ACOSOG Z0011 Research Articles

Whole breast radiotherapy in cN0 early breast cancer patients with pathological sentinel lymph nodes (pN1mic, pN1a) without axillary dissection: preliminary results of the observational LISEN trial

PurposeAxillary management remains unclear when sentinel lymph node (SLN) results are positive in cN0 patients with breast cancer (BC). The trial ACOSOG Z0011 represented a revolution with axillary lymph node dissection (ALND) omission in SLN+ patients, despite critiques regarding non-uniformity of radiation fields. We conducted an observational study (LISEN) where whole breast radiotherapy (WBRT) was planned with tangential fields without nodal irradiation in patients eligible for the Z0011 trial.MethodsInclusion criteria were female patients with histologically proven BC, cT1-2cN0, planned conservative surgery, no neoadjuvant therapy. Patients were stratified into two groups: micrometastatic (pN1mic, group 1) and macrometastatic (pN1a, group 2) lymph nodes. Tangential field WBRT was mandatory. Clinical outcomes were analysed, measured from surgery until the first event.ResultsIn all, 199 patients underwent conservative surgery and SLN biopsy; 133 patients meeting criteria were analysed: 41 patients (30.8%) pN1mic and 92 (69.2%) pN1a. The 5‑year disease-free survival (DFS) was 95.0% (85.9–100%) in group 1 and 93.0% (86.3–100.0%) in group 2 (p = 0.78). Overall survival (OS) was 100% (100–100%) in group 1 and 97.4% (92.4–100%) in group 2 (p = 0.74). For the whole cohort DFS and OS were 93.6% (88.2–99.4%) and 96.9% (91.5–100.0%), respectively. For groups 1 and 2, the 5‑year outcomes were 5.0% (0.0–14.4%) and 2.3% (0.0–6.1%) for local recurrence (p = 0.51), and 6.2% (0.0–17.4%) and 7.0% (0.0–13.7%) for distant metastasis (p = 0.61), respectively. In group 1, regional recurrence (RR) and local regional recurrence (LRR) were 5.0% (0.0–14.1%; p = 0.13). In group 2, RR and LRR were 0.0% (0.0–0.0%).ConclusionOur results showed good regional control in patients who met the Z0011 trial criteria. WBRT, without nodal surgery or RT, avoiding axillary morbidity, seems to be a good choice.

UK practice patterns of axillary management in patients with needle biopsy proven nodal metastases at presentation after neoadjuvant chemotherapy - Results of ATNEC feasibility survey

Background: ACOSOG Z1071 demonstrated the reliability of sentinel node biopsy (SNB) at assessing residual nodal disease post-neoadjuvant chemotherapy (NACT), in patients with nodal metastasis at presentation. However, we do not know whether local axillary therapy can be modified based on NACT response.

No axillary surgical treatment for lymph node-negative patients after ultra-sonography [NAUTILUS]: protocol of a prospective randomized clinical trial

BackgroundFollowing sentinel lymph node biopsy (SLNB), the axillary recurrence rate is very low although SLNB has a false-negative rate of 5–10%. In the ACOSOG Z0011 trial, non-sentinel positive-lymph nodes were found in more than 20% of the axillary dissection group; the SLNB only group did not have a higher axillary recurrence rate. These findings raised questions about the direct therapeutic effect of the SLNB. SLNB has post-surgical complications including lymphedema. Considering advances in imaging modalities and adjuvant therapies, the role of SLNB in early breast cancer needs to be re-evaluated.MethodsThe NAUTILUS trial is a prospective multicenter randomized controlled trial involving clinical stage T1–2 and N0 breast cancer patients receiving breast-conserving surgery. Axillary ultrasound is mandatory before surgery with predefined imaging criteria for inclusion. Ultrasound-guided core needle biopsy or needle aspiration of a suspicious node is allowed. Patients will be randomized (1:1) into the no-SLNB (test) and SLNB (control) groups. A total of 1734 patients are needed, considering a 5% non-inferiority margin, 5% significance level, 80% statistical power, and 10% dropout rate. All patients in the two groups will receive ipsilateral whole-breast radiation according to a predefined protocol. The primary endpoint of this trial is the 5-year invasive disease-free survival. The secondary endpoints are overall survival, distant metastasis-free survival, axillary recurrence rate, and quality of life of the patients.DiscussionThis trial will provide important evidence on the oncological safety of the omission of SLNB for early breast cancer patients undergoing breast-conserving surgery and receiving whole-breast radiation, especially when the axillary lymph node is not suspicious during preoperative axillary ultrasound.Trial registrationClinicalTrials.gov, NCT04303715. Registered on March 11, 2020.

