Completion Axillary Lymph Node Dissection Research Articles

Residual Nodal Burden After Neoadjuvant Chemotherapy in cN1 Breast Cancer Patients with Positive Nodes at Targeted Axillary Dissection.

Targeted axillary dissection (TAD) facilitates nodal staging in cN1 breast cancer after neoadjuvant chemotherapy (NAC). Completion axillary node dissection (cALND) remains the standard of care for TAD-positive patients. This study investigated factors associated with additional positive nodes at cALND (cALND+) and the impact on the residual cancer burden (RCB). Retrospective review of cN1 breast cancer patients treated with NAC and TAD was conducted from July 2013 to June 2023. The review defined cN1 status by ultrasound (US) and biopsy. Patient, tumor, and treatment characteristics were evaluated. Multivariate analysis was performed to identify factors associated with cALND+, and RCB was calculated. Of 902 patients who underwent TAD, 554 (61.4%) were TAD-positive. 457 underwent cALND, and 124 (27%) were cALND+ (average 4.1 additional +nodes). The cALND+ patients had larger primary tumors at diagnosis (4 vs 3.5 cm; p=0.04), more than three suspicious nodes on initial US (30% vs 13%; p≤0.0001), larger residual primary tumors on pathology (median, 3 vs 2.1 cm; p=0.0004), and more positive TAD nodes (median, 2 vs 1; p≤0.0001). In the multivariate analysis, the factors associated with cALND+ were more than three suspicious nodes on initial US (odds ratio [OR], 2.9; p≤0.0001), more positive TAD nodes (OR, 1.1; p≤0.0001), larger clipped node metastasis (OR, 1.1; p≤0.0001), and larger residual tumor on pathology (OR, 1.1; p=0.006). Of 65 cALND+ patients with RCB class I or II, 29 (45%) had an increase in RCB based on cALND. Of cN1 breast cancer patients treated with NAC who are TAD-positive, approximately 25% will have additional nodal disease on cALND. In these patients, positive cALND is associated with greater disease burden, which has potential implications for RCB status and prognosis.

Prediction of High Nodal Burden in Patients With Sentinel Node–Positive Luminal ERBB2-Negative Breast Cancer

In patients with clinically node-negative (cN0) breast cancer and 1 or 2 sentinel lymph node (SLN) macrometastases, omitting completion axillary lymph node dissection (CALND) is standard. High nodal burden (≥4 axillary nodal metastases) is an indication for intensified treatment in luminal breast cancer; hence, abstaining from CALND may result in undertreatment. To develop a prediction model for high nodal burden in luminal ERBB2-negative breast cancer (all histologic types and lobular breast cancer separately) without CALND. The prospective Sentinel Node Biopsy in Breast Cancer: Omission of Axillary Clearance After Macrometastases (SENOMAC) trial randomized patients 1:1 to CALND or its omission from January 2015 to December 2021 among adult patients with cN0 T1-T3 breast cancer and 1 or 2 SLN macrometastases across 5 European countries. The cohort was randomly split into training (80%) and test (20%) sets, with equal proportions of high nodal burden. Prediction models were developed by multivariable logistic regression in the complete luminal ERBB2-negative cohort and a lobular breast cancer subgroup. Nomograms were constructed. The present diagnostic/prognostic study presents the results of a prespecified secondary analysis of the SENOMAC trial. Herein, only patients with luminal ERBB2-negative tumors assigned to CALND were selected. Data analysis for this article took place from June 2023 to April 2024. Predictors of high nodal burden. High nodal burden was defined as ≥4 axillary nodal metastases. The luminal prediction model was evaluated regarding discrimination and calibration. Of 1010 patients (median [range] age, 61 [34-90] years; 1006 [99.6%] female and 4 [0.4%] male), 138 (13.7%) had a high nodal burden and 212 (21.0%) had lobular breast cancer. The model in the training set (n = 804) included number of SLN macrometastases, presence of SLN micrometastases, SLN ratio, presence of SLN extracapsular extension, and tumor size (not included in lobular subgroup). Upon validation in the test set (n = 201), the area under the receiver operating characteristic curve (AUC) was 0.74 (95% CI, 0.62-0.85) and the calibration was satisfactory. At a sensitivity threshold of ≥80%, all but 5 low-risk patients were correctly classified corresponding to a negative predictive value of 94%. The prediction model for the lobular subgroup reached an AUC of 0.74 (95% CI, 0.66-0.83). The predictive models and nomograms may facilitate systemic treatment decisions without exposing patients to the risk of arm morbidity due to CALND. External validation is needed. ClinicalTrials.gov Identifier: NCT02240472.

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.

Nodal Response and Survival After Neoadjuvant Endocrine Therapy in Hormone Receptor-Positive Breast Cancer: 20-Year Experience from a Single Institution.

