Selection for axillary clearance in breast cancer (ultrasound negative, sentinel node positive patients have low rates of further metastases)

[Is preoperative axillary radio-cytology justified after ACOSOG Z001?]

INTRODUCTION

Invasive breast cancer without clinical adenopathy (cN0) is currently explored by the sentinel node (GS) technique, except in the case of positive preoperative radio-cytological screening, where axillary curage (CA) remains systematic from the outset. Since the publication of the ACOSOG-Z0011 trial, abstention from CA is possible in patients presenting less than three metastatic GS. As a result, the value of axillary radio-cytological screening is being questioned as it could potentially lead to axillary surgical over-treatment. The objective of this study was to study clinically N0 patients with positive axillary cytology and to compare it to a group of patients with positive GS.

METHOD

One hundred and forty-seven patients with cN0 pN+ breast cancer treated between 2014 and 2016 were selected retrospectively. Two groups were constituted according to the initial radio-cytological evaluation. A CA was systematically performed.

RESULTS

Thirty-one patients with positive axillary cytology (n=31 vs. n=116) had more metastatic lymph nodes (P=0.01) in the AC, larger (P<0.001), less differentiated (P<0.001) tumours, and shorter recurrence-free survival (P=0.0114). It also appeared that 38.7 % of patients with a positive cytology had at most two metastatic nodes and could, according to the results of ACOSOG, benefit from therapeutic de-escalation.

CONCLUSION

X-ray cytological screening remains essential in order to select a subgroup of patients with a high lymph node tumour load. Additional studies are necessary in order to be able to offer therapeutic de-escalation to 1/3 of these patients without the risk of under-treatment for the remaining 2/3.

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

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

Preoperative Axillary Ultrasound versus Sentinel Lymph Node Biopsy in Patients with Early Breast Cancer

Background and objectives: With improved diagnostic means of early breast cancer, the percentage of cases with metastasis in axillary lymph nodes has decreased from 50–75% to 15–30%. Lymphadenectomy and sentinel lymph node biopsy are not treatment procedures, as they aim at axillary nodal staging in breast cancer. Being surgical interventions, they can lead to various complications. Therefore, recently much attention has been paid to the identification of non-invasive methods for axillary nodal staging. In many countries, ultrasound is a first-line method to evaluate axillary lymph node status. The aim of this study was to evaluate the prognostic value of ultrasound in detecting intact axillary lymph nodes and to assess the accuracy of ultrasound in detecting a heavy nodal disease burden. The additional objective was to evaluate patients’ and tumor characteristics leading to false-negative results. Materials and Methods: A total of 227 women with newly diagnosed pT1 breast cancer were included to this prospective study conducted at the Breast Surgery Unit, Clinic of Surgery, Hospital of Lithuanian University of Health Sciences Kauno Klinikos, between May 1, 2016, and May 31, 2018. All patients underwent preoperative axillary ultrasound examination. Ultrasound data were compared with the results of histological examination. The accuracy and true-negative rate of ultrasound were calculated. The reasons of false-negative results were analyzed. Results: Of the 189 patients who had normally appearing axillary lymph nodes on preoperative ultrasound (PAUS-negative), 173 (91.5%) patients were also confirmed to have intact axillary lymph nodes (node-negative) by histological examination after surgery. The accuracy and the negative predictive value of ultrasound examination were 84.1% and 91.5%, respectively. In ≥3 node-positive cases, the accuracy and the negative predictive value increased to 88.7% and 98.3%, respectively. In total, false-negative results were found in 8.5% of the cases (n = 16); in the PAUS-negative group, false-negative results were recorded only in 1.6% of the cases (n = 3). The results of PAUS and pathological examination differed significantly between patients without and with lymphovascular invasion (LV0 vs. LV1, p < 0.001) as well as those showing no human epidermal growth factor receptor 2 (HER2) expression and patients with weakly or strongly expressed HER2 (HER2(0) vs. HER2(1), p = 0.024). Paired comparisons revealed that the true-negative rate was significantly different between the LV0 and LV1 groups (91% vs. 66.7%, p < 0.05), and the false-negative rate was statistically significant different between the HER2(0) and HER2(1) groups (10.5% vs. 1.2%, p < 0.05). Evaluation of other characteristics showed both the groups to be homogenous. Conclusions: Negative axillary ultrasound excluded axillary metastatic disease in 91.5% of the patients. PAUS had an accuracy of 88.7% in detecting a heavy nodal disease burden. With the absence of lymphovascular invasion (LV0), we can rely on PAUS examination that axillary lymph nodes are intact (PAUS-negative), and this patients’ group could avoid sentinel lymph node biopsy. Patients without HER2 expression are at a greater likelihood of false-negative results; therefore, the findings of ultrasound that axillary lymph nodes are intact (PAUS-negative results) should be interpreted with caution.