Abstract OT1-04-02: The NAUTILUS trial (No Axillary sUrgical Treatment In clinically Lymph node negative patients after UltraSonography): A prospective multicenter randomized phase III trial (NCT04303715)

Abstract Background. Sentinel lymph node biopsy (SLNB) is currently the standard axillary staging procedure for clinically node-negative breast cancer. According to the ACOSOG Z0011 trial, axillary lymph node dissection (ALND) is now often omitted for clinically node-negative cT1-2 breast cancer patients undergoing breast-conserving surgery even if 1 or 2 metastatic lymph nodes (LN) are identified. It was shown that radiotherapy contributes to regional control of the axilla non-inferior to ALND even in the presence of metastatic LNs. Furthermore, LN metastasis has a limited role in planning adjuvant systemic therapy for hormone receptor-negative breast cancers, and also for hormone receptor-positive, HER2-negative breast cancer with increased use of genomic assays. SLNB is not without complications and omitting axillary staging operation could improve quality of life. Trial Design. In this multicenter, phase III randomized controlled trial including 9 study sites in South Korea, we plan to 1:1 randomize 1734 patients to either omit SLNB (Arm 1) or receive SLNB (Arm 2). Additional ALND can be performed according to the discretion of the surgeon according to the SLNB results. All patients must receive whole-breast irradiation ± tumor bed boost. The recommended upper margin of the radiation field is within 2cm of the humeral head. ClinicalTrials.gov identifier: NCT04303715. Eligibility. Inclusion criteria: women ≥19 years; cT1-2N0M0 unilateral invasive breast carcinoma; all molecular subtypes; clinically and radiologically tumor size ≤ 5cm; clinically- and ultrasonogram-negative axillary lymph nodes, or no tumor on core needle biopsy or fine needle aspiration cytology in case of suspicious lymph nodes; candidate for breast-conserving surgery with no restriction to radiotherapy and adequate systemic therapy. Exclusion criteria: history of any malignancy within 5 years (exception: thyroid cancer and well-treated skin cancer except melanoma); bilateral breast cancer; neoadjuvant chemotherapy; candidate for total mastectomy; male breast cancer. Specific Aims. Primary objective is to test the hypothesis that omitting SLNB for breast cancer is non-inferior to axillary staging operation in terms of 5-year disease-free survival. Secondary objectives are to compare overall survival, distant metastasis-free survival, locoregional recurrence, quality of life assessment, and DFS and axillary recurrence according to molecular subtypes. Statistical Methods. With an expected 5-year DFS of 86% for Arm 2, Arm 1(SLNB omission) will be assessed with a non-inferiority limit of 5% and hazard ratio of 1.4, power 80%, and significance level of 5%, where 224 events are required. The calculated sample size is 780 per study arm, resulting in a total of 1,734 patients assuming a 10% drop-out rate. Present Accrual and Target Accrual. The first patient was randomized on September 15, 2020. As of July 9, 2021, 480 patients have been randomized. Target accrual of 1734 patients is expected to be complete by April 2023, with the primary endpoint analysis expected in 2028. Citation Format: Han-Byoel Lee, Ji Gwang Jung, Jung Min Chang, Ji Hyun Chang, Woo Kyung Moon, Kyung Hwan Shin, Il Yong Chung, Seok Jin Nam, Eun-Kyu Kim, Seeyoun Lee, Seho Park, Woo Sung Lim, Yongsik Jung, Wonshik Han. The NAUTILUS trial (No Axillary sUrgical Treatment In clinically Lymph node negative patients after UltraSonography): A prospective multicenter randomized phase III trial (NCT04303715) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-04-02.

