accurate. False positives may preclude a sentinel lymph node in an otherwise eligible woman; in contrast, false negatives may lead to an unnecessary SLNB and the need for a second surgical procedure. In this review, we aim to describe the anatomy of the axilla and breast regional lymph node, and their diagnostic features to discriminate between normal and pathological nodes at Ultrasound (US) and Magnetic Resonance Imaging (MRI). Moreover, the technical aspects, the advantage and limitations of MRI versus US, and the possible future perspectives are also analyzed, through the analysis of the recent literature.

Rates of pathologic nodal disease among cN0 and cN1 patients undergoing routine axillary ultrasound and neoadjuvant chemotherapy

PURPOSE

Routine axillary ultrasound (AxUS) in patients receiving neoadjuvant chemotherapy (NAC) remains controversial. Here, we report rates of AxUS-detected nodal disease among patients with normal clinical exams, and rates of pathologic nodal disease after NAC based on method of nodal disease detection.

METHODS

Clinicopathologic findings were prospectively collected for stage I-III breast cancer patients selected for NAC. All patients had pre-treatment AxUS, suspicious nodes were biopsied. The following four patient cohorts were examined: patients with suspicious exam or AxUS but negative biopsy (Suspicious cN0); those with normal exam and normal AxUS (Not Suspicious cN0); those with normal exam but suspicious AxUS and positive biopsy (AxUS-detected cN1); and those with abnormal exam and positive biopsy (exam-detected cN1). Sentinel (SLN) and non-sentinel lymph nodes (non-SLN) were evaluated by immunohistochemistry; nodal metastases of any size were considered positive.

RESULTS

500 patients were included. Of 310 patients with normal axillary exams, 160 had suspicious AxUS, 65 were biopsy-negative (Suspicious cN0) and 95/310 (30.6%) were biopsy-positive (AxUS-detected cN1). Of 190 with abnormal axillary exams, 166 were biopsy-proven node-positive (exam-detected cN1) and 24 were AxUS or biopsy-negative (Suspicious cN0). Rates of pathologic nodal disease were 20/150 (13.3%) among Not Suspicious cN0 patients, 12/89 (13.5%) among Suspicious cN0 (p = 0.97). Rates of residual nodal disease were 55/95 (57.9%) among AxUS-detected cN1 patients, 102/166 (61.4%) among exam-detected cN1 (p = 0.57).

CONCLUSION

AxUS detected nodal disease in 30.6% of patients with normal clinical exams selected for NAC. Rates of pathologic nodal disease were similar among AxUS-detected and exam-detected cN1 patients.

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.

Axillary Needle Biopsy in the Era of American College of Surgeons Oncology Group (ACOSOG) Z0011: Institutional Experience With a Largely Urban Minority Population and Review of the Literature

Background: The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial demonstrated that sentinel lymph node biopsy (SLNB) alone is adequate for axillary control in patients with one to two positive axillary lymph nodes. However, axillary lymph node dissection (ALND) is required in patients with N1 disease diagnosed with a preoperative needle biopsy. In this report, we determined how many patients could potentially have had SNB alone based on finding only one to two positive nodes in the axilla.

Methods: A retrospective review of patients with positive preoperative axillary needle biopsy undergoing ALND was used to identify rates of high volume axillary disease (>2 positive nodes). Wilcoxon’s rank-sum and Fisher’s exact test were used for statistical analysis. A review of the literature is included for comparison.

Results: 73% of 51 total patients with a positive needle biopsy had >2 positive nodes on axillary dissection. The high-volume axillary disease was significantly more likely with the presence of lymphovascular invasion and extranodal extension.

Conclusions: Patients with positive preoperative axillary needle biopsies have a significantly higher rate of high volume axillary disease. However, at least one-quarter of these patients will have <3 positive nodes and potentially could have been treated with SNB alone.

Does ultrasound evaluation of the axilla increase the rate of axillary lymph node dissection in early stage clinically node negative breast cancer patients?

Background

Management and axillary staging of breast cancer has become less invasive and more conservative, over the decades. Considering Z011, axillary lymph node dissection (ALND) can be avoided in T1-2 N0-1 breast cancers with one or two positive sentinel lymph nodes (SLNs), if they are candidates for breast conserving surgery and radiotherapy. The aim of this study was to recognize if pre-operative axillary US evaluation in early-stage breast cancer could lead to more ALND in post Z011 era.

Method

463 breast cancer patients were evaluated. 368 early-stage breast cancer patients (T1-2 N0) were included. We did not perform axillary US in early stage clinically node negative patients; however, 97 patients had axillary US prior to our visit. If axillary US could detect more than two suspicious LNs, US guided biopsy was performed. The remaining clinically node negative patients underwent upfront SLNB. ALND was performed if more than two SLNs were metastatic, or US-guided ALN biopsy proved metastatic involvement.

Results

97 patients had axillary US evaluation before the surgery. 67 patients (69.2%) did not have any suspicious US detected axillary LNs, 17 patients (17.5%) had one, 7 patients (7.2%) had two, and 6 patients (6.2%) had more than two suspicious LNs according to their axillary US evaluation. Those with more than two suspicious LNs underwent ALN US-guided biopsy. Metastatic involvement of the LNs was proved in all of them and they underwent upfront ALND. ALND revealed more than 2 metastatic LNs in 2/6 patients (33.3%). 91 patients who were evaluated by axillary US, had less than two US detected suspicious LNs and underwent SLNB. Amongst 24 patients with one or two US detected suspicious LNs, 1/24 patient had more than two positive SLNs and underwent ALND. In this group 15.6% underwent ALND and 5.2% of them were unnecessary according to the recent guidelines. Axillary US had a false positive rate of 36.6%. The sensitivity of axillary US in distinguishing patients with more than two suspicious LNs in clinically node negative patients was 25%. In the second group (without pre-operative axillary US evaluation), SLNB was performed. 204/272 patients (75%) did not have LN metastasis. 54/272 patients (19.9%) had one or two metastatic SLNs and according to Z011, ALND was omitted. 5.1% had more than two metastatic SLNs and underwent ALND.