Axillary response to neoadjuvant endocrine therapy (NET) for the treatment of hormone receptor-positive breast cancer (HR+ BC) is not well-described. This study was designed to characterize nodal response after NET. Patients receiving NET followed by curative intent surgery at a comprehensive cancer center from 1998 to 2022 in a prospectively collected registry were included. Patients with distant metastasis were excluded. Primary outcome was nodal pathologic complete response (pCR). Downstaging was defined as post-NET decrease in category. We included 123 patients; the majority were cT2 (n = 59) or cT3 (n = 35), and cN0 (n = 81). Median age was 70.0 years (interquartile range 62.1-76.0). Forty-two patients (34.1%) were clinically node-positive. After NET, 73 (59.8%) underwent breast-conserving surgery. All patients underwent sentinel lymph node biopsy, and 12 (9.8%) underwent completion axillary lymph node dissection. In-breast downstaging was achieved in 51 (41.5%) patients, 1 (0.8%) had breast pCR, and 14 (11.4%) had breast upstaging. Axillary downstaging was achieved in 10 (23.8%), 6 patients (14.3%) had nodal pCR, and 14 (33.3%) had axillary upstaging. At 10-year follow-up, local recurrence was 1% and distant recurrence was 14%, while disease-free survival was 82%. After adjusting for demographic and clinical factors, age was the only characteristic associated with mortality (hazard ratio 1.07, 95% confidence interval 1.01-1.13). In HR+ BC treated with NET, long-term disease-free survival is good, although nodal pCR is uncommon for cN+ patients. Future studies are needed to elucidate optimal neoadjuvant systemic therapy and to delineate oncologically safe strategies to deescalate axillary management for residual microscopic disease.

Completion axillary lymph node dissection for the identification of pN2–3 status as an indication for adjuvant CDK4/6 inhibitor treatment: a post-hoc analysis of the randomised, phase 3 SENOMAC trial

In luminal breast cancer, adjuvant CDK4/6 inhibitors (eg, abemaciclib) improve invasive disease-free survival. In patients with T1-2, grade 1-2 tumours, and one or two sentinel lymph node metastases, completion axillary lymph node dissection (cALND) is the only prognostic tool available that can reveal four or more nodal metastases (pN2-3), which is the only indication for adjuvant abemaciclib in this setting. However, this technique can lead to substantial arm morbidity in patients. We aimed to pragmatically describe the potential benefit and harm of this strategy on the individual patient level in patients from the ongoing SENOMAC trial. In the randomised, phase 3, SENOMAC trial, patients aged 18 years or older, of any performance status, with clinically node-negative T1-T3 breast cancer and one or two sentinel node macrometastases from 67 sites in five European countries (Denmark, Germany, Greece, Italy, and Sweden) were randomly assigned (1:1), via permutated block randomisation (random block size of 2 and 4) stratified by country, to either cALND or its omission (ie, they had a sentinel lymph node biopsy only). The primary outcome is overall survival, which is yet to be reported. In this post-hoc analysis, patients from the SENOMAC per-protocol population, with luminal oestrogen-receptor positive, HER2-negative, T1-2, histological grade 1-2 breast cancer, with tumour size of 5 cm or smaller were selected to match the characteristics of cohort 1 of the monarchE trial who would only have an indication for adjuvant abemaciclib if found to have 4 or more nodal metastases. The primary study objective was to determine the number of patients who developed patient-reported severe or very severe impairment of physical arm function after cALND (as measured by the Lymphedema Functioning, Disability, and Health [Lymph-ICF] Questionnaire) 1 year after surgery to avoid one invasive disease-free survival event at 5 years with 2 years of adjuvant abemaciclib, using invasive disease-free survival event data from cohort 1 of the monarchE trial. The SENOMAC trial is registered with ClincialTrials.gov, NCT02240472, and is closed to accrual and ongoing. Between Jan 31, 2015, and Dec 31, 2021, 2766 patients were enrolled in SENOMAC and randomly assigned to cALND (n=1384) or sentinel node biopsy only (n=1382), of whom 2540 were included in the per-protocol population. 1705 (67%) of 2540 patients met this post-hoc study's eligibility criteria, of whom 802 (47%) had a cALND and 903 (53%) had a sentinel lymph node biopsy only. Median age at randomisation was 62 years (IQR 52-71), 1699 (>99%) of 1705 patients were female, and six (<1%) were male. Among 1342 patients who responded to questionnaires, after a median follow-up of 45·2 months (IQR 25·6-59·8; data cutoff Nov 17, 2023), patient-reported severe or very severe impairment of physical arm function was reported in 84 (13%) of 634 patients who had cALND versus 30 (4%) of 708 who had sentinel lymph node biopsy only (χ2 test p<0·0001). To avoid one invasive disease-free survival event at 5 years with adjuvant abemaciclib, cALND would need to be performed in 104 patients, and would result in nine patients having severe or very severe impairment of physical arm function 1 year after surgery. As a method to potentially identify an indication for abemaciclib, and subsequently avoid invasive disease-free survival events at 5 years with 2 years of adjuvant abemaciclib, cALND carries a substantial risk of severe or very severe arm morbidity and so cALND should be discouraged for this purpose. Swedish Research Council, the Swedish Cancer Society, the Nordic Cancer Union, and the Swedish Breast Cancer Association.

Risk Factors for Non-sentinel Lymph Node Metastasis in HR+/HER2- Breast Cancer With cN0.

This study aimed to identify the risk factors associated with non-sentinel lymph node (non-SLN) metastasis in case of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer with cN0 on preoperative exam, where the sentinel lymph node (SLN) is positive. We conducted a retrospective review of medical records from the Chonnam National University Hwasun Hospital, spanning from January 2013 to January 2020, focusing on patients with HR+, HER2- breast cancer. Specifically, we collected the clinical and pathological data for those patients who underwent axillary lymph node dissection (ALND) due to positive SLN. Among the 166 patients who underwent ALND after positive SLNs, median patient age was 52 years. Univariate analyses demonstrated a significant association between non-SLN metastasis and the number of positive SLNs (p=0.039), SLN positive ratio (p<0.001), and primary tumor size (p=0.018). Multivariate analysis revealed that an SLN ratio >0.55 (p=0.004, HR=3.007, 95% CI=1.427-6.335) was independently associated with non-SLN metastasis. However, neither the number of positive SLN nor primary tumor size showed associations with non-SLN metastases. In patients with HR+, HER2- breast cancer who are cN0, completion of ALND should be considered when the positive SLN ratio is ≥0.55. This approach aims to provide the opportunity for survival benefit through additional adjuvant therapy or to contribute to de-escalation of unnecessary surgery.

