Axilla In Breast Cancer Research Articles

Management of the axilla in breast cancer patients: critical review, regional modified Delphi consensus and implementation in the Tuscan breast network.

Data from recently trials have provided practice-changing recommendations in management of the axilla in early breast cancer (eBC). However, further controversies have been raised, resulting in heterogeneous diffusion of these recommendations. Our purpose was to obtain a better homogeneity. In 2021, the Tuscan Breast Network (TBN) established a consensus with the aim to update recommendations in this area. We performed a literature review on axillary management in eBC patients which led to an expert Delphi consensus aiming to explore the gray areas, build consensus and propose evidence-based suggestions for an appropriate management. Thereafter, we investigate their implementation in clinical practice. (1) DCIS patients should have SLN biopsy only in case of mastectomy or in conservative surgery if tumor is in a location that would preclude future nodal sampling or in case of a mass; (2) ALND may be omitted for 1-2 positive SLN patients undergoing BCS in T1-2 tumors with 1-2 SLN positive, eligible for whole-breast irradiation and adjuvant systemic therapies; (3) consider the option of RNI in patients with 1-3 positive lymph nodes and one or more high-risk characteristics; (4) the population identified in 2) should NOT undergo lymph node irradiation as an alternative to axillary surgery and (5) patients with clinically (pre-operatively) positive axilla, or undergoing primary systemic therapy, or outside the criteria reported in 2) must receive additional ALND and/or RT as per local policy. This consensus provided a practical tool to stimulate local and national breast surgical and radiotherapy protocols.

Reducing the Use of Frozen Section for Sentinel Node Biopsy in Breast Carcinoma: Feasibility and Outcome.

Sentinel lymph node biopsy (SLNB) is a standard practice for staging the axilla in breast cancer. Initially, intraoperative frozen section (FS) examination was used but was time-consuming and often provided false-negative results. Delayed permanent section (PS) analysis is currently performed; FS-SLNB is maintained for selected high-risk cases. The aim of this study was to evaluate the feasibility of this approach. All patients with breast cancer with clinically negative lymph nodes undergoing SLNB at our institution from 2004 to 2020 were analyzed, comparing operative time, re-operation rate and clinical outcome in terms of regional lymphatic recurrence-free and overall survival by type of SLNB (FS vs. PS). FS-SLNB comprised 100% of the procedures in 2004 and 18.2% at the end of the study period. The use of PS-SLNB instead of FS-SLNB was associated with a significantly reduced rate of axillary dissection (AD): 4.4% vs. 27.2, respectively (p<0.001). There was no significant difference in re-operation rate for AD: 3.9% vs. 6.9%, respectively (p=0.20). The use of PS-SLNB significantly reduced the operative time (mean=51 minutes) (p<0.001). After a mean follow-up of 70.9 months (range=16-180 months) there were no differences in regional lymphatic recurrence free or overall survival. The reduced use of FS-SLNB resulted in a significantly lower rate of AD, and significant operative time and costs savings, without any increase in the reoperation rate and lymphatic recurrences. Therefore, this approach is feasible, safe and beneficial, both for patients and healthcare services.

The Current Status of Ultrasonography and Fine-Needle Aspiration Citology for the Management of the Axilla in Breast Cancer

