Evaluation of axillary lymph node metastasis burden by preoperative ultrasound in early-stage breast cancer with needle biopsy-proven metastasis

Prediction of the axillary lymph-node metastatic burden of breast cancer by 18F-FDG PET/CT-based radiomics

BACKGROUND

The axillary lymph-node metastatic burden is closely associated with treatment decisions and prognosis in breast cancer patients. This study aimed to explore the value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT)-based radiomics in combination with ultrasound and clinical pathological features for predicting axillary lymph-node metastatic burden in breast cancer.

METHODS

A retrospective analysis was conducted and involved 124 patients with pathologically confirmed early-stage breast cancer who had undergone 18F-FDG PET/CT examination. The ultrasound, PET/CT, and clinical pathological features of all patients were analysed, and radiomic features from PET images were extracted to establish a multi-parameter predictive model.

RESULTS

The ultrasound lymph-node positivity rate and PET lymph-node positivity rate in the high nodal burden group were significantly higher than those in the low nodal burden group (χ2 = 19.867, p < 0.001; χ2 = 33.025, p < 0.001). There was a statistically significant difference in the PET-based radiomics score (RS) for predicting axillary lymph-node burden between the high and low lymph-node burden groups. (-1.04 ± 0.41 vs. -1.47 ± 0.41, t = -4.775, p < 0.001). The ultrasound lymph-node positivity (US_LNM) (odds ratio [OR] = 3.264, 95% confidence interval [CI] = 1.022-10.423), PET lymph-node positivity (PET_LNM) (OR = 14.242, 95% CI = 2.960-68.524), and RS (OR = 5.244, 95% CI = 3.16-20.896) are all independent factors associated with high lymph-node burden (p < 0.05). The area under the curve (AUC) of the multi-parameter (MultiP) model was 0.895, which was superior to those of US_LNM, PET_LNM, and RS models (AUC = 0.703, 0.814, 0.773, respectively), with statistically significant differences (Z = 2.888, 3.208, 3.804, respectively; p = 0.004, 0.002, < 0.001, respectively). Decision curve analysis indicated that the MultiP model provided a higher net benefit for all patients.

CONCLUSION

A MultiP model based on PET-based radiomics was able to effectively predict axillary lymph-node metastatic burden in breast cancer.

TRIAL REGISTRATION

This study was registered with ClinicalTrials.gov (registration number: NCT05826197) on May 7, 2023.

The extent of agreement between frozen and paraffin block data from axillary samples in patients with early-stage breast cancer

INTRODUCTION

Patients with early-stage breast cancer currently undergo sentinel lymph node dissection to evaluate the axillary region. Frozen tissue blocks are evaluated intra operatively and paraffin-embedded samples are studied postoperatively. We explored whether sentinel lymph node dissection adequately reflected axillary involvement (as revealed by the paraffin blocks) in patients with early-stage breast cancer; we sought to avoid axillary dissection.

METHODS

The agreement/non-agreement rates between the results of axillary ultrasonography and biopsy, sentinel lymph node and axillary dissections, and frozen and paraffin block results, were retrospectively analyzed for 200 patients with early-stage breast cancer. The positive predictive values and accuracies were recorded in those who were positive on both ultrasonography and biopsy. The negative predictive values were calculated for doubly negative cases.

RESULTS

The frozen and paraffin block results disagreed in 19 (9.5 %) cases and agreed in 181 (90.5 %). The frozen block and dissection results differed in five of 38 patients who underwent axillary dissection (AD) (one patient did not undergo AD); the results were in agreement in 32. Of the 19 block-disagreement cases, 16 were in the non-neoadjuvant chemotherapy (NAC) group and three in the NAC treatment group. Clinically, the negative predictive values of the frozen and paraffin block data were 80 % in patients lacking axillary involvement.

CONCLUSION

Paraffin block evaluations only (thus, without frozen block examinations) of early-stage breast cancer lymph nodes seem to be sufficient to guide treatment. Also, a thorough clinical examination (with ultrasonography and axillary biopsy) reduces the dissection rate and the associated functional impairments.

Surgical Management of the Axilla for Breast Cancer

This review discusses the contemporary surgical management of the axilla in patients with breast cancer. Surgical paradigms are highlighted by clinical nodal status at presentation and treatment approach, including upfront surgery and neoadjuvant systemic therapy settings. This review focuses on the increasing opportunities for de-escalating the extent of axillary surgery in the era of sentinel lymph node biopsy, while also reviewing the remaining indications for axillary clearance with axillary lymph node dissection.

MRI characteristics of breast edema for assessing axillary lymph node burden in early-stage breast cancer: a retrospective bicentric study

OBJECTIVES

To investigate whether breast edema characteristics at preoperative T2-weighted imaging (T2WI) could help evaluate axillary lymph node (ALN) burden in patients with early-stage breast cancer.

