Omission Of Axillary Lymph Node Dissection Research Articles

Omission of Axillary Lymph Node Dissection in Patients with Residual Nodal Disease After Neoadjuvant Chemotherapy.

Axillary management after neoadjuvant chemotherapy (NAC) is evolving but axillary lymph node dissection (ALND) remains the standard of care for patients with residual nodal disease. The results of the Alliance A011202 trial evaluating the oncologic safety of ALND omission in this cohort are pending but we hypothesize that ALND omission is already increasing. The National Cancer Database was queried to identify patients diagnosed with cT1-3N1M0 breast cancer who underwent NAC and had residual nodal disease (ypN1mi-2) from 2012 to 2021. Temporal trends in omission of completion ALND were assessed annually. Multivariable logistic and Cox regression models were used to identify factors associated with ALND omission and overall survival (OS), respectively. A total of 6101 patients were included; the majority presented with cT2 disease (57%), with 69% HER2+, 23% triple-negative, and 8% hormone receptor-positive/HER2-. Overall, 34% underwent sentinel lymph node biopsy (SLNB) alone. Rates of ALND were the lowest in the last 4years of observation. After adjustment, treatment at community centers (vs. academic) and lower pathologic nodal burden were associated with omission of ALND. ALND omission was associated with a higher unadjusted OS (5-year OS: 86% SLNB alone vs. 84% ALND; log-rank p=0.03), however this association was not maintained after adjustment. Despite the impending release of the Alliance A011202 results, omission of ALND in patients with residual nodal disease after NAC is increasing. This practice appears more prominent in community centers and in patients with a lower burden of residual nodal disease. No association with OS was noted.

Contemporary Axillary Surgical Management in Patients with Pathologically Node Positive Disease After Neoadjuvant Chemotherapy: A Survey of Members of the American Society of Breast Surgeons.

Axillary lymph node dissection (ALND) is increasingly omitted for breast cancer patients with pathologic nodal disease after neoadjuvant chemotherapy (NAC). This study aimed to understand when and why surgeons consider omitting ALND after NAC. The American Society of Breast Surgeons membership was surveyed, and responses were tabulated. To identify patterns, multiple correspondence analyses followed by cluster analysis on coordinates provided by the former were performed. Chi-squared analyses determined whether cluster characteristics were significantly (P < 0.05) associated with omission of ALND. Of members, 328/2172 (15.1%) completed the survey. Most (60.7%) always offer sentinel lymph node surgery to cN1 patients who respond to NAC, and many (43.9%) sometimes omit ALND in the setting of residual nodal disease. Respondents less often consider omitting ALND with increasing volume of pathologic nodal disease after NAC and are less likely to omit ALND among patients with cN1 disease at presentation than cN0 (P < 0.05 across all volumes). Respondents cited radiation administration (74.1%) and belief that ALND would not improve locoregional (48.2%), distant recurrence or survival (47.6%) outcomes when axillary radiation is administered as reasons to omit ALND. The respondent group comprising male private practice surgeons, practicing ≥ 21 years, consider omitting ALND significantly more frequently. Surgeons sometimes consider ALND omission for patients with pathologic nodal disease after NAC but are more likely to do so in cN0 patients and patients with smaller volumes of nodal disease. These decisions are largely based on perceived lack of oncologic benefit despite absence of prospective data supporting this deescalation.

Abstract GS02-02: Are nodal ITCs after neoadjuvant chemotherapy an indication for axillary dissection? The OPBC05/EUBREAST-14R/ICARO study

Abstract GS02-02: Are nodal ITCs after neoadjuvant chemotherapy an indication for axillary dissection? The OPBC05/EUBREAST-14R/ICARO study

Abstract PO4-19-07: Tailored Axillary Surgery (TAS) in Patients with Clinically Node-Positive Breast Cancer in the Upfront Surgery Setting: A Prospective, Single-Arm, Multicenter Trial

Abstract A brief background discussion: Axillary lymph node dissection (ALND), which can induce lymphedema, has been omitted in clinically node-negative(cN0) patients with positive sentinel lymph nodes (SLNs) if they meet the eligibility criteria of ACOSOG Z0011. Furthermore, the omission of ALND has been attempted through targeted axillary dissection (TAD) in patients whose clinically node-positive(cN+) status converts to ycN0 after neoadjuvant chemotherapy. However, ALND remains the standard of care in patients with cN+ who undergo upfront surgery. Trial design: This is a prospective, single-arm, multicenter phase II feasibility trial with the participation of 41 hospitals belonging to the breast cancer study group of Japan Clinical Oncology Group (JCOG). Tailored axillary surgery (TAS) removes labeled lymph node (LN) with clip, wire, or tattoo, palpable LNs, and SLNs. ALND is performed after TAS. These LNs removed by ALND other than TAS are defined as non-TAS LNs. Eligibility criteria: The eligibility criteria are as follows: 1) histologically-proven invasive breast cancer, 2) upfront surgery is planned, 3) pathologically diagnosed metastatic LN (cytology or core needle biopsy), 4) 1-3 LN metastases in level I by imaging, 5) cT1-3, and 6) females aged ≥18 and ≤74 years on the enrollment date. Specific aims: This trial aims to establish a surgical method of tailored axillary surgery (TAS) among patients with cN+ who undergo upfront surgery and to determine the appropriate criteria for the next phase III TAS trial, which omits ALND by TAS safely. The primary endpoint is the non-TAS LNs positive rate. Clinicopathological factors (the number of suspected metastases by imaging, the number of metastases in LNs resected by TAS, tumor size, and invasive ductal/lobular carcinoma) are analyzed to predict the non-TAS LN metastasis rate (e.g., &amp;lt; 10%). The secondary endpoints are the TAS LNs identification rate, marked LN resection rate, arm edema incidence rate, and QOL (FACT-B, QuickDASH). Statistical methods: In this trial, among the combinations of factors involved in treatment selection, the objective is to narrow down the combinations that will result in a non-TAS metastasis-positive rate of less than 10% when TAS is performed. For a single combination, 167 cases need to be considered to reject a non-TAS metastasis-positive rate of 10% or more (5% one-sided alpha error, 70% power, and 5% expected value). However, performing these studies for all combinations lacks feasibility. Therefore, we decided to improve the estimation accuracy by using a regression model with the non-TAS metastasis-positive rate as the outcome variable and the factors involved in treatment selection as explanatory variables and to search for combinations of factors with a non-TAS metastasis-positive rate less than 10%. Based on the rule of thumb that a sample size of at least ten times the number of factors is required when using regression methods, a regression model is used when 60 cases are accumulated. The combinations with a 90% confidence upper limit of less than 10% of non-TAS metastasis positivity as the predictive value of the regression model will be selected as candidate combinations that fulfill the conditions. If the accuracy of the predictive value is considered insufficient, 60 cases will be added sequentially up to a maximum of 300 cases. Present accrual and target accrual: The patient recruitment was started in April 2023. Up to 300 patients will be enrolled over a 2-year recruitment period. Twenty-one patients were already enrolled until July 2023. Citation Format: Kaori Terata, Yasuaki Sagara, Tadahiko Shien, Takehiko Sakai, Shin Takayama, Dai Kitagawa, Tsuguo Iwatani, Takahiro Tsukioki, Mami Ogita, Naoko Sanuki, Masayuki Yoshida, Hitoshi Tsuda, Seiichiro Yamamoto, Hiroji Iwata. Tailored Axillary Surgery (TAS) in Patients with Clinically Node-Positive Breast Cancer in the Upfront Surgery Setting: A Prospective, Single-Arm, Multicenter Trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-19-07.