Objetive: to analyze whether ultrasonography with fine-needle aspiration cytology of an axillary suspicious node, in patients with breast cancer, could help to differentiate between patients with low involvement of the axilla (up to 2 nodes with macrometastasis) of those with high involvement of the axilla (more than 2 lymph nodes with macrometastasis). Material and methods: A total of 115 consecutive patients with breast cancer (up to 5 cm in diameter), with clinically negative axilla and pathologically positive axilla. All patients underwent preoperative axillary ultrasound and ultrasound-guided fine-needle aspiration cytology was performed in patients with suspicious nodes. In all patients with positive cytology, lymphadenectomy was performed. In all patients with negative ultrasound and cytology, sentinel lymph node biopsy was performed, and when it was positive, lymphadenectomy was performed. The number of pathological lymph nodes was evaluated after lymphadenectomy. Results: A total of 61 patients had positive axillary ultrasound and cytology. In 42 of them (69%), there were more than 2 pathological lymph nodes. There were 54 patients with negative axillary ultrasound and cytology. In 49 of them (90%), there were only 1 or 2 pathological lymph nodes. Axillary ultrasound and fine-needle aspiration cytology were able to identify 42 of the 47 patients (89%) with more than 2 pathological lymph nodes. Conclusion: ultrasound and ultrasound-guided fine-needle aspiration citology was able to identify, in a preoperative stage, those patients with high axillary involvement (more than 2 lymph nodes with macrometastasis). The latter are the patients who would benefit from lymphadenectomy of the axilla, ignoring the sentinel lymph node biopsy stage.

The Use of Machine Learning to Reduce Overtreatment of the Axilla in Breast Cancer: Retrospective Cohort Study.

Patients with early breast cancer undergoing primary surgery, who have low axillary nodal burden, can safely forego axillary node clearance (ANC). However, routine use of axillary ultrasound (AUS) leads to 43% of patients in this group having ANC unnecessarily, following a positive AUS. The intersection of machine learning with medicine can provide innovative ways to understand specific risks within large patient data sets, but this has not yet been trialed in the arena of axillary node management in breast cancer. The objective of this study was to assess if machine learning techniques could be used to improve preoperative identification of patients with low and high axillary metastatic burden. A single-center retrospective analysis was performed on patients with breast cancer who had a preoperative AUS, and the specificity and sensitivity of AUS were calculated. Standard statistical methods and machine learning methods, including artificial neural network, naive Bayes, support vector machine, and random forest, were applied to the data to see if they could improve the accuracy of preoperative AUS to better discern high and low axillary burden. The study included 459 patients; 142 (31%) had a positive AUS; among this group, 88 (62%) had 2 or fewer macrometastatic nodes at ANC. Logistic regression outperformed AUS (specificity 0.950 vs 0.809). Of all the methods, the artificial neural network had the highest accuracy (0.919). Interestingly, AUS had the highest sensitivity of all methods (0.777), underlining its utility in this setting. We demonstrated that machine learning improves identification of the important subgroup of patients with no palpable axillary disease, positive ultrasound, and more than 2 metastatically involved nodes. A negative ultrasound in patients with no palpable lymphadenopathy is highly indicative of low axillary burden, and it is unclear whether sentinel node biopsy adds value in this situation. Further studies with larger patient numbers focusing on specific breast cancer subgroups are required to refine these techniques in this setting.

268 (PB-092) Poster - Sonographic assessment of the axilla in breast cancer: changing the threshold

Background: Ultrasound assessment of the axilla remains an important diagnostic component in the pre-operative investigation of breast cancer, which helps determine the surgical management of the axilla. The threshold to biopsy an axillary node based on its cortical thickness can vary between centres, with no current nationally agreed consensus within the UK. Our centre recently changed its threshold for axillary node biopsy from a cortical thickness of 2.5 mm to 3 mm, based on recent evidence. We retrospectively analysed our own data to assess the potential impact of this change on patient management.

Surgical Management of the Axilla in Breast Cancer: Evolving but Still Necessary.

Surgical Management of the Axilla in Breast Cancer: Evolving but Still Necessary.

Are supero-lateral group of nodes affected in axilla in breast cancer? A validation study

Introduction: ALND is a standard intervention for high volume axillary disease. The arm lymphatics are indistinguishable from breast-lymphatics and are sacrificed in non-targeted dissection. Based on literature review and our experience with ICG-guided-ARM, we hypothesized that superolateral group nodes drain arm lymphatics exclusively. Preservation of the lymph nodes and lymphatics in this zone can reduce lymphedema. The axillary nodes are divided into groups in relation to three anatomical landmarks (thoracodorsal pedicle, 2nd intercostobrachial nerve and pectoralis-minor muscle).