Preliminary results of the MUltimodal TArgeted axillary Surgery (MUTAS) study (ClinicalTrials.gov: NCT04039893): tailoring axillary dissection in breast cancer patients with infiltrated lymph nodes.

Background: The surgical management of breast cancer patients with infiltrated axillary lymph nodes (ALNs) at diagnosis is controversial, as some centres perform upfront axillary dissection (AD) while other centres perform the sentinel node (SN) mapping, so that some patients may benefit from the ACOSOG Z0011 trial criteria to skip further surgery. The primary aim of the MUTAS trial is to establish if performing the SN in breast cancer patients with confirmed infiltrated ALNs could be useful to tailor axillary surgery.

Choice of Mastectomy May Increase the Extent of Axillary Surgery in Women with Breast Cancer

Based on the ACOSOG Z0011 trial, women who undergo breast conservation therapy (BCT) and have limited disease in the axilla on sentinel lymph node (SLN) biopsy do not require axillary lymph node dissection (ALND). In this study we investigate the incidence of ALND in patients undergoing elective mastectomy with limited disease in the axilla to identify how many women may have been spared additional axillary surgery if they chose BCT. All women with invasive breast cancer treated at a single tertiary care breast center from 2010-2018 who were candidates for BCT but elected mastectomy and underwent SLN biopsy were identified through retrospective review of a prospectively maintained database. The primary outcome of interest was the incidence of ALND in women found to have a limited burden of disease in the axilla (1-2 positive SLNs). The study population comprised 151 patients with invasive breast cancer eligible for BCT who chose mastectomy. On final pathology, 34 patients had 1-2 positive SLNs, and 16 of these patients underwent completion ALND. These 16 patients out of 151 overall lumpectomy candidates electing mastectomy (10.6%) could have been spared ALND if they did not elect mastectomy. BCT candidates electing mastectomy have a 10.6% chance of undergoing more extensive axillary surgery than would have been recommended with BCT alone. The increased risk of undergoing additional axillary surgery should be incorporated into the preoperative discussion for patients choosing between BCT and mastectomy.

Axillary Treatment of Early Breast Cancer Patients in The Era of ACOSOG Z0011. Our experience

Axillary Treatment of Early Breast Cancer Patients in The Era of ACOSOG Z0011. Our experience

Efficacy of the Management of Node Negative Early Stage Breast Cancer Using 1% Methylene Blue in Sentinel Lymph Node Biopsy:prospective study, kasrAlaini University Hospital

Background:Accurate staging and proper management of axillary lymph nodes are important for the treatment of breast cancer. Sentinel lymph node biopsy (SLNB) provides accurate assessment of nodal status.Aimof work:Evaluation the safety, the accuracy and the cost of the application of SLNB using methylene blue 1% (MB 1%) in cases of node negative early stage breast cancer.Patients and methods:This study was conducted at Kasr Al-Ainy university Hospitals, Faculty of Medicine, Cairo University. Fifty-two female patients with node negative early stage breast cancer who agreed on undergoing breast conservative surgery( BCS), SLNB using 1% methylene blue and frozen section examination then managed according to ACOSOG Z0011 criteria .Results:Identification in 50 surgical specimens (identification rate 96.15%). By evaluating frozen section examination of the lymph nodes in relation to paraffin section examination we found that the sensitivity of the frozen section examination was 100% and specificity was 97.5% with positive predictive value 90.9%, negative predictive value 100% and overall accuracy was 98%.Conclusion:One % MB dye is very effective as a single agent in SLNB in node negative early stage breast cancer with very high identification rate compared to patent blue and radiocolloids. Implementation of ACOSOG Z0011 criteria proved its validity throughout our study as average 12 months follow up showed no locoregional recurrence