Omission of Completion Axillary Lymph Node Dissection for Patients with Breast Cancer Treated by Upfront Mastectomy and Sentinel Node Isolated Tumor Cells or Micrometastases.

Omission of completion axillary lymph node dissection (cALND) in patients undergoing mastectomy with sentinel node (SN) isolated tumor cells (ITC) or micrometastases is debated due to potential under-treatment, with non-sentinel node (NSN) involvement detected in 7% to 18% of patients. This study evaluated the survival impact of cALND omission in a cohort of breast cancer (BC) patients treated by mastectomy with SN ITC or micrometastases. Among 554 early BC patients (391 pN1mi, 163 ITC), the NSN involvement rate was 13.2% (49/371). With a median follow-up of 66.46 months, multivariate analysis revealed significant associations between cALND omission and overall survival (OS, HR: 2.583, p = 0.043), disease-free survival (DFS, HR: 2.538, p = 0.008), and metastasis-free survival (MFS, HR: 2.756, p = 0.014). For Her2-positive or triple-negative patients, DFS was significantly affected by cALND omission (HR: 38.451, p = 0.030). In ER-positive Her2-negative BC, DFS, OS, recurrence-free survival (RFS), and MFS were significantly associated with cALND omission (DFS HR: 2.358, p = 0.043; OS HR: 3.317; RFS HR: 2.538; MFS HR: 2.756). For 161 patients aged ≤50 years with ER-positive/Her2-negative cancer, OS and breast cancer-specific survival (BCSS) were notably impacted by cALND omission (OS HR: 103.47, p = 0.004; BCSS HR: 50.874, p = 0.035). These findings suggest a potential negative prognostic impact of cALND omission in patients with SN micrometastases or ITC. Further randomized trials are needed.

Clipping the Positive Lymph Node in Patients with Clinically Node Positive Breast Cancer Treated with Neoadjuvant Chemotherapy: Impact on Axillary Surgery in the ISPY-2 Clinical Trial

BackgroundFor patients with clinically node-positive (cN+) breast cancer undergoing neoadjuvant chemotherapy (NAC), retrieving previously clipped, biopsy-proven positive lymph nodes during sentinel lymph node biopsy [i.e., targeted axillary dissection (TAD)] may reduce false negative rates. However, the overall utilization and impact of clipping positive nodes remains uncertain.Patients and MethodsWe retrospectively analyzed cN+ ISPY-2 patients (2011–2022) undergoing axillary surgery after NAC. We evaluated trends in node clipping and associations with type of axillary surgery [sentinel lymph node (SLN) only, SLN and axillary lymph node dissection (ALND), or ALND only] and event-free survival (EFS) in patients that were cN+ on a NAC trial.ResultsAmong 801 cN+ patients, 161 (20.1%) had pre-NAC clip placement in the positive node. The proportion of patients that were cN+ undergoing clip placement increased from 2.4 to 36.2% between 2011 and 2021. Multivariable logistic regression showed nodal clipping was independently associated with higher odds of SLN-only surgery [odds ratio (OR) 4.3, 95% confidence interval (CI) 2.8–6.8, p < 0.001]. This was also true among patients with residual pathologically node-positive (pN+) disease. Completion ALND rate did not differ based on clip retrieval success. No significant differences in EFS were observed in those with or without clip placement, both with or without successful clip retrieval [hazard ratio (HR) 0.85, 95% CI 0.4–1.7, p = 0.7; HR 1.8, 95% CI 0.5–6.0, p = 0.3, respectively].ConclusionClip placement in the positive lymph node before NAC is increasingly common. The significant association between clip placement and omission of axillary dissection, even among patients with pN+ disease, suggests a paradigm shift toward TAD as a definitive surgical management strategy in patients with pN+ disease after NAC.

Targeted axillary dissection reduces residual nodal disease in clinically node- positive breast cancer after neoadjuvant chemotherapy

BackgroundAny advantage of performing targeted axillary dissection (TAD) compared to sentinel lymph node (SLN) biopsy (SLNB) is under debate in clinically node-positive (cN+) patients diagnosed with breast cancer. Our objective was to assess the feasibility of the removal of the clipped node (RCN) with TAD or without imaging-guided localisation by SLNB to reduce the residual axillary disease in completion axillary lymph node dissection (cALND) in cN+ breast cancer.MethodsA combined analysis of two prospective cohorts, including 253 patients who underwent SLNB with/without TAD and with/without ALND following NAC, was performed. Finally, 222 patients (cT1-3N1/ycN0M0) with a clipped lymph node that was radiologically visible were analyzed.ResultsOverall, the clipped node was successfully identified in 246 patients (97.2%) by imaging. Of 222 patients, the clipped lymph nodes were non-SLNs in 44 patients (19.8%). Of patients in cohort B (n=129) with TAD, the clipped node was successfully removed by preoperative image-guided localisation, or the clipped lymph node was removed as the SLN as detected on preoperative SPECT-CT. Among patients with ypSLN(+) (n=109), no significant difference was found in non-SLN positivity at cALND between patients with TAD and RCN (41.7% vs. 46.9%, p=0.581). In the subgroup with TAD with axillary lymph node dissection (ALND; n=60), however, patients with a lymph node (LN) ratio (LNR) less than 50% and one metastatic LN in the TAD specimen were found to have significantly decreased non-SLN positivity compared to others (27.6% vs. 54.8%, p=0.032, and 22.2% vs. 50%, p=0.046).ConclusionsTAD by imaging-guided localisation is feasible with excellent identification rates of the clipped node. This approach has also been found to reduce the additional non-SLN positivity rate to encourage omitting ALND in patients with a low metastatic burden undergoing TAD.