Impact of Neo-Adjuvant Chemotherapy on the Management of Axilla in Breast Cancer and patient outcomes in a District General Hospital.

Background: Neo-adjuvant chemotherapy (NAC) has no survival advantage over adjuvant chemotherapy however it is increasingly being used as it provides in vivo tumour response and downsizing and down staging of the disease which can result in less invasive surgery in both breast and axilla. With the emerging trend of treatment de-escalation in breast cancer patients we aim to look at practice in our institution in breast cancer patient who undergo NAC.

Accuracy Of Axillary Node Status On PET CT Scan In Predicting Nodal Metastases in Patients Having Sentinel Lymph Node Biopsy

Background: Sentinel lymph node biopsy (SLNBx) has become the standard of care for management of axilla in breast cancer. Currently, prior to SLNBx, axillary assessment is recommended by axillary ultrasound with/without FNAC or biopsy. Whole body PET CT scan is carried out as a staging investigations in many patients of breast cancer and suspicious axillary findings are reported. We have analyzed our database of SLNBx to assess the performance of whole body PET CT as a predictor of sentinel node metastases.

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

Simple SummaryPET/MRI is a relatively new, hybrid imaging tool that allows practitioners to obtain both a local and systemic staging in breast cancer patients in a single exam. To date, the available evidence is not sufficient to determine the role of PET/MRI in breast cancer management. The aims of this paper are to provide an overview of the current literature on PET/MRI in breast cancer, and to illustrate two ongoing trials aimed at defining the eventual role of PET/MRI in axillary staging in two different settings: patients with early breast cancer and patients with positive axillary nodes that are candidates for primary systemic therapy. In both cases, findings from PET/MRI will be compared with the final pathology and could be helpful to better tailor axillary surgery in the future.Axillary surgery in breast cancer (BC) is no longer a therapeutic procedure but has become a purely staging procedure. The progressive improvement in imaging techniques has paved the way to the hypothesis that prognostic information on nodal status deriving from surgery could be obtained with an accurate diagnostic exam. Positron emission tomography/magnetic resonance imaging (PET/MRI) is a relatively new imaging tool and its role in breast cancer patients is still under investigation. We reviewed the available literature on PET/MRI in BC patients. This overview showed that PET/MRI yields a high diagnostic performance for the primary tumor and distant lesions of liver, brain and bone. In particular, the results of PET/MRI in staging the axilla are promising. This provided the rationale for two prospective comparative trials between axillary surgery and PET/MRI that could lead to a further de-escalation of surgical treatment of BC. • SNB vs. PET/MRI 1 trial compares PET/MRI and axillary surgery in staging the axilla of BC patients undergoing primary systemic therapy (PST). • SNB vs. PET/MRI 2 trial compares PET/MRI and sentinel node biopsy (SNB) in staging the axilla of early BC patients who are candidates for upfront surgery. Finally, these ongoing studies will help clarify the role of PET/MRI in BC and establish whether it represents a useful diagnostic tool that could guide, or ideally replace, axillary surgery in the future.

Predicting pathological axillary lymph node status with ultrasound following neoadjuvant therapy for breast cancer