Abstract ED05-01: Demystifying the Axilla: Challenging scenarios in the upfront surgery setting and after NAC

Abstract Management of the axilla has evolved significantly over time, with a trend toward less extensive axillary surgery. While historically, all patients underwent axillary lymph node dissection (ALND) due to the Halstedian belief that ALND was essential for the cure of breast cancer, advances in systemic therapy, radiotherapy, and understanding of tumor biology have resulted in the abandonment of ALND for a large proportion of patients having upfront surgery with limited nodal disease, and in those with no residual nodal disease after neoadjuvant systemic therapy. Over time, axillary management has become increasingly complicated, with significant variability in real-world management for different clinical scenarios. In this talk, we will address challenging scenarios in axillary management, both in the upfront surgery setting and after neoadjuvant chemotherapy (NAC). In the upfront surgery setting, we will address management of a positive sentinel node in patients treated with mastectomy, management of ≥ 3 positive sentinel nodes after lumpectomy or mastectomy, and the use of sentinel lymph node biopsy for patients with clinically node-positive hormone receptor (HR) positive/human epidermal growth factor receptor 2 (HER2) negative breast cancer. In the setting of patients receiving NAC, we will discuss the optimal approach to the axilla in patients with residual disease after NAC, and in those with locally advanced breast cancer. As we move away from ALND in low-risk scenarios where data from randomized and prospective trials have demonstrated oncologic safety, we await results from ongoing clinical trials to provide us with high-level evidence regarding the safety of omission of ALND in high-risk patients with more extensive nodal disease. Citation Format: A. Barrio. Demystifying the Axilla: Challenging scenarios in the upfront surgery setting and after NAC [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr ED05-01.

Omission of Axillary Dissection in Node Positive Breast Cancer After Neoadjuvant Systemic Therapy

IntroductionGuidelines recommend axillary lymph node dissection (ALND) for ypN + positive patients as patients receiving neoadjuvant systemic therapy (NST) were excluded from trials omitting ALND in pN + patients. We sought to characterize trends in omission of ALND in patients with ypN + disease. MethodsAdult women with invasive breast carcinoma in the National Cancer Database between 2012 and 2019 who received NST (chemotherapy or endocrine) and had ypN + disease were included. Patients were excluded if they did not have definitive surgery within eight months of diagnosis. The primary study outcome was completion of ALND versus omission. Differences in demographics, tumor characteristics, and treatment were identified using bivariate and multivariate logistic regression models. ResultsIn total, 103,121 women were included. Most had cT1 (26%) or cT2 (45%) tumors, cN + disease (71%), and ductal histology (83%). 69% of patients received neoadjuvant chemotherapy and 31% neoadjuvant endocrine without chemotherapy (30% both). ALND was performed in 77% of patients. Omission of ALND became more prevalent each year from 2012 (14%) to 2019 (34%). On multivariate modeling, year of diagnosis, black race, cN status, higher grade, estrogen receptor+/HER2-receptor subtype, and mastectomy were associated with increased prevalence of ALND. Age, Charlson/Deyo comorbidity index score, endocrine versus chemotherapy, and adjuvant radiation were not associated with receipt of ALND. ConclusionsDespite guidelines recommending ALND, omission is common in patients with ypN + breast cancer after NST. Omission of ALND increased significantly over time and is associated with clinical and demographic factors. Future study is needed to determine the oncologic safety of this approach.

Can axillary lymph node dissection (ALND) be omitted in patients with breast cancer with persistent axillary disease after neoadjuvant chemotherapy?

e12624 Background: Axillary lymph node dissection (ALND) is the standard of care for patients (pts) with persistent node-positive (N+) disease after neoadjuvant chemotherapy (NAC). In those with a clinical response to NAC, it is appropriate to perform limited axillary surgery to evaluate axillary status, with ALND reserved for those who remain N+. We define the directed-sentinel node biopsy (dSLNB) as pre-operative localization of the previously positive lymph node combined with dual-tracer sentinel node biopsy. We hypothesize that omission of ALND in those that have residual N+ disease after NAC, is associated with less morbidity, without impacting outcomes. Methods: This is a single-institution, retrospective analysis of consecutive pts with N+ breast cancer (BC) who received NAC and dSLNB +/- ALND from 2014-2021. A clip was placed in the positive node at the time of biopsy and excised using radioactive seed localization (RSL) with an I-125 seed. Only those with persistent disease in the RSL on pathology were included (RSL+). We assessed the impact of extent of axillary surgery on primary outcomes, including recurrence, disease-free survival (DFS) and overall survival (OS), and secondary outcomes, including location of recurrence and lymphedema. Results: 156 female pts with N+ BC received NAC, underwent dSLNB +/- ALND with RSL+. Mean age was 52.1 years (SD 12.2). Median follow-up was 32.5 months (IQR 22.9-51.6). Phenotype distribution was 55.8% luminal, 21.2% HER2 positive, and 23.1% triple negative, with no difference between ALND or dSLNB. Pts who had ALND had a higher nodal stage at presentation compared to dSLNB (N1: 72.9% vs. 91.8%, N2: 20.6% vs. 8.2%, N3: 6.5% vs. 0%, p = 0.016). 90.4% received adjuvant radiation with no difference between ALND and dSLNB. Lymphedema rates were higher in the ALND group (47.7% vs. 16.3%, p &lt; 0.001). Fifteen patients died with no difference between ALND and dSLNB in overall mortality rates (9.3% vs. 10.2%, p = 1.000). Nineteen pts recurred with 73.7% occurring at distant sites (ALND 76.5% vs. dSLNB 50%, p = 0.468). There was a higher recurrence rate after ALND (15.9% vs. 4.1%, p = 0.038) as well as higher rates of extracapsular LN extension (46.7% vs. 14.9%, p &lt; .001) and breast lymphovascular invasion (49% vs. 30.4%, p = 0.035). Comparing ALND to dSLNB, there was no difference in DFS (30 months vs. 37 months, p = 0.650) or OS (36.4 months vs. 36.2 months, p = 0.982). Conclusions: For pts with persistent N+ disease in the RSL node after NAC, there was no difference in DFS or OS regardless of extent of axillary surgery. ALND led to higher rates of morbidity, namely lymphedema, but did not contribute to better outcomes. Most recurrences were distant, suggesting aggressive tumor biology as the driver for poor oncologic outcomes rather than the extent of axillary surgery. In this light, the results of the Alliance 11202 are awaited as it answers the question on a randomized, multi-institutional level.