Quality assessment of radiotherapy in the prospective randomized SENOMAC trial

Background and purposeRecommendations for regional radiotherapy (RT) of sentinel lymph node (SLN)-positive breast cancer are debated. We here report a RT quality assessment of the SENOMAC trial. Materials and MethodsThe SENOMAC trial randomized clinically node-negative breast cancer patients with 1–2 SLN macrometastases to completion axillary lymph node dissection (cALND) or SLN biopsy only between 2015–2021. Adjuvant RT followed national guidelines. RT plans for patients included in Sweden and Denmark until June 2019 were collected (N = 1176) and compared to case report forms (CRF). Dose to level I (N = 270) and the humeral head (N = 321) was analyzed in detail. ResultsCRF-data and RT plans agreed in 99.3 % (breast/chest wall) and in 96.6 % of patients (regional RT). Congruence for whether level I was an intended RT target was lower (78 %). In accordance with Danish national guidelines, level I was more often an intended target in the SLN biopsy only arm (N = 334/611, 55 %,) than in the cALND arm (N = 174/565, 31 %,). When an intended target, level I received prescribed dose to 100 % (IQR 98–100 %) of the volume. However, even when not an intended target, full dose was delivered to > 80 % of level I (IQR 75–90 %). The intentional inclusion of level I in the target volume more than doubled the dose received by ≥ 50 % of the humeral head. ConclusionCongruence between CRF data and RT plans was excellent. Level I received a high dose coverage even when not intentionally included in the target. Including level I in target significantly increased dose to the humeral head.

Is a completion axillary dissection in patients with early breast cancer with a positive sentinel node necessary? An NCDB-based trial emulation of ACOSOG Z0011.

e12592 Background: The ACOSOG Z0011 Study is a practice-changing phase III clinical trial that promotes the de-escalation of axillary surgery in early breast cancer patients, which supports no completion axillary lymph node dissection (ALND) in clinically node negative patients with 1 or 2 positive sentinel lymph nodes (pSLN). Strong evidence for patients with 3 positive SLN was still lacking. We emulated the Z0011 trial using the National Cancer Database (NCDB) to validate the post-trial evidence in the real-world setting followed by a deeper investigation in the subgroups by the number of pSLN. Methods: NCDB PUF 2020 was queried for clinical T1-2 N0 M0 breast cancer patients diagnosed 2010-2017. The inclusion and exclusion criteria were the same as in the Z0011 trial except for the inclusion of 3 positive sentinel lymph nodes. Sentinel lymph node biopsy (SLNB) alone and ALND were defined using Site-Specific Factor 19. The primary endpoint, overall survival (OS), was modeled by the Cox proportional hazard model. The propensity score-based average treatment effect on the treated (ATT) weighting schema was implemented to generate pseudo samples based on this eligible study population and its subgroups as pSLN = 1, 2, and 3, where covariate balance between the two cohorts was achieved for all observed demographic and disease characteristics. Results: 25,774 patients were included in the analysis. 20311 (78.8%) patients were in the SLNB alone group, and 5463 (21.2%) patients were in the ALND group respectively. The utility rate of SLNB increased steadily over the years from 53.7% in 2010 to 91.0% in 2017. The median age was 60, which was older than that in the Z0011 trial (55). The median follow-up time was 6.78 [95% CI: 4.98-8.81] years. By multivariable analysis using the original sample, SLNB alone and the ALND group had similar survival (HR = 0.99 [95% CI: 0.90-1.09]; P = 0.83). By ATT weighting, the SLNB group had significantly improved survival (HR= 0.88 [95% CI: 0.82-0.95]; P = 0.001). The magnitude of HR is close to that in the Z0011 trial (HR= 0.87 [95% CI: 0.62-1.23]), but the statistical significance was mainly driven by a much larger sample size in this study. In the subgroup ATT weighting analysis for pSLN = 1, the SLNB group had significantly better survival compared to the ALND group (HR = 0.85 [95% CI: 0.79-0.93]; P &lt; 0.001). Survival was equivalent for subgroup patients with pSLN = 2 (HR = 1.04 [95% CI: 0.91-1.19]; P = 0.54), while in the subgroup of pSLN = 3 patients, the SLNB group had a significantly worse survival when compared to the ALND group (HR, 1.22 [95% CI, 1.04-1.45]; P = 0.02). Conclusions: This NCDB-based Trial-Emulation study validates the result of the ACOSOG Z0011 clinical trial through a post-trial and real-world setting, where we confirmed that patients with 1 or 2 pSLN are suitable for SLNB alone, but for patients with 3 pSLN, ALND may still maintain a viable option.

Evaluating the role of level 3 axillary lymph node dissection in metastatic melanoma: Can we predict involvement?