METHODS

This retrospective study included women with clinical T1 and T2 stage breast cancer and preoperative MRI examination in two independent cohorts from May 2014 to December 2020. Low (< 3 LNs+) and high (≥ 3 LNs+) pathological ALN (pALN) burden were recorded as endpoint. Breast edema score (BES) was evaluated at T2WI. Univariable and multivariable analyses were performed by the logistic regression model. The added predictive value of BES was examined utilizing the area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

A total of 1092 patients were included in this study. BES was identified as the independent predictor of pALN burden in primary (n = 677) and validation (n = 415) cohorts. The analysis using MRI-ALN status showed that BES significantly improved the predictive performance of pALN burden (AUC: 0.65 vs 0.71, p < 0.001; IDI = 0.045, p < 0.001; continuous NRI = 0.159, p = 0.050). These results were confirmed in the validation cohort (AUC: 0.64 vs 0.69, p = 0.009; IDI = 0.050, p < 0.001; continuous NRI = 0.213, p = 0.047). Furthermore, BES was positively correlated with biologically invasive clinicopathological factors (p < 0.05).

CONCLUSIONS

In individuals with early-stage breast cancer, preoperative MRI characteristics of breast edema could be a promising predictor for pALN burden, which may aid in treatment planning.

KEY POINTS

• In this retrospective study of 1092 patients with early-stage breast cancer from two cohorts, the MRI characteristic of breast edema has independent and additive predictive value for assessing axillary lymph node burden. • Breast edema characteristics at T2WI positively correlated with biologically invasive clinicopathological factors, which may be useful for preoperative diagnosis and treatment planning for individual patients with 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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Rates of pathologic nodal disease among cN0 and cN1 patients undergoing routine axillary ultrasound and neoadjuvant chemotherapy

PURPOSE

Routine axillary ultrasound (AxUS) in patients receiving neoadjuvant chemotherapy (NAC) remains controversial. Here, we report rates of AxUS-detected nodal disease among patients with normal clinical exams, and rates of pathologic nodal disease after NAC based on method of nodal disease detection.

METHODS

Clinicopathologic findings were prospectively collected for stage I-III breast cancer patients selected for NAC. All patients had pre-treatment AxUS, suspicious nodes were biopsied. The following four patient cohorts were examined: patients with suspicious exam or AxUS but negative biopsy (Suspicious cN0); those with normal exam and normal AxUS (Not Suspicious cN0); those with normal exam but suspicious AxUS and positive biopsy (AxUS-detected cN1); and those with abnormal exam and positive biopsy (exam-detected cN1). Sentinel (SLN) and non-sentinel lymph nodes (non-SLN) were evaluated by immunohistochemistry; nodal metastases of any size were considered positive.

RESULTS

500 patients were included. Of 310 patients with normal axillary exams, 160 had suspicious AxUS, 65 were biopsy-negative (Suspicious cN0) and 95/310 (30.6%) were biopsy-positive (AxUS-detected cN1). Of 190 with abnormal axillary exams, 166 were biopsy-proven node-positive (exam-detected cN1) and 24 were AxUS or biopsy-negative (Suspicious cN0). Rates of pathologic nodal disease were 20/150 (13.3%) among Not Suspicious cN0 patients, 12/89 (13.5%) among Suspicious cN0 (p = 0.97). Rates of residual nodal disease were 55/95 (57.9%) among AxUS-detected cN1 patients, 102/166 (61.4%) among exam-detected cN1 (p = 0.57).

CONCLUSION

AxUS detected nodal disease in 30.6% of patients with normal clinical exams selected for NAC. Rates of pathologic nodal disease were similar among AxUS-detected and exam-detected cN1 patients.

The new perspective of PET/CT for axillary nodal staging in early breast cancer patients according to ACOSOG Z0011 trial PET/CT axillary staging according to Z0011

OBJECTIVE

Post Z0011 trial, axillary lymph node dissections (ALNDs) can be performed in patients with ≥3 positive axillary lymph nodes (ALNs). We investigated the diagnostic performance of 18F-fluorodeoxyglucose PET/computed tomography (FDG PET/CT) to predict ≥3 metastasis [high nodal burden (HNB)].

METHODS

We retrospectively analyzed preoperative FDG PET/CT from January 2010 to June 2012. Patients had clinical T1-2N0 primary invasive breast cancer and underwent breast-conserving surgery with sentinel lymph node biopsy ± ALND. All suspicious ALNs were counted considering FDG-avidity with morphologic changes. Images were considered positive if the axillary basin took up more FDG than the surrounding tissue. On CT, abnormal ALNs were round/ovoid or had cortical thickening with contrast enhancement. PET/CT results were compared with the histology and follow-up findings.