Conclusion

US evaluation of the axilla in early stage, clinically node negative breast cancer patients, is not sensitive enough to recognize more than two metastatic ALNs. It leads to more unnecessary ALND. Despite the small number of patients in this study, these results question the rationale of axillary US guided biopsy in low burden (less than two) suspicious LNs. looking for an imaging modality with a higher sensitivity in detecting the Burdon of axillary metastatic involvement is mandatory.

To Look or Not to Look? Axillary Imaging: Less May Be More

Axillary lymph node status in patients with breast cancer is an important prognostic indicator and often guides vital treatment decisions. Although in many cases imaging plays a crucial role in the assessment of the axilla, it is essential that targeted axillary US and/or image-guided biopsy of an axillary lymph node be performed by the radiologist only when clinically appropriate. This decision-making process requires multidisciplinary communication and collaboration among radiologists, surgeons, medical oncologists, and radiation oncologists. Our goal is to review axillary imaging for patients with breast cancer in two distinct clinical settings, the patient with newly diagnosed breast cancer who meets American College of Surgeons Oncology Group Z0011 criteria and patients undergoing neoadjuvant chemotherapy, with a specific focus on potential reasons to not perform axillary US and/or image-guided biopsy in these settings.

Imaging Evaluation of the Axilla-A National Survey of Clinical Practice Among Radiologists

OBJECTIVE

To assess awareness and implementation of the American College of Surgeons Oncology Group Z0011 trial findings, approaches to axillary nodal imaging, and to identify differences in practice based on respondent characteristics.

METHODS

An online survey was distributed to members of the Society of Breast Imaging. Questions regarded demographics, evaluation approaches, and impact of the Z0011 trial. Poisson regression with robust standard errors to regression was used to generate multivariable-adjusted relative risks and 95% confidence intervals (CIs) for associations.

RESULTS

The response rate was 21.7% (430/2007). The majority (295/430, 68.6%) reported always performing axillary US in patients with a BI-RADS 4B, 4C, or 5 breast mass. Most respondents (299/430, 69.5%) were familiar with the findings of the Z0011 trial. Radiologists in academic practice were 0.67 (95% CI: 0.54-0.83) times less likely than private practice radiologists to perform axillary US in all masses and 1.31 (95% CI: 1.13-1.52) times more likely to be very familiar with the trial. Frequency of axillary US showed no association with time spent in breast imaging, years in practice, or presence of dedicated breast surgeons. Increased time in breast imaging and presence of dedicated breast surgeons was strongly associated with familiarity with the trial. No association was observed with years in practice. Most respondents (291/430, 67.7%) made little or no change to their practice based on trial findings.

CONCLUSION

There is wide variability in approaches to axillary nodal evaluation, demonstrating a need for improved education and guidelines for axillary imaging in breast cancer patients.

Palpable Adenopathy Does Not Indicate High-Volume Axillary Nodal Disease in Hormone Receptor-Positive Breast Cancer

BACKGROUND

Axillary metastases in the form of palpable adenopathy indicate the need for neoadjuvant chemotherapy or axillary lymph node dissection (ALND). Patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) disease infrequently have nodal pathologic complete response to neoadjuvant chemotherapy and often require ALND. Sentinel lymph node biopsy is an accepted treatment for patients with two or fewer non-palpable nodal metastases who are undergoing breast conservation. The proportion of patients with HR+/HER2- disease with palpable adenopathy and two or fewer nodal metastases is unknown.

METHODS

Patients with cT1-T3N1 HR+/HER2- disease with palpable adenopathy were identified from a prospective database. Patients who underwent mastectomy or breast-conserving therapy with ALND were included in this study, whereas patients who received neoadjuvant chemotherapy were excluded. Clinicopathologic characteristics were compared between patients with two or fewer or more than two positive nodes on ALND.

RESULTS

Of 180 patients included, 78 (43%) had two or fewer positive nodes on ALND, including 40/72 patients (56%) who underwent lumpectomy. On univariate analysis, cT1 tumor, unifocal tumor, only one palpable node, and two or fewer suspicious nodes on ultrasound were associated with two or fewer positive nodes on ALND. On multivariable analysis, number of suspicious nodes on ultrasound and cT stage were independently associated with two or fewer positive nodes on ALND.

CONCLUSIONS

A substantial minority of patients with cT1-3N1 HR+/HER2- disease with palpable adenopathy had two or fewer positive nodes on ALND. Standard clinicopathologic features and ultrasound findings can help identify candidates for upfront sentinel lymph node biopsy as a strategy to avoid ALND. Prospective studies evaluating this approach are warranted.

Is image-guided core needle biopsy of borderline axillary lymph nodes in breast cancer patients clinically helpful?

BACKGROUND

When borderline axillary lymph nodes (bALN) are identified on ultrasound (US) for breast cancer (BC) patients, preoperative management is unclear. We aimed to evaluate if core needle biopsy (CNB) for bALN is clinically helpful or disruptive.