Omitting axillary lymph node dissection after positive sentinel lymph node in the post-Z0011 era: Compliance with NCCN and ASCO clinical guidelines and Z0011 criteria in a large prospective cohort

In the ACOSOG Z0011 trial, patients with primary breast cancer and 1-2 tumor-involved sentinel lymph nodes (SLNs) undergoing breast-conserving surgery had no oncological outcome benefit after axillary lymph node dissection (ALND), despite a relevant rate of non-SLN metastases of 27%. According to the St Gallen expert consensus, and NCCN and ASCO clinical guidelines, ALND may be avoided in patients who meet all ACOSOG Z0011 inclusion criteria. This recommendation can also be extended to patients undergoing mastectomy, with 1 or 2 positive SLNs and an indication for chest wall radiation, in whom axillary radiotherapy can be proposed as an alternative to completion ALND. The aim of this study was to assess non-compliance with the NCCN and ASCO clinical guidelines and Z0011 criteria, namely the rate of performance of completion ALND when it was not recommended, and the rate of failure to perform completion ALND when recommended. Data were prospectively analysed from T1-2 N0 breast cancer patients undergoing an SLN procedure and treated at the Georges-François Leclerc Cancer Center between November 2015 and May 2017. Factors associated with non-compliance treatment decisions were identified using logistic regression. Among 563 patients included, 122 (21.7%) had at least one positive SLN. ALND was not recommended for 76 patients (62.3%), and was recommended in 46 patients (37.7%). The rate of non-compliant treatment was 32% (39/122) overall: ALND was performed despite not being recommended in 16/76 patients (21.1%) and was not performed in 50% of patients in whom it was recommended (23/46). By multivariate analyses, lymphovascular invasion ((Odds Ratio (OR)=6.1; 95% confidence interval (CI): 1.4-26.7; P=0.02)) and only one SLN removed (OR=9.1; 95%CI: 2.2-33.3; P=0.002) were associated with performance of completion ALND when not recommended. Conversely, >1 SLN removed (OR=5.1; 95%CI: 1.2-22.2; P=0.03) was associated with the failure to perform completion ALND when recommended. Almost one third of patients with invasive breast cancer receive treatment that is not in compliance with recommendations regarding completion ALND.

ASO Visual Abstract: The Attitudes of Brazilian Breast Surgeons on Axillary Management in Early Breast Cancer 10 Years After the ACOSOG Z0011 Trial First Publication

ASO Visual Abstract: The Attitudes of Brazilian Breast Surgeons on Axillary Management in Early Breast Cancer 10 Years After the ACOSOG Z0011 Trial First Publication

EP.TH.930Contemporary trends in the management of micrometastatic axillary disease in the setting of mastectomy – a 5 year single institution experience

Abstract Background Since the ACOSOG Z0011 trial, rates of axillary node clearance (ANC) for micrometastatic axillary disease have declined among women undergoing breast conservation surgery (BCS). However, for women undergoing mastectomy, it remains unclear whether omission of ANC is a safe and feasible option. Aims Identify current practice relating to management of the axilla in women with early stage, clinically node negative breast cancer, found to have micrometastatic disease on SNB, who undergo mastectomy Methods From 2013 to 2017 patients with clinical T1-T2Nmi breast cancer undergoing upfront surgery were identified from a prospective institutional database. Receipt of adjuvant radiotherapy or subsequent ANC were assessed. Patients who received neoadjuvant chemotherapy or BCS were excluded. Results 47 patients undergoing mastectomy for ESBC had micrometastasis identified on SNB. The majority of tumours had invasive ductal histology. 16/27 women underwent completion ANC (34%). Six patients had further nodal disease identified in the ANC specimen. 2 had >5 nodes positive. During the study period 31 patients (65%) received adjuvant radiotherapy. Of the patients who did not undergo ANC, 21 (67.7%) received adjuvant radiotherapy. Conclusion At this institution the majority of patients requiring mastectomy with micrometastatic disease on SNB do not undergo subsequent ANC (>60%). Although this is a small patient cohort, these data indicate the rate of residual axillary disease is low, and are in keeping with trends in the literature, and may help inform management decisions in this patient group.