PurposeHigh-performing imaging and predictive markers are warranted to minimize surgical overtreatment of the axilla in breast cancer (BC) patients receiving neoadjuvant chemotherapy (NACT). Here we have investigated whether axillary ultrasound (AUS) could identify axillary lymph node (ALN) metastasis (ALNM) pre-NACT and post-NACT for BC. The association of tumor, AUS features and mammographic density (MD) with axillary-pathological complete response (axillary-pCR) post-NACT was also assessed.MethodsThe NeoDense-study cohort (N = 202, NACT during 2014–2019), constituted a pre-NACT cohort, whereas patients whom had a cytology verified ALNM pre-NACT and an axillary dissection performed (N = 114) defined a post-NACT cohort. AUS characteristics were prospectively collected pre- and post-NACT. The diagnostic accuracy of AUS was evaluated and stratified by histological subtype and body mass index (BMI). Predictors of axillary-pCR were analyzed, including MD, using simple and multivariable logistic regression models.ResultsAUS demonstrated superior performance for prediction of ALNM pre-NACT in comparison to post-NACT, as reflected by the positive predictive value (PPV) 0.94 (95% CI 0.89–0.97) and PPV 0.76 (95% CI 0.62–0.87), respectively. We found no difference in AUS performance according to neither BMI nor histological subtype. Independent predictors of axillary-pCR were: premenopausal status, ER-negativity, HER2-overexpression, and high MD.ConclusionBaseline AUS could, to a large extent, identify ALNM; however, post-NACT, AUS was insufficient to determine remaining ALNM. Thus, our results support the surgical staging of the axilla post-NACT. Baseline tumor biomarkers and patient characteristics were predictive of axillary-pCR. Larger, multicenter studies are needed to evaluate the performance of AUS post-NACT.

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

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

Radiomics MRI for lymph node status prediction in breast cancer patients: the state of art.

To create a review of the existing literature on the radiomic approach in predicting the lymph node status of the axilla in breast cancer (BC). Two reviewers conducted the literature search on MEDLINE databases independently. Ten articles on the prediction of sentinel lymph node metastasis in breast cancer with a radiomic approach were selected. The study characteristics and results were reported. The quality of the methodology was evaluated according to the Radiomics Quality Score (RQS). All studies were retrospective in design and published between 2017 and 2020. The majority of studies used DCE-MRI sequences and two investigated only pre-contrast images. The sample size was lower than 200 patients for 7 studies. The pre-processing used software, feature extraction and selection methods and classifier development are heterogeneous and a standardization of results is not yet possible. The average RQS score was 11.1 (maximum possible value = 36). The criteria with the lowest scores were the type of study, validation, comparison with a gold standard, potential clinical utility, cost-effective analysis and open science data. The field of radiomics is a diagnostic approach of relative recent development. The results in predicting axillary lymph node status are encouraging, but there are still weaknesses in the quality of studies that may limit the reproducibility of the results.

Abstract PS1-38: Role of MR spectroscopy in evaluation of axilla in breast cancer

