Preoperative Axillary Ultrasound Research Articles

Abstract PO3-03-03: Prospective non-randomized study to compare accuracy of clinical examination under anesthesia, axillary ultrasound and histo-pathological evaluation for axillary nodal staging in women with clinically N0 early breast cancer

Abstract Introduction: Accurate assessment of axillary lymph nodes is crucial in the management of early breast cancer (EBC), especially in clinically node negative (cN0) axilla to avoid extensive axillary surgery. Clinical examination alone underestimates nodal disease in nearly 30% women with cN0 axilla. The current study compares, in cN0 axilla, the benefit of axillary ultrasonography (USG) and clinical axillary examination under anesthesia (EUA) to predict involvement of axillary lymph nodes. The gold standard in these patients however remains pathological evaluation after sentinel node biopsy/low axillary sampling (SNB/LAS) and a complete axillary lymph node dissection (ALND) if node positive. Methodology: Prospectively, 500 women with cN0 EBC were enrolled from Aug 2015 to April 2023 in a study approved by Institutional Ethics Committee. After informed consenting, a preoperative axillary USG was carried out in addition to standard breast imaging to determine number of axillary node(s) and its architecture. The USG assessment was labeled as suspicious or not and the result was blinded to the surgeons. A USG-guided FNAC was not performed as it would then be difficult to blind the surgeon and pathologist preoperatively. During surgery, an initial axillary EUA was performed before starting and any suspicious node was documented. This was followed by axillary staging by standard dual tracer SNB/LAS. A complete axillary dissection was done (level 1-3) if any node was positive on frozen section evaluation or final histopathology. Axillary node histopathology was the gold standard for comparison of effectiveness of clinical exam, USG, EUA, and SNB/LAS for prediction of axilla. Standard diagnostic tests such as sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were used. Results: Thirty-six patients were excluded in the final analysis (disease progression, chemotherapy first, or had a surgery elsewhere). Of the eligible 464 cN0 patients, 129 were detected to have axillary metastases (27.8%) in final histopathology. The 2 interventions namely USG axilla, EUA were compared to final axillary nodal histopathology. Axillary USG reported suspicious/indeterminate node(s) in 129 (27.8%) patients. USG had a low sensitivity of 46.5% and a low PPV of 46.5% to identify a positive node. However, the specificity and NPV both were 79.4%. Axillary USG was 70.2% accurate in predicting axillary nodal involvement. EUA also had sensitivity of 60% and low PPV of 14.8%. However, the specificity of EUA was 73.4%, NPV of 95.9%; higher than that of USG. EUA was 72.4% accurate. SNB/LAS had the sensitivity of 93.3%, specificity 79.2%, NPV 82.9%, PPV 91.6% and accuracy rate 89.2% in predicting a positive axilla. Conclusions: While the fallacy of clinical exam remains at 27.8%, both USG alone (without FNAC) and EUA failed in predicting a positive axillary node. EUA fared better at predicting a negative axilla. USG guided FNAC would perhaps improve the sensitivity of USG, however additional investigations are difficult in resource constraint and high-volume center, especially, when surgical interventions like SNB or LAS remain standard of care. Table 1 Citation Format: Vani Parmar, Zeal Sanghvi, Shalaka Joshi, Nita Nair, Palak Popat, Seema Kembhavi, Souwmyashree KN, Soujanya Mynalli, Purvi Thakkar, Garvit Chitkara, Sangeeta Desai, Tanuja Shet, Rajendra Badwe. Prospective non-randomized study to compare accuracy of clinical examination under anesthesia, axillary ultrasound and histo-pathological evaluation for axillary nodal staging in women with clinically N0 early breast cancer [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 PO3-03-03.