METHODS

Retrospective review of BC patients with bALN from 2014 to 2019 was performed. Clinicopathologic data were compared for those who did and did not have CNB.

RESULTS

CNB (n = 34) and no CNB (n = 31) were similar with respect to clinicopathologic factors. Surgical LN-positive rate was the same between cohorts (p = 0.26). CNB was disruptive in 58.8 %; all had CNB for pN0 disease. CNB was helpful in 34.2 %: 14.7 % proceeded directly to axillary dissection; 17.6 % had positive LN localized after neoadjuvant chemotherapy.

CONCLUSIONS

CNB for bALN is more likely clinically disruptive and did not impact surgical LN positive rate. BC patients with bALN should undergo CNB only if it will change clinical management.

PET/MRI for Staging the Axilla in Breast Cancer: Current Evidence and the Rationale for SNB vs. PET/MRI Trials

Simple Summary

PET/MRI is a relatively new, hybrid imaging tool that allows practitioners to obtain both a local and systemic staging in breast cancer patients in a single exam. To date, the available evidence is not sufficient to determine the role of PET/MRI in breast cancer management. The aims of this paper are to provide an overview of the current literature on PET/MRI in breast cancer, and to illustrate two ongoing trials aimed at defining the eventual role of PET/MRI in axillary staging in two different settings: patients with early breast cancer and patients with positive axillary nodes that are candidates for primary systemic therapy. In both cases, findings from PET/MRI will be compared with the final pathology and could be helpful to better tailor axillary surgery in the future.

Abstract

Axillary surgery in breast cancer (BC) is no longer a therapeutic procedure but has become a purely staging procedure. The progressive improvement in imaging techniques has paved the way to the hypothesis that prognostic information on nodal status deriving from surgery could be obtained with an accurate diagnostic exam. Positron emission tomography/magnetic resonance imaging (PET/MRI) is a relatively new imaging tool and its role in breast cancer patients is still under investigation. We reviewed the available literature on PET/MRI in BC patients. This overview showed that PET/MRI yields a high diagnostic performance for the primary tumor and distant lesions of liver, brain and bone. In particular, the results of PET/MRI in staging the axilla are promising. This provided the rationale for two prospective comparative trials between axillary surgery and PET/MRI that could lead to a further de-escalation of surgical treatment of BC. • SNB vs. PET/MRI 1 trial compares PET/MRI and axillary surgery in staging the axilla of BC patients undergoing primary systemic therapy (PST). • SNB vs. PET/MRI 2 trial compares PET/MRI and sentinel node biopsy (SNB) in staging the axilla of early BC patients who are candidates for upfront surgery. Finally, these ongoing studies will help clarify the role of PET/MRI in BC and establish whether it represents a useful diagnostic tool that could guide, or ideally replace, axillary surgery in the future.

Minimal Invasive and Individualizing Management of the Axillary Nodes

The status of the axillary lymph nodes is one of the most important prognostic factors for patients with breast cancer. For over 100 years, axillary lymph node dissection was the standard approach to obtain and manage axillar lymph node, but now, sentinel lymph node biopsy has become a standard approach with less morbidity and equal accuracy in clinical node-negative patients. In addition, numerous studies are on the way to omit axillary lymph node dissection in specific patient subgroups. The recent trials like the ACOSOG Z0011 showed the evidence that omitting an ALND in patients with low burden nodal disease is safe in patients receiving whole-breast radiation. To reduce the use of ALND is the goal to consider when selecting an axillary management strategy.

Added Value of MRI for Invasive Breast Cancer including the Entire Axilla for Evaluation of High-Level or Advanced Axillary Lymph Node Metastasis in the Post-ACOSOG Z0011 Trial Era

Background In the post-American College of Surgeons Oncology Group Z0011 trial era, radiologists have increasingly focused on excluding high-level or advanced axillary lymph node metastasis (ALNM) by using an additional MRI scan positioned higher than lower axillae; however, the value of these additional scans remains undetermined. Purpose To evaluate whether a standard MRI protocol is sufficient to exclude high-level or advanced ALNM in breast cancer or additional MRI of entire axilla is needed. Materials and Methods This retrospective study evaluated women with invasive breast cancer who underwent breast MRI from April 2015 to December 2016. Some underwent neoadjuvant chemotherapy (NAC) and others underwent upfront surgery. Standard (routine axial scans including the lower axillae) and combined (routine axial scans plus additional scans including the entire axilla) MRI protocols were compared for high-level or advanced ALNM detection. Clinical-pathologic characteristics were analyzed. Uni- and multivariable logistic regression was performed to identify predictors of high-level or advanced ALNM. Results A total of 435 women (mean age ± standard deviation, 52 years ± 11) were evaluated (65 in the NAC group, 370 in the non-NAC group). With the standard MRI protocol, predictors of high-level ALNM were peritumoral edema (odds ratio [OR], 12.3; 95% CI: 3.9, 39.4; P < .001) and positive axilla (OR, 5.9; 95% CI: 2.0, 15.2; P < .001). Only three of 289 women with negative axillae without peritumoral edema had high-level ALNM. Predictors of advanced ALNM were positive axillae (OR, 8.9; 95% CI: 3.7, 21.5; P < .001) and peritumoral edema (OR, 2.8; 95% CI: 1.1, 6.9; P = .03). Only six of 310 women who had negative axillae without peritumoral edema had advanced ALNM. Conclusion The performance of standard MRI was satisfactory in excluding high-level and advanced axillary lymph node metastasis in most patients with breast cancer. However, the presence of peritumoral edema or positive axillae in the MRI findings emphasizes the benefits of a combined MRI protocol. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Abe in this issue.