To Look or Not to Look? Yes to Nodal Ultrasound!

Knowledge of axillary nodal status is highly important for correct staging and treatment planning in patients with breast cancer. Axillary US is a recognized highly specific and cost-effective tool for assessing nodal status and guiding appropriate treatment. Axillary US imaging with US-guided biopsy is routinely performed throughout the world. However, because of recent developments in the surgical management of the axilla in patients with newly diagnosed breast cancer (American College of Surgeons Oncology Group [ACOSOG] Z0011 trial) and in patients with breast cancer receiving neoadjuvant systemic therapy (ACOSOG Z1071, SENTinel NeoAdjuvant [SENTINA] and Sentinel Node biopsy aFter NeoAdjuvant Chemotherapy [SN FNAC] trials), some have questioned the utility of axillary US for nodal staging. Here, we review the evidence to date supporting the additional value of axillary US for patients with breast cancer. Nodal US in patients with newly diagnosed breast cancer is useful for staging; in a significant proportion of patients, nodal US identifies additional axillary level II or level III nodal disease, which allows for appropriate treatment of disease. Furthermore, ongoing clinical trials may show that axillary surgery can be omitted in patients with negative findings on axillary US. In patients with lymph node-positive disease undergoing neoadjuvant systemic therapy, nodal US can guide the approach to axillary surgery. A more personalized patient approach, taking into the account tumor biology, among other factors, may help to mitigate the controversy surrounding the role of axillary US in breast cancer patients.

The Attitudes of Brazilian Breast Surgeons on Axillary Management in Early Breast Cancer-10 Years after the ACOSOG Z0011 Trial First Publication.

To evaluate the impact of the ACOSOG Z0011 trial on axillary breast cancer surgery management in Brazil following publication of that study (2010) and again in 2020. A survey of members of the Brazilian Society of Mastology. Of 1627 breast surgeons, 799 (49.1%) completed and returned the questionnaire. For patients with the Z11 inclusion criteria, following detection of a positive sentinel lymph node (SLN), axillary dissection (AD) was recommended by 99.2% of respondents before publication of the study, 47.5% in 2010 and 18.5% in 2020 (p < 0.001). In breast-conserving surgery, if there were micro-metastases, 2.6% would perform AD, 30.3% axillary radiotherapy, and 67.1% no additional axillary treatment, while with macro-metastases, these proportions were 21.3%, 52.2%, and 26.5%, respectively. In cases of mastectomy and of nodal extracapsular extension, 43.4% and 36% of surgeons, respectively, recommended AD. For clinically negative axilla and suspicious findings at ultrasonography, 69% of the surgeons would apply the Z11 approach. Most applied the Z11 criteria in cases of younger patients (83.6%) and triple-negative and/or HER2 positive tumors (74%). AD was significantly more likely to be recommended by surgeons who did not work in academic institutes, who worked in locations other than capital cities, who were not board-certified, and who were ≥ 50 years old. This survey revealed substantial changes in axillary surgery management in cN0/pathologically positive SLN, particularly following publication of the updated Z11 results and other similar studies. A better education environment and long-term follow-up were factors associated with the incorporation of Z11-related changes in practice.

Axillary management based on American college of surgeons oncology group Z0011 criteria makes it possible to omit intraoperative diagnosis of sentinel lymph nodes in early breast cancer patients.