Abstract The role of surgery for women with breast cancer presenting with clinically negative axilla is being questioned. Trials are underway to evaluate axillary ultrasound (AUS) for non-invasive evaluation of axilla instead of sentinel node biopsy. However, AUS has a sensitivity of 50-59%. Thus, there is a need for non-invasive test to complement AUS. MR Spectoroscopy (MRS) identifies metabolites, viz. glycerophosphocholine (GPC), phosphocholine (PC), threonine (Thr), lactate (Lac), Choline (Cho) etc that are associated with presence of metastasis in axillary lymph nodes (LN) . Biochemical changes in tumor infiltrated LNs occur earlier than morphological changes and MRS can detect these chemical changes, it can be a useful investigation in evaluation of axilla. Aim: To evaluate the role of MR Spectroscopy (MRS) in identifying biochemical changes in axillary lymph nodes in breast cancer and correlate the findings with Histopathology (HP) to predict presence of metastasis.Methods: Axillary lymph nodes were obtained from 59 patients with early breast cancer with clinically negative axilla who underwent surgery. Each LN was bisected into two equal halves. One half of LN was snap frozen in liquid nitrogen (-196°C) and then stored at −80°C until perchloric acid extraction was carried out. Other half of LN was subjected to HP evaluation with standard Eosin and Hematoxylin staining . METHOD OF MR Spectroscopy: Water-soluble metabolites from the tissue samples were extracted using PCA extraction procedure (Seenu et al Magn Reson Imaging 2005 doi: 10.1016/j.mri.2005.10.004). Proton (1H) NMR spectroscopy of specimen was performed. Concentrations of GPC, PC, Thr, Lac, Cho and other metabolites were determined by comparing the integrated intensity of isolated resonances of the compounds of interest with that of the TSP signal, correcting for the number of contributing protons and with the tissue weight . Intensity ratio for metabolites, GPC, PC and Thr (GPC+PC/Thr) was also determined.Statistical Analyses: Levels of concentrations of various metabolites were compared between involved and non-involved lymph nodes using Wilcoxon rank sum test. Diagnostic indices of MRS were assessed in terms of sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratios and overall accuracy taking final histopathology as ‘gold standard’ with 95% confidence intervals.Results: Mean concentrations of GPC, PC and Thr were significantly increased in involved as compared to non-involved node (table 1). Cho and Lac were not significantly increased. A cut-off value of 0.80 for the GPC-PC/Thr ratio was chosen to obtain a maximum accuracy of 89% based on previous study. MRS accurately predicted metastasis in 21 of the 24 patients who had LN metastasis on HP. Out of 35 patients with no LN metastasis, MRS correlated accurately with HP in 30 of them. Sensitivity, specificity, PPV, NPV and overall accuracy for MRS in detecting LN metastasis were 87.5%; 88%; 80.7%; 90.9%; and 86.4% respectively. Likelihood ratio for positive test and negative test for MRS to detect LN metastasis were 6.1 and 0.14 respectively.Conclusion: MRS can accurately predict presence of metastasis in axillary lymph nodes in vitro. In vivo studies are essential to corroborate these findings. Mean concentrations of metabolites in axillary lymph nodesInvolvedNon involvedP valueGPC0.5923(SD=0.5726)0.3648(SD=0.6774)0.02PC0.7347(SD=0.9466)0.5286(SD=1.1111)0.03Cho0.6930(SD=0.6756)0.8435(SD=0.5030)0.21Thr2.9656(SD=2.2397)1.1674(SD=1.2274)0.02Lac4.5515(SD=2.3271)3.2907(SD=1.3296)0.31 Citation Format: Srineil Vuthaluru, Anurag Srivastava. Role of MR spectroscopy in evaluation of axilla in breast cancer [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 PS1-38.

Abstract PS1-45: Surgical management of the axilla in breast cancer in Latin American countries: Surgeon´s conduct

Abstract IntroductionAfter knowing the safety of the sentinel lymph node and the omission of axillary dissection inpatients with clinically negative and / or positive (1-2 lymph nodes) breast cancer withconservative surgery and the evidence from the ACOSOG Z011 randomized clinical trial andother evidence caution against proceeding with the use of axillary lymph node dissection inbreast cancer patients; a standardization of this practice is established globally, however indeveloping countries where treatments are affected by their availability, little is known aboutthe frequency of acquisition of these practices.MethodsAn online survey was carried out in different Latin American countries, which was distributedvia electronic link and QR code, with an open invitation to congresses and medical associations.The study lasted from August 16th, 2019 to April 30th, 2020. Surgeons with low, intermediateand high clinical practice in breast cancer were categorized, their type of clinical practice(private or public) and the period of clinical practice after discharge of the specialty.ResultsIn total, 260 replies were collected from surgeons from 10 different countries: Bolivia (1),Colombia (15), Ecuador (6), El Salvador (19), Guatemala (12), Nicaragua (12), Mexico (182),Paraguay (1), Peru (1) and Venezuela (11).Of these, the group that participated the most was the Surgical Oncologists (surgeons andgynecologists with a subspecialty in oncology), representing 82% of the participants, the rest ofthe participants being: Mastologists, Gynecologists and General Surgeons.The age group with the highest participation was 30-40 years old with 51.92% of the total(135), followed by the 41-50 year old group with 24% (63). 60% of the participants reported aprofessional practice of 10 years or less. In addition to referring to a mixed but mostly publicpractice in 48%, however, 56.93% of the participants reported a low practice (10 or less casesof breast cancer per month) of which between 60-100% of the occasions they offer earlysurgical treatment to their patients; responding that they always perform Sentinel Ganglion incN0 only 50% of the total, however it was mentioned that on average 85% of the occasions it isobtained between 2-3 lymph nodes number. The question was asked about completing theaxillary dissection when having 1-2 positive nodes with the scenarios of "always complete""almost always" "only in mastectomy" "only in breast conservation" and 63% answered thatalways or almost always will perform axillary dissection, 38.83% even referred the probabilityof doing it with micrometastasis in the setting of conservative surgery. In an exploratory manner, a question was added about the possibility of sentinel node after neoadjuvanttherapy, for which 52% answered that they would not perform such a procedure.ConclusionThe result of this survey shows a trend of resistance of less extensive surgical treatments in theaxilla for patients with breast cancer. Thus, reflecting that Latino populations are perhapsoverexposed to locoregional treatment; similar findings were reported by Dr. Morrow in astudy published in 2018 which showed the substantial variation in surgeon acceptance formore limited procedures. Citation Format: Nereida Esparza-Arias, Juan E Bargallo-Rocha, Sarish Del Real-Ordoñez, Yessica Pacheco-Vallejo, Sarina Navarro-Santiesteban, María A Salazar-Alvarez, Rafael E Vasquez-Cordoba, Karen A Girón-Orellana, Juan C Guerrero-Mogrovejo, Cesar E Alvarez. Surgical management of the axilla in breast cancer in Latin American countries: Surgeon´s conduct [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 PS1-45.