Axillary management in early breast cancer with onset surgical management and positive sentinel lymph node

Over the years, the management of early breast cancer has evolved by leaps and bounds, as has the concept of axillary staging and armpit surgical management. Five randomised studies exist that evaluate the possibility of omitting regional locus surgical axillary treatment in patients with early breast cancer and positive sentinel lymph nodes without it having an impact on the prognosis of the disease in selected cases. A review of the literature on the management of the axilla in early breast cancer is presented.

Does axillary lymph node size predict better metastatic involvement than apparent diffusion coefficient (ADC) value in women with newly diagnosed breast cancer?

BACKGROUND

It has been demonstrated that the number of metastatic axillary lymph nodes (mALNs) influence disease-free and overall survival in patients with breast cancer.

PURPOSE

To determine if the ALN size is more accurate than the ALN apparent diffusion coefficient (ADC) value to predict metastatic involvement in newly diagnosed breast cancer.

MATERIAL AND METHODS

A total of 44 patients with breast cancer were included. Magnetic resonance imaging (MRI) examinations were performed on a 1.5-T system with sagittal T1-weighted fast spin-echo non-fat saturated, sagittal T2-weighted fast spin-echo non-fat saturated, axial diffusion-weighted imaging echo-planar (b values of 0 and 700 s/mm²), and non-contrast axial VIBRANT sequences. The size and the ADC value were obtained for ALN ipsilateral and contralateral to breast cancer. The reference standard was the histopathologic lymph node status.

RESULTS

mALN had a greater cortical thickness compared to contralateral non-mALN (10.3 ± 5.32 mm vs. 4 ± 1.17 mm, P ≤ 0.001). The threshold of ≥6.7 mm for predicting axillary metastatic involvement had a sensitivity and a specificity of 80.0% and 97.7%, respectively. The ADC value of mALN was significantly higher than the contralateral non-mALN (0.90 ± 0.12 × 10^-3mm²/s vs. 0.78 ± 0.12 × 10^-3mm²/s; P = 0.001). The threshold of ≥0.86 × 10^-3mm²/s had a sensitivity and a specificity of 66.7% and 76.7%, respectively.

CONCLUSION

Our results indicate that the cortical thickness has a better diagnostic performance in the differentiation of metastatic and non-metastatic lymph nodes than the lymph node ADC.

Axillary lymph node dissection is not obligatory in breast cancer patients with biopsy-proven axillary lymph node metastasis

PURPOSE

The ACOSOG Z0011 trial demonstrated that axillary lymph node dissection (ALND) is unnecessary in select patients with cT1-2N0 tumors undergoing breast-conserving therapy with 1-2 positive sentinel lymph nodes (SLNs). However, patients with preoperatively confirmed ALN metastasis were not included and may be subjected to unnecessary ALND. The aim of this study is to identify patients who can be considered for ALND omission when the preoperative ALN biopsy results are positive.

METHODS

Breast cancer patients who underwent preoperative ALN biopsy and primary surgery were retrospectively reviewed. Among patients with positive ALN biopsy results, clinicopathological and imaging characteristics were compared according to LN disease burden (1-2 positive LNs vs. ≥ 3 positive LNs).

RESULTS

A total of 542 patients were included in the analysis. Among them, 225 (41.5%) patients had a preoperative positive ALN biopsy. More than 40% of the patients (n = 99, 44.0%) with a positive biopsy had only 1-2 positive ALNs. The association between nodal burden and imaging factors was strongest when ≥ 2 suspicious LNs were identified on PET/CT images (HR 8.795, 95% CI 4.756 to 13.262). More than one imaging modality showing ≥ 2 suspicious LNs was also strongly correlated with ≥ 3 positive ALNs (HR 5.148, 95% CI 2.881 to 9.200).

CONCLUSIONS

Nearly half of patients with a preoperative biopsy-proven ALN metastasis had only 1-2 positive LNs on ALND. Patients meeting ACOSOG Z0011 criteria with only one suspicious LN on PET/CT or those presenting with few abnormal ALNs on only one imaging modality appear appropriate for SLNB and consideration of ALND omission.

Axillary Nodal Evaluation in Breast Cancer: State of the Art

Axillary lymph node (LN) metastasis is the most important predictor of overall recurrence and survival in patients with breast cancer, and accurate assessment of axillary LN involvement is an essential component in staging breast cancer. Axillary management in patients with breast cancer has become much less invasive and individualized with the introduction of sentinel LN biopsy (SLNB). Emerging evidence indicates that axillary LN dissection may be avoided in selected patients with node-positive as well as node-negative cancer. Thus, assessment of nodal disease burden to guide multidisciplinary treatment decision making is now considered to be a critical role of axillary imaging and can be achieved with axillary US, MRI, and US-guided biopsy. For the node-positive patients treated with neoadjuvant chemotherapy, restaging of the axilla with US and MRI and targeted axillary dissection in addition to SLNB is highly recommended to minimize the false-negative rate of SLNB. Efforts continue to develop prediction models that incorporate imaging features to predict nodal disease burden and to select proper candidates for SLNB. As methods of axillary nodal evaluation evolve, breast radiologists and surgeons must work closely to maximize the potential role of imaging and to provide the most optimized treatment for patients.

Is axillary lymph node dissection necessary for positive preoperative aspiration cytology lymph node results?

INTRODUCTION

Based on international guidelines, axillary lymph node dissection (ALND) is recommended in cases of breast cancer if preoperative examinations confirm axillary metastasis. We examined which set of preoperative parameters might render ALND unnecessary.