Axillary ultrasonography for early-stage invasive breast cancer

BackgroundAmong women with early invasive breast cancer and 1–2 positive sentinel nodes, sentinel lymph node biopsy (SLNB) is non-inferior to axillary lymph node dissection (ALND).1-3 However, preoperative axillary ultrasonography (AxUS) may not be sensitive enough to discriminate burden of nodal metastasis in these patients, potentially leading to overtreatment.4-6 This study compares axillary operation rates in patients who did and did not receive preoperative AxUS, assessing its utility and risks for overtreatment. MethodsThis is a retrospective cohort study of patients with clinical T1/T2 breast tumors who were clinically node negative and underwent an axillary operation. ResultsPatients who had preoperative AxUS received more ALND compared to patients who did not (5.6% vs. 1.4%, p ​< ​0.001). There was no significant difference in the number of additional axillary operations following SLNB (2.1% vs. 2.3%, p ​= ​0.77). ConclusionEliminating preoperative AxUS is associated with fewer invasive ALND procedures, without increased rate of axillary reoperations.

Sentinel Lymph Node Biopsy vs No Axillary Surgery in Patients With Small Breast Cancer and Negative Results on Ultrasonography of Axillary Lymph Nodes

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary node staging of patients with early breast cancer (BC), but its necessity can be questioned since surgery for examination of axillary nodes is not performed with curative intent. To determine whether the omission of axillary surgery is noninferior to SLNB in patients with small BC and a negative result on preoperative axillary lymph node ultrasonography. The SOUND (Sentinel Node vs Observation After Axillary Ultra-Sound) trial was a prospective noninferiority phase 3 randomized clinical trial conducted in Italy, Switzerland, Spain, and Chile. A total of 1463 women of any age with BC up to 2 cm and a negative preoperative axillary ultrasonography result were enrolled and randomized between February 6, 2012, and June 30, 2017. Of those, 1405 were included in the intention-to-treat analysis. Data were analyzed from October 10, 2022, to January 13, 2023. Eligible patients were randomized on a 1:1 ratio to receive SLNB (SLNB group) or no axillary surgery (no axillary surgery group). The primary end point of the study was distant disease-free survival (DDFS) at 5 years, analyzed as intention to treat. Secondary end points were the cumulative incidence of distant recurrences, the cumulative incidence of axillary recurrences, DFS, overall survival (OS), and the adjuvant treatment recommendations. Among 1405 women (median [IQR] age, 60 [52-68] years) included in the intention-to-treat analysis, 708 were randomized to the SLNB group, and 697 were randomized to the no axillary surgery group. Overall, the median (IQR) tumor size was 1.1 (0.8-1.5) cm, and 1234 patients (87.8%) had estrogen receptor-positive ERBB2 (formerly HER2 or HER2/neu), nonoverexpressing BC. In the SLNB group, 97 patients (13.7%) had positive axillary nodes. The median (IQR) follow-up for disease assessment was 5.7 (5.0-6.8) years in the SLNB group and 5.7 (5.0-6.6) years in the no axillary surgery group. Five-year distant DDFS was 97.7% in the SLNB group and 98.0% in the no axillary surgery group (log-rank P = .67; hazard ratio, 0.84; 90% CI, 0.45-1.54; noninferiority P = .02). A total of 12 (1.7%) locoregional relapses, 13 (1.8%) distant metastases, and 21 (3.0%) deaths were observed in the SLNB group, and 11 (1.6%) locoregional relapses, 14 (2.0%) distant metastases, and 18 (2.6%) deaths were observed in the no axillary surgery group. In this randomized clinical trial, omission of axillary surgery was noninferior to SLNB in patients with small BC and a negative result on ultrasonography of the axillary lymph nodes. These results suggest that patients with these features can be safely spared any axillary surgery whenever the lack of pathological information does not affect the postoperative treatment plan. ClinicalTrials.gov Identifier: NCT02167490.

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.

81 (PB-081) Poster - Efficacy of pre-operative axillary ultrasonography in excluding nodal disease – can it replace sentinel lymph node biopsy in early stage breast cancer?

81 (PB-081) Poster - Efficacy of pre-operative axillary ultrasonography in excluding nodal disease – can it replace sentinel lymph node biopsy in early stage breast cancer?

The role of pre-operative axillary ultrasound in assessment of axillary tumor burden in breast cancer patients: a systematic review and meta-analysis.