Abstract PS1-55: Clipping of involved axillary lymph nodes before Neo adjuvant chemotherapy may improve in identification rates &amp; staging of axilla in breast cancer

Abstract Introduction: Neo adjuvant chemotherapy is increasingly being employed in breast cancer to reduce tumour size &amp; down stage axilla. To reduce false negative rates in axillary lymph nodes after down staging with chemotherapy and to improve axillary conservation ultrasound guided clips were placed in involved axillary lymph nodes prior to commencement of NACT. The study aimed at whether preoperative lymph node clipping had any benefit in identification of lymph node after NACT.Methods: This is a single centre study of 55 patients (Mean age 53 years) with invasive breast cancer with biopsy proven involved lymph nodes (T1-3 N1) who underwent ultrasound guided axillary marker clip insertion before start of NACT. If Post chemotherapy imaging showed normal lymph nodes patients underwent SLNB with additional Lymph Nodes sampled to achieve a total of 4 lymph nodes. All sampled nodes were x rayed at the time of surgery to identify marker clip.Results: We had no procedure related complications with insertion of marker clip in any patients. The median number of nodes was 4.0. Average lymph nodes retrieved was 4.9. SLNB was identified in 47/55 patients (85.5%). Median number of sentinel nodes was 3.0 (Range 1-7) Marker was identified in 41/55 patients (74.5%) 30 (54.5%) patients had marker in sentinel node and 11 (20%) patients had marker in non-sentinel node. Histologically clip was reported in 21 (51.2%) patients. Overall pathological complete response (pCr) in axilla was seen 31/55 (56.45%). Tumours with Her2 over expression showed pCr in axilla 83% n=19/23 while triple negative tumours showed pCr in axilla 64% n=9/14. Er+ Her2- tumours showed low pCr rate 16.7% n=3/18. Completion axillary clearance was performed in 14/24 patients and 10/24 received radiotherapy to axilla.Conclusions: Clips in axillary lymph nodes are safe &amp; relatively easy to deploy without any increased morbidity. Our clip identification rate (74.5%) co relates with other well-known publications (Caudel et al 80%, Z1071-76%). Our study findings validate that clip placement improves the identification of involved lymph nodes and hence improve the accuracy of limited axillary dissection in staging axilla. Citation Format: Mohammad Bilal Elahi, Raouef Ahmed Bichoo, Kartikae Grover, Eiman Khalifa, Naila Bint Ihsan, Peter J Kneeshaw, Brendan Paul Wooler, Dorin Dumitru, Ronjabati Roychaudhury, Ayesha Rahman, Tapan Kumar Mahapatra. Clipping of involved axillary lymph nodes before Neo adjuvant chemotherapy may improve in identification rates &amp; staging of axilla in breast cancer [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 PS1-55.