The ACOSOG Z0011 trial has resulted in the omission of axillary lymph node dissection (ALND) in early breast cancer patients with one or two metastatic sentinel lymph nodes (SLNs). There has been increasing interest in the necessity of intraoperative assessment of SLNs in patients treated based on the Z0011 criteria. We evaluated the utility of intraoperative assessment in these eligible patients. A total of 1396 patients were treated following the Z0011 criteria from April 2012 to December 2019. We examined the proportion and clinicopathological features of patients who underwent ALND due to three or more metastatic SLNs and the sensitivity of intraoperative assessment. Only 16 (1.1%) patients had three or more metastatic SLNs diagnosed by intraoperative assessment, and they immediately underwent ALND. Of the clinicopathological factors, high clinical tumor stage (p=0.002) and high Ki-67 labeling index value (p=0.056) were more likely to be associated with the presence of three or more metastatic SLNs. The major independent risk factor for three or more metastatic SLNs was high clinical tumor stage (OR 3.94 [95% CI 1.42-11.0]; p=0.009). Intraoperative assessment had low sensitivity (70.5%) and a high false-negative rate (29.5%) in detecting SLN metastases. The main finding of our study was the small proportion of patients who required ALND due to three or more metastatic SLNs according to the Z0011 criteria. The Z0011 strategy enables intraoperative assessment of SLNs to be omitted in early breast cancer patients.

The new perspective of PET/CT for axillary nodal staging in early breast cancer patients according to ACOSOG Z0011 trial PET/CT axillary staging according to Z0011.

Post Z0011 trial, axillary lymph node dissections (ALNDs) can be performed in patients with ≥3 positive axillary lymph nodes (ALNs). We investigated the diagnostic performance of 18F-fluorodeoxyglucose PET/computed tomography (FDG PET/CT) to predict ≥3 metastasis [high nodal burden (HNB)]. We retrospectively analyzed preoperative FDG PET/CT from January 2010 to June 2012. Patients had clinical T1-2N0 primary invasive breast cancer and underwent breast-conserving surgery with sentinel lymph node biopsy ± ALND. All suspicious ALNs were counted considering FDG-avidity with morphologic changes. Images were considered positive if the axillary basin took up more FDG than the surrounding tissue. On CT, abnormal ALNs were round/ovoid or had cortical thickening with contrast enhancement. PET/CT results were compared with the histology and follow-up findings. In total, 221 females with 224 axillae were enrolled; 161 had negative, 53 had 1-2 metastasis [low nodal burden (LNB)] and 10 had HNB. The sensitivity, specificity, negative predictive value and positive predictive value of PET/CT for HNB were 70, 100, 98.6 and 100%, respectively. There was a correlation between the number of suspicious ALNs on PET/CT and the metastatic nodes on final histology. There were no significant differences in age, tumor size and FDG-avidity between patients with negative or LNB and HNB. During follow-up, 25 patients had a recurrence. The three false-negative patients did not show recurrence. Preoperative PET/CT predicts HNB with high accuracy and is useful for evaluating clinical T1-2N0 invasive breast cancer.

The effect of omitting axillary dissection and the impact of radiotherapy on patients with breast cancer sentinel node macrometastases: a cohort study following the ACOSOG Z0011 and AMAROS trials.

