Axillary Ultrasound Identifies Residual Nodal Disease After Chemotherapy: Results From the American College of Surgeons Oncology Group Z1071 Trial (Alliance)

Factors Associated with Nodal Positivity Following Neoadjuvant Systemic Therapy in Breast Cancer Patients Who are Initially Node-Negative on MRI

BACKGROUND

The objective of this study is to determine the rate of positive axillary lymph nodes on surgical specimens (ypN+) following neoadjuvant systemic therapy (NST) in patients who were classified as node negative (cN0) on diagnostic dynamic contrast-enhanced MRI and to identify clinicopathological factors that predict ypN+ status.

PATIENTS AND METHODS

This retrospective study included consecutive cases of newly diagnosed invasive breast cancer patients who had breast MRI for locoregional evaluation prior to NST at our institution between 1 February 2013 and 1 February 2018. Clinically node-positive or recurrent breast cancers were excluded. Clinicopathologic features, molecular subtype data, pre- and post-NST imaging results, and definitive surgery results were recorded. Patient and tumor histopathologic characteristics' association with cN0 status was assessed with chi-squared, Fisher's exact, and Mann-Whitney U tests. We developed a model to predict axillary metastasis using tenfold cross-validation with least absolute shrinkage and selection operation for variable selection, reporting mean area under the curve and 95% confidence intervals (CI).

RESULTS

Of 971 patients with breast cancer who underwent magnetic resonance imaging (MRI), 194 (20.5%) met the inclusion criteria. The mean age was 53 years (SD ± 11.5). All patients underwent axillary surgical staging after NST (174 [89.7%] sentinel lymph node biopsy alone, 2 [1.0%] axillary lymph node dissection alone, and 18 [9.3%] both). Residual nodal disease (ypN+) was identified in 27 patients (13.9%: ypN1 in 24 [12.4%], ypN2-3 in 3 [1.6%], median, 1 [1-14]). Patients with triple negative subtype had a lower ypN+ rate (4.8%) compared with the human epidermal growth factor 2 (HER2)-positive (11.8%) and hormone receptor-positive (25.0%) subtypes (p < 0.01). All patients with pathologic complete response in the primary tumor were ypN0. Our model showed modest performance for predicting ypN+ status (AUC: 0.62, 95% CI 0.50-0.75).

CONCLUSIONS

In our cohort, breast cancer patients who were assessed as cN0 by breast MRI prior to receiving NST had a ypN+ rate of 13.9%, with a median of a single metastatic node.

The role and potential of digital breast tomosynthesis in neoadjuvant systemic therapy evaluation for optimising breast cancer management: a pictorial essay

Neoadjuvant therapy (NT) has become the gold standard for treating locally advanced breast cancer (BC). The assessment of pathological response (pR) post-NT plays a crucial role in predicting long-term survival, with contrast-enhanced MRI currently recognised as the preferred imaging modality for its evaluation. Traditional imaging techniques, such as digital mammography (DM) and ultrasonography (US), encounter difficulties in post-NT assessments due to breast density, lesion changes, fibrosis, and molecular patterns. Digital breast tomosynthesis (DBT) offers solutions to prevalent challenges in DM, such as tissue overlap, and facilitates a comprehensive assessment of lesion morphology, dimensions, and margins. Studies suggest that DBT correlates more accurately with pathology than DM and US, showcasing its potential advantages. This pictorial essay demonstrates the potential of DBT as a complementary tool to DM for assessing pR after NT, including instances of true- and false-positive assessments correlated with histopathological findings. In conclusion, DBT emerges as a valuable adjunct to DM, effectively addressing its limitations in post-NT assessment. The technology's potential to diminish tissue overlap, improve discrimination, and provide multi-dimensional perspectives demonstrates promising results, indicating its utility in scenarios where MRI is contraindicated or inaccessible.

A Multicenter Cohort Study on Ultrasound-based Deep Learning Nomogram for Predicting Post-Neoadjuvant Chemotherapy Axillary Lymph Node Status in Breast Cancer Patients

RATIONALE AND OBJECTIVES

The aim of this study was to evaluate the capability of an ultrasound (US)-based deep learning (DL) nomogram for predicting axillary lymph node (ALN) status after neoadjuvant chemotherapy (NAC) in breast cancer patients and its potential to assist radiologists in diagnosis.

METHODS

Two medical centers retrospectively recruited 535 node-positive breast cancer patients who had undergone NAC. Center 1 included 288 patients in the training cohort and 123 patients in the internal validation cohort, while center 2 enrolled 124 patients for the external validation cohort. Five DL models (ResNet 34, ResNet 50, VGG19, GoogLeNet, and DenseNet 121) were trained on pre- and post-NAC US images, and the best model was chosen. A US-based DL nomogram was constructed using DL predictive probabilities and clinicopathological characteristics. Furthermore, the performances of radiologists were compared with and without the assistance of the nomogram.

RESULT

ResNet 50 performed best among all DL models, achieving areas under the curve (AUCs) of 0.837 and 0.850 in the internal and external validation cohorts, respectively. The US-based DL nomogram demonstrated strong predictive ability for ALN status post-NAC, with AUCs of 0.890 and 0.870 in the internal and external validation cohorts, respectively, outperforming both the clinical model and the DL model (p all < 0.05, except p = 0.19 for DL model in external validation cohort). Moreover, the nomogram significantly improved radiologists' diagnostic ability.

CONCLUSION

The US-based DL nomogram is promising for predicting ALN status post-NAC and could assist radiologists for better diagnostic performance.

Predicting Additional Metastases in Axillary Lymph Node Dissection After Neoadjuvant Chemotherapy: Ratio of Positive/Total Sentinel Nodes

BACKGROUND/OBJECTIVES

The aim of the study was to determine the clinical value of the sentinel lymph node ratio (SLN-R) in predicting additional positive lymph nodes during axillary lymph node dissection (ALND) in breast cancer patients following neoadjuvant chemotherapy (NAC).

METHODS

A cross-sectional study was performed at a single institution evaluating data from 1521 BC patients. Inclusion criteria comprised cT1/cT4, cN0/cN1 status with positive post-NAC axillary staging by SLN/TAD, respectively, and subsequent ALND.

RESULTS

The study included 118 patients, divided into two groups based on the presence or absence of additional node metastasis at ALND: 39 in the residual disease group (RD) and 79 in the non-residual disease group (nRD). Univariate logistic regression analysis of SLN-R was conducted to assess its predictive value, yielding an odds ratio (OR) of 7.79 (CI 1.92-29.5, p = 0.003). An SLN-R cut-off point of <0.35 was identified using ROC curve analysis, with a false-negative rate of 10.2%, as a predictor for no additional metastasis at ALND following post-NAC SLN/TAD positivity.

CONCLUSIONS

The study concludes that SLN-R is a valuable predictor for determining the omission of ALND in cases where SLN/TAD is positive after NAC. This metric, in combination with other clinical variables, could help develop a nomogram to spare patients from ALND.

Development and Validation of a Nomogram for Axillary Lymph Node Metastasis Risk in Breast Cancer

Purpose: Preoperative assessment of axillary lymph node (ALN) status is essential for breast cancer treatment planning. This study prospectively analyzed risk factors for ALN metastasis by comparing high-resolution computed tomography (HRCT) imaging with pathology and developed a nomogram to aid in diagnosis. Methods: From April 2023 to May 2024, breast cancer patients confirmed by pathology participated in the study. All had chest HRCT before surgery, and ALN samples were anatomically matched to HRCT imaging and pathology. The least absolute shrinkage and selection operator (LASSO) regression helped refine metastasis features, and a nomogram was constructed using the final selected features determined by multivariate logistic regression. The nomogram's performance was evaluated with concordance index (C-index), calibration plot, and decision curve analysis, with internal validation through bootstrapping. Results: A total of 302 ALN from 98 patients were included in this study. The predictors included in the nomogram encompassed the mean CT value, short diameter, border, and shape of ALN, as well as the Ki-67 status and histological grade of the primary tumor. The model exhibited satisfactory discrimination, with a C-index of 0.869 (95% CI: 0.826-0.912) and an AUC of 0.862 (95% CI, 0.815-0.909). The calibration curve demonstrated a high degree of concordance between the predicted and actual probabilities. The decision curve analysis demonstrated that the nomogram was clinically useful when the threshold for intervention was set at the metastasis possibility range of 1% to 86%. Conclusion: The nomogram combined with preoperative pathology and HRCT imaging have the potential to improve the evaluation of ALN status.