Tailored axillary surgery (TAS) in patients with clinically node-positive breast cancer in the upfront surgery setting: A prospective, single-arm, multicenter trial.

TPS628 Background: Axillary lymph node dissection (ALND), which can induce lymphedema, has been omitted in clinically node-negative(cN0) patients with positive sentinel lymph nodes (SLNs) if they meet the eligibility criteria of ACOSOG Z0011. Furthermore, the omission of ALND has been attempted through targeted axillary dissection (TAD) in patients whose cN+ status converts to ycN0 after neoadjuvant chemotherapy. However, ALND remains the standard of care in patients with cN+ who undergo upfront surgery. The aims of this trial are to establish a surgical method of tailored axillary surgery (TAS), which combines TAD and SLN biopsy among patients with cN+ who undergo upfront surgery, and to determine the appropriate criteria for a Phase III TAS trial. Methods: We have planned a single-arm Phase II trial to confirm the feasibility and assess patient eligibility for TAS. A total of 300 patients will be enrolled from 33 study sites in Japan. The eligibility criteria are as follows: 1) histologically-proven invasive breast cancer, 2) upfront surgery is planned, 3) pathologically-diagnosed metastatic lymph node (cytology or core needle biopsy), 4) 1-3 LN metastases in level I by imaging, 5) cT1-3, and 6) females aged ≥18 and ≤74 years on the enrollment date. TAS involves removing marking lymph nodes by TAD (clip, wire, or tattoo) and SLNB, and ALND up to Level II are performed after TAS. These LNs are defined as non-TAS LNs. The primary endpoint is the non-TAS LNs positive rate. Clinicopathological factors (the number of suspected metastases by imaging, the number of metastases in LNs resected by TAS, tumor size, and invasive ductal/lobular carcinoma) are analyzed to predict the non-TAS LN metastasis rate (e.g., &lt; 10%). By using these clinicopathological factors, we determine the eligibility of TAS to omit ALND safely. The secondary endpoints are TAS LNs identification rate, labeled LNs identification rate, marked lymph node resection rate, arm edema incidence rate, and QOL (FACT-B, QuickDASH). After this feasibility study, we will conduct a phase III trial that omits ALND using TAS to investigate the regional recurrence rate.

Abstract GS4-02: Oncological Outcomes Following Omission of Axillary Lymph Node Dissection in Node Positive Patients Downstaging To Node Negative with Neoadjuvant Chemotherapy: the OPBC-04/EUBREAST-06/OMA study

Abstract Background: Data on the oncologic safety of omission of axillary lymph node dissection (ALND) in node positive (N+) patients who downstage to ypN0 with neoadjuvant chemotherapy (NAC) is sparse. Additionally, there is no consensus on which axillary staging procedure should be used in this setting, sentinel lymph node biopsy (SLNB) alone or in combination with localization and retrieval of the clipped positive node, also known as targeted axillary dissection (TAD). Whether the reduction in the false negative rate observed with TAD translates into a significant reduction in the rate of axillary recurrence is unknown. We sought to evaluate oncologic outcomes after omission of ALND in a large, real-world cohort of breast cancer (BC) patients and to compare rates of axillary recurrence after SLNB with dual tracer mapping vs. TAD. Methods: Data were collected from 19 centers in the Oncoplastic Breast Consortium (OPBC) and EUBREAST networks. Patients with T1-4 biopsy-proven N1-3 BC who underwent NAC followed by axillary staging with either SLNB with dual tracer mapping or TAD and who were pathologically node negative (ypN0) were included. ypN0 was defined as the absence of any tumor or isolated tumor cells. Competing risk analysis was performed to assess the cumulative incidence rates of axillary recurrence, locoregional recurrence, and any invasive (locoregional or distant) recurrence. Two-year cumulative incidence rates were compared between TAD and SLNB using the Gray’s test. Type I error rate was set to 0.05 (α). Results: We included 785 patients (565 treated with SLNB and 220 with TAD) treated with NAC followed by surgery from 01/2014-12/2020. Median patient age was 50 years. The majority (57%) of patients had clinical T2 tumors, and 95% had N1 disease. Most (55%) were HER2+, and 21% were triple negative. Most patients (81%) received anthracycline and taxane-based chemotherapy regimens, but NAC regimens differed between patients treated with TAD and those treated with SLNB (Table 1). All patients with HER2+ tumors received anti HER2 therapy. Nodal radiotherapy was administered to 76% of patients, and was more common in patients who underwent TAD (82% TAD vs 74% SLNB, p=0.017). Breast pathologic complete response (ypT0/is) was more frequent among those patients that had TAD (80% TAD vs. 66% SLNB, p&amp;lt; 0.001). TAD localization was with wire in 46%, radioactive seed in 40%, ultrasound in 5%, tattoo in 2%, and with a combination of these techniques in 7%. The clipped node was successfully retrieved in 94% of TAD cases. The median number of lymph nodes removed was lower in the TAD group compared to the SLNB group [3 (IQR 3-5) vs 4 IQR 3-5), p&amp;lt; 0.001], as was the median number of sentinel lymph nodes [3 (IQR 2-4) vs 4 IQR 3-5), p&amp;lt; 0.001] (Table 1). The 5-year rates of any axillary recurrence, locoregional recurrence, and any invasive recurrence in the entire cohort were 1.1% (95%CI 0.39-2.4%), 3.1% (95%CI 1.6-5.3%) and 10% (95%CI 7.6-13%), respectively. The two-year cumulative incidence of axillary recurrence did not differ between patients treated with TAD compared to SLNB (0% vs 0.9%, p=0.19). Conclusion: Early axillary recurrence after omission of ALND in patients who successfully downstage from N+ to ypN0 with NAC is a rare event following both SLNB or TAD, and was not significantly lower in TAD than SLNB. Although longer follow-up is needed to confirm these findings, the main advantage of TAD seems to be a reduction in the number of lymph nodes removed. Overall, these results support omission of ALND in patients who successfully downstage to node negative disease after NAC. Table 1: Clinicopathological Features of the Study Cohort, Stratified by Axillary Staging Technique Citation Format: Giacomo Montagna, Mary Mrdutt, Astrid Botty, Andrea V. Barrio, Varadan Sevilimedu, Judy C. Boughey, Tanya L. Hoskin, Laura H. Rosenberger, E Shelley Hwang, Abigail Ingham, Bärbel Papassotiropoulos, Bich Doan Nguyen-Sträuli, Christian Kurzeder, Danilo Diaz Aybar, Denise Vorburger, Dieter Michael Matlac, Edvin Ostapenko, Fabian Riedel, Florian Fitzal, Francesco Meani, Franziska Fick, Jacqueline Sagasser, Jörg Heil, Konstantin J. Dedes, Laszlo Romics, Maggie Banys-Paluchowski, Maria Del Rosario Cueva Perez, Marcelo Chavez Diaz, Martin Heidinger, Mathias K. Fehr, Mattea Reinisch, Nadia Maggi, Nicola Rocco, Nina Ditsch, Oreste Davide Gentilini, Regis Resende Paulinelli, Sebastian Sole Zarhi, Sherko Küemmel, Simona Bruzas, Simona Di Lascio, Tamara Parissenti, Uwe Güth, Valentina Ovalle, Christoph Tausch, Monica Morrow, Thorsten Kühn, Walter P. Weber. Oncological Outcomes Following Omission of Axillary Lymph Node Dissection in Node Positive Patients Downstaging To Node Negative with Neoadjuvant Chemotherapy: the OPBC-04/EUBREAST-06/OMA study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS4-02.