To report the outcomes of implementing the ACOSOG Z0011 and AMAROS trials relevant to clinical practice, and to define target groups in whom to avoid or recommend axillary radiotherapy (ART). We also aimed to analyse the reduction in morbidity when axillary lymph node dissection (ALND) was omitted. A retrospective cohort study of T1-T2 patients with macrometastases at sentinel lymph node (SLN) who were treated between 2011 and 2020. Breast surgery included either lumpectomy or mastectomy. Patients with ≤ 2 positive SLN were divided into two cohorts by whether they received ART or not. Survival outcomes and morbidity were analysed by Kaplan-Meyer curves and Cox-regression, respectively. 260 pN1a patients were included and ALND was avoided in 167 (64.2%). According the Z0011 results, 72 (43.1%) received no further ART; and based on AMAROS criteria 95 (56.9%) received ART. Median follow-up was 54months. The 5-year overall survival was 96.8% in the non-RT cohort and 93.4% in the RT cohort (p = 0.19), while the respective 5-year disease-free survivals were 100% and 92.3% (p = 1.06). Lymphedema developed in 3.6% of patients after SLNB versus 43% after ALND (OR 20.25; 95%CI 8.13-50.43). Decreased upper-extremity range of motion appeared in 8.4% of patients after SLNB versus 31.2% after ALND (OR 4.95; 95%CI 2.45-9.98%). Our study confirms that omitting ALND is safe and has high survival rates in patients with T1-T2 tumours and ≤ 2 positive SLNs. Adding ART could be a treatment option for patients who present other risk factors. Avoiding ALND with or without ART was associated with significantly less arm morbidity.

The applicability of the ACOSOG Z0011 Criteria to breast cancer patients in Hong Kong.

The ACOSOG Z0011 trial demonstrated safe omission of axillary lymph node dissection (ALND) in patients with one or two positive sentinel lymph nodes (SLNs) receiving breast conservative surgery, followed by whole breast irradiation and adjuvant systemic treatment. This study aims to evaluate the exportability of the ACOSOG Z0011 criteria in an Asian/Chinese cohort residing in Hong Kong. Retrospective analysis of a prospectively maintained database in a University affiliated tertiary breast centre was performed from June 2014 to May 2019. All breast cancer patients with no palpable adenopathy before surgery, one or more positive sentinel lymph nodes on histological examination and no prior neoadjuvant systemic treatment were recruited. Patients were grouped as eligible or ineligible according to the ACOSOG Z0011 criteria. The eligible group was compared with the sentinel alone group in the ACOSOG Z0011 cohort. Two hundred and forty-eight patients were recruited into the study. Sixty patients (24%) met the ACOSOG Z0011 criteria and could potentially avoid ALND. A higher percentage of clinical T2 tumors were observed in our eligible group than in the ACOSOG Z0011 trial (P=0.002). The histological subtype, tumor grade, estrogen receptor (ER)/progestogen receptor (PR) status and lymphovascular invasion status did not differ. There was no statistically significant difference in the proportion of SLN micrometastasis and macrometastasis between the two groups. This study demonstrated clinical similarities between our eligible cohort and the ACOSOG Z0011 cohort, which confirms exportability of the ACOSOG Z0011 criteria to a subset of population in Hong Kong.

107 COVID 19 - Developing A Second Brain for Axillary Conservation During the Pandemic By Extrapolating Evidence On Technical Trends Of Sentinel Node Staging Of Axilla Into A Streamlined Recommendation

IntroductionAxillary conservation is the way forward after game changing trials like ACOSOG Z0011, surrogate trials like IBCSG,AMAROS, ALMANAC, on-going POSNOC, and newbie ATNEC have decreased the need to fiddle with the axilla. Current standard is the utilisation of double technique with radioisotope and blue dye to decrease false negative rates for true sentinel node retrieval.MethodLiterature search on the topic in the last two decades.ResultsThe search yielded 197 publications which were subjected to a meticulous review.ConclusionsSingle agent radioisotope is recommended in palpable and good biology breast tumours. Use of single agent blue dye can be standardised in axillary tail tumours. It is also recommended when isotope mapping is logistically not feasible or during pandemics like COVID 19 where looming infrastructure challenges are prevalent. Dual agent technique should be considered in previously treated breast and axilla, neoadjuvant chemotherapy cohort, bad tumour biology, high BMI and macromastia groups for true nodal retrieval. Optimal number of nodes taken out should not be more than three (n = 3). Lower axillary sampling of not more than 3 nodes is recommended for troubleshooting. Magnetic tracing can be used as an adjunct to either single agent (RI/BD) technique when there is failure to localise the sentinel node.

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.

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.