Development of an Ultrasound-based Nomogram for Predicting Pathologic Complete Response and Axillary Response in Node-Positive Patients with Triple- Negative Breast Cancer

BACKGROUND

The accurate prediction of pathological complete response (pCR) in the breast and axillary lymph nodes (ALN) before neoadjuvant chemotherapy (NAC) is of utmost importance for the development of treatment strategies. We aim to construct a nomogram on ultrasound (US) and clinical-pathologic factors to predict breast and ALN pCR in node-positive triple-negative breast cancers (TNBCs).

METHODS

Patients identified with TNBCs from institution 1 (n = 328) were used for training cohort and those from institution 2 (n = 192) were for validation cohort. US was conducted before and after NAC, and characteristics were obtained from medical records. Univariate and multivariate regression analysis were performed to identify US and clinical-pathologic factors associated with breast and ALN pCR in the training cohort. The assessment of predictive performance was conducted using the receiving operating characteristic curve (ROC), discrimination, and calibration.

RESULTS

Overall, 34.6% of patients achieved breast pCR and 48.1% of patients achieved ALN pCR. The nomogram 1 used for predicting pCR in the breast (AUC, 0.84; 95% CI: 0.79, 0.88) outperformed the clinical (AUC, 0.73; 95% CI: 0.68, 0.78) and US models (AUC, 0.79; 95% CI: 0.74, 0.83). The nomogram 2 used for predicting pCR in the axllia (AUC, 0.83; 95% CI: 0.78, 0.87) also outperformed the clinical (AUC, 0.64; 95% CI: 0.58, 0.69) and US models (AUC, 0.80; 95% CI: 0.75, 0.84). The calibration curve and discrimination curve indicate that the nomogram has good calibration performance and clinical applicability.

CONCLUSION

The nomogram showed promising predictive performance for predicting breast and ALN pCR in patients with TNBCs.

Nomogram Based on US and Clinicopathologic Characteristics: Axillary Nodal Evaluation Following Neoadjuvant Chemotherapy in Patients With Node-Positive Breast Cancer

BACKGROUND

To develop a convenient modality to predict axillary response to neoadjuvant chemotherapy (NAC) in breast cancer patients.

MATERIALS AND METHODS

In this multi-center study, a total of 1019 breast cancer patients with biopsy-proven positive lymph node (LN) receiving NAC were randomly assigned to the training and validation groups at a ratio of 7:3. Clinicopathologic and ultrasound (US) characteristics of both primary tumors and LNs were used to develop corresponding prediction models, and a nomogram integrating clinicopathologic and US predictors was generated to predict the axillary response to NAC.

RESULTS

Axillary pathological complete response (pCR) was achieved in 47.79% of the patients. The expression of estrogen receptor, human epidermal growth factor receptor -2, Ki-67 score, and clinical nodal stage were independent predictors for nodal response to NAC. Location and radiological response of primary tumors, cortical thickness and shape of LNs on US were also significantly associated with nodal pCR. In the validation cohort, the discrimination of US model (area under the curve [AUC], 0.76) was superior to clinicopathologic model (AUC, 0.68); the combined model (AUC, 0.85) demonstrates strong discriminatory power in predicting nodal pCR. Calibration curves of the nomogram based on the combined model demonstrated that substantial agreement can be observed between the predictions and observations. This nomogram showed a false-negative rates of 16.67% in all patients and 10.53% in patients with triple negative breast cancer.

CONCLUSION

Nomogram incorporating routine clinicopathologic and US characteristics can predict nodal pCR and represents a tool to aid in treatment decisions for the axilla after NAC in breast cancer patients.

ACR Appropriateness Criteria® Imaging of Invasive Breast Cancer

As the proportion of women diagnosed with invasive breast cancer increases, the role of imaging for staging and surveillance purposes should be determined based on evidence-based guidelines. It is important to understand the indications for extent of disease evaluation and staging, as unnecessary imaging can delay care and even result in adverse outcomes. In asymptomatic patients that received treatment for curative intent, there is no role for imaging to screen for distant recurrence. Routine surveillance with an annual 2-D mammogram and/or tomosynthesis is recommended to detect an in-breast recurrence or a new primary breast cancer in women with a history of breast cancer, and MRI is increasingly used as an additional screening tool in this population, especially in women with dense breasts. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Impact of neoadjuvant chemotherapy on breast cancer-related lymphedema after axillary lymph node dissection: a retrospective cohort study

PURPOSE

We aimed to evaluate whether neoadjuvant chemotherapy (NAC) could be a risk factor for breast cancer-related lymphedema (BCRL) associated with axillary lymph node dissection (ALND).

PATIENTS AND METHODS

A total of 596 patients with cT0-4N0-3M0 breast cancer who underwent ALND and chemotherapy were retrospectively analyzed between March 2012 and March 2022. NAC was administered in 188 patients (31.5%), while up-front surgery in 408 (68.5%). Univariate and multivariable Cox regression analyses were performed to determine whether NAC was an independent risk factor for BCRL. With propensity score matching (PSM), the NAC group and up-front surgery group were matched 1:1 by age, body mass index (BMI), molecular subtypes, type of breast surgery, and the number of positive lymph nodes. Kaplan-Meier survival analyses were performed for BCRL between groups before and after PSM. Subgroup analyses were conducted to explore whether NAC differed for BCRL occurrence in people with different characteristics.

RESULTS

At a median follow-up of 36.3 months, 130 patients (21.8%) experienced BCRL [NAC, 50/188 (26.60%) vs. up-front surgery, 80/408 (19.61%); P = 0.030]. Multivariable analysis identified that NAC [hazard ratio, 1.503; 95% CI (1.03, 2.19); P = 0.033] was an independent risk factor for BCRL. In addition, the hormone receptor-negative/human epidermal growth factor receptor 2-negative (HR-/HER2-) subtype, breast-conserving surgery (BCS), and increased positive lymph nodes significantly increased BCRL risk. After PSM, NAC remained a risk factor for BCRL [hazard ratio, 1.896; 95% CI (1.18, 3.04); P = 0.007]. Subgroup analyses showed that NAC had a consistent BCRL risk in most clinical subgroups.

CONCLUSION

NAC receipt has a statistically significant increase in BCRL risk in patients with ALND. These patients should be closely monitored and may benefit from early BCRL intervention.

National trends in neoadjuvant chemotherapy utilization in patients with early-stage node-negative triple-negative breast cancer: the impact of the CREATE-X trial

PURPOSE

Neoadjuvant chemotherapy (NAC) for triple-negative breast cancer (TNBC) allows for assessment of tumor pathological response and has survival implications. In 2017, the CREATE-X trial demonstrated survival benefit with adjuvant capecitabine in patients TNBC and residual disease after NAC. We aimed to assess national rates of NAC for cT1-2N0M0 TNBC before and after CREATE-X and examine factors associated with receiving NAC vs adjuvant chemotherapy (AC).

METHODS

A retrospective cohort study of women with cT1-2N0M0 TNBC diagnosed from 2014 to 2019 in the National Cancer Database (NCDB) was performed. Variables were analyzed via ANOVA, Chi-squared, Fisher Exact tests, and a multivariate linear regression model was created.

RESULTS

55,633 women were included: 26.9% received NAC, 52.4% AC, and 20.7% received no chemotherapy (median ages 53, 59, and 71 years, p < 0.01). NAC utilization significantly increased over time: 19.5% in 2014-15 (n = 3,465 of 17,777), 27.1% in 2016-17 (n = 5,140 of 18,985), and 33.6% in 2018-19 (n = 6,337 of 18,871, p < 0.001). On multivariate analysis, increased NAC was associated with younger age (< 50), non-Hispanic white race/ethnicity, lack of comorbidities, cT2 tumors, care at an academic or integrated-network cancer program, and diagnosis post-2017 (p < 0.05 for all). Patients with government-provided insurance were less likely to receive NAC (p < 0.01). Women who traveled > 60 miles for treatment were more likely to receive NAC (p < 0.01).

CONCLUSION

From 2014 to 2019, NAC utilization increased for patients with cT1-2N0M0 TNBC. Racial, socioeconomic, and access disparities were observed in who received NAC vs AC and warrants interventions to ensure equitable care.

Nonsentinel Axillary Lymph Node Status in Clinically Node-Negative Early Breast Cancer After Primary Systemic Therapy and Positive Sentinel Lymph Node: A Predictive Model Proposal

BACKGROUND

In clinically node-negative (cN0) early stage breast cancer (EBC) undergoing primary systemic treatment (PST), post-treatment positive sentinel lymph node (SLN+) directs axillary lymph node dissection (ALND), with uncertain impacts on outcomes and increased morbidities.