PATIENTS AND METHODS

Preoperative examinations (axillary ultrasound and aspiration cytology) confirmed axillary metastasis in 190 cases out of 2671 patients with breast cancer; primary ALN dissection was performed on these patients with or without prior neoadjuvant therapy. The clinicopathological results were analysed to determine which parameter might predict the presence of no more than 2 or 3 metastatic ALNs.

RESULTS

The final histological examination confirmed 1-3 metastatic lymph nodes in ALND samples in 116 cases and over 3 metastatic lymph nodes in 74 cases. For patients receiving neoadjuvant therapy (59 out of the 190 cases), if the size of the primary tumour was 2 cm or smaller and/or the metastatic ALN was 15 mm or smaller, then the patient was likely to have no more than 3 positive ALNs (stage N0-1 disease) (p < 0.001). If the patient did not receive neoadjuvant therapy, stage N2 or N3 disease was very likely. No correlation was found between other clinicopathological characteristics of the tumour and involvement of the ALNs.

CONCLUSION

Axillary lymph node dissection is not necessary for selected breast cancer patients with axillary metastasis receiving neoadjuvant therapy. In these cases, sentinel lymph node biopsy with or without radiation therapy and close follow-up may serve as adequate therapy.

Imaging-Based Approach to Axillary Lymph Node Staging and Sentinel Lymph Node Biopsy in Patients With Breast Cancer

OBJECTIVE. This review provides historical and current data to support the role of imaging-based axillary lymph node staging and sentinel lymph node biopsy as the standard of care for axillary management in women with a diagnosis of breast cancer, before and after neoadjuvant systemic therapy. CONCLUSION. The implications of surgical trials (American College of Surgeons Oncology Group [ACOSOG] Z011 and ACOSOG Z1071) on imaging protocols for the axilla are reviewed, in conjunction with the American Joint Committee on Cancer nodal staging guidelines.

Evaluating the preoperative breast cancer characteristics affecting the accuracy of axillary ultrasound staging

We evaluate the preoperative breast cancer (BC) characteristics that affect the diagnostic accuracy of axillary ultrasound (US) and determine the reliability of US in the different subgroups of BC patients. Axillary US assessments in women with invasive BC diagnosed between 2009 and 2016 in a single institution were retrospectively reviewed. The diagnostic accuracy of axillary US was obtained using surgical nodal histology as the gold standard. Preoperative breast tumor sonographic and histological factors affecting axillary US diagnostic accuracy were examined. Of the 605 newly diagnosed invasive BC cases reviewed, 251 (41.5%) had nodal metastases. Axillary US sensitivity was 75.7%, specificity 92.9%, positive predictive value 88.4%, negative predictive value 84.4%, and false-negative rate 24.3%. Lower US sensitivity was seen with invasive lobular cancer (ILC) (P = .043), grade I/II, (P = .021), unifocal (P = .039), and smaller tumors (P < .001). US specificity was lower in grade III (P < .001), estrogen receptor (ER)-negative (P < .001), progesterone receptor (PR)-negative (P = .004), HER2-positive (P = .015), triple-negative (P = .001), and larger breast tumors (P < .001). US has moderate sensitivity and good specificity in detecting metastatic axillary lymph nodes. Based on preoperative cancer characteristics, US was less sensitive for nodal metastases from ILC, unifocal, lower grade, and smaller breast tumors. It was also less specific in grade III, ER-negative, PR-negative, HER2-positive, triple-negative, and larger breast tumors. Caution is suggested in interpreting the US axillary findings of patients with these preoperative tumor features.

Patterns of Axillary Management in Stages 2 and 3 Hormone Receptor-Positive Breast Cancer by Initial Treatment Approach

BACKGROUND

Data regarding axillary management after neoadjuvant endocrine therapy (NET) are lacking. This study examined axillary management of hormone receptor-positive (HR+) patients based on initial treatment with NET, neoadjuvant chemotherapy (NAC), or upfront surgery.

METHODS

Patients with stage 2 or 3 HR+/HER2- breast cancer treated between 2012 and 2015 were identified in the National Cancer Database. The study examined axillary surgery [sentinel lymph node biopsy (SLNB), SLNB followed by axillary lymph node dissection (ALND), or upfront ALND] by initial treatment stratified by cN0/N1 using pairwise comparisons and multivariable logistic regression.

RESULTS

Of 92,204 eligible patients, 2138 (2.3%) received NET, 11,014 (12%) received NAC, and 79,052 (85.7%) received surgery. Among 60,998 cN0 patients, attempted SLNB was more likely for surgery patients (86.2%, 47,159/54,684) and NET patients (85.8%, 1342/1564) than for NAC patients (79.9%, 3793/4750) (both p < 0.001). Among 31,206 cN1 patients, attempted SLNB was more likely for the surgery patients (46.0%, 11,201/24,368) than for the NET patients (41.8%, 240/574; p = 0.05) or the NAC patients (39.8%, 2491/6264; p < 0.0001). The differences between surgery and NET did not persist in the adjusted analyses. Among both the cN0 patients (n = 13,856) and the cN1 patients (n = 8688) with pN1 disease shown by SLNB, the NET patients were treated with ALND less frequently than those receiving NAC or surgery (p < 0.0001 for all comparisons). In the multivariate analysis, for the patients with pN1 disease shown by SLNB, NET use was associated with increased odds of undergoing SLNB alone [cN0 patients: odds ratio (OR), 1.31, 95% confidence interval (CI), 1.04-1.64; cN1 patients: OR 1.45; 95% CI 1.00-2.10].