Abstract OT1-06-01: Preservation of axillary lymph nodes in breast cancer patients undergoing mastectomy with 1-2 metastatic sentinel lymph nodes: The current status and future perspectives of the multicenter randomized clinical trial SINODAR-ONE

Abstract Introduction: Axillary lymph node dissection (ALND) has always been part of breast cancer (BC) treatment. However, during the past 25 years, the surgical management of the axilla has shifted towards a more conservative approach. Until now, ALND has remained the standard surgical technique when the sentinel lymph node (SLN) is macrometastatic. However, ALND may now be considered overtreatment for early-stage BC. The SINODAR-ONE trial is a prospective non-inferiority multicenter randomized study aimed at assessing the role of ALND in patients undergoing either breast-conserving surgery (BCS) or mastectomy for T1-2 BC presenting 1-2 macrometastatic SLNs. Objectives: The primary endpoint was to evaluate whether sentinel lymph node biopsy (SLNB) only was associated with clinically relevant worsening of the prognosis compared with ALND in terms of overall survival (OS). The secondary endpoint was to evaluate whether there was increased regional (lymph node recurrence) or distant recurrence in terms of recurrence-free survival (RFS) in patients with macrometastatic SLN who did not undergo ALND. Methods: Patients were randomly assigned (1:1 ratio) to either removal of ≥10 axillary level I/II non-SLNs followed by adjuvant therapy (standard arm) or no further axillary treatment (experimental arm). Results: The trial started in April 2015 and ceased in April 2020, involving 889 patients. The majority of the patients (75.2%) underwent BCS; 328 of 439 patients (74.7%) in the standard treatment arm, and 333 of 440 patients (75.7%) in the experimental treatment arm. 218 patients (24.8%) underwent mastectomy. SLN status at randomization was comparable between the two groups of treatment, with a median number of two SLNs removed and a median number of one positive SLN in both arms. The median number of non-SLNs identified at definitive histopathological evaluation was 16 (interquartile range [IQR] 12–21) in the ALND group. Overall, 193 of 439 patients (44.0%) in the standard treatment arm had additional macrometastases in the removed axillary lymph nodes. However, the median number of positive non SLNs was 0 (IQR 0–1) in the ALND group. Median follow-up was 34.0 months. There were eight deaths (ALND, 4; SNLB only, 4), with a 5-year cumulative mortality of 5.8% and 2.1% in the standard and experimental arm, respectively (p = 0.984). There were 26 recurrences (ALND 11; SNLB only, 15), with a 5-year cumulative incidence of recurrence of 6.9% and 3.3% in the standard and experimental arm, respectively (p = 0.444). Only one axillary lymph node recurrence was observed in each arm. The 5-year OS rates were 98.9% and 98.8%, in the ALND and SNLB only arm, respectively (p = 0.936). Conclusion: The 3-year survival and relapse rates of T1-2 BC patients with 1-2 macrometastatic SLNs treated with SLNB only, and adjuvant therapy, were not inferior to those of patients treated with ALND. These results do not support the use of routine ALND in patients undergoing BCS. However, given the low number of patients treated with mastectomy, there is no certainty that ALND omission can be extended also to this sub-group. In order to collect further evidence regarding the safety of the experimental treatment in patients candidates for mastectomy, the reopening of the enrollment of these patients as part of a single-arm experimental study started in June 2022. Citation Format: Damiano Gentile, Wolfgang Gatzemeier, Andrea Sagona, Erika Barbieri, Alberto Testori, Valentina Errico, Alberto Bottini, Simone Di Maria Grimaldi, Giulia Caraceni, Luca Boni, Paolo Bruzzi, Bethania Fernandes, Davide Franceschini, Ruggero Spoto, Rosalba Torrisi, Marta Scorsetti, Armando Santoro, Giuseppe Canavese, Corrado Tinterri. Preservation of axillary lymph nodes in breast cancer patients undergoing mastectomy with 1-2 metastatic sentinel lymph nodes: The current status and future perspectives of the multicenter randomized clinical trial SINODAR-ONE [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT1-06-01.