Recent studies have suggested that a significant proportion of patients with axillary nodal metastases diagnosed by pre-operative axillary ultrasound (AUS)-guided needle biopsy were over-treated with axillary lymph node dissection (ALND). The role of routine AUS and needle biopsy in early breast cancer was questioned. This review aims to determine if pre-operative AUS could predict the extent of axillary tumor burden and need of ALND. PubMed and Embase literature databases were searched systematically for abnormal AUS characteristics and axillary nodal burden. Studies were eligible if they correlated the sonographic abnormalities in AUS with the resultant axillary nodal burden in ALND according to the ACOSOG Z0011 criteria. Eleven retrospective studies and one prospective study with 1658 patients were included. Sixty-five percent of patients with one abnormal lymph node in AUS and 56% of those with two had low axillary nodal burden. Using one abnormal lymph node as the cut-off, the pooled sensitivity and specificity in prediction of axillary nodal burden were 66% (95%CI 63-69%) and 73% (95% CI 70-76%), respectively. Across the six studies that evaluated suspicious nodal characteristics, increased nodal cortical thickness may be associated with high axillary nodal burden. More than half of the patients with pre-operative positive AUS and biopsy proven axillary nodal metastases were over-treated by ALND. Quantification of suspicious nodes and extent of cortical morphological changes in AUS may help identify suitable patients for sentinel lymph node biopsy.

Preoperative axillary ultrasonography in patients with breast cancer: a prospective study to evaluate its ability to predict axillary tumor load

ObjectiveThis study aimed to determine the ability of axillary ultrasonography to predict the number of lymph nodes with metastases found in sentinel node axillary surgery or axillary lymph node resection in patients recently diagnosed with breast cancer after percutaneous biopsy. MethodsThis prospective study included patients diagnosed with invasive breast cancer by percutaneous biopsy. Axillary lymph nodes were classified at ultrasound examination as suspicious or not suspicious, and the number of suspicious nodes was compared with the number classified as suspicious in the surgical specimen. ResultsWe included 142 patients, 4 of whom had bilateral cancer; 133 of the 146 tumors were clinically classified as T1-T2 N0. The median number of suspicious lymph nodes at ultrasound was 2 (1–6), and the median number of suspicious lymph nodes in the surgical biopsy specimen was 1 (1–16); the difference was not significant (p = 0.1). The correlation between the number of positive lymph nodes on axillary ultrasound and the number of metastatic lymph nodes in the surgical specimen was 72.7% p = 0.0002 and the concordance was 79% (95%CI 62.4%–95.6%) p = 0.0001. For diagnosing high axillary tumor load (≥3 metastatic lymph nodes) versus low axillary tumor load (<3 metastatic lymph nodes), axillary ultrasound had 86.6% sensitivity, 83.3% specificity, 92% PPV, and 71.4% NPV. ConclusionOur results show that preoperative axillary ultrasound can differentiate between low and high tumor load and can be used as a tool to select the type of treatment. These results need to be confirmed in randomized multicenter studies.

Preoperative Axillary Ultrasound-guided Wire Localization and Lymphoscintigraphy for Sentinel Lymph Node Biopsy in Breast Cancer Patients