CONCLUSIONS

For stages 2 and 3 HR+/HER2- patients, SLNB use after NET was similar to that for upfront surgery. Among those with pN1 disease, the NET patients were less likely to undergo ALND. Additional outcomes data are needed to guide axillary management after NET.

MRI evaluation of axillary and intramammary lymph nodes in the postoperative period

Our study aimed to evaluate if breast‐conserving surgery and adjuvant treatment could affect the morphological features of axillary and intramammary lymph nodes on magnetic resonance imaging (MRI) in patients with invasive breast cancer and clinically negative axilla. In this single‐center study, we retrospectively evaluated 50 patients who had (a) breast‐conserving surgery, (b) clinically negative axilla, (c) preoperative MRI within 3 months before surgery, and (d) postoperative MRI within 12 months after surgery. Axillary and intramammary lymph nodes on postoperative MRI were identified and then compared with preoperative MRI by two breast radiologists with regards to the following: enlargement, cortical thickening, presence of fatty hilum, irregularity, heterogeneity, matting, and axillary lymph node asymmetry. Three hundred and two axillary and eight intramammary lymph nodes were evaluated. Enlargement and cortical thickening were seen in 5/50 (10%) patients in three axillary and two intramammary lymph nodes. None of the lymph nodes on postoperative MRI demonstrated occurrence of lack of fatty hilum, irregularity, heterogeneity, matting or axillary lymph node asymmetry. No evidence of recurrence was observed on 2‐year follow‐up. Lymph node enlargement and cortical thickening may be observed in a few patients in the postoperative period. Nevertheless, in patients with clinically negative axilla, these changes in morphology are often related to treatment rather than malignancy and favor short‐term follow‐up as an alternative to lymph node biopsy.

Pretreatment Tattoo Marking of Suspicious Axillary Lymph Nodes: Reliability and Correlation with Sentinel Lymph Node

BACKGROUND

Tattooing is an alternative method for marking biopsied axillary lymph nodes (ALNs) before initiation of treatments for newly diagnosed breast cancer. Detection of black ink-stained nodes is performed under direct visualization at surgery and is combined with sentinel node (SLN) mapping procedures.

METHODS

Women with newly diagnosed breast cancer who underwent fine or core-needle biopsy of suspicious ALNs were recruited. The nodal cortex and perinodal soft tissue was injected with 0.1-1.0 ml of Spot™ (GI Supply) black ink under ultrasound guidance. Intraoperatively, black stained nodes were removed along with SLNs, noting concordance between the two.

RESULTS

Sixty-six evaluable patients were enrolled (2013-2017). Nineteen received surgery first (Group 1) and 47 neoadjuvant therapy (NAT, Group 2). The average number of nodes tattooed was 1.16 for Group 1 and 1.04 for Group 2. The average interval from tattoo to surgery was 21 days (range 1-62) for Group 1 and 148 days (range 71-257) for Group 2. The tattooed node(s) were visually identified at surgery and corresponded to the sentinel lymph node(s) in 98.5% of cases (18/19 in Group 1 and 47/47 in Group 2). Of the 14 patients in Group 2 whose nodes remained positive following NAT, the tattooed node was the SLN associated with carcinoma.

CONCLUSIONS

Tattooing is an alternative method for marking biopsied ALNs. Tattooed nodes coincided with SLNs in 98.5% of cases. This technique is advantageous, because it allows for fewer procedures and lower costs compared with other methods.

Is axillary ultrasound imaging necessary for all patients with breast cancer?

Better use selectively

Overview of Breast Cancer Therapy

Breast cancer treatment is multidisciplinary. Most women with early stage breast cancer are candidates for breast-conserving surgery with radiotherapy or mastectomy. The risk of local recurrence and the chance of survival does not differ with these approaches. Sentinel node biopsy is used for axillary staging, and individualized approaches are minimizing the need for axillary dissection in women with positive sentinel nodes. Adjuvant systemic therapy is used in most women based on proven survival benefit, and molecular profiling to individualize treatment based on risk is now a clinical reality for patients with hormone receptor-positive cancers.

3.0 T relaxation time measurements of human lymph nodes in adults with and without lymphatic insufficiency: Implications for magnetic resonance lymphatic imaging

The purpose of this work was to quantify 3.0 T (i) T1 and T2 relaxation times of in vivo human lymph nodes (LNs) and (ii) LN relaxometry differences between healthy LNs and LNs from patients with lymphatic insufficiency secondary to breast cancer treatment-related lymphedema (BCRL). MR relaxometry was performed over bilateral axillary regions at 3.0 T in healthy female controls (105 LNs from 20 participants) and patients with BCRL (108 LNs from 20 participants). Quantitative T1 maps were calculated using a multi-flip-angle (20, 40, 60°) method with B1 correction (dual-TR method, TR1 /TR2  = 30/130 ms), and T2 maps using a multi-echo (TE  = 9-189 ms; 12 ms intervals) method. T1 and T2 were quantified in the LN cortex and hilum. A Mann-Whitney U-test was applied to compare LN relaxometry values between patients and controls (significance, two sided, p < 0.05). Linear regression was applied to evaluate how LN relaxometry varied with age, BMI, and clinical indicators of disease. LN substructure relaxation times (mean ± standard deviation) in healthy controls were T1 cortex, 1435 ± 391 ms; T1 hilum, 714 ± 123 ms; T2 cortex, 102 ± 12 ms, and T2 hilum, 119 ± 21 ms. T1 of the LN cortex was significantly reduced in the contralateral axilla of BCRL patients compared with the axilla on the surgical side (p < 0.001) and compared with bilateral control values (p < 0.01). The LN cortex T1 asymmetry discriminated cases from controls (p = 0.004) in a multiple linear regression, accounting for age and BMI. Human 3.0 T T1 and T2 relaxation times in axillary LNs were quantified for the first time in vivo. Measured values are relevant for optimizing acquisition parameters in anatomical lymphatic imaging sequences, and can serve as a reference for novel functional and molecular LN imaging methods that require quantitative knowledge of LN relaxation times.