Abstract PS1-63: A survey of radiation oncologists on contemporary axillary management in post-mastectomy breast cancer patients

Abstract Background: Local-regional treatment (LRT) of the axilla in breast cancer has evolved over the past several decades. The AMAROS trial demonstrated that dedicated axillary radiation therapy (aRT) can provide local control and allow for less invasive axillary surgery in select patients. Since the AMAROS data was published in 2014, there are no large-scale studies specifically analyzing how this data has impacted clinical practice. Methods: An anonymous case-based survey was sent to 4,254 Radiation Oncologists (RO) who identified as practicing physicians in the US as of May 2020. Those who identified that they do not treat breast cancer patients were excluded. The survey was conducted through the Qualtrics™ platform. Descriptive analyses were performed by the survey software and analytical statistics were performed using R (v4.0.2) utilizing ANOVA, t-tests, and chi-squared analysis. Results: A total of 293 RO completed the survey. Mean years in practice was 18.4 and most were in private practice (41.4%), followed by academic practice (28.2%) and hospital-employed (25.7%). Most (65%) reported that the type of post-mastectomy breast reconstruction does not influence their axillary treatment algorithm. Cases and responses are as follows: Case 1: A 57-year-old female with a cT1N0, ER-positive, Her2-negative breast cancer undergoes mastectomy and sentinel node biopsy (SLNB). Pathology reveals a T1 tumor with 2 of 3 sentinel lymph nodes with 2mm tumor deposits. The majority (75.4%) of RO reported they would proceed with aRT, while 8.7% preferred ALND alone, 7.1% elected for both aRT and ALND, 3.3% chose no further axillary therapy, and 4.5% needed more case information to make a decision. Treatment decision was dictated by clinical trial evidence (62.2%) and national guidelines (26.4%), but 11.2% reported their decision was largely impacted by clinical experience. The ACOSOG Z11 and AMAROS trials had the largest impact on clinical decision-making. For RO who chose to treat with aRT, AMAROS and MA-20 had the highest impact in determining radiation fields, and 88.7% would give RT to both the chest wall and axilla. Choice of axillary treatment did not differ by years in practice (p=0.54), percentage of breast patients treated (p=0.22), or by clinical practice setting (p=0.44). Case 2: A 69-year-old female with a cT1N0 ER/PR-negative, Her2-positive breast cancer undergoes mastectomy and SLNB. Pathology demonstrates a T1 tumor and 4 of 4 sentinel nodes with disease but without extra-nodal extension. Treatment results were mixed: 45.5% recommended both ALND and aRT, 38.5% chose aRT alone, and 14.3% recommend ALND alone. Most (85%) cited that their decision was based upon clinical trial evidence and/or national guidelines. MA-20 and AMAROS were cited as having the highest impact on the decision to perform aRT and determining RT fields. 96.2% of those recommending RT would treat both the chest wall and axilla. On average, RO who were in practice for a shorter period of time preferred both ALND and aRT, while those in practice for more years preferred that patients undergo either ALND or aRT alone (mean 12.9 vs 20.3 years, p&amp;lt;0.001). Treatment decision to undergo dual or single LRT was not associated with percentage of breast patients treated (p=0.41), or by practice setting (p=0.92). Conclusion: There remains significant heterogeneity in axillary treatment patterns for N+ breast cancer patients amongst RO in the US. Those patients with significant nodal burden (≥4+ nodes) were more likely to receive additional axillary therapy, and with combination LRT when treated by RO in practice for a shorter number of years. Physician education on clinical trial inclusion criteria and development of clearer axillary treatment guidelines can aid in appropriate identification of axillary de-escalation opportunities. Citation Format: Chandler S Cortina, Carmen Bergom, Morgan Ashley Craft, British Fields, Adam Currey, Amanda L Kong. A survey of radiation oncologists on contemporary axillary management in post-mastectomy breast cancer patients [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 PS1-63.