Background: Breast cancer has the highest incidence and mortality among female malignant tumors. Breast cancer with negative axillary lymph nodes has been diag- nosed mainly at an early stage. Sentinel lymph node biopsy (SLNB) is a standard screening technique for patients with early-stage breast cancer and clinically nega- tive lymph nodes. Lymphoscintigraphy (sentinel lymph node mapping) has been reg- ularly used as the standard method for SLNB. Today, ultrasound-guided wire locali- zation (USGWL) is a well-established technique with superior outcomes. Therefore, we attempted to determine whether preoperative UGWL and lymphoscintigraphy (blue dye and isotope injection) improve SLN detection and false-negative rate in breast cancer patients undergoing SLNB and identify clinical factors that may affect the diagnostic accuracy of axillary ultrasound (AUS).&#x0D; Methods: Between December 2018 and June 2019, 55 patients with clinical T1- 3N0 breast cancer eligible for an SLNB at Imam Khomeini Hospital in Tehran were included in our study. Tumor characteristics and demographic data were collect- ed by reviewing medical records and questionnaires prepared by our surgical team. The day before SLNB, all patients underwent ultrasound-guided wire localization of SLN. Lymphoscintigraphy was performed with an unfiltered 99mTc-labelled sulfur colloid peritumoral injection followed by methylene blue dye injection. The results were analyzed based on the permanent pathology report.&#x0D; Results: Among the 55 patients, 71.8% of SLNs were detected by wire localization, while 57.8% were found by methylene blue mapping and 59.6% by gamma probe detection. Compared with wire localization and isotope injection, the methylene blue dye technique had a low sensitivity (72.2%), while both wire localization and isotope injection reached 77.8%. The sensitivity, specificity, and accuracy of UGWL were 77.8%, 42.1%, and 65.4%, respectively. Otherwise, methylene blue dye and isotope injection accuracy was 47.3% and 50.1%, respectively. Furthermore, there was a significant relationship between BMI, tumor size, laterality, reactive ALN, and the accuracy of preoperative AUS. But there was no significant correlation between age, weight, height, tumor biopsy, tumor location, the time interval between methylene blue dye and isotope injection to surgery, and also the type of surgery to the accuracy of preoperative AUS.&#x0D; Conclusion: Preoperative UGWL can effectively identify SLNs compared to lym- phoscintigraphy (blue dye and isotope injection) in early breast cancer patients un- dergoing SLNB.

Can preoperative axillary ultrasound and biopsy of suspicious lymph nodes be an alternative to sentinel lymph node biopsy in clinical node negative early breast cancer?

The aim of this study was to assess the efficacy of preoperative axillary ultrasonography (AUS) and preoperative axillary fine-needle aspiration biopsy (FNAB) from suspicious lymph nodes in clinically node-negative breast cancer to compare with radiologically positive and sentinel lymph node biopsy (SLNB) positive involvement. Clinically node-negative early-stage breast cancer patients were included in the study. These patients underwent preoperative AUS examination, suspicious lymph nodes were evaluated with FNAB. AUS-FNAB results were compared with those of SLNB or axillary dissection. Of 181 patients undergoing AUS, 32 were reported to have axillary metastasis, 25 suspicious, and 124 benign nodes. The suspicious group underwent FNAB examination and metastasis was found in 9 of them. The sensitivity of AUS-FNAB was found to be 64.06%, specificity 100%, positive predictive value 100%, and negative predictive value (NPV) 83.5%. The false negativity rate (FN) of this method was 16,4%. Lymphovascular invasion and tumour size were found statistically significant factors for false negativity. It was concluded that axillary AUS-FNAB with its high NPV, low FN rate, may be a clinical alternative to SLNB for early-stage breast cancer patients.

O30: EVALUATION OF AXILLARY LYMPH NODE METASTATIC BURDEN BY PREOPERATIVE ULTRASOUND

Abstract Introduction Sentinel lymph node biopsy (SLNB) is the gold standard for determining axillary nodal status. There is growing interest in using preoperative axillary ultrasound (AUS) as a non-invasive means of assessing the axilla. However, AUS has limited sensitivity and is subject to operator dependency. This study aimed to quantify axillary nodal burden in preoperative AUS. Method This retrospective study used an institutional database of all primary invasive breast carcinomas from 2006–2019. Those with pathologically proven axillary metastatic disease were included. Patients were considered in two groups, low nodal burden/LNB(1-2LN) and high nodal burden/HNB(≥3LN) based on total positive lymph node count(SLNB+ALND). Preoperative AUS reports were assessed to determine those suspicious for axillary metastasis. Result Of the 347 patients (n=349 axillae), 77.9% had LNB and 22.1% had HNB. In patients with LNB, 228(83.8%) had a normal AUS versus 44(16.2%) suspicious AUS. In those with HNB 60(77.9%) had normal AUS findings versus 17(22.1%) suspicious findings. On multivariate analysis Nottingham Grade-3 was associated with suspicious AUS findings (p=0.02). However, receptor status, SLN macro-metastasis and extra-nodal extension were not associated with abnormal AUS. Conclusion As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. In this cohort, AUS did not reliably identify patients with axillary metastasis. These results highlight the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging. Take-home message As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. This study highlights the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging.