Abstract P5-01-05: A Predictive Model for Axillary Pathologic Response after Neoadjuvant Chemotherapy for Clinically Node-Positive Breast Cancer

Abstract Purpose: Neoadjuvant chemotherapy (NAC) has resulted in the eradication of axillary lymph node metastasis in approximately 40% of patients. Sentinel lymph node biopsy (SLNB) could be an alternative surgical procedure for these patients to avoid complications from axillary lymph node dissection (ALND). However, high false-negative rates of SLNB for clinically node-positive patients were reported in previous prospective trials. The aim of the present study was to evaluate clinicopathological factors and imaging characteristics by MRI and ultrasound (US) as predictors of axillary pathologic complete response (ypN0) after NAC, which enables to identify candidates for SLNB in patients with clinically node-positive disease. Patients and methods: We identified 177 patients with clinically node-positive breast cancer who received NAC from May 2009 to May 2021. All patients underwent MRI and US before and after NAC. Patients were judged to be node-positive when they have the cytologically-proven nodal disease by fine-needle aspiration (FNA) or suspicious lymph nodes by diagnostic imaging. Lymph nodes with the cortical thickness (&amp;gt;3.5mm), loss of fatty hilum, or round shape (short-axis/long-axis ratio &amp;gt; 0.5) were defined as suspicious lymph nodes. To develop a predictive model for ypN0, the association between ypN0 status and clinicopathological and imaging characteristics was assessed by multivariate logistic regression analysis. The area under the receiver operating characteristic (ROC) curve was used to evaluate discrimination by the model. The model was further evaluated in the validation cohort with 20 patients who received NAC from March 2021 to December 2021. Results: The median age was 54.0 (range: 22-79) years and the mean tumor size was 3.97 ±2.29cm. Of 177 patients, 90 (50.8%) patients had luminal, 47 (26.6%) had HER2-positive, and 40 (22.6%) had triple-negative disease. Sequential anthracycline and taxane were administered for 157 (88.7%) patients, and 45 (95.7%) patients with HER2-positive-disease received concomitant anti-HER2 agents preoperatively. Overall, 77 (43.5%) patients achieved ypN0. Independent predictors of ypN0 status were clinical stage N1 (odds ratio [OR]: 9.17 vs. cN2-3, p=0.002), absence of lymphadenopathy after NAC (OR: 8.54, p&amp;lt; 0.001), breast complete response (CR) by MRI (OR: 5.96, p&amp;lt; 0.001), HER2 positivity (OR: 3.80, p=0.008), nuclear grade (NG) 3 (OR: 2.77 vs. NG1-2, P=0.020) and hormone receptor negativity (OR: 2.52, p=0.048). In a model using these predictors, the area under the ROC curve was 0.887 (95% confidence interval: 0.839-0.935, p&amp;lt; 0.001). The sensitivity, specificity, positive predictive value and negative predictive value of the model were 80.0%, 82.8%, 77.9% and 84.5%, respectively. In the validation cohort, the sensitivity, specificity, positive predictive value and negative predictive value were 66.7%, 90.9%, 85.7% and 76.9%, respectively. Among 84 patients who were predicted ypN0 by the model, SLNB was performed in 42 (50.0%) patients, and the identification rate of SLN was 95.2% (40/42). Overall, ALND was omitted in 38 (45.2%) patients and irradiation to regional lymph nodes was performed in 23 (60.5%) out of 38 patients. After a median follow-up of 53.9 months, 5-year recurrence-free survival was comparable between patients with or without ALND (78.0% vs. 94.4%, p=0.259). Conclusions: Our predictive model based on clinicopathological factors and imaging characteristics by MRI and US could help to identify good candidates for the omission of ALND after NAC in patients with clinically node-positive breast cancer. Citation Format: Akiko Matsumoto, Saki Naruse, Yuka Isono, Yuka Maeda, Ayana Sato, Miki Yamada, Tatsuhiko Ikeda, Hiromitsu Jinno. A Predictive Model for Axillary Pathologic Response after Neoadjuvant Chemotherapy for Clinically Node-Positive Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-01-05.

Ultrasound contrast-enhanced patterns of sentinel lymph nodes: predictive value for nodal status and metastatic burden in early breast cancer

In the post-Z0011 era, sentinel lymph node (SLN) status and metastatic burden determine whether axillary management entails conservative sentinel lymph node biopsy (SLNB) or radical axillary lymph node dissection (ALND) in breast cancer patients. However, SLN status and metastatic burden cannot be evaluated preoperatively in clinical practice. This study explored the predictive value of contrast-enhanced ultrasound (CEUS) patterns of SLN to assess the nodal status and metastatic burden in early breast cancer patients. A retrospective study was conducted on 88 consecutive patients who were diagnosed with clinical T1-2N0 breast cancer between December 2020 and November 2021 at the Lanzhou University Second Hospital and scheduled for SLNB. Preoperative CEUS was performed to confirm the location and enhancement pattern of the SLN, and the conventional ultrasonic characteristics of the primary breast lesions and SLN were recorded. Intraoperative localized SLN and postoperative pathological results were used as the gold standard for comparison with preoperative ultrasound findings. CEUS successfully identified at least 1 SLN in 88 patients, with a total of 118 SLNs identified in the entire cohort. Univariate analysis showed that lesion size, blood flow grade, SLN longitudinal diameter, cortical thickness, and enhancement pattern were significant predictive features of SLN metastasis. Further multiple regression analysis indicated that the enhancement pattern of the SLN was an independent risk factor for SLN metastasis, with a sensitivity and a specificity of 84.2% (32/38) and 80.0% (40/50), respectively. Meanwhile, the SLN enhancement pattern could predict the lymph node metastasis burden (P<0.001). In patients presenting with a type I (homogeneous enhancement) or type II (heterogeneous enhancement) SLN, 91.5% (65/71) had ≤2 positive SLNs, whereas in patients with a type III (no enhancement) SLN, 70.6% (12/17) had >2 metastatic nodes. The contrast-enhanced pattern of the SLN is an independent risk factor for SLN status. Patients presenting with a type I or type II SLN enhanced pattern are unlikely to have high-burden metastases detected at their final surgical treatment and omission of ALND may be appropriate.