RESULTS

In total, 221 females with 224 axillae were enrolled; 161 had negative, 53 had 1-2 metastasis [low nodal burden (LNB)] and 10 had HNB. The sensitivity, specificity, negative predictive value and positive predictive value of PET/CT for HNB were 70, 100, 98.6 and 100%, respectively. There was a correlation between the number of suspicious ALNs on PET/CT and the metastatic nodes on final histology. There were no significant differences in age, tumor size and FDG-avidity between patients with negative or LNB and HNB. During follow-up, 25 patients had a recurrence. The three false-negative patients did not show recurrence.

CONCLUSION

Preoperative PET/CT predicts HNB with high accuracy and is useful for evaluating clinical T1-2N0 invasive breast cancer.

The prognostic impact of mode of detection of axillary metastases for women with invasive breast cancer: A retrospective observational study

AIM

To identify the breast cancer specific survival (BCSS) associated with nodal metastasis identified by axillary core biopsy (ACB), and by sentinel node biopsy (SNB) compared with node negative patients. A further aim was to assess the prognostic effects of axillary ultrasound (US) features and amount of tumour in ACB specimens.

METHODS

Consecutive patients with cancer were identified from a database of US lesions undergoing breast biopsy. The three study groups were: a) those with metastasis identified by ACB, b) those undergoing immediate surgery with positive SNB and c) those undergoing immediate surgery with a negative SNB. US features and the amount of tumour in the ACB specimen were assessed by review of US images and pathological reports. BCSS was assessed using Kaplan Meier survival curves.

RESULTS

967 patients were included, with mean follow-up of 6.0 yrs. There were 90 breast cancer deaths: 26% of those with a positive ACB, 11% with a positive SNB and 4% of those with a negative SNB. BCSS was significantly different between the groups (p < 0.001) with hazard ratio, compared with the negative SNB group, of 7.8 (95% CI 4.4-13.7) for patients with positive ACB and 2.5 (95% CI 1.3-4.6) for positive SNB. Axillary US findings and assessment of the amount of tumour in the ACB did not influence survival.

CONCLUSION

This study suggests that women with a positive ACB have a worse BCSS compared to those with a positive SNB. This should be borne in mind when systemic therapy is being considered.

Deep learning radiomics can predict axillary lymph node status in early-stage breast cancer

Accurate identification of axillary lymph node (ALN) involvement in patients with early-stage breast cancer is important for determining appropriate axillary treatment options and therefore avoiding unnecessary axillary surgery and complications. Here, we report deep learning radiomics (DLR) of conventional ultrasound and shear wave elastography of breast cancer for predicting ALN status preoperatively in patients with early-stage breast cancer. Clinical parameter combined DLR yields the best diagnostic performance in predicting ALN status between disease-free axilla and any axillary metastasis with areas under the receiver operating characteristic curve (AUC) of 0.902 (95% confidence interval [CI]: 0.843, 0.961) in the test cohort. This clinical parameter combined DLR can also discriminate between low and heavy metastatic burden of axillary disease with AUC of 0.905 (95% CI: 0.814, 0.996) in the test cohort. Our study offers a noninvasive imaging biomarker to predict the metastatic extent of ALN for patients with early-stage breast cancer.

Breast cancer is frequently diagnosed using ultrasound. Here, the authors show that, in addition to ultrasound, shear wave elastography can be used to diagnose breast cancer and, in conjunction with deep learning and radiomics, can predict whether the disease has spread to axillary lymph nodes.

Can We Identify or Exclude Extensive Axillary Nodal Involvement in Breast Cancer Patients Preoperatively?

Background

Breast cancer treatment has rapidly changed in the last few years. Particularly, treatment of patients with axillary nodal involvement has evolved after publication of several randomized clinical trials. Omitting axillary lymph node dissection in selected early breast cancer patients with one or two positive sentinel nodes did not compromise overall survival nor regional disease control in these trials. Hence, either excluding or identifying extensive axillary nodal involvement becomes increasingly important.

Purpose

To evaluate whether the current diagnostic modalities can accurately identify or exclude extensive axillary nodal involvement. Evaluated modalities were axillary ultrasound, ultrasound-guided needle biopsy, MRI, and PET/CT.

Methods

A literature search was performed in the Cochrane Library, EMBASE, and PubMed databases up to June 2019. The search strategy included terms for breast cancer, lymph nodes, and the different imaging modalities. Only articles that reported pathological N-stage or the total number of positive axillary lymph nodes were considered for inclusion. Studies with patients undergoing neoadjuvant systemic therapy were excluded.

Conclusion

There is no evidence that any of the current preoperative axillary imaging modalities can accurately exclude or identify breast cancer patients with extensive nodal involvement. Both negative PET/CT and negative MRI scans (with gadolinium-based contrast agents) are promising in excluding extensive nodal involvement. Larger studies should be performed to strengthen this conclusion. False-negative rates of axillary ultrasound and ultrasound-guided needle biopsy are too high to rely on negative results of these modalities in excluding extensive nodal involvement.