MSLT-2 and DECOG-SLT established that immediate complete axillary lymph node dissection (CLND) did not correlate with an increase in melanoma-specific survival when compared with active ultrasound observation in patients with sentinel lymph node(SLN)-positivedisease. After those trials, there was a shift towardperforming CLND only for clinically node-positive disease. With these changes, we sought to determine the role of level III axillary lymph nodes in bulky disease and how the use of neoadjuvant therapy may impact the rate of positivity in level III axillary nodes. We performed a retrospective chart review on all patients who underwent axillary CLND for cutaneous melanoma by one surgeon at an academic center from 2014 to 2022. These patients underwent CLND based on either having SLN+ disease or having clinically palpable or radiographically bulky disease. Of 95 patients included, there were 7 (7.3%) patients with level III positivity. One was SLN+ (1.0%), while 3 (3.1%) had bulky disease and neoadjuvant therapy, and 3 (3.1%) had bulky disease without neoadjuvant therapy. No preoperative factors were identified that predicted level III involvement. After performing CLND, the patients who had clinically palpable or radiographically bulky disease and neoadjuvant therapy had higher percent necrosis of nodes in levels I and II but not III.At 5 years, overall survival and recurrence-free survival were improved in those without level III involvement (58%and 64%, respectively) when compared to those with level III involvement (41% and50%), though this was not statistically significant. Further study may identify better prognostic factors for level III positivity, allowing for the possibility of dissecting only levels I and II or even replacing CLND with targeted node dissections.

Factors Associated With Additional Axillary Disease in Patients With Positive Sentinel Lymph Nodes After Neoadjuvant Chemotherapy for Breast Cancer.

Background: In previous studies, breast cancer patients with positive sentinel lymph node(s) (SLN) after neoadjuvant chemotherapy (NAC) frequently had additional nonSLN involvement. Per guidelines, residual SLN disease warrants completion axillary lymph node dissection (cALND), which has increased morbidity. Given recent improvements in NAC, we hypothesized that nonSLN positivity may be lower than previously reported for certain subgroups.Methods: We retrospectively reviewed breast cancer patients who received NAC and had positive lymph nodes on SLN biopsy or targeted axillary dissection and underwent cALND at one institution in 1/2018-8/2023. Associations between nonSLN positivity and clinicopathologic factors were assessed with Fisher's exact test and multivariable logistic regression.Results: There were 122 female patients. Median age was 48years. Initially, 15 patients (12.3%) were cN0 and 107 patients (87.7%) were cN1. Largest SLN deposit was macrometastasis in 96 patients (78.7%), micrometastasis in 23 patients (18.9%), and isolated tumor cells in 3 patients (2.5%). Overall, 53 patients (43.4%) had nonSLN involvement. NonSLN positivity was higher in patients with cN1, ER+ HER2-, ypT2-3, SLN macrometastasis, and multiple positive SLN. On multivariable analysis, cN1 and ER+ HER2- remained associated with nonSLN positivity.Discussion: Among patients with positive SLN after NAC, clinically node positive and ER+ HER2- patients were more likely to have nonSLN involvement. Our findings support guidelines to consider omitting cALND in clinically node negative patients. With improving NAC, optimal axillary sampling, and radiation, omitting cALND may be safe in some clinically node positive triple negative or HER2+ patients with low volume residual disease, but further research is needed.

Évaluation du creux axillaire en 2024 : point de vue du chirurgien et rôle du radiologue

For patients with breast cancer, de-escalation of armpit surgical treatments happened during the last twenty years to reduce the morbidity mainly induced by complete axillary lymph node dissection, with a broadening of sentinel lymph node biopsy indications and, more recently, the development of targeted lymph node excision, with no impact on patient survival. Axillary ultrasound combined with clinical examination can predict the tumour burden in the axilla. At the same time, the radiologist's role has evolved, as they must describe the number of suspicious lymph nodes, which determines surgical management. Patients having fewer than two suspicious lymph nodes are eligible for sentinel lymph node biopsy. Ultrasound-guided fine-needle aspiration or core biopsy will provide proof of lymph node involvement.

Abstract GS02-06: Recurrence-free survival following sentinel node-positive breast cancer without completion axillary lymph node dissection – first results from the international randomized SENOMAC trial