Omission of axillary lymph node dissection in patients with ypN+ breast cancer after neoadjuvant chemotherapy: A retrospective multicenter study (KROG 21-06)

BackgroundWe evaluated the impact of omitting axillary lymph node dissection (ALND) on oncological outcomes in breast cancer patients with residual nodal disease after neoadjuvant chemotherapy (NAC). MethodsThe medical records of patients who underwent NAC followed by surgical resection and had residual nodal disease were retrospectively reviewed. In total, 1273 patients from 12 institutions were included; all underwent postoperative radiotherapy. Axillary surgery consisted of ALND in 1103 patients (86.6%) and sentinel lymph node biopsy (SLNBx) alone in 170 (13.4%). Univariate and multivariate analyses of disease-free survival (DFS) and overall survival (OS) were performed before and after propensity score matching (PSM). ResultsThe median follow-up was 75.3 months (range, 2.5–182.7). Axillary recurrence rates were 4.8% in the ALND group (n = 53) and 4.7% in the SLNBx group (n = 8). Before PSM, univariate analysis indicated that the 5-year OS rate was inferior in the ALND group compared to the SLNBx group (86.6% vs. 93.3%, respectively; P = 0.002); multivariate analysis did not show a difference between groups (P = 0.325). After PSM, 258 and 136 patients were included in the ALND and SLNBx groups, respectively. There were no significant differences between the ALND and SLNBx groups in DFS (5-year rate, 75.8% vs. 76.9%, respectively; P = 0.406) or OS (5-year rate, 88.7% vs. 93.1%, respectively; P = 0.083). ConclusionsSLNBx alone did not compromise oncological outcomes in patients with residual nodal disease after NAC. The omission of ALND might be a possible option for axillary management in patients treated with NAC and postoperative radiotherapy.

Higher risk tumor features are not associated with higher nodal stage in patients with estrogen receptor-positive, node-positive breast cancer.

Studies support omission of axillary lymph node dissection (ALND) for patients with sentinel node-positive disease, with ALND recommended for patients who present with clinically positive nodes. Here, we evaluate patient and tumor characteristics and pathologic nodal stage of patients with estrogen receptor-positive (ER +) breast cancer who undergo ALND to determine if differences exist based on nodal presentation. Retrospective chart review from 2010 to 2019 defined three groups of patients with ER + breast cancer who underwent ALND for positive nodes: SLN + (positive node identified at SLN biopsy), cNUS (abnormal preoperative US and biopsy), and cNpalp (palpable adenopathy). Patients who received neoadjuvant chemotherapy or presented with axillary recurrence were excluded. Of 191 patients, 94 were SLN + , 40 were cNUS, and 57 were cNpalp. Patients with SLN + compared with cNpalp were younger (56 vs 64years, p < 0.01), more often pre-menopausal (41% vs 14%, p < 0.01), and White (65% vs 39%, p = 0.01) with more tumors that were low-grade (36% vs 8%, p < 0.01). Rates of PR + (p = 0.16), levels of Ki67 expression (p = 0.07) and LVI (p = 0.06) did not differ significantly among groups. Of patients with SLN + disease, 64% had pN1 disease compared to 38% of cNUS (p = 0.1) and 40% of cNpalp (p = 0.01). On univariable analysis, tumor size (p = 0.01) and histology (p = 0.04) were significantly associated with pN1 disease, with size remaining an independent predictor on multivariable analysis (p = 0.02). Historically, higher risk features have been attributed to patients with clinically positive nodes precluding omission of ALND, but when restricting evaluation to patients with ER + breast cancer, only tumor size is associated with higher nodal stage.

Variation in Deescalated Axillary Surgical Practices in Older Women with Early-Stage Breast Cancer.

Randomized controlled trials show that certain axillary surgical practices can be safely deescalated in older adults with early-stage breast cancer. Hospital volume is often equated with surgical quality, but it is unclear whether this includes performance of low-value surgeries. We sought to describe how utilization of two low-value axillary surgeries has varied by time and hospital volume. Women aged ≥ 70 years diagnosed with breast cancer from 2013 to 2016 were identified in the National Cancer Database. The outcomes of interest were sentinel lymph node biopsy (SLNB) in cT1N0 hormone receptor-positive cancer patients and axillary lymph node dissection (ALND) in cT1-2N0 patients undergoing breast-conserving surgery with ≤ 2 pathologically positive nodes. Time trends in procedure use and multivariable regression with restricted cubic splines were performed, adjusting for patient, disease, and hospital factors. Overall, 83.4% of 44,779 women eligible for omission of SLNB underwent SLNB and 20.0% of 7216 patients eligible for omission of ALND underwent ALND. SLNB rates did not change significantly over time and remained significantly different by age group (70-74 years: 93.5%; 75-79 years: 89.7%, 80-84 years: 76.7%, ≥ 85 years: 48.9%; p < 0.05). ALND rates decreased over the study period across all age groups included (22.5 to 16.9%, p < 0.001). In restricted cubic splines models, lower hospital volume was associated with higher likelihood of undergoing SLNB and ALND. ALND omission has been more widely adopted than SLNB omission in older adults, but lower hospital volume is associated with higher likelihood of both procedures. Practice-specific deimplementation strategies are needed, especially for lower-volume hospitals.

Abstract GS4-05: Preservation of axillary lymph nodes compared to complete dissection in T1-T2 breast cancer patients presenting 1-2 metastatic sentinel lymph nodes. A multicenter randomized clinical trial. Sinodar One