Breast cancer patients with a negative axillary ultrasound may have clinically significant nodal metastasis.

The non-invasive nature of the preoperative axillary ultrasound (AUS) fits the current trend of increasingly conservative axillary management. Recent publications suggest that early disease patients with clinically and radiologically negative axillae do not require sentinel lymph node biopsy (SLNB). This study aims to determine the true extent of axillary node disease in negative preoperative AUS patients. A 10-year breast cancer registry was reviewed to identify women with pathologically confirmed T1-2 invasive breast cancer and a negative preoperative AUS. Patients who received neoadjuvant chemotherapy were excluded. Combined positive lymph node count of SLNB ± ALND was used to determine total nodal burden (TNB). Axillae were classified into low nodal burden (LNB) defined as 1-2 positive nodes and high nodal burden (HNB) defined as ≥ 3 positive nodes. 762 patients with negative AUS were included. There were 46.9% and 53.0% T1 and T2 tumours, respectively. 76.9% were node negative (0 LN +), 18.9% had LNB (1-2 LN +) and 4.2% had HNB (≥ 3LN +). Specifically, HNB disease was seen in 2% of T1 tumours and 6.2 % of T2 tumours with a negative AUS. In multivariate analysis, T2 strongly associated with ≥ 3 positive ALNs (OR 2.66 CI 1.09-6.51 p = 0.03) as did lymphovascular invasion (OR 3.56 CI 1.52-8.30 p = < 0.01). This study shows that AUS in its current form cannot exclude HNB axillary metastasis to the extent of eliminating the need for surgical staging of the axilla. Thismay impact axillary local-regional recurrence and disease-free survival. We caution that a negative AUS has a rate of 4.2% of HNB. Therefore, in cases of negative AUS with a T2 tumour, we advocate continued use of SLNB.

Abstract PS1-40: Can sentinel lymph node biopsy be avoided in patients of breast cancer with normal preoperative ultrasound of axilla

Abstract Introduction: Need for any form of surgery for axillary lymph nodes in breast cancer with clinical and radiologically negative axilla is being increasingly questioned. Randomized controlled trials are underway to answer this question. This study was undertaken to evaluate the results of sentinel node lymph biopsy (SLNB) in patients with normal preoperative axillary ultrasound (AUS) after obtaining institution ethics committee approval. Materials and Methods: All patients of operable breast cancer seen in the Breast Cancer Clinic at Sultan Qaboos University Hospital, underwent routine preoperative AUS as part of staging work up. In patients with suspicious lymph nodes, fine needle aspiration cytology (FNAC) was performed. Patients with clinical and radiologically normal axilla underwent BCS/ mastectomy with SLNB (Group 1), while patients with positive lymph nodes underwent neoadjuvant chemotherapy (NACT) and repeat AUS after completion of chemotherapy. Patients who were reported to have normal AUS post NACT underwent SLNB (Group 2). Negative Predictive Value (NPV) and probability of positive SLN when AUS was normal were calculated for the entire cohort, group 1 and group 2. A comparison of NPV between two groups was performed at a 5% level of significance (MedCalc 12.7, 2013). Results: Between 2016-2018, 165 patients with normal AUS underwent SLNB. One hundred and thirteen of these patients underwent ‘upfront’ SLNB, while 52 patients had received NACT and then underwent SLNB. Mean age of patients was 49.33 years (range: 32-74 years ) and was similar in both groups. Mean number of lymph nodes obtained was 4.7 (range 2-8) in group 1 and 4.69 (range 2-6) in group 2. Mean number of positive lymph nodes was 1.69 in group 1 and 2.4 in group 2. Out of 165 patients with normal AUS, 51 patients had metastasis in SLNs. Twenty nine of 113 patients in group 1 showed metastasis in SLNs while 22 out 52 patients in group 2 showed metastasis. NPV for AUS for the whole group was 69.1% (95% CI=62.0%-76.2%), and for group 1 &amp; 2 were 74.3% (95%CI=66.2%-82.4%) and 57.6% (95% CI=44.2%-71.0%), respectively. A significant higher NPV was found in group 1 than in group 2 (χ2=3.873, p=0.049). Thus, the probability of positive SLN even when AUS was normal was 0.31 for whole group, 0.25 for group 1 and 0.42 for group 2. Conclusion: Probability of metastasis in SLN when AUS with or without FNAC is normal is more than 20%. Thus there is need for better preoperative imaging of axilla in patients of breast cancer with clinically and radiologically negative axilla before abandoning SLNB altogether. Citation Format: AlJarrah Adil, Seenu V, Badriya Al Qassabi, Hajar Nasser Alsaadi, Safa Abdullah Al-abadi, Srineil Vuthaluru, Moon-Fai Chan, Radiya Al Ajmi. Can sentinel lymph node biopsy be avoided in patients of breast cancer with normal preoperative ultrasound of axilla [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 PS1-40.