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.

Shortcomings of ultrasound-guided fine needle aspiration in the axillary management of women with breast cancer

Background

Ultrasound, along with ultrasound-guided fine needle aspiration, is currently used for the axillary evaluation of breast cancer patients in order to identify candidates for axillary lymph node dissection. The aim of this study is to evaluate the accuracy of this tool in correctly identifying patients who may or may not benefit from axillary clearance in light of the ACOSOG Z0011 trial recommendations.

Methods

One hundred one patients (65 with positive US-FNA with corresponding axillary lymph node dissection (ALND), and 36 with negative US-FNA with corresponding ALND/sentinel lymph node biopsy) were studied for the number of involved axillary lymph nodes, tumor clinicopathologic features, and axillary radiologic findings.

Results

From the positive US-FNA group, 43% of patients had two or fewer positive lymph nodes upon ALND pathologic examination. In the US-FNA negative group, the negative predictive value for detecting axillary disease was 72.7%. With both groups combined, the sensitivity, specificity, PPV, and NPV of US-FNA for selecting patients based on axillary disease burden were 86%, 51.7%, 57%, and 83.3%, respectively.

Conclusion

Based on Z0011 guidelines, US-FNA is not a reliable tool in triaging patients in need for ALND and leads to overtreatment of 43% patients when positive, while depriving a small but significant percentage of patients from necessary therapy, when negative.

A comparative analysis of axillary nodal burden in ultrasound/biopsy positive axilla vs ultrasound negative sentinel lymph node biopsy positive axilla

BACKGROUND

Axillary Ultrasound (AUS) is now performed as a protocol in every newly diagnosed breast cancer in most European countries. It is an inexpensive and sensitive tool in hands of a trained operator. All AUS negative patients undergo Sentinel Lymph Node Biopsy (SLNB), while AUS positive patients bypass SLNB and undergo axillary nodal clearance (ANC) as a standard protocol. We wish to analyse these two groups to see if ANC can be foregone in these patients.

AIMS AND OBJECTIVES

To compare and analyse the axillary disease burden in early breast cancer patients, with positive axilla, detected by AUS+ Biopsy versus those patients with normal axillary ultrasound or negative axillary biopsy that underwent ANC due to positive SLNB.

MATERIAL AND METHODS

A retrospective review of all patients who underwent axillary lymph node clearance following histologically confirmed positive ultrasound (US) axilla (year 2009-2014) was performed and was compared with data collected for patients with USG negative but SLNB (OSNA- One Step Nucleic Acid Amplification) positive axilla.

RESULTS

Axillary clearances performed for positive US axilla yielded significantly more positive lymph nodes than SLNB/OSNA positive axilla (p = 0.00496). These patients also had larger primary tumours (median 33 mm versus 21 mm, p = 0.01242) of a higher grade. Almost half of the patients in AUS positive group (49%) had high axillary nodal burden (>4 LNs). This is in great contrast with AUS negative, SLNB/OSNA positive group where 82.7% of patients had <4 positive nodes with more than half patients (51.7%) having no further positive nodes in their final histopathology specimen.