Can machine learning be used to reduce overtreatment of the axilla in breast cancer? Results from a retrospective cohort study

Background: Patients with early breast cancer undergoing primary surgery who have low axillary nodal burden can safely forego axillary node clearance (ANC). However, routine use of axillary ultrasound (AUS) leads to 43% of patients in this group having ANC unnecessarily following a positive AUS. The intersection of machine learning with medicine can provide innovative ways to understand specific risk within large patient data sets, but this has not yet been trialled in the arena of axillary node management in breast cancer.

Axillary Primary and Breast Cancer Management

Axillary primary breast cancer, also known as occult primary breast cancer, is a rare entity representing less than 1% of all breast cancers. The surgical management of the axilla in breast cancer has changed significantly, with implications for the management of axillary primary breast cancer. Much of the data is limited by era, small cohorts, or large retrospective database studies. The purpose of this review is to reinforce the diagnostic work up of occult breast cancer, review updated management strategies of the axilla and breast, and summarize changes and updates in practice management and outcomes. Pathologic confirmation of breast primary disease and MRI are critical for the diagnostic work up of axillary primary breast cancer. A recent axillary primary specific meta-analyses and several National Cancer Database studies (NCDB) have reinforced that mastectomy versus breast conservation with whole breast radiation has equivalent outcomes. Surgical axillary management is under evolution, with multiple large trials reporting the role of neoadjuvant chemotherapy to downstage the node-positive axilla and decrease the morbidity of axillary lymph node dissection by allowing accurate sentinel node biopsy. Use of neoadjuvant chemotherapy and adjuvant radiation therapy is increasingly used, although no prospective data exists specifically in occult primary breast cancer. Appropriate diagnostic work up includes MRI to identify possible primary breast lesions in all patients with metastatic axillary disease and negative exam, mammography, and ultrasound. Axillary primary breast cancer should be treated with contemporary management strategies as other anatomic stage II breast cancers. Appropriate management strategies based on recent trial data suggest the use of neoadjuvant chemotherapy to downstage the axilla and allow for less morbid axillary surgery. Outcomes are equivalent with mastectomy or whole breast radiation.

SENTINEL LYMPH NODE BIOPSY AFTER NEOADJUVANT CHEMOTHERAPY IN CLINICALLY NODE POSITIVE AXILLA OF BREAST CANCER

Background: In the modern treatment of breast cancer, the Sentinel Lymph node biopsy indication is present in many clinical circumstances, instead of classical axillary lymphadenectomy. It presents the advantage of conservative surgery, which significantly decreases the rate of postoperative complications, offering the patients a better quality of Life and reducing the costs of patients care after surgery. Sentinel Lymph node biopsy (SLNB) vs. axillary Lymph node dissection (ALND) in the current surgical treatment of early stage breast cancer.Aim of the Work: The aim of the present study is to evaluate staging the axilla with sentinel lymph node biopsy after neoadjuvant chemotherapy in previous clinically node positive axilla in breast cancer to avoid the morbidity of an ALND.Patients and Methods: This was a prospective cohort study was held in El Demerdash hospital Ain Shams University hospitals, Cairo, Egypt started with one hundred and twenty female patients with clinically node positive axilla in breast cancer. Approval of the Ethical Committee and written informed consent from all participants were obtained. Patient selection was achieved through a number of inclusion and exclusion criteria.Results: Our study showed that SLNB is acceptable in cN1/2 patients who become cN0 after neoadjuvant therapy: particularly in those with no residual disease in the breast, because SN status maintains its expected prognostic role, but also in cases with residual disease, because Axillary dissection (AD) has no influence on outcomes.Conclusion: Sentinel lymph node biopsy will replace axillary lymph node dissection (ALND) in those patients with clinically node positive axilla without compromising their oncologic outcomes. Especially, rates of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) have increased. In the neoadjuvant setting, SLN after NAC is feasible and accurate in clinically node positive patients as a continuous effort to avoid the morbidity of ALND.