Diagnostic Accuracy of Axillary Ultrasound for Prediction of Axillary Pathologic Response after Neoadjuvant Treatment in Breast Cancer.

Background: In the era of NAT, to accurately predict pathologic response is a great challenge, which might influence surgical approach for breast and axilla. Axillary staging via imaging methods as an adjunct have long been used with various reported accuracy rates. However, the role of preoperative axillary ultrasonography (AUS) in clinical N0 patients after NAT is still controversial. The primary goal of the present study was to evaluate the precision of preoperative AUS for identifying pathologic complete response (ypCR = ypT0, ypN0) after NAT. Methods: A single-institution, retrospective review of a prospectively maintained database was analyzed to identify breast cancer patients treated with NAT. Only those patients who underwent AUS and 18F-FDG-PET/CT before and after NAT with documentation of clinical and radiological response were incorporated for outcome analysis. Results: In 253 consecutive invasive breast cancer patients axillary ypN0 disease was achieved in 67.19%. In 11.23% ynon-pCR patients AUS failed to detect residual disease presence 80% of which were ITCs and micrometastases. Macrometastasis was present in 21.73% (55/253) of the cases 98.18% (54/55) of which was determined by AUS. Overall accuracy for axillary pCR was found to be 89.32% for AUS and 76.28 % for 18-FDG-PET/CT. The false negative rate (FNR) of AUS and 18-FDG-PET/CT was 12.04% and 15.59%, respectively. The PPV of AUS was higher in Luminal-like tumors (%87.69), whereas HER-2 positive (%100) and triple-negative (93.47%) subtypes had higher NPV. Conclusions: AUS is a beneficial tool with the potential of accurate prediction of pCR in more than 80% of patients following NAT. Nevertheless, in cases of residual ITCs and micrometastasis the accuracy of US should be interrogated cautiously.

Interobserver variability between experienced radiologists in evaluating the number of abnormal lymph nodes seen on preoperative axillary ultrasound

To determine the interobserver variability of experienced radiologists in evaluating the number of suspicious lymph nodes (LNs) seen on axillary ultrasound (AUS) examination, and to evaluate the effects of clinicopathological features on the discordance. A prospective non-randomised triple-blind study was conducted from July 2016 to December 2017 at Shanghai Ruijin Hospital. Three experienced radiologists performed AUS on 462 patients (469 axillae) with invasive breast cancer independently and assessed the number of abnormal LNs during the real-time AUS examination. Interobserver agreement was determined according to the kappa statistic. The mean numbers of metastatic LNs on final histology study were 0.35, 0.98, 3.05 and 4.70 for patients with 0, 1, 2 and >2 abnormal nodes on preoperative AUS. When the cut-off (the number of abnormal LNs seen on AUS was >1) at which the maximal sum of sensitivity and specificity for diagnosis of ≥3 tumour-involved LNs was achieved was applied, the Az values ranged from 0.776 to 0.811. When the number of abnormal LNs was grouped into two-category classification (0-1 versus ≥2 abnormal LNs detected by AUS), good interobserver agreement (kappa: 0.601-0.687) was found, and disagreement between the radiologists was more frequently found in patients with T2-stage tumour and in those with one or two tumour-involved nodes. Abnormal LN count according to two-category classification (0-1 versus ≥2 abnormal LNs detected by AUS) was a feasible method with good accuracy and high repeatability to select patients with heavy nodal disease in the post-Z0011 trial era.