CONCLUSIONS

ANC should be a standard protocol in AUS positive patients as they invariably have high axillary disease burden while ANC can be omitted in case of select AUS negative and SLNB patients. However, further studies with more subjects may be require to substantiate the findings.

Different outcome in node-positive breast cancer patients found by axillary ultrasound or sentinel node procedure

Background

The Z0011 trial initiated a paradigm shift in the axillary treatment of breast cancer patients with a positive sentinel lymph node biopsy (SLNB), disregarding patients with a positive ultrasound-guided lymph node biopsy (UGLNB). We examined whether relevant differences exist between these patients to determine if the conclusions of the ACOSOG Z0011 trial are applicable to UGLNB-positive patients.

Methods

Patients diagnosed with invasive breast cancer in the Netherlands between January 2008 and December 2014 were selected from the Netherlands Cancer Registry.

Results

A total of 11,820 cases were included: 9149 cases in the SLNB group and 2671 in the UGLNB group. Multivariate analyses showed that UGLNB-positive patients were older (p < 0.001), more likely to have a poorly differentiated tumor (p < 0.001), had a negative hormone receptor status (p < 0.001), and more often had extensive nodal involvement (p < 0.001). However, they were less likely to undergo adjuvant radiation (p = 0.004) or systemic therapy (p < 0.001). Even after adjusting for these factors, UGLNB-positive patients had a worse overall survival (HR = 1.38; 95% CI 1.23–1.56) than SLNB-positive patients.

Conclusion

This nationwide retrospective study shows that young patients found positive by UGLNB have less favorable disease characteristics and a worse prognosis compared to patients with a positive SLNB. Selection by ultrasound plays an important role when axillary treatment strategies are considered. Hence, the conclusions of the Z0011 trial cannot unconditionally be applied to patients with a positive UGLNB.

The clinical utility of assessment of the axilla in women with suspicious screen detected breast lesions in the post Z0011 era

Axillary ultrasound (AUS) and biopsy are now part of the preoperative assessment of breast cancer based on the assumption that any nodal disease is an indication for axillary clearance (AC). The Z0011 trial erodes this assumption. We applied Z0011 eligibility criteria to patients with screen detected cancers and positive axillary assessment to determine the relevance of AUS to contemporary practice. Women screened between 1/1/2012 and 30/6/2013 and assessed for lesions with highly suspicious imaging features are included. We analysed demographic and assessment data and ascertained the final histopathology with particular reference to axillary nodal status. Among 449 lesions, AUS was recorded in 303 lesions (67.5 %). 290 (96 %) were carcinomas, 30.3 % with nodal disease. AUS was abnormal in 46 (15.9 %). AUS had a sensitivity of 39.8 %, specificity 94.6 %, positive predictive value (PPV) 79.2 % and negative predictive value (NPV) 78.1 %. Axillary FNAB was positive in 27 women, suspicious in two, benign in 16 and not performed in one. In one FNA positive case, the lesion was a nodular breast primary in the axillary tail in a multifocal breast cancer. Combining AUS and FNAB, the sensitivity was 76.5 %, specificity 90.9 %, PPV 96.3 % and NPV 55.6 %. Applying the Z0011 inclusion criteria, 24 of the 27 (88.9 %) women with abnormal AUS and positive FNA were ineligible for Z0011-based management. Of three women eligible for Z0011, one proceeded to AC after SN biopsy, leaving only two women (7.4 %) who might have been considered for SN only management had it not been for the results of the axillary assessment. Among women with negative AUS, nodal metastasis was demonstrated in 21.7 %, 86.8 % of these women having only 1-2 positive nodes. Abnormal AUS and FNA preferentially identify candidates for AC. Negative AUS predicts negative or low nodal burden. Axillary assessment streamlines care.