PATIENTS AND METHODS

We conducted an observational study on imaging-confirmed cN0 EBC, who underwent PST and breast surgery that resulted in SLN+ and underwent ALND. The association among baseline/postsurgical clinic-pathological factors and positive nonsentinel additional axillary lymph nodes (non-SLN+) was analyzed with logistic regression. LASSO regression (LR) identified variables to include in a predictive score of non-SLN+ (ALND-predict). The accuracy and calibration were assessed, an optimal cut-point was then identified, and in silico validation with bootstrap was undertaken.

RESULTS

Non-SLN+ were detected in 22.2% cases after ALND. Only progesterone receptor (PR) levels and macrometastatic SLN+ were independently associated to non-SLN+. LR identified PR, Ki67, and type and number of SLN+ as the most efficient covariates. The ALND-predict score was built based on their LR coefficients, showing an area under the curve (AUC) of 0.83 and an optimal cut-off of 63, with a negative predictive value (NPV) of 0.925. Continuous and dichotomic scores had a good fit (p = 0.876 and p = 1.00, respectively) and were independently associated to non-SLN+ [adjusted odds ratio (aOR): 1.06, p = 0.002 and aOR: 23.77, p < 0.001, respectively]. After 5000 bootstrap-adjusted retesting, the estimated bias-corrected and accelerated 95%CI included the aOR.

CONCLUSIONS

In cN0 EBC with post-PST SLN+, non-SLN+ at ALND are infrequent (~22%) and independently associated to PR levels and macrometastatic SLN. ALND-predict multiparametric score accurately predicted absence of non-SLN involvement, identifying most patients who could be safely spared unnecessary ALND. Prospective validation is required.

The circRNA-0001361/miR-491/FGFR4 axis is associated with axillary response evaluated by ultrasound following NAC in subjects with breast cancer

Background

miR-491-5p has been reported to regulate the expression of FGFR4 and promote gastric cancer metastasis. Hsa_circ_0001361 was demonstrated to play an oncogenic role in bladder cancer invasion and metastasis by sponging the expression of miR-491-5p. This work aimed to study the molecular mechanism of the effect of hsa_circ_0001361 on axillary response in the treatment of breast cancer.

Methods

Ultrasound examinations was performed to evaluate the response of breast cancer patients receiving NAC treatment. Quantitative real-time PCR, IHC assay, luciferase assay and Western blot were performed to analyze the molecular interaction between miR-491, circRNA_0001631 and FGFR4.

Results

Patients with low circRNA_0001631 expression had a better outcome after NAC treatment. The expression of miR-491 was remarkably higher in the tissue sample and serum collected from patients with lower circRNA_0001631 expression. On the contrary, the FGFR4 expression was notably suppressed in the tissue sample and serum collected from patients with lower circRNA_0001631 expression when compared with patients with high circRNA_0001631 expression. The luciferase activities of circRNA_0001631 and FGFR4 were effectively suppressed by miR-491 in MCF-7 and MDA-MB-231 cells. Moreover, inhibition of circRNA_0001631 expression using circRNA_0001361 shRNA effectively suppressed the expression of FGFR4 protein in MCF-7 and MDA-MB-231 cells. Up-regulation of circRNA_0001631 expression remarkably enhanced the expression of FGFR4 protein in MCF-7 and MDA-MB-231 cells.

Conclusion

Our study suggested that the up-regulation of hsa_circRNA-0001361 could up-regulate the expression of FGFR4 via sponging the expression of miR-491-5p, resulting in the alleviated axillary response after neoadjuvant chemotherapy (NAC) in breast cancer.

ACR Appropriateness Criteria® Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer: 2022 Update

Imaging plays a vital role in managing patients undergoing neoadjuvant chemotherapy, as treatment decisions rely heavily on accurate assessment of response to therapy. This document provides evidence-based guidelines for imaging breast cancer before, during, and after initiation of neoadjuvant chemotherapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

A Model Incorporating Axillary Tail Position on Mammography for Preoperative Prediction of Non-sentinel Lymph Node Metastasis in Patients with Initial cN+ Breast Cancer after Neoadjuvant Chemotherapy

RATIONALE AND OBJECTIVES

This study aimed to develop a model incorporating axillary tail position on mammography (AT) for the prediction of non-sentinel Lymph Node (NSLN) metastasis in patients with initial clinical node positivity (cN+).

METHODS AND MATERIALS

The study reviewed a total of 257 patients with cN+ breast cancer who underwent both sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) following neoadjuvant chemotherapy (NAC). A logistic regression model was developed based on these factors and the results of post-NAC AT and axillary ultrasound (AUS).

RESULTS

Four clinical factors with p<0.1 in the univariate analysis, including ycT0(odds ratio [OR]: 4.84, 95% confidence interval [CI]: 2.13-11.91, p<0.001), clinical stage before NAC (OR: 2.68, 95%CI: 1.15-6.58, p=0.025), estrogen receptor (ER) expression (OR: 3.29, 95%CI: 1.39-8.39, p=0.009), and HER2 status (OR: 0.21, 95%CI: 0.08-0.50, p=0.001), were independent predictors of NSLN metastases. The clinical model based on the above four factors resulted in the area under the curve (AUC) of 0.82(95%CI: 0.76-0.88) in the training set and 0.83(95% CI: 0.74-0.92) in the validation set. The results of post-NAC AUS and AT were added to the clinical model to construct a clinical imaging model for the prediction of NSLN metastasis with AUC of 0.87(95%CI: 0.81-0.93) in the training set and 0.89(95%CI: 0.82-0.96) in the validation set.

CONCLUSIONS

The study incorporated the results of post-NAC AT and AUS with other clinal factors to develop a model to predict NSLN metastasis in patients with initial cN+ before surgery. This model performed excellently, allowing physicians to select patients for whom unnecessary ALND could be avoided after NAC.

Prediction of axillary lymph node pathological complete response to neoadjuvant therapy using nomogram and machine learning methods

Purpose

To determine the feasibility of predicting the rate of an axillary lymph node pathological complete response (apCR) using nomogram and machine learning methods.

Methods

A total of 247 patients with early breast cancer (eBC), who underwent neoadjuvant therapy (NAT) were included retrospectively. We compared pre- and post-NAT ultrasound information and calculated the maximum diameter change of the primary lesion (MDCPL): [(pre-NAT maximum diameter of primary lesion – post-NAT maximum diameter of preoperative primary lesion)/pre-NAT maximum diameter of primary lesion] and described the lymph node score (LNS) (1): unclear border (2), irregular morphology (3), absence of hilum (4), visible vascularity (5), cortical thickness, and (6) aspect ratio <2. Each description counted as 1 point. Logistic regression analyses were used to assess apCR independent predictors to create nomogram. The area under the curve (AUC) of the receiver operating characteristic curve as well as calibration curves were employed to assess the nomogram’s performance. In machine learning, data were trained and validated by random forest (RF) following Pycharm software and five-fold cross-validation analysis.

Results

The mean age of enrolled patients was 50.4 ± 10.2 years. MDCPL (odds ratio [OR], 1.013; 95% confidence interval [CI], 1.002–1.024; p=0.018), LNS changes (pre-NAT LNS – post-NAT LNS; OR, 2.790; 95% CI, 1.190–6.544; p=0.018), N stage (OR, 0.496; 95% CI, 0.269–0.915; p=0.025), and HER2 status (OR, 2.244; 95% CI, 1.147–4.392; p=0.018) were independent predictors of apCR. The AUCs of the nomogram were 0.74 (95% CI, 0.68–0.81) and 0.76 (95% CI, 0.63–0.90) for training and validation sets, respectively. In RF model, the maximum diameter of the primary lesion, axillary lymph node, and LNS in each cycle, estrogen receptor status, progesterone receptor status, HER2, Ki67, and T and N stages were included in the training set. The final validation set had an AUC value of 0.85 (95% CI, 0.74–0.87).

Conclusion

Both nomogram and machine learning methods can predict apCR well. Nomogram is simple and practical, and shows high operability. Machine learning makes better use of a patient’s clinicopathological information. These prediction models can assist surgeons in deciding on a reasonable strategy for axillary surgery.

Accuracy of ultrasonographic changes during neoadjuvant chemotherapy to predict axillary lymph node response in clinical node-positive breast cancer patients

Purpose

To evaluate whether changes in ultrasound features during neoadjuvant chemotherapy (NAC) could predict axillary node response in clinically node-positive breast cancer patients.