Preoperative Axillary Ultrasound Helps in the Identification of a Limited Nodal Burden in Breast Cancer Patients.

Since the Z0011 trial, the clinical evaluation of axillary status has been redirected to predicting nodal tumor burden rather than nodal metastases. Our study aimed to evaluate the value of clinicopathological factors and axillary ultrasound (US) for the prediction of a high nodal burden (≥3 metastatic lymph nodes) in breast cancer patients. A total of 532 consecutive patients who underwent preoperative axillary US and subsequent surgery for clinical T1-2 breast cancer with a final pathologic analysis were included. Clinical and pathologic variables were retrospectively evaluated. Univariate and multivariate statistical analyses were performed to identify the variables that were associated with a high nodal burden. Among the 532 patients, 110 (20.7%) had a high axillary nodal burden and 422 (79.3%) had a limited nodal burden. The multivariate analysis showed that suspicious axillary US findings (P < 0.001), clinical T2 stage (P = 0.011), the presence of lymphovascular invasion (P < 0.001), and estrogen receptor positivity (P < 0.001) were significantly associated with a high nodal burden. Patients with negative axillary US findings seldom had a high nodal burden, with a negative predictive value of 93.0% (294/316). Patients with suspicious axillary US findings, clinical T2 stage, lymphovascular invasion, and estrogen receptor positivity are more likely to have a high nodal burden, which may provide additional information for the treatment plan of breast cancer patients. Preoperative axillary US helps identify a limited nodal burden in breast cancer patients and has implications for axillary lymph node dissection and adjuvant treatment.

The Accuracy of Preoperative Axillary Ultrasound in the Diagnosis of Lymph Node Involvement at Motamed Cancer Institute, Iran

Background: Axillary lymph node (LN) status plays an important role in the local and systemic treatment of patients with breast cancer. Preoperative axillary ultrasound (AUS) is routinely used for the evaluation of axillary lymph nodes as a non-invasive method. Objectives: The purpose of this study was to evaluate the sensitivity and specificity of axillary ultrasound in comparison with pathology in a referral breast center. Methods: During a cross-sectional study all patients with breast cancer presenting to the imaging department between September 2015 and August 2016 were evaluated for axillary lymph node status by ultrasound. After comparing these results with the pathology of LNs, the sensitivity, specificity, and accuracy of the ultrasound in the diagnosis of axillary lymph node involvement were measured. Results: Overall 140 patients were enrolled in the study. The mean age of patients was 48.87 (± 10.46) years with an age range between 25 - 81 years. The sensitivity, specificity, and accuracy of the ultrasound were reported as 56%, 88%, and 76%, respectively. The highest sensitivity rate was related to AUS + Physical examination (PE) with 70%. The best specificity was for AUS, about 88%, and the accuracy of AUS+PE was the highest about 80%. Conclusions: The sensitivity of the AUS in the diagnosis of axillary involvement in the Motamed Cancer Institute was moderate and the specificity was good. The combination of physical examination and ultrasound could improve the sensitivity in comparison to each one alone. If both are suspicious, axillary dissection could be considered when fine needle aspiration (FNA) or core needle biopsy (CNB) of the lymph node is not available.