Abstract Background The omission of a completion axillary lymph node dissection (cALND) after a positive sentinel lymph node (SLN) biopsy in patients with clinically node-negative breast cancer has been demonstrated to yield survival outcomes non-inferior to routine cALND in breast-conserving surgery followed by whole-breast irradiation (ACOSOG Z0011 and IBCSG 23-01 trials), and to axillary radiotherapy (RT) regardless of breast surgery (EORTC AMAROS trial). Mainly due to the under-representation of mastectomy patients, and a limited number of observed events compromising statistical power, the international randomized SENOMAC trial was initiated in 2015. The main aim of this non-inferiority trial was to address knowledge gaps relating to individuals treated by mastectomy, those with larger tumors and those with SLN extracapsular extension. Method The SENOMAC trial (NCT 02240472) enrolled patients with cT1-3cN0 primary breast cancer and 1-2 SLN macrometastases at 67 sites in five countries between January 27, 2015, and December 31, 2021. Participants were randomized 1:1 between cALND (standard) and omission of cALND (intervention). Stratification was per country. Breast-conserving surgery and mastectomy were eligible surgical interventions. Preoperative axillary ultrasound was mandatory; patients with non-palpable suspicious axillary lymph nodes, even if proven metastatic by biopsy, were eligible. SLN extracapsular extension was allowed. Adjuvant radiotherapy was dictated by national guidelines and not by the trial protocol. Statistical sample size calculation was based on the primary outcome overall survival. Non-inferiority was defined as a 5-year overall survival not worsened by more than 2.5% when refraining from cALND after the observation of 190 all-cause deaths in a target sample size of 3000 included patients. In the present analysis, the pre-specified secondary outcome of recurrence-free survival is reported. Results Out of 2766 randomized individuals, 2539 comprised the per-protocol population: 1204 in the standard and 1335 in the intervention group. Median follow-up was 37.1 months (1.5-75.0) and median age at inclusion 61 years (range 20-94). Most tumors belonged to the luminal subtype (93.6%); tumor stage was T1 in 1358 (53.5%), T2 in 1034 (40.7%) and T3 in 146 participants (5.8%). Out of 347 participants with suspicious lymph nodes on ultrasound, 36 had confirmed non-palpable metastasis. SLN extracapsular extension was reported in 866 (34.1%). The breast was conserved in 1621 (63.8%) and a mastectomy performed in 918 (36.2%) patients. Most patients (2127, 83.8%) received radiotherapy including nodal target volumes. In 34.1% of the standard group, additional non-SLN metastases were identified on cALND. Overall, 104 recurrences were reported, 54 (4.5%) in the standard and 50 (3.7%) in the intervention group. Of these, 11 recurrences were found in the ipsilateral axilla: 5 (0.4%) and 6 (0.5%), respectively. Recurrence-free survival did not differ between groups (country-adjusted HR 0.89, 95% CI 0.65-1.20). Conclusion Despite extended inclusion criteria, there was no difference in recurrence-free survival whether cALND was omitted (intervention) or not (standard). Patients undergoing mastectomy will specifically be addressed in subgroup analyses. Long-term follow-up is crucial considering the high proportion of luminal cancers. Citation Format: Jana de Boniface, Tove Tvedskov, Bergkvist Leif, Jan Frisell, Yvette Andersson, Sara Alkner, Malin Sund, Roger Olofsson Bagge, Dan Lundstedt, Oreste Davide Gentilini, Michalis Kontos, Toralf Reimer, Birgitte Offersen, Thorsten Kühn, Lisa Rydén, Peer Christiansen. Recurrence-free survival following sentinel node-positive breast cancer without completion axillary lymph node dissection – first results from the international randomized SENOMAC 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 GS02-06.

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 PO4-20-05: An open label phase III randomized trial to evaluate the efficacy of Post-chemotherapy Axillary Conservation Surgery in breast cancer (PACS)

Abstract Background- Axillary lymph nodes (ALN) status is the most important prognostic factor in breast cancer. Traditionally, a complete axillary lymph node dissection (ALND) has been standard of care for those patients who have a positive node pre-chemotherapy. However, lately axillary conservation is paving its way in the post-chemotherapy setting as well to avoid significant morbidity of ALND. Most sentinel node biopsy studies have failed to achieve the desired false negative rate(FNR). (Boughey JC et al, JAMA. 2013 Oct; Kuehn T et al, Lancet Oncol. 2013; Boileau JF et al, J Clin Oncol. 2015 Jan).We previously reported a low FNR of low axillary sampling (LAS) in the post-chemotherapy setting. (Parmar et al, JCO-GO, 2021) We are conducting a phase III, randomised controlled trial of LAS versus complete ALND in post-chemotherapy negative (ypN0) axilla. Aims and objectives- The primary objective is to assess the non-inferiority of LAS in patients who are rendered ypN0 by pre-operative chemotherapy with disease-free survival as primary end point. The secondary objectives are comparing the morbidity of ALND (lymphedema, paraesthesia, and shoulder dysfunction) in the LAS and ALND arms, and to evaluate the impact on overall survival, local, regional, and distant recurrence free survival and quality of life. Trial design- This is a prospective, open label, randomised, phase III trial where histologically proven, non-metastatic, cT1-4,N0-2 breast cancer patients who are rendered ycN0 after pre-operative systemic chemotherapy are being accrued. Patients with prechemo N3 disease, inflammatory breast cancer, recurrent disease, pregnancy associated breast cancer are being excluded from the study. The chemotherapy regimens and surgical assessment is as per standard institutional protocols. After obtaining informed consent, patients undergo LAS during surgery and lymph nodes(LN) are sent for frozen section analysis. If any LN is found to be involved, a complete ALND is carried out. If the staging procedure is negative, then patients are randomised into 2 groups- observation v/s complete ALND. Stratification factors are T stage, N stage, Hormone receptor status, Her2 receptor status and number of chemotherapy cycles taken. Morbidity assessment is done with- Constans shoulder score, arm volumetry, paraesthesia assessment, and a QOL questionnaire- Self-reported Breast cancer Lymphedema Symptom Experience Index (BCLSEI). A baseline assessment pre-surgery is followed by 6 monthly morbidity assessments and regular oncologically relevant follow-up up to 5 years. A two-sided log-rank test with an overall sample size of 2316 with a 10% dropout rate (1158 in ALND and 1158 in LAS group) achieves 80% power at a 0.05 significance level to detect a hazard ratio of 1.16 (upper limit of non-inferiority) when the proportion surviving in the control group is 0.71. An interim analysis will be carried out at 25% events and conditional power will be calculated. If the conditional power is below 20%, then the study will be discontinued for futility. The study has been approved by Institutional Ethics Committee (CTRI/2022/07/044461) Expected Study and Results- We started accrual in February 2023 and have screened 63 and randomized 45 patients until now. Ours is a first large randomised prospective study in the post-chemotherapy axillary management setting which will help us understand the efficacy of axillary conservation surgery in patients who are node negative post neoadjuvant chemotherapy. In future, lesser morbid procedures than LAS like targeted axillary dissection can be tested in the same trial. However, LAS as a technique of axillary conservation suits resource constraints and high volume setting such as ours. Citation Format: Shalaka Joshi, Jessicka Shah, Pallavi Daphale, Rohini Hawaldar, Anuradha Daptardar, Ayushi Sahay, Tanuja Shet, Palak Popat, Tabassum Wadasadawala, Nita Nair, Vani Parmar, Bipin Bandre, Shabina Siddique, Vaibhav Vanmali, Sudeep Gupta, Rajendra Badwe. An open label phase III randomized trial to evaluate the efficacy of Post-chemotherapy Axillary Conservation Surgery in breast cancer (PACS) [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 PO4-20-05.