Methods

Patients with biopsy-proven node-positive disease receiving NAC between February 2009 and March 2021 were included. Ultrasound (US) images were obtained using a 5-12-MHz linear array transducer before NAC, after two cycles, and at the completion of NAC. Long and short diameter, cortical thickness, vascularity, and hilum status of the metastatic node were retrospectively reviewed according to breast imaging-reporting and data system (BI-RADS). The included population was randomly divided into a training set and a validation set at a 2:1 ratio using a simple random sampling method. Factors associated with node response were identified through univariate and multivariate analyses. A nomogram combining clinical and changes in ultrasonographic (US) features was developed and validated. The receiver operating characteristic (ROC) and calibration plots were applied to evaluate nomogram performance and discrimination.

Results

A total of 296 breast cancer patients were included, 108 (36.5%) of whom achieved axillary pathologic complete response (pCR) and 188 (63.5%) had residual nodal disease. Multivariate regression indicated that independent predictors of node pCR contain ultrasound features in addition to clinical features, clinical features including neoadjuvant HER2-targeted therapy and clinical response, ultrasound features after NAC including cortical thickness, hilum status, and reduction in short diameter ≥50%. The nomogram combining clinical features and US features showed better diagnostic performance compared to clinical-only model in the training cohort (AUC: 0.799 vs. 0.699, P=0.001) and the validation cohort (AUC: 0.764 vs. 0.638, P=0.027).

Conclusions

Ultrasound changes during NAC could improve the accuracy to predict node response after NAC in clinically node-positive breast cancer patients.

Le-Petross HT, Slanetz PJ, Lewin AA, Bao J, Dibble EH, Golshan M, Hayward JH, Kubicky CD, Leitch AM, Newell MS, Prifti C, Sanford MF, Scheel JR, Sharpe RE, Weinstein SP, Moy L. ACR Appropriateness Criteria® Imaging of the Axilla

This publication reviews the current evidence supporting the imaging approach of the axilla in various scenarios with broad differential diagnosis ranging from inflammatory to malignant etiologies. Controversies on the management of axillary adenopathy results in disagreement on the appropriate axillary imaging tests. Ultrasound is often the appropriate initial imaging test in several clinical scenarios. Clinical information (such as age, physical examinations, risk factors) and concurrent complete breast evaluation with mammogram, tomosynthesis, or MRI impact the type of initial imaging test for the axilla. Several impactful clinical trials demonstrated that selected patient's population can received sentinel lymph node biopsy instead of axillary lymph node dissection with similar overall survival, and axillary lymph node dissection is a safe alternative as the nodal staging procedure for clinically node negative patients or even for some node positive patients with limited nodal tumor burden. This approach is not universally accepted, which adversely affect the type of imaging tests considered appropriate for axilla. This document is focused on the initial imaging of the axilla in various scenarios, with the understanding that concurrent or subsequent additional tests may also be performed for the breast. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Combining conventional ultrasound and sonoelastography to predict axillary status after neoadjuvant chemotherapy for breast cancer

OBJECTIVE

To determine the ability of conventional ultrasound (US) combined with shear wave elastography (SWE) to reveal axillary status after neoadjuvant chemotherapy (NAC) in breast cancer patients.

METHODS

From September 2016 to December 2021, 201 patients with node-positive breast cancer who underwent NAC were enrolled in this prospective study. Conventional US features of axillary lymph nodes and SWE characteristics of breast lesions after NAC were analyzed. The diagnostic performances of US, SWE, and their combination were assessed using multivariate logistic regression and receiver operator characteristic curve (ROC) analyses.

RESULTS

The area under the ROC curve (AUC) for the ability of conventional US features to determine axillary status after NAC was 0.82, with a sensitivity of 85.23%, a specificity of 67.39%, and an accuracy of 76.11%. Shear wave velocity (SWV) displayed moderate performance for predicting axilla status after NAC with SWV_mean demonstrating an AUC of 0.85. Cortical thickness and shape of axillary nodes and SWV_mean of breast tumors were independently associated with axillary nodal metastasis after NAC. Compared to conventional US, the combination of conventional US of axillary lymph nodes with SWE of breast lesions achieved a significantly higher AUC (0.90 vs 0.82, p < 0.01, Delong's test) with a sensitivity of 87.50%, improved specificity of 82.61% and accuracy of 85.00%.

CONCLUSIONS

Breast SWE was independently associated with residual metastasis of axillary node after NAC in patients with initially diagnosed positive axilla. Combining SWE with conventional US showed good diagnostic performance for axillary node disease after NAC.

KEY POINTS

• Breast SWE can serve as a supplement to axilla US for the evaluation of the axilla after NAC. • The combination of axilla US with breast SWE may be a promising method to facilitate less-invasive treatment in patients receiving NAC.

Neoadjuvant approach in patients with early breast cancer: patient assessment, staging, and planning

Neoadjuvant treatment (NAT) has become an option in early stage (stage I-II) breast cancer (EBC). New advances in systemic and targeted therapies have increased rates of pathologic complete response increasing the number of patients undergoing NAT. Clear benefits of NAT are downstaging the tumor and the axillary nodes to de-escalate surgery and to evaluate response to treatment. Selection of patients for NAT in EBC rely in several factors that are related to patient characteristics (i.e, age and comorbidities), to tumor histology, to stage at diagnosis and to the potential changes in surgical or adjuvant treatments when NAT is administered.

Imaging and histologic confirmation is performed to assess extent of disease y to confirm diagnosis. Besides mammogram and ultrasound, functional breast imaging MRI has been incorporated to better predict treatment response and residual disease. Contrast enhanced mammogram (CEM), shear wave elastography (SWE), or Dynamic Optical Breast Imaging (DOBI) are emerging techniques under investigation for assessment of response to neoadjuvant therapy as well as for predicting response. Surgical plan should be delineated after NAT taking into account baseline characteristics, tumor response and patient desire.

In the COVID era, we have witnessed also the increasing use of NAT in patients who may be directed to surgery, unable to have it performed as surgery has been reserved for emergency cases only.

Pathological Response in the Breast and Axillary Lymph Nodes after Neoadjuvant Systemic Treatment in Patients with Initially Node-Positive Breast Cancer Correlates with Disease Free Survival: An Exploratory Analysis of the GeparOcto Trial

Simple Summary

The extent of axillary surgery has been reduced in recent years to minimize side effects. However, a negative impact of reduced surgery on outcome must be avoided. We investigated for whom the extent of surgery can be safely reduced by examining early-stage breast cancer patients converting from lymph node (LN)-positive to LN-negative disease after neoadjuvant systemic treatment (NAST). Of 242 initially LN-positive patients treated within the GeparOcto trial, 54.5% were classified as LN-negative after NAST, 31.8% as LN-positive, and for 13.6% data were missing. Overall, 92.1% of patients underwent complete axillary LN dissection, with 6.6% undergoing sentinel LN dissection only. At surgery, 55.4% of patients had no signs of cancer in the LN, 45.0% had no signs of cancer in the breast (of those 8.3% had involved LN), and 41.3% had no signs of cancer at all. Patients with involved LN still had a bad prognosis. Conversion from LN-positive to LN-negative after NAST is of highest prognostic value. Surgical axillary staging after NAST is essential in these patients to offer tailored treatment.

Abstract

Background: The conversion of initially histologically confirmed axillary lymph node-positive (pN+) to ypN0 after neoadjuvant systemic treatment (NAST) is an important prognostic factor in breast cancer (BC) patients and may influence surgical de-escalation strategies. We aimed to determine pCR rates in lymph nodes (pCR-LN), the breast (pCR-B), and both (tpCR) in women who present with pN+ BC, to assess predictors for response and the impact of pCR-LN, pCR-B, and tpCR on invasive disease-free survival (iDFS). Methods: Retrospective, exploratory analysis of 242 patients with pN+ at diagnosis from the multicentric, randomized GeparOcto trial. Results: Of 242 patients with initially pN+ disease, 134 (55.4%) had a pCR-LN, and 109 (45.0%) a pCR-B. Of the 109 pCR-B patients, 9 (8.3%) patients had involved LN, and 100 (41.3%) patients had tpCR. Those with involved LN still had a bad prognosis. As expected, pCR-B and intrinsic subtypes (TNBC and HER2+) were identified as independent predictors of pCR-LN. pCR-LN (ypN0; hazard ratio 0.42; 95%, CI 0.23–0.75; p = 0.0028 for iDFS) was the strongest independent prognostic factor. Conclusions: In initially pN+ patients undergoing NAST, the conversion to ypN0 is of high prognostic value. Surgical axillary staging after NAST is still essential in these patients to offer tailored treatment.