AB030. Assessing axillary nodal burden using preoperative axillary ultrasound

Background: Sentinel lymph node biopsy (SLNB) is the gold standard for determining axillary nodal status. There is growing interest in using preoperative axillary ultrasound (AUS) as a non-invasive means of assessing the axilla. However, AUS has limited sensitivity and is subject to operator dependency. This study aimed to quantify axillary nodal burden in false-negative preoperative AUS.

Is Preoperative Ultrasound of the Axilla Necessary in Screen-detected Breast Cancer?

Background: Axillary ultrasound (US) with fine needle aspiration biopsy (FNAB) of suspicious lymph nodes helps identify patients (pts) with axillary metastases preoperatively, avoiding a 2-step axillary procedure. However, it does not accurately differentiate between low and high axillary tumor burden. Our aim was to determine the rationale of preoperative axillary US in screen-detected breast cancer by finding out the proportion of screen-detected pts in whom axillary US changes axillary surgical approach and to evaluate the potential of overtreatment as a consequence of a positive FNAB in pts that otherwise meet the ACOSOG Z0011 eligibility criteria.

Is preoperative ultrasound of the axilla necessary in screen-detected breast cancer?

BackgroundAxillary ultrasound (US) with fine needle aspiration biopsy (FNAB) of suspicious lymph nodes helps identify patients with axillary metastases preoperatively avoiding a 2-step axillary procedure. However, it does not accurately differentiate between low and high axillary tumour burden. Our aim was to determine the rationale of preoperative axillary US in screen-detected breast cancer. MethodsWe retrospectively analysed patients, aged between 50 and 69 years, which had an invasive breast cancer diagnosed in the Slovenian National Breast Cancer Screening program between January 2012 and June 2017. Proportion of patients that proceeded directly to ALND and the proportion of patients with unnecessary ALND as a result of positive US-FNAB were calculated. ResultsAltogether 892 patients were eligible for analysis. Preoperative US of the axilla was performed in 856/892 (96%) patients, while 36/892 patients (4%) did not undergo US of the axilla. We have found out that upfront ALND due to positive US-FNAB was performed in 91/856 (10.6%) patients. 116/856 patients (13.6%) had tumours in inner quadrants and maximal mammographic tumour size ≤ 2 cm. Among them only 1/116 (0.9%) proceeded directly to ALND due to positive US-FNAB.The final pathology of those who underwent upfront ALND due to positive US-FNAB showed low axillary tumour burden not meeting the indications for ALND in 13/91 (14.3%) patients.Among patients without preoperative axillary US, only 1/36 (2.8%) met the indications for ALND. ConclusionOur results showed that performing US of the axilla is not justified in screen detected breast cancer patients.

Histopathological and Tumor Characteristics Associated with False Negative Axillary Ultrasonography Results in Breast Cancer.

As the false-negative rates of axillary ultrasonography (AUS) (21%-48%) are not optimal, the demand for axillary surgery remains even if AUS is negative. The aim of this study is to determine the histopathological and tumor characteristics associated with false-negative AUS results. Patients with normal AUS were divided into two groups as true-negative and false-negative according to the histopathology results of axillary lymph nodes. Two groups were compared in terms of age, histological grade of the primary tumor, histological size of the primary tumor, histological type, lymphovascular invasion (LVI), and ultrasonography BI-RADS classification of the primary tumor. The number of metastatic lymph nodes, size of the largest metastatic lymph node and the number of micrometastatic lymph nodes were also noted in the false-negative group. There were 152 patients with normal preoperative AUS in the study group. The false-negative AUS rate was 20.4%. The incidence of invasive lobular carcinoma (ILC) and the mean tumor size was significantly greater in the false-negative group. Micrometastasis was present in 3 patients (3/31, 9.6%), the mean of the largest metastatic lymph nodes was 12.5 mm, the mean total number of malignant lymph nodes was 1.9 in the false-negative group. In 25/31 (80.6%) of the patients, there were less than or equal to 2 metastatic lymph nodes. The presence of LVI was higher in the false-negative group. There was no significant difference between the groups in terms of the other parameters. Before stating that the axilla is normal on ultrasonography, a careful evaluation should be made in patients with a mass >2 cm in size and/ or ILC diagnosis.