Abstract Introduction: Sentinel lymph node (SLN) staging is currently used to avoid complete axillary lymph node dissection (ALND) in breast cancer (BC) patients. The SLN is the only site of axillary metastasis (MTS) in ≥60% of cases. Recently, a randomized controlled trial (Z0011) comparing SLN biopsy (SLNB) alone with SLNB followed by ALND in patients with 1-2 SLNs+ demonstrated no significant statistical difference in relapse and overall survival (OS) rates among the two different groups. However, this study had some limitations: small tumor size (≤2cm in 70% of cases), frequent presence of only microMTS in SLN (40%), prevalent use of “whole breast” adjuvant radiotherapy (&amp;gt;90%). Given these considerations, the SINODAR-ONE study started in April 2015. Objectives: The aims are to assess whether ALND omission in BC patients with 1-2 SLNs+ is associated with worse survival and/or increased rate of regional/distant relapse. Thus evaluating whether SLNB is or is not inferior to ALND. Primary endpoint is OS. Secondary endpoints are disease-free survival (DFS) referring to distant MTS and loco-regional recurrence. Methods: Patients received either mastectomy or conservative surgery plus radiotherapy. They all underwent SLNB and were randomly divided into two arms of treatment: standard (SLNB plus ALND) or experimental treatment (only SLNB). According to multidisciplinary evaluation, patients could undergo additional adjuvant radiotherapy, chemo- and/or hormonal therapy, or no further therapy. Eligibility criteria: age 40-75 years; primary invasive T1-T2 tumor; axillary nodes cN0; no more than 2 macro-metastatic SLNs; no distant MTS; no neo-adjuvant therapy; no previous invasive BC. Exclusion criteria: in situ, inflammatory, contralateral BC; micro-metastatic SLNs; pregnancy or breast feeding; comorbidity impeding adjuvant therapy. All analyses were performed both on all patients according to the Intention-To-Treat principle and excluding those patients who did not receive the axillary treatment randomly assigned. Statistical analysis: OS and DFS were calculated using the Kaplan-Meier Product Limit Estimator and differences between arms were assessed with the log-rank test. Results: The enrollment of patients ended in April 2020 with a total of 889 cases (443: standard arm; 446: experimental arm). In April 2021, we conducted a preliminary analysis on 889 patients. We found the two groups homogeneous for epidemiologic characteristics (age and menopausal status), tumor characteristics (tumor size, pTNM, immunohistochemistry, histology, grading, vascular and lymphatic invasion), and adjuvant therapies. The majority of patients (77.2%) received breast conserving surgery, while 22.8% of patients underwent mastectomy. A median of 2 SLNs were removed in both arms. Overall, only 3 micro-metastatic SNLs were found (1 in the standard arm and 2 in the experimental arm). Conclusion: In sum, OS rate is 99.1% and 99.3% in the standard and experimental arm, respectively; DFS rate is 96.8% and 95.9% in the standard and experimental arm, respectively. After a median follow-up of 36 months, there has been only one axillary recurrence in the experimental arm. Additionally, we found seven distant relapses in both arms; four and three deaths in the standard and experimental arm, respectively. Citation Format: Damiano Gentile, Wolfgang Gatzemeier, Erika Barbieri, Andrea Sagona, Alberto Bottini, Valentina Errico, Alberto Testori, Marta Scorsetti, Giuseppe Canavese, Corrado Tinterri. Preservation of axillary lymph nodes compared to complete dissection in T1-T2 breast cancer patients presenting 1-2 metastatic sentinel lymph nodes. A multicenter randomized clinical trial. Sinodar One [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 GS4-05.

Abstract P1-01-07: Factors predicting a lower likelihood of residual nodal disease in clinically-node positive patients undergoing sentinel node surgery after neoadjuvant chemotherapy for breast cancer

Abstract Background: Residual nodal disease at the completion axillary lymph node dissection (ALND) has been reported in over 60% in patients with a positive sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC). This study aimed to explore whether any clinical or histopathological characteristics of patients may be associated with a lower likelihood of having non-SLN metastasis at ALND. Methods: Between January 2004 to January 2021, 459 patients with cT1-4/N1-3 underwent ALND due to a positive SLNB after NAC. Demographic, clinical and histopathological characteristics of patients were analyzed to predict the non-SLN metastasis at ALND. Sentinel lymph node ratio was defined as the ratio of the number of positive SLN to the total excised SLNs. Results: Median age was 47 (21-84). Of those, the majority of the patients had cT1-2 (67.8%) and cN1 disease (78.1%), whereas 76.5% of tumors were invasive ductal carcinoma. The frequency of non-SLN metastases according to the tumor subtypes were 59.5% in luminal A, 73.8% in HER2(-) luminal B, 60.3% in HER2(+) luminal B, 66.7% in non-luminal HER2(+), and 66.7% in triple negative breast carcinoma. Of those with removal more than 2 SLNs, having 1 positive SLN, or breast pathologic complete response, or cT1-2 disease , or a SLN ratio &amp;lt;50% or low volume metastatic disease including isolated tumor cell (ITC)/micrometastasis were statistically less likely found to have a non-SLN metastasis (p&amp;lt;0.05). Factors associated with a non-SLN involvement less than 40% were a SLN ratio &amp;lt;50% (39.2%) and low volume metastatic disease (36.4%). Multivariate logistic regression analysis revealed a decreased likelihood for non-SLN metastasis at ALND for patients with cT1-2 (OR= 0.45; 95% CI: 0.25-0.82; p=0.009), ITC and micrometastasis (OR=0.24; 95% CI: 0.09-0.65; p=0.006), and a SLN-ratio &amp;lt;50% ((OR=0.15; 95% CI: 0.08-0.26; p&amp;lt;0.001). A subgroup of patients with cT1-2/N1 having a SLN ratio &amp;lt;50% or ITC/micrometastasis were found to have 25.9% and 28.6% non-SLN positivity at ALND, respectively. Conclusions: In patients with a positive SLN after NAC, the likelihood of having residual disease at ALND was high across all tumor subtypes and clinical patient and tumor characteristics. However, the residual nodal disease rate was found to be lower than 30% in carefully selected patient subgroups with cT1-2/N1 along with ITC/micrometastasis or a SLN ratio &amp;lt;50% (Table 1) . These results suggest omission of ALND could be considered in meticulously selected patients with cT1-2 and low volume metastatic disease as long as axillary radiation and effective systemic treatment provided Table 1. Factors associated with non-SLN metastasis at ALND FactorsOR(95%CI)p-valuecT0.009*1&amp;20.45(0.25-0.82)3&amp;4Reference (1)SLN Status0.006*ITC and micrometastasis0.24(0.09-0.65)MacrometastasisReference (1)SLN-Ratio (%)&amp;lt;0.001*&amp;lt;50%Reference(1)≥50%0.15(0.08-0.26)*:p&amp;lt;0.05, Logistic regression(enter method), OR:Odds Ratio; Dependent variable:Non-SLN positivity Citation Format: Neslihan Cabioglu, Hasan Karanlık, Abdullah Igci, Mahmut Muslumanoglu, Mustafa Tukenmez, Selman Emiroglu, Enver Ozkurt, Semen Onder, Pinar Saip, Yesim Eralp, Adnan Aydiner, Ekrem Yavuz, Vahit Ozmen. Factors predicting a lower likelihood of residual nodal disease in clinically-node positive patients undergoing sentinel node surgery after neoadjuvant chemotherapy for breast cancer [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 P1-01-07.

Omission of sentinel node biopsy for breast cancer: Historical context and future perspectives on a modern controversy.