Axillary Imaging Following a New Invasive Breast Cancer Diagnosis-A Radiologist's Dilemma

Traditionally, patients with newly diagnosed invasive breast cancer underwent axillary US to assess for suspicious axillary lymph nodes (LNs), which were then targeted for image-guided needle biopsy to determine the presence of metastasis. Over the past decade, there has been a shift towards axillary preservation. For patients with palpable lymphadenopathy, the decision to perform axillary imaging with documentation of the number and location of abnormal LNs in preparation for image-guided LN sampling is straightforward. Since LN involvement correlates with cancer size, it is reasonable to image the axilla in patients with tumors larger than 5 cm; however, for tumors smaller than 5 cm, axillary imaging is often deferred until after the tumor molecular subtype and treatment plan are established. Over the last decade, neoadjuvant chemotherapy (NACT) is increasingly used for smaller cancers with more aggressive molecular subtypes. In most cases, detecting axillary metastasis is critical when deciding whether the patient would benefit from NACT. There is increasing evidence that abnormal axillary US findings correlates with LN metastases and reliably establishes a baseline to monitor response to NACT. Depending on hormone receptor status, practices may choose to image the axilla in the setting of clinical stage T1 and T2 cancers to evaluate nodal status and help determine further steps in care. Radiologists should understand the nuances of axillary management and the scope and challenges of LN marking techniques that significantly increase the precision of limited axillary surgery.

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

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

Axillary ultrasonography combined with pre-operative wire localisation of clipped node in nodal restaging after neoadjuvant chemotherapy in node positive breast cancer patients: a pilot study

OBJECTIVE

To evaluate the role of axillary ultrasonography (axUS) and ultrasound-guided pre-operative wire localisation of pre-treatment positive clipped node (CN) for prediction of nodal response to neoadjuvant chemotherapy (NACT) in node positive breast carcinoma patients.

METHODS AND MATERIALS

A prospective study was conducted between June 2018 and August 2020 after Ethics Committee approval. Breast carcinoma patients (cT1-cT4b) with palpable axillary nodes (cN1-cN3) and suitable for NACT were recruited after written informed consent. Single, most suspicious node was biopsied and clipped. Nodal response to NACT was assessed on axUS. Wire localisation of CN was performed prior to axillary lymph node dissection (ALND). Diagnostic performances of axUS and CN excision were assessed.

RESULTS

Of the 69 patients evaluated, 32 patients (mean age, 43.5 ± 11.8 years; females, 31/32 [97%]; pre-menopausal, 18/32 [56.3%]) with metastatic nodes who received NACT were included. Nodal pathological complete response rate was 34.4% (11/32) overall and 70% (7/10) in patients with ≤2 suspicious nodes on pre-NACT axUS. False-negative rates (FNRs) of axUS and CN excision were 4.8% and 28.6% respectively. Combination of post-NACT axUS and CN excision had an FNR of 4.8% overall and 0% in patients with ≤2 suspicious nodes on pre-NACT axUS.

CONCLUSION

Combination of AxUS and ultrasound-guided wire localisation of pre-treatment positive CN has high diagnostic accuracy for nodal restaging after NACT in node positive breast cancer patients.

ADVANCES IN KNOWLEDGE

Addition of axUS assessment to wire localisation of CN reduces its FNR for detecting residual metastasis after NACT.

Breast cancer subtypes affect the ultrasound performance for axillary lymph node status evaluation after neoadjuvant chemotherapy: a retrospective analysis

PURPOSE

The aim of our study was to investigate the effect of breast cancer subtypes on the diagnostic value of axillary ultrasound for node status evaluation after neoadjuvant chemotherapy.

PATIENTS AND METHODS

Pathologic node-positive breast cancer patients underwent axillary ultrasound imaging after neoadjuvant chemotherapy were retrospectively reviewed. The enrolled patients were classified into four subtypes: Luminal A, Luminal B, human epidermal growth factor receptor 2-enriched and triple-negative. Ultrasound images of axillary nodes were reviewed and were evaluated as normal or abnormal and were associated with final pathologic results. Diagnostic value of axillary ultrasound was assessed in four subtypes based on sensitivity, specificity, positive predictive value and negative predictive value. The diagnostic value of axillary ultrasound as well as clinical and pathological characteristics was compared between four breast cancer subtypes using chi-square test or fisher's exact test.

RESULT

Luminal A subtype had highest positive predictive value (92.1%), lowest sensitivity (43.8%) and lowest negative predictive value (11.8%). Triple-negative subtype had lowest positive predictive value (73.2%), highest sensitivity (76.9%) and highest negative predictive value (59.1%) (P < 0.05). Luminal B and human epidermal growth factor receptor 2-enriched subtypes had medium sensitivity, positive predictive value and negative predictive value.

CONCLUSION

The diagnostic value of axillary ultrasound for node residue disease assessment after neoadjuvant chemotherapy is different between four breast cancer subtypes.

Ultrasound guided needle biopsy of axilla to evaluate nodal metastasis after preoperative systemic therapy in cohort of 106 breast cancers enriched with BRCA1/2 pathogenic variant carriers

BACKGROUND

Aim of the study is to evaluate the role of ultrasound guided fine needle aspiration cytology (FNAC) in the restaging of node positive breast cancer after preoperative systemic therapy (PST).

METHODS

From January 2016 - October 2020 106 node positive stage IIA-IIIC breast cancer cases undergoing PST were included in the study. 18 (17 %) were carriers of pathogenic variant in BRCA1/2. After PST restaging of axilla was performed with ultrasound and FNAC of the marked and/or the most suspicious axillary node. In 72/106 cases axilla conserving surgery and in 34/106 cases axillary lymph node dissection (ALND) was performed.

RESULTS

False Positive Rate (FPR) of FNAC after PST in whole cohort and BRCA1/2 positive subgroup is 8 and 0 % and False Negative Rate (FNR) - 43 and 18 % respectively. Overall Sensitivity - 55 %, specificity- 93 %, accuracy 70 %.

CONCLUSION

FNAC after PST has low FPR and is useful to predict residual axillary disease and to streamline surgical decision making regarding ALND both in BRCA1/2 positive and negative subgroups. FNR is high in overall cohort and FNAC alone are not able to predict ypCR and omission of further axillary surgery. However, FNAC performance in BRCA1/2 positive subgroup is more promising and further research with larger number of cases is necessary to confirm the results.

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

Purpose

High-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.

Methods

The 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.

Results

AUS 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.

Conclusion

Baseline 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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06283-8.

Oncologic Safety of Sentinel Lymph Node Biopsy Alone After Neoadjuvant Chemotherapy for Breast Cancer

BACKGROUND

The oncologic safety of sentinel lymph node biopsy (SLNB) alone for clinically node-positive (cN1-2) patients who convert to pathologic node-negativity (ypN0) after neoadjuvant chemotherapy (NAC) is not well established.

METHODS

This study retrospectively identified 244 consecutive patients with a diagnosis of cT1-3cN0-2 breast cancer who underwent NAC followed by SLNB at the authors' institution between 2013 and 2018. The patients were categorized as clinically node-negative (cN0) or cN1-2 before the onset of NAC, and the Kaplan-Meier method was used to compare locoregional and distant recurrence rates after SLNB alone for ypN0 patients.

RESULTS

Among 244 patients who underwent NAC followed by surgery with SLNB for axillary staging, 112 (45.9%) were cN0 at presentation, whereas 132 (54.5%) had biopsy-proven cN1-2 disease and converted to cN0 after treatment. Of the patients presenting with cN0 disease, 102 (91.1%) were ypN0 on SLNB pathology compared with 60 cN1/2 patients (45.5%; p < 0.001). Regional nodal irradiation was administered to 5% of the cN0/ypN0 patients compared with 70.7% of the cN1-2/ypN0 patients (p < 0.001). Overall, 211 patients were treated with SLNB alone and had a median follow-up period of 36 months (interquartile range [IQR], 24-53 months). For 101 cN0/ypN0 patients who underwent SLNB alone, the 5-year local and regional recurrence rates were respectively 5.7% (95% confidence interval [CI], 2.4-13.8) and 1% (95% CI 0.1-7.0). For 58 cN1-2/ypN0 patients who underwent SLNB alone, the 5-year local and regional recurrence rates were respectively 4.1% (95% CI 1.0-15.5) and 0%, with no axillary recurrences noted.

CONCLUSION

For ypN0 patients, SLNB alone after NAC is associated with low and acceptable short-term axillary recurrence rates. Additional follow-up data from prospective clinical trials are needed to confirm long-term oncologic safety and define optimal local therapy recommendations.