Axillary ultrasound-guided core biopsy in breast cancer: identifying higher nodal burden and more aggressive clinicopathological characteristics

BACKGROUND

Patients with sentinel lymph node (SLN) metastases may not require axillary lymph node dissection (ALND) but it remains unclear if patients with a positive ultrasound-guided axillary core biopsy (ACB) would satisfy such criteria.

AIMS

The aim of this study was to assess if breast cancer patients with a positive pre-operative ACB have more aggressive tumour characteristics/higher axillary nodal burden compared to those with a positive SLN.

METHODS

Data was extracted from a prospectively maintained breast cancer database between 2012 and 2015. Patients who underwent ALND after either positive ACB or SLN were included and tumour characteristics/nodal burden were compared.

RESULTS

One hundred eighty patients underwent ALND, 125/180 after positive ACB and 55/180 after positive SLNB. Patients with positive ACB were more likely to undergo mastectomy (chi-square test; p = 0.03) and have higher tumour grades (Mann-Whitney test; p < 0.01) compared to the SLNB group. Median positive nodes excised during ALND were 2 (1-22) and 1 (1-11) for ACB and SLNB groups respectively (p < 0.001). Fifty-six patients received neoadjuvant chemotherapy (NCT). Of 72/125 patients in the ACB group not receiving NCT, the median number of positive nodes was 4 (range, 1-22). Ten patients within the ACB group satisfied ACOSOG Z011 criteria.

CONCLUSION

Breast cancer patients with a positive ACB are more likely to have aggressive tumour characteristics and higher nodal burden compared to those identified as having axillary nodal disease on SLNB, which may affect surgical decision making.

Are Lymph Node Characteristics on Axillary Ultrasound Associated with ≥3 Positive Lymph Nodes in Patients Managed by the American College of Surgeons Oncology Group Z0011 Trial Criteria?

Patients often receive axillary ultrasound-biopsy (AUS-B) before clinical evaluation. One positive biopsy in the absence of palpable disease rarely indicates additional nodal involvement, but it eliminates patients from being managed by the American College of Surgeons Oncology Group Z0011 trial criteria. To determine which patients may benefit from AUS-B, we analyzed whether characteristics on AUS were associated with large-volume axillary disease and, thus, the need for axillary lymph node (LN) dissection. A retrospective review identified patients who met Z0011 criteria and underwent AUS. Clinicopathologic and ultrasound characteristics were compared between patients with ≤2 versus ≥3 positive LNs. Two hundred and seven patients with cT1-2N0 tumors underwent preoperative AUS and breast-conserving surgery. On multivariate analysis, three AUS combinations were associated with ≥3 positive LNs: cortical thickness (CT) > 4 mm + loss of fatty hilum + round shape (P = 0.0218), CT > 4 mm + loss of fatty hilum (P = 0.0211), and CT > 4 mm + round shape (P = 0.0155). Preoperative axillary LN biopsy in patients with a single abnormal LN characteristic on AUS may be unnecessary because a positive finding will eliminate management according to Z0011 criteria. Cortical thickness >4 mm combined with any other abnormal characteristic was associated with ≥3 positive LNs, supporting the performance of AUS-B in this population.

Preoperative predictors of high and low axillary nodal burden in Z0011 eligible breast cancer patients with a positive lymph node needle biopsy result

BACKGROUND

Z0011 trial showed that early breast cancer patients with low axillary nodal burden, may be spared an axillary lymph node dissection with no survival compromise. Axillary lymph node dissection can be reserved for patients with a high axillary nodal burden. We aim to determine the preoperative factors that could distinguish between low and high axillary nodal burden in Z0011 eligible patients with a needle biopsy proven metastatic node.

METHOD

Patients who fulfilled Z0011 trial criteria with a positive lymph node needle biopsy and had axillary lymph node dissection (ALND) were recruited. These patients were classified into low and high nodal burden subgroups, defined as having 1-2 and ≥3 metastatic lymph nodes, respectively. The clinical, radiological and pathological features between the 2 subgroups were compared.

RESULTS

70 (40%) and 105 (60%) patients had low and high nodal burden respectively. The high nodal burden subgroup was more likely to have on ultrasound ≥3 abnormal lymph nodes (37.14% versus 4.29%) (P < 0.0001) and maximum cortical thickness >4 mm (31.43% versus 10.0%) (P = 0.0036). Multivariate analysis revealed abnormal lymph nodes ≥3 to have an odds ratio of 20.72 (95% CI 5.91-72.65) P < 0.0001.

CONCLUSION

≥3 abnormal lymph nodes on ultrasound was the most significant predictor of high nodal burden subgroup in Z0011 eligible patients with a positive lymph node needle biopsy. This information could allow this subgroup to proceed to an upfront ALND and avoid the need of a sentinel lymph node biopsy in the post Z0011 trial era.