Abstract PS18-07: Trends in Guideline Concordant Care for Inflammatory Breast Cancer: An analysis of the National Cancer Database

Abstract Background: Inflammatory breast carcinoma (IBC) is an aggressive form of breast cancer associated with worse survival outcomes compared with other subtypes of breast cancer. Black patients with IBC have worse survival outcomes than White patients. Trimodality treatment (TMT) which includes neoadjuvant chemotherapy (NCT) followed by modified radical mastectomy without immediate reconstruction (MRM), and postmastectomy radiotherapy (PMRT), has been associated with improved survival outcomes for patients with IBC. Whether receipt of TMT varies by race, ethnicity, and insurance status and its impact on survival is largely unknown. Methods: Adult female patients with non-metastatic IBC treated from 2010-2018 were identified from the NCDB. Guideline concordant care (GCC) was defined as TMT administered in the correct sequence. In addition, clinical tumor/nodal stage, age, race, ethnicity, facility type, patient location, insurance status, and pathologic complete response (pCR) were examined for each patient. Additional quality metrics of GCC examined included time to initiation of NACT &amp;lt; 60 days (TTNC) and proper surgical care defined as complete axillary lymph node dissection (&amp;gt;6 lymph nodes removed) at the time of MRM without reconstruction. Univariate and multivariate mixed methods were performed to determine association between patient, treatment, and facility-level factors and receipt of GCC, TTNC &amp;lt; 60 days, and proper surgical care. OS was estimated using the Kaplan-Meier method, and the log-rank test was used to compare groups. Results: 7,374 women with non-metastatic IBC were included. 78% were White, 17% Black, and 2.5% Asian/Pacific Islander patients; 7.7% identified as Hispanic and 92% as non-Hispanic. The majority had private insurance (51%), 29% Medicare, 14% Medicaid, 4.9% uninsured, and 1.3% other government insurance.Only 2,418 patients (32.7%) received GCC with only 29% undergoing MRM without reconstruction.Receipt of GCC was more common among patients age &amp;gt;50 years, patients with higher clinical nodal burden and those treated from 2010-2013 (p=0.001).Receipt of GCC did not differ by race, ethnicity, insurance status, or location.92% (6,005/7,374 patients) received NAC within 60 days of diagnosis. Both Black (OR 0.58, 95% CI 0.46-0.74, p= &amp;lt; 0.001) and Asian (OR 0.52, 95% CI 0.30-0.90, p= &amp;lt; 0.001) patients with IBC were less likely to have TTNC &amp;lt; 60 days when compared to White patients. Non-Hispanic patients (OR 2.24, 95% CI 1.65-3.03, p= &amp;lt; 0.001) and those with private insurance (OR 1.82, 95% CI 1.23-2.68, p= &amp;lt; 0.001) were more likely to have TTNC within 60 days of diagnosis. Patients with lower clinical nodal burden(cN0) were less likely to undergo proper surgery compared to patients with higher nodal burden(cN1-3) (p &amp;lt; 0.001). In addition, patients treated in a more contemporary cohort (2014-2018) were less likely to undergo proper surgery compared to patients treated earlier (2010-2013) (OR 0.82, 95% CI 0.73-0.92, p&amp;lt; 0.001).Among IBC patients receiving GCC, Black patients had significantly worse overall survival compared to White patients (p &amp;lt; 0.001) Conclusions: The majority of patients with IBC do not receive GCC and GCC has decreased since 2014 with fewer patients undergoing appropriate surgical treatment. The very low level of GCC indicates a need for multidisciplinary education, while improvement in TTNC may improve outcomes among racial/ethnic minorities. Citation Format: Brian Diskin, Audree Tadros, Varadan Sevilimedu, Amy Xu, Perri Vingan, Jonas Nelson, Yoshiko Iwai, Monica Morrow, Oluwadamilola (Lola) Fayanju. Trends in Guideline Concordant Care for Inflammatory Breast Cancer: An analysis of the National Cancer Database [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 PS18-07.