Enhanced axillary assessment using intradermally injected microbubbles and contrast-enhanced ultrasound (CEUS) before neoadjuvant systemic therapy (NACT) identifies axillary disease missed by conventional B-mode ultrasound that may be clinically relevant

PURPOSE

The purpose of this study is to measure pre-treatment diagnostic yield of malignant lymph nodes (LN) using contrast-enhanced ultrasound (CEUS) in addition to B-mode axillary ultrasound and compare clinicopathological features, response to NACT and long-term outcomes of patients with malignant LN detected with B-mode ultrasound versus CEUS.

METHODS

Between August 2009 and October 2016, NACT patients were identified from a prospective database. Follow-up data were collected until May 2019.

RESULTS

288 consecutive NACT patients were identified; 77 were excluded, 110 had malignant LN identified by B-mode ultrasound (Group A) and 101 patients with negative B-mode axillary ultrasound had CEUS with biopsy of sentinel lymph nodes (SLN). In two cases CEUS failed. Malignant SLN were identified in 35/99 (35%) of B-mode ultrasound-negative cases (Group B). Patients in Group A were similar to those in Group B in age, mean diagnostic tumour size, grade and oestrogen receptor status. More Group A patients had a ductal phenotype. In the breast, 34 (31%) Group A patients and 8 (23%) Group B patients achieved a pathological complete response (PCR). In the axilla, 41 (37%) and 13 (37%) Groups A and B patients, respectively, had LN PCR. The systemic relapse rate was not statistically different (5% and 16% for Groups A and B, respectively).

CONCLUSIONS

Enhanced assessment with CEUS before NACT identifies patients with axillary metastases missed by conventional B-mode ultrasound. Without CEUS, 22 (63%) of cases in Group B (negative B-mode ultrasound) may have been erroneously classed as progressive disease by surgical SLN excision after NACT.

Factors Associated with Pathological Node Negativity in Inflammatory Breast Cancer: Are There Patients Who May be Candidates for a De-Escalation of Axillary Surgery?

BACKGROUND

Modified radical mastectomy (MRM), which includes axillary dissection, is the standard of care for inflammatory breast cancer (IBC). While more limited axillary staging after neoadjuvant chemotherapy (NAC) in clinically node-positive non-IBC has been increasingly adopted, the impact of these techniques in IBC is not clear. To inform patient selection for further study of limited axillary surgery, we aimed to describe the frequency and factors associated with pathological node-negativity (ypN0) in IBC.

METHODS

Patients with IBC who received NAC and MRM were identified from a prospective institutional database (2004-2019). Binary logistic regression analyses were conducted to identify factors associated with ypN0.

RESULTS

Of 453 patients, 189 (41.7%) had a post-NAC clinical nodal stage (ycN stage) of N0 (ycN1: 150, 33.1%; ycN2: 4, 0.9%; ycN3: 47, 10.4%; unknown: 63, 13.9%); 156 (34%) were ypN0. On multivariable analysis, higher tumor grade was not associated with ypN0 (odds ratio [OR] 1.59, 95% confidence interval [CI] 0.90-2.81, p =0.11). Compared with hormone receptor (HR)-negative/human epidermal growth factor receptor 2 (HER2)-negative tumors (n =113, 24.9%), HR-positive/HER2-negative tumors (n =169, 37.3%) had a trend toward less ypN0 (OR 0.55, 95% CI 0.29-1.02, p =0.06); HR-positive/HER2-positive tumors (n =79, 17.4%) were similar to HR-negative/HER2-negative tumors (OR 0.72, 95% CI 0.35-1.48, p =0.37); and HR-negative/HER2-positive tumors (n =92, 20.3%) were associated with increased ypN0 (OR 4.82, 95% CI 2.41-9.63, p <0.001). As ycN stage increased, the likelihood of ypN0 decreased compared with ycN0 patients (ycN1/2: OR 0.54, 95% CI 0.32-0.89, p =0.02; ycN3: OR 0.29, 95% CI 0.13-0.67, p =0.004).

CONCLUSIONS

One-third of patients with IBC who received NAC and MRM had pathologically negative nodes. Factors associated with ypN0 included ycN0 status and HR-negative/HER2-positive subtype. Large, prospective studies are needed to investigate the feasibility of alternative nodal evaluation strategies in IBC, with consideration to these subgroups.

Factors Associated With Lymphedema in Women With Node-Positive Breast Cancer Treated With Neoadjuvant Chemotherapy and Axillary Dissection

Importance

Most lymphedema studies include a heterogeneous population and focus on patients treated with adjuvant chemotherapy.

Objective

To examine factors associated with lymphedema after neoadjuvant chemotherapy (NAC) and axillary lymph node dissection in women with node-positive breast cancer.

Design, Setting, and Participants

This cohort study included data from 701 women 18 years or older with cT0-T4N1-2M0 breast cancer with documented axillary nodal metastasis at diagnosis who were enrolled in the American College of Surgeons Oncology Group Z1071 (Alliance for Clinical Trials in Oncology) trial, which took place from January 1, 2009, to December 31, 2012. Data analysis was performed from January 11, 2018, to November 9, 2018.

Interventions

All participants received NAC, breast operation, and axillary lymph node dissection. Participants underwent prospective arm measurements and symptom assessment after NAC completion and at 6-month intervals to 36 months postoperatively.

Main Outcomes and Measures

Factors associated with lymphedema were defined as self-reported arm heaviness or swelling (lymphedema symptoms) or an arm volume increase of 10% or more (V10) or 20% or more (V20).

Results

A total of 486 patients (mean [SD] age, 50.1 [10.8] years) were included in this study. Median follow-up for the 3 measures was 2.2 to 3.0 years. Cumulative lymphedema incidence at 3 years was 37.8% (95% CI, 33.1%-43.2%) for lymphedema symptoms, 58.4% (95% CI, 53.2%-64.1%) for V10, and 36.9% (95% CI, 31.9%-42.6%) for V20. Increasing body mass index (hazard ratio [HR], 1.04; 95% CI, 1.01-1.06) and NAC for 144 days or longer (HR, 1.48; 95% CI, 1.01-2.17) were associated with lymphedema symptoms. The V20 incidence was higher among patients who received NAC for 144 days or longer (HR, 1.79; 95% CI, 1.19-2.68). The V10 incidence was highest in patients with 30 nodes or more removed (HR, 1.70; 95% CI, 1.15-2.52) and increased with number of positive nodes (HR, 1.03; 95% CI, 1.00-1.06). On multivariable analysis, obesity was significantly associated with lymphedema symptoms (HR, 1.03; 95% CI, 1.01-1.06), and NAC length was significantly associated with V20 (HR, 1.74; 95% CI, 1.15-2.62).

Conclusions and Relevance

In this study, longer NAC duration and obesity were associated with increased lymphedema incidence, suggesting that patients in these groups may benefit from enhanced prospective lymphedema surveillance.

Axillary ultrasound during neoadjuvant systemic therapy in triple-negative breast cancer patients

PURPOSE

To investigate the value of performing mid-treatment axillary ultrasound (AUS) in triple-negative breast cancer (TNBC) patients who are undergoing neoadjuvant systemic therapy (NAST) by determining the optimal cutoff number of abnormal nodes associated with residual nodal disease on surgical pathology.

MATERIALS AND METHODS

This sub-study, an interim analysis of an ongoing single-institution clinical trial enrolling patients with stage I-III TNBC, included 106 patients. Number of abnormal nodes at mid-treatment was assessed and recorded by experienced breast radiologists, who empirically categorized lymph nodes using a binary approach of sonographically-normal versus abnormal. Pathologic lymph node positivity was defined as presence of macrometastasis or micrometastasis in ≥1 axillary node from sentinel lymph node biopsy and/or axillary lymph node dissection.

RESULTS

Of 106 patients, 26 (25 %) had residual nodal disease and 80 (75 %) had no nodal disease at surgery. Median number of abnormal nodes at mid-treatment was 5 (standard deviation [SD], 5) for patients with residual nodal disease and 0 (SD, 2) for patients with no nodal disease at surgery (p < 0.0001). TNBC patients with >4 abnormal nodes at mid-treatment had a significantly higher chance of being node-positive at surgery (AUC = 0.908, p < 0.0001; PPV = 90 %).

CONCLUSION

Our data suggest that a cutoff of >4 abnormal nodes on mid-treatment AUS is associated with residual disease post-NAST. If our findings are substantiated by subsequent analyses, then mid-treatment AUS could be used to identify patients unlikely to achieve nodal pathologic complete response and who should be offered alternative therapy.