The impact of axillary ultrasound with biopsy in overtreatment of early breast cancer

PURPOSE

(a) To compare the axillary tumor burden detected by fine-needle aspiration cytology (FNAC) versus sentinel lymph node biopsy (SLNB). (b) To evaluate the relationship between axillary tumor burden and the number of suspicious lymph nodes detected by axillary ultrasonography (US). (c) To calculate the false-positive and false-negative rates for FNAC in patients fulfilling ACOSOG Z0011 criteria.

METHODS

Retrospective multicenter cross-sectional study of 355 pT1 breast cancers. SLNB and axillary lymph node dissection (ALND) were gold standards. Low axillary burden (≤2 positive lymph nodes); high burden (>2 positive lymph nodes). Patients ACOSOG Z0011: false-positive (positive FNAC+low burden), false-negative (negative FNAC+high burden).

RESULTS

High axillary burden: in entire series 38.5% FNAC+ vs. 5.7% SLNB+ (p<0.0001). In subgroup fulfilling ACOSOG Z0011 criteria: 45.5% vs 6.7%, respectively (p<0.001). 61 positive axillary US. With 1 suspicious node on axillary US: 95.6% had ≤2 involved nodes (including pN0); with 2 suspicious nodes: 60% had >2 involved nodes. In ACOSOG Z0011 patients, with 1 suspicious node, 93.7% had ≤2 involved nodes. Of the 37 FNAC in ACOSOG Z0011patients: 54.5% false-positives for high burden; 3.8% false-negatives.

CONCLUSIONS

FNAC-positive tumors have greater axillary burden, even in patients fulfilling ACOSOG Z0011 criteria. Using axillary US/FNAC to triage patients meeting Z0011 criteria may result in axillary overtreatment. The number of suspicious nodes seen in axillary US is related with the final axillary burden and should be taken into account when deciding to do FNAC in patients fulfilling ACOSOG Z0011 criteria.

The Optimal Treatment Plan to Avoid Axillary Lymph Node Dissection in Early-Stage Breast Cancer Patients Differs by Surgical Strategy and Tumor Subtype

BACKGROUND

Strategies to reduce the likelihood of axillary lymph node dissection (ALND) include application of Z0011 or use of neoadjuvant chemotherapy (NAC). Indications for ALND differ by treatment plan, and nodal pathologic complete response rates after NAC vary by tumor subtype. This study compared ALND rates for cT1-2N0 tumors treated with upfront surgery versus those treated with NAC.

METHODS

The ALND rates for cT1-2N0 breast cancer patients were compared by tumor subtype among women undergoing upfront surgery to NAC. Multivariable analysis with control for age, cT stage, and lymphovascular invasion, and stratification by subtype was performed.

RESULTS

The study identified 1944 cancers in 1907 women who underwent sentinel lymph node (SLN) biopsy with or without ALND (669 upfront breast-conserving surgeries [BCSs], 1004 upfront mastectomies, 271 NACs). Compared with the NAC group, the ALND rates in the BCS group were lower for estrogen receptor (ER), progesterone receptor-positive (PR+), human epidermal growth factor 2-negative (HER2-) tumors (15 vs 34%; p < 0.001). The ALND rates in the upfront mastectomy group were higher than in the NAC group for HER2+ or TN tumors. In the multivariable analysis, receipt of NAC compared with upfront BCS remained significantly associated with higher odds of ALND in the ER/PR+ HER2- subtype (hazard ratio [HR], 3.35; p < 0.001), whereas NAC versus upfront mastectomy remained significantly associated with lower odds of ALND in the HER2+ and TN subtypes (HR for HER2+, 0.19, p < 0.001; HR for TN, 0.25, p = 0.007).

CONCLUSION

The study showed that ALND rates differ according to surgery type and tumor subtype secondary to differing ALND indications and nodal response to NAC. These factors can be used to personalize treatment planning to minimize ALND risk for patients with early-stage breast cancer.

Axillary Dissection and Nodal Irradiation Can Be Avoided for Most Node-positive Z0011-eligible Breast Cancers: A Prospective Validation Study of 793 Patients

OBJECTIVE

To determine rates of axillary dissection (ALND) and nodal recurrence in patients eligible for ACOSOG Z0011.

BACKGROUND

Z0011 demonstrated that patients with cT1-2N0 breast cancers and 1 to 2 involved sentinel lymph nodes (SLNs) having breast-conserving therapy had no difference in locoregional recurrence or survival after SLN biopsy alone or ALND. The generalizability of the results and importance of nodal radiotherapy (RT) is unclear.

METHODS

Patients eligible for Z0011 had SLN biopsy alone. Prospectively defined indications for ALND were metastases in ≥3 SLNs or gross extracapsular extension. Axillary imaging was not routine. SLN and ALND groups and radiation fields were compared with chi-square and t tests. Cumulative incidence of recurrences was estimated with competing risk analysis.

RESULTS

From August 2010 to December 2016, 793 patients met Z0011 eligibility criteria and had SLN metastases. Among them, 130 (16%) had ALND; ALND did not vary based on age, estrogen receptor, progesterone receptor, or HER2 status. Five-year event-free survival after SLN alone was 93% with no isolated axillary recurrences. Cumulative 5-year rates of breast + nodal and nodal + distant recurrence were each 0.7%. In 484 SLN-only patients with known RT fields (103 prone, 280 supine tangent, 101 breast + nodes) and follow-up ≥12 months, the 5-year cumulative nodal recurrence rate was 1% and did not differ significantly by RT fields.

CONCLUSIONS

We confirm that even without preoperative axillary imaging or routine use of nodal RT, ALND can be avoided in a large majority of Z0011-eligible patients with excellent regional control. This approach has the potential to spare substantial numbers of women the morbidity of ALND.