Abstract PO5-02-07: Multifocal breast cancer: tumor biology and prognostic importance

Abstract &amp;gt;Multifocal breast cancer: tumor biology and prognostic importance Background The incidence of multifocal breast cancer (MBC) varies widely in the literature and recent reports indicate that the incidence of MBC is increasing. Several studies have shown similar tumor biology in the different foci of multifocal tumors, and it has been suggested that multifocal tumors may in fact be intramammary metastases and thus be a sign of a more aggressive cancer type than unifocal tumors. Knowledge regarding outcome and optimal treatment of MBC compared to unifocal breast cancer (UBC) is still limited. The aim of the present study was to explore if multifocal breast cancers have less favorable characteristics and prognosis compared to unifocal breast cancers. Method Patient and tumor characteristics were obtained from Breast Cancer database Sweden (BcBaSe3) including women with invasive breast cancer 2008-2019 who had undergone primary surgery. Women with distant metastases at time of diagnosis, women receiving neoadjuvant systemic therapy, and men were excluded. Overall- and breast cancer specific survival were calculated with Kaplan-Meier and Cox-regression analyses. Results A total of 71607 women met our inclusion criteria, 11961 (16.7%) with MBC and 59512 (83.3%) with UBC. Among women with MBC, 64.1% underwent mastectomy compared to 32.4% of women with UBC and 40.1% with MBC underwent complete axillary lymph node dissection compared to 23.5% of the women with UBC. MBC was associated with higher T-stage (T2 31.9% vs. 25.8% and T3 4.6% vs. 2.6%. p&amp;lt; 0.001) and higher N-stage (N+ 13.7% vs. 8.4%, P&amp;lt; 0.001), compared to UBC. MBC were more often of lobular type (18.8% vs. 12.4%, P&amp;lt; 0.001), of higher grade (grade 3 29.3% vs. 27.3%, p&amp;lt; 0.001), with positive hormone receptor status (88.4% vs. 86.7%, p&amp;lt; 0.001), and Her2 positivity (13.3% vs. 10.9%, p&amp;lt; 0.001). Adjuvant systemic treatment was more frequently administered to women with MBC, adjuvant chemotherapy (45.3% vs. 33.3%, p&amp;lt; 0.001) and endocrine treatment (82.9% vs. 75.3%, p&amp;lt; 0.001). Breast cancer specific 10- year survival was 86.4% and 88.5% for MBC and UBC respectively, hazard ratio for breast cancer death 1.19 (95 % confidence interval, 1.11- 1.28). Overall survival did not differ between the two groups (10-year survival 76.0%, p=0.35) Conclusion MBC appears to have a more aggressive tumor biology than UBC, with the exception of hormone receptor status and MBC is associated with decreased breast cancer specific survival. Further analysis of possible interactions with different treatment methods will be conducted. Citation Format: Emma Söderberg, Malin Sund, Fredrik Wärnberg, Hans Garmo, Anna-Karin Wennstig, Lars Holmberg, Greger Nilsson, Charlotta Wadsten. Multifocal breast cancer: tumor biology and prognostic importance [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 PO5-02-07.

Abstract PO3-23-01: Triple-tracer Technique for Sentinel Lymph Node Biopsy of Breast Cancer after neoadjuvant Chemotherapy using Blue-dye, Radioisotope combined with Real-time Indocyanine green(ICG) Fluorescence Imaging Procrdures

Abstract Background: For post-neoadjuvant chemotherapy (NAC) patients (pts) with BC, sentinel lymph node biopsy (SNB) was recommended using the dual-tracer mapping technique (radioisotope plus blue dye) or placing a biopsy clip into the positive node at diagnosis and identifying it at the time of surgery due to SN identification rates (IR) were lower and false negative rates (FNR) were greater for pts with local advanced breast cancer (BC) than those of pts with early stage BC in the absence of NAC. Our previous clinical trial has indicated that the real-time ICG fluorescence (RT-ICG) imaging technique could improve the diagnostic sensitivity and detection accuracy for SNB. Methods: Between April 2019 and May 2022, post-NAC SNB were successfully identified in 45 of 52 patients with stage ⅡA to ⅢB (T1-T3, N0-2, M0) who had histologically confirmed breast cancer selected to receive NAC and the standard surgeries were performed after finishing NAC. The SNs was detected by conventional procedures of blue-dye (Indigo carmine) plus 99mTc radioisotope (dual-tracer) and combined with concurrent RT-ICG technique. Clinical node positive (cN+) was diagnosed by the radiologists using axillary ultrasound, MRI and/or CT scan or assessed by fine needle aspiration cytology (FNAC). The positivity of each single SN by each single tracer (blue dye, ICG, or isotope alone) was counted and identified, respectively. All patients are required to undergo SNB followed by completion axillary lymph node dissection (CND). Then the IR and FNR of each single tracer and their summation (triple tracer) were calculated by comparing the results of the SNB and the histopathology of the resection specimens of CND. Results: Among 45 post-NAC pts, the IR and FNR of each single procedure for SNB was 45.7% and 55.6% when used Indigo Carmine blue, 70.3% and 11.1% when used RI, 82.6% and 0 when used ICG fluorescence, respectively. In contrast, the total calculation of triple tracer showed that IR reached to 100% and FNR was 0, respectively. The IR of triple tracer were 83.9% and 100% for ypN0 and ypN(+) pts after NAC, both FNR were 0%. Conclusion: Our results suggested that the triple tracer technique combining blue dye, ICG, and isotope is effective method for detection of SNs in post-neoadjuvant cN+ BC pts. The IR and FNR of SNB might be improved by this multiple tracer mapping technique, particularly for pts with ypN(+) after NAC. It is considered that the multi-tracer can complement each other for what was not able to be traced and detected by the single tracer with one mapping material, and that result in totally the improvement of identification rate of SNB. Citation Format: Hidetaka Watanabe, Yuko Takao, Yuriko Katagiri, Rie Sugihara, Uhi Toh. Triple-tracer Technique for Sentinel Lymph Node Biopsy of Breast Cancer after neoadjuvant Chemotherapy using Blue-dye, Radioisotope combined with Real-time Indocyanine green(ICG) Fluorescence Imaging Procrdures [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 PO3-23-01.