Axillary Nodal Evaluation in Breast Cancer: State of the Art

Axillary lymph node (LN) metastasis is the most important predictor of overall recurrence and survival in patients with breast cancer, and accurate assessment of axillary LN involvement is an essential component in staging breast cancer. Axillary management in patients with breast cancer has become much less invasive and individualized with the introduction of sentinel LN biopsy (SLNB). Emerging evidence indicates that axillary LN dissection may be avoided in selected patients with node-positive as well as node-negative cancer. Thus, assessment of nodal disease burden to guide multidisciplinary treatment decision making is now considered to be a critical role of axillary imaging and can be achieved with axillary US, MRI, and US-guided biopsy. For the node-positive patients treated with neoadjuvant chemotherapy, restaging of the axilla with US and MRI and targeted axillary dissection in addition to SLNB is highly recommended to minimize the false-negative rate of SLNB. Efforts continue to develop prediction models that incorporate imaging features to predict nodal disease burden and to select proper candidates for SLNB. As methods of axillary nodal evaluation evolve, breast radiologists and surgeons must work closely to maximize the potential role of imaging and to provide the most optimized treatment for patients.

Best Foot Forward: Neoadjuvant Systemic Therapy as Standard of Care in Triple-Negative and HER2-Positive Breast Cancer

Neoadjuvant systemic treatment of early-stage breast cancer has been used to improve resectability and reduce the extent of breast and axillary surgery. More recently, several other merits of neoadjuvant systemic treatment have emerged, including the ability to tailor clinically available adjuvant systemic therapy options based on pathologic response and to serve as a platform for early assessment of novel agents and response biomarkers and as an avenue for treatment optimization investigations (local and systemic therapy escalation and de-escalation trials guided by pathologic response). Attainment of a pathologic complete response (pCR) is associated with excellent long-term outcomes; conversely, the presence of residual disease is associated with a high risk of recurrence for patients with HER2-positive breast cancer and triple-negative breast cancer (TNBC). Treatment strategies in early-stage HER2-positive breast cancer include regimens incorporating trastuzumab, pertuzumab, ado-trastuzumab emtansine, and neratinib, resulting in high pCR rates and overall excellent long-term outcomes. Currently available cytotoxic regimens yield pCR for 35% to 55% of patients with TNBC, and immune checkpoint inhibition is showing early promise for this subtype. New drug and predictive biomarker evaluations in the neoadjuvant setting aim to develop optimal treatment strategies for the individual patient, with the ultimate goal of maximizing efficacy and minimizing toxicity. Research efforts involving novel agents are being undertaken to address the high risk of recurrence for patients with residual disease. Omission of breast surgery following neoadjuvant chemotherapy requires further development of imaging and biopsy techniques to accurately assess the extent of residual disease before clinical application.

Application of the Z1071 criteria: classification of axillary lymph nodes on ultrasound after neoadjuvant chemotherapy in initially node-positive breast cancer

PURPOSE

The American College of Surgeons Oncology Group (ACOSOG) Z1071 trial assessed the accuracy of sentinel lymph node biopsies in clinically node-positive patients who underwent neoadjuvant chemotherapy (NAC). Axillary ultrasound (US) images after NAC were reviewed, and the accuracy of classifying nodes into six types according to the ACOSOG Z1071 trial was determined.

METHODS

This study included 69 patients who underwent NAC followed by curative surgery for breast cancer including axillary lymph node dissection between January 2010 and July 2019. All patients were pathologically confirmed as being initially node positive. Lymph nodes were retrospectively classified into one of six types based on the appearance of the nodal cortex and hilum. Types I and II were classified as having normal nodal morphology, whereas types III, IV, V, and VI were classified as having suspicious nodal morphology. These node types on US images after NAC were compared between patients with an axillary complete response (Ax-pCR) and those with residual metastatic lymph nodes (Ax-non-pCR) using Chi-square tests.

RESULTS

Twenty-four (35%) of the 69 patients achieved Ax-pCR. Patients with nodes classified as type I or II were more likely to achieve Ax-pCR (83% vs. 36%, p = 0. 0002).

CONCLUSION

The classification of six node types was associated with nodal status.

A New Model Incorporating Axillary Ultrasound After Neoadjuvant Chemotherapy to Predict Non-Sentinel Lymph Node Metastasis in Invasive Breast Cancer

Purpose

Few models with good discriminative power have been introduced to predict the risk of non-sentinel lymph node (non-SLN) metastasis in breast cancer after neoadjuvant chemotherapy (NAC). We aimed to develop a new and simple model for predicting the probability of non-SLN metastasis in breast cancer and facilitate the selection of patients who could avoid unnecessary axillary lymph node dissection following NAC.

Patients and Methods

A total of 298 patients diagnosed with invasive breast cancer, who underwent SLN biopsy after completing NAC and subsequently breast surgery, were included and classified into the training set (n=228) and testing set (n=70). Univariate and multivariate analyses were used to select factors that could be determined prior to breast surgery and significantly correlated with non-SLN metastasis in the training set. A logistic regression model was developed based on these factors and validated in the testing set.

Results

Nodal status before NAC, post-NAC axillary ultrasound status, SLN number, and SLN metastasis number were independent predictors of non-SLN metastases in breast cancer after NAC. A predictive model based on these factors yielded an area under the curve of 0.838 (95% confidence interval: 0.774-0.902, p< 0.001) in the training set. When applied to the testing set, this model yielded an area under the curve of 0.808 (95% confidence interval: 0.609-1.000, p= 0.003).

Conclusion

A new and simple model, which incorporated factors that could be determined prior to breast surgery, was developed to predict non-SLN metastasis in invasive breast cancer following NAC. Although this model performed excellently in internal validation, it requires external validation before it can be widely utilized in the clinical setting.

Neoadjuvant chemotherapy in patients with breast cancer: Does response in the breast predict axillary node response?

INTRODUCTION

Determining the extent of residual disease in the breast and axilla following neoadjuvant chemotherapy (NACT) is vital for surgical planning. Traditionally patients with incomplete radiological response in the breast after NACT undergo axillary node clearance, regardless of axillary clinical and radiological response. The aim of this study was to determine whether radiological and/or pathological response in the breast to NACT were predictive of axillary response.

MATERIALS AND METHODS

A retrospective cohort study of patients with operable breast cancer with histologically proven axillary lymph node involvement who received NACT and underwent definitive surgical treatment between 1/1/2016 and 31/12/2018 were included. All had MRI and/or US of the breast and axilla before, mid-treatment and at the end of NACT.

RESULTS

The 83 patients had a median age of 50 years (range 25-77). MRI had a positive predictive value (PPV) of 52.6% and negative predictive value (NPV) of 81.8% for breast pathological complete response (pCR). For axillary pCR, US had a PPV of 60.0% and NPV of 89.6%. Only 71% of patients had radiological concordance; 15.9% had radiological complete response (rCR) in breast and axilla whilst 55.1% had neither breast nor axillary rCR. 85.6% of patients had pathological concordance (20.5% with breast and axillary pCR: 65.1% with residual disease in both).

CONCLUSION

Radiological and pathological response in the breast to NACT does not accurately predict axillary response. The axilla and the breast should be viewed and assessed as two separate entities for treatment plans.

Axillary Lymph Node Ultrasound Following Neoadjuvant Chemotherapy in Biopsy-Proven Node-Positive Breast Cancer: Results from the SN FNAC Study

BACKGROUND

The sentinel node biopsy following neoadjuvant chemotherapy (SN FNAC) study has shown that in node-positive (N+) breast cancer, sentinel node biopsy (SNB) can be performed following neoadjuvant chemotherapy (NAC), with a low false negative rate (FNR = 8.4%). A secondary endpoint of the SN FNAC study was to determine whether axillary ultrasound (AxUS) could predict axillary pathological complete response (ypN0) and increase the accuracy of SNB.

METHODS

The SN FNAC trial is a study of patients with biopsy-proven N+ breast cancer who underwent SNB followed by completion node dissection. All patients had AxUS following NAC and the axillary nodes were classified as either positive (AxUS+) or negative (AxUS-). AxUS was compared with the final axillary pathology results.

RESULTS

There was no statistical difference in the baseline characteristics of patients with AxUS+ versus those with AxUS-. Overall, 82.5% (47/57) of AxUS+ patients had residual positive lymph nodes (ypN+) at surgery and 53.8% (42/78) of AxUS- patients had ypN+. Post NAC AxUS sensitivity was 52.8%, specificity 78.3%, and negative predictive value 46.2%. AxUS FNR was 47.2%, versus 8.4% for SNB. If post-NAC AxUS- was used to select patients for SNB, FNR would decrease from 8.4 to 2.7%. However, using post-NAC AxUS in addition to SNB as an indication for ALND would have led to unnecessary ALND in 7.8% of all patients.