For older patients with clinically lymph node-negative breast cancer who have estrogen receptor-positive tumors and are treated with tamoxifen, randomized trials comparing axillary lymph node dissection (ALND) versus no ALND show that the omission of ALND improves patient quality of life and has no adverse effects on mortality. These results have served to justify sentinel node biopsy (SNB) omission in selected older patients with breast cancer. More recently, clinical trials were launched to assess SNB omission in younger patients, with recurrence and survival as the primary outcomes of interest. Three important considerations serve as the basis for these ongoing trials. First, it is assumed that SNB omission will improve patient quality of life, although, to date, there is no level I evidence to support this assumption. Second, axillary surgery has never been shown to reduce breast cancer mortality, but it does reduce the risk of axillary recurrences, although adjuvant systemic therapy and radiotherapy also reduce these recurrence risks. Finally, nodal status is losing importance as a guide for adjuvant systemic therapy decision making because these decisions are now increasingly predicated on tumor biomarkers and gene profiling, but it is gaining importance for adjuvant radiotherapy decision making. Because quality-of-life considerations are the primary motivation for abandoning SNB, there is a need for randomized trials comparing SNB versus no SNB/no axillary surgery, with quality of life as the primary end point (level I evidence). Moreover, suitable alternatives to guide adjuvant radiotherapy decision making will require validation before SNB omission can be justified for patients of all ages who have clinically node-negative breast cancer. LAY SUMMARY: In this review article, the authors provide a brief historical overview of the role of axillary surgery in breast cancer management and discuss additional studies and ramifications that should be considered before abandoning the sentinel node biopsy (SNB) procedure. Specifically, there is a need for level I evidence demonstrating that omission of the SNB procedure will improve patient quality of life and a need to validate suitable alternatives to SNB as a guide for adjuvant radiotherapy decision making.

Neoadjuvant endocrine therapy use in early stage breast cancer during the covid-19 pandemic.

PurposePhysician treatment preferences for early stage, estrogen positive breast cancer (ER + BC) patients were evaluated during the initial surge of the COVID-19 pandemic in the US when neoadjuvant endocrine therapy (NET) was recommended to allow safe deferral of surgery.MethodsA validated electronic survey was administered May–June, 2020 to US medical oncologists (MO), radiation oncologists (RO), and surgeons (SO) involved in clinical trials organizations. Questions on NET use included practice patterns for locoregional management following NET.Results114 Physicians from 29 states completed the survey—42 (37%) MO, 14 (12%) RO, and 58 (51%) SO. Before COVID-19, most used NET ‘rarely’ (49/107, 46%) or ‘sometimes’ (36, 33%) for ER + BC. 46% would delay surgery 2 months without NET. The preferred NET regimen was tamoxifen for premenopausal and aromatase inhibitor for postmenopausal women. 53% planned short term NET until surgery could proceed. Most recommended omitting axillary lymph node dissection (ALND) for one micrometastatic node after 1, 2, or 3 months of NET (1 month, N = 56/93, 60%; 2 months, N = 54/92, 59%; 3 months, N = 48/90, 53%). With longer duration of NET, omission of ALND decreased, regardless of years in practice, percent of practice in BC, practice type, participation in multidisciplinary tumor board, or number of regional COVID-19 cases.ConclusionMore physicians preferred NET for ER + BC during the pandemic, compared with pre-pandemic times. As the duration of NET extended, more providers favored ALND in low volume metastatic axillary disease. The Covid-19 pandemic affected practice of ER + BC; it remains to be seen how this may impact outcomes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10549-021-06153-3.

Abstract PS1-53: Does the axilla surgical management for limited sentinel lymph nodes involvement vary between total mastectomy and breast-conserving surgery

Abstract Purpose: The ACOSOG Z0011 study demonstrated that axillary lymph node dissection (ALND) can be safely omitted in patients with one to two positive sentinel lymph node (SLN) who underwent breast-conserving surgery (BCS) with planned whole-breast irradiation. This study aimed to analysis the surgical management in patients with one to two positive SLNs, and further evaluate the rates of non-sentinel lymph node (non-SLN) metastasis between patients receiving BCS or total mastectomy (TM). Methods: We performed a retrospective analysis of patients with early breast carcinoma from the Shanghai Jiao Tong University-Breast Cancer Database (SJTU-BCDB) between 2011 to 2018. The inclusion criteria were (1) cT1-2N0M0 invasive breast cancer, (2) aged ≥18 years at diagnosis, (3) received surgical treatment for the primary tumor and the axilla, (4) had one to two positive SLNs, (5) no history of previous or concurrent malignant disease, and (6) no neoadjuvant therapy. Patients were classified into the BCS and TM groups. Time trends of ALND rates were analyzed with Chi-square tests. And the rates of non-SLN metastasis between BCS and TM groups were also analyzed with Chi-square tests. Multivariable logistic regression was used to determine factors influencing the completion of ALND and non-SLN metastasis. And Kaplan-Meier estimator and log-rank tests were used to analysis the recurrence-free survival (RFS) between SLNB alone and SLNB+ALND arms. Results: Of the 891 patients enrolled, 586 (65.8%) received TM and 305 (34.2%) received BCS. Between 2011 and 2018, the completion of ALND for 1-2 positive SLN decreased from 100% to 72.7% (P &amp;lt;0.001). And the rate of ALND was significantly higher in the TM group compared with the BCS group (n = 541, 92.3% vs n = 195, 63.9%; P &amp;lt;0.001).Earlier year of diagnosis (P &amp;lt;0.001), primary mastectomy (P &amp;lt;0.001), SLN positive-total ratio &amp;gt;50% (P =0.001), and SLN macro-metastasis (P &amp;lt;0.001) were all independently associated with a higher probability of completing ALND. Among the 736 patients undergone ALND, the rates of non-SLN metastasis were significantly higher in the TM group, compared to the BCS groups (TM: n = 170, 31.4% vs BCS: n = 46, 23.6%; P =0.044). The multivariable regression analysis indicated that non-SLN metastasis was significantly associated with SLN positive-total ratio &amp;gt;50% (OR=3.43, 95%CI 2.28-5.17; P &amp;lt;0.001), Her-2 positive disease (OR=1.63, 95%CI 1.09-2.46; P =0.019), and pT2-3 disease (OR=1.46, 95%CI 1.01-2.09; P =0.042). However, surgery of the breast was not independently associated with the rate of non-SLN metastasis (P =0.090). After a median follow-up time of 31.9 months (range, 1.0-96.5 months), there were no significant difference in RFS between the SLNB alone and SLNB+ALND arms, regardless of the surgery of the breast (TM group: Log-rank P = 0.910; BCS group: Log-rank P =0.840). Conclusion: There is an increasing trend toward omitting ALND in patients with one to two positive SLNs. Compared with the patients undergone BCS, the rate of non-SLN metastasis was significantly higher in patients undergone TM. However, the omission of ALND had limited influence on disease outcome among those patients received TM. Citation Format: Weiqi Gao, Xiaosong Chen, Kunwei Shen. Does the axilla surgical management for limited sentinel lymph nodes involvement vary between total mastectomy and breast-conserving surgery [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-53.