CONCLUSION

AxUS is not appropriate as a standalone staging procedure, and SNB itself is sufficient to assess the axilla post NAC in patients who present with N+ breast cancer.

Predicting Axillary Response to Neoadjuvant Chemotherapy: Breast MRI and US in Patients with Node-Positive Breast Cancer

Background In patients who are expected to achieve axillary pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC), omission of axillary lymph node (LN) dissection could prevent morbidity and complications. Purpose To develop a clinical model to predict residual axillary LN metastasis in patients with clinically node-positive breast cancer after NAC by using MRI and US. Materials and Methods In this retrospective study, women with clinically node-positive breast cancer who were treated with NAC following surgery between January 2015 and September 2017 were included. The patients were randomly assigned to a test and validation set (7:3 ratio). Univariable and multivariable logistic regression analyses were performed to evaluate the independent predictors of residual axillary LN metastasis in the test set. A prediction risk score was developed based on the odds ratios from the multivariable analysis and validated in both sets. Results A total of 408 women were included (mean age ± standard deviation, 47.9 years ± 9.6). The axillary pCR rate was 56.6% (231 of 408). Independent predictors of residual axillary LN metastasis were clinical stage N2 or N3, presence of axillary lymphadenopathy at US after NAC, tumor size reduction less than 50% at MRI, Ki-67 negativity, hormone receptor positivity, and human epidermal growth factor receptor 2 negativity (all, P < .05). In a model using these predictors, the area under the receiver operating characteristic curve in the test and validation sets was 0.84 (95% confidence interval: 0.79, 0.88) and 0.78 (95% confidence interval: 0.70, 0.87), respectively. When the patients had a simplified risk score of 1, the false-negative rates ranged between 5%-10%. Conclusion A prediction model incorporating nodal status stage, US finding, MRI response, and molecular receptor status shows good diagnostic performance for residual axillary lymph node metastasis after neoadjuvant chemotherapy in patients with clinically node-positive breast cancer. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Whitman in this issue.

Axillary Surgery Following Neoadjuvant Chemotherapy - Multidisciplinary Guidance From the Association of Breast Surgery, Faculty of Clinical Oncology of the Royal College of Radiologists, UK Breast Cancer Group, National Coordinating Committee for Breast Pathology and British Society of Breast Radiology

AIMS

These multidisciplinary guidelines aim to provide clinically helpful, evidence-based recommendations on the surgical management of the axilla in patients who have received neo-adjuvant chemotherapy for early breast cancer.

MATERIALS & METHODS

Following a review of published evidence, a writing group representing all disciplines quorate within a breast cancer multidisciplinary meeting prepared the guidelines.

KEY RECOMMENDATIONS

In patients presenting with clinically node negative axillae, sentinel node biopsy (SNB) may be performed prior to or on completion of neo-adjuvant chemotherapy (NACT). In patients presenting with clinically node positive axillae, SNB may be safely considered following completion of NACT. Four nodes should be removed with dual mapping. If evidence of complete pathological response of previous metastases is seen, axillary radiotherapy may be offered. If residual cancer (isolated tumour cells, micro- or macrometastes) is seen within the SNB, offer axillary node dissection.

Debating the Optimal Approach to Nodal Management After Pathologic Complete Response to Neoadjuvant Chemotherapy in Patients With Breast Cancer

Greater use of neoadjuvant chemotherapy in patients with breast cancer has led surgeons and radiation oncologists to have frequent encounters with women with upfront node-positive disease and a clinical complete response. These cases raise many important questions about what the optimal locoregional management should be to minimize recurrence risk while minimizing treatment-related toxicities. A particular point of debate is whether all patients who are known to have had node-positive disease before neoadjuvant chemotherapy should receive complete axillary lymph node dissection (ALND) if they have had a complete clinical and radiologic response. In this article, we present arguments and evidence in favor of and against axillary dissection after a complete response to neoadjuvant chemotherapy, followed by a brief data-driven review of implications for adjuvant radiotherapy in this context. We conclude that as trials continue to gather more evidence to guide decisions in the future, we must encourage patients to enroll in clinical trials when eligible, and otherwise support them to make decisions that are informed and congruent with their personal values in areas where there is clinical equipoise.

Preoperative axillary nodal staging with ultrasound and magnetic resonance imaging: predictive values of quantitative and semantic features

OBJECTIVE:

Although axillary imaging has recently received renewed interest for preoperative staging in tandem with the evolving minimally invasive surgical approaches, axillary imaging is limited by the lack of standardization in the interpretation. We aimed to classify imaging features in ultrasound and MRI into quantitative and semantic features and evaluate predictive value of each feature for predicting nodal metastases.

METHODS:

A total of 316 breast cancers patients who underwent ultrasound and MRI prior to axillary surgery were included. Retrospective reviews of our breastimaging database were done for the quantitative features [cortical thickness (CT) and CT-derived parameters, long diameter (LD), short diameter (SD), and LD/SD ratio] and semantic features (eccentricity, loss of fatty hilum, and irregularity) of the axillary lymph node in images. Odd ratios (ORs) for each imaging feature were calculated with adjustment for clinicopathological characteristics significantly associated with nodal metastases.

RESULTS:

All CT-derived parameters were significantly associated with nodal metastases in both ultrasound and MRI (OR, 3.3-3.5 for ultrasound and 3.3-3.9 for MRI, respectively; Ps < .05). For the ultrasound, LD/SD ratio (OR, 2.1), eccentricity (OR, 2.4), and fatty hilum loss (OR, 27.2) were significantly associated with nodal metastases (Ps < .05). For the MRI, SD (OR, 2.1) and eccentricity (OR, 3.0) were significantly associated with nodal metastases (Ps < .05).

CONCLUSION:

Among the quantitative features, all CT-derived parameters can be used for predicting nodal metastases. Significant predictors of semantic features were heterogeneous between ultrasound and MRI.

ADVANCES IN KNOWLEDGE:

(1) Imaging features of ultrasound and MRI for preoperative axillary nodal staging can be classified into quantitative and semantic features. (2) Predictive values of each imaging features are heterogeneous for predicting nodal metastases.

Meta-analysis of the diagnostic accuracy of ultrasound-guided fine-needle aspiration and core needle biopsy in diagnosing axillary lymph node metastasis

Background

Axillary lymph node status remains a significant prognostic indicator in breast cancer. Here, the diagnostic accuracy of ultrasound-guided fine-needle aspiration (US-FNA) and ultrasound-guided core needle biopsy (US-CNB) in axillary staging was compared.

Methods

A comprehensive search was undertaken of all published studies comparing the diagnostic accuracy of US-CNB and US-FNA of axillary lymph nodes in breast cancer. Studies were included if raw data were available on the diagnostic performance of both US-FNA and US-CNB, and compared with final histology results. Relevant data were extracted from each study for systematic review. Meta-analysis was performed using a random-effects model. The pooled sensitivity and specificity of US-FNA and US-CNB were obtained using a bivariable model. Summary receiver operating characteristic (ROC) graphs were created to confirm diagnostic accuracy.

Results

Data on a total of 1353 patients from six studies met the inclusion criteria and were included in the final analysis. US-CNB was superior to US-FNA in diagnosing axillary nodal metastases: sensitivity 88 (95 per cent c.i. 84 to 91) versus 74 (70 to 78) per cent respectively. Both US-CNB and US-FNA had a high specificity of 100 per cent. Reported complication rates were significantly higher for US-CNB compared with US-FNA (7·1 versus 1·3 per cent; P &lt; 0·001). Conversely, the requirement for repeat diagnostic procedures was significantly greater for US-FNA (4·0 versus 0·5 per cent; P &lt; 0·001).

Conclusion

US-CNB is a superior diagnostic technique to US-FNA for axillary staging in breast cancer.

Conservative Management of Positive Axilla After Neoadjuvant Systemic Therapy-The Need for, and Review of, Techniques Used for Lymph Node Localization

Involvement of axillary lymph nodes is an important prognostic factor in relationship to the management of breast cancer. However, the use of neoadjuvant systemic therapy is widespread in the treatment of positive axilla and such treatment leads to downstaging of axillary disease. Hence, the role of targeted axillary lymph node biopsy appears to play a vital role after primary systemic therapy. Given that this is a relatively novel approach, we have discussed the evidence for this approach and the different techniques currently available for localization of biopsy-proven metastatic axillary lymph nodes. We have also highlighted the need for universal guidelines for conservative management of positive axilla after systemic therapy.