Impact of axillary ultrasound (AUS) on axillary dissection in breast conserving surgery (BCS)

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.

Imaging Evaluation of the Axilla-A National Survey of Clinical Practice Among Radiologists

OBJECTIVE

To assess awareness and implementation of the American College of Surgeons Oncology Group Z0011 trial findings, approaches to axillary nodal imaging, and to identify differences in practice based on respondent characteristics.

METHODS

An online survey was distributed to members of the Society of Breast Imaging. Questions regarded demographics, evaluation approaches, and impact of the Z0011 trial. Poisson regression with robust standard errors to regression was used to generate multivariable-adjusted relative risks and 95% confidence intervals (CIs) for associations.

RESULTS

The response rate was 21.7% (430/2007). The majority (295/430, 68.6%) reported always performing axillary US in patients with a BI-RADS 4B, 4C, or 5 breast mass. Most respondents (299/430, 69.5%) were familiar with the findings of the Z0011 trial. Radiologists in academic practice were 0.67 (95% CI: 0.54-0.83) times less likely than private practice radiologists to perform axillary US in all masses and 1.31 (95% CI: 1.13-1.52) times more likely to be very familiar with the trial. Frequency of axillary US showed no association with time spent in breast imaging, years in practice, or presence of dedicated breast surgeons. Increased time in breast imaging and presence of dedicated breast surgeons was strongly associated with familiarity with the trial. No association was observed with years in practice. Most respondents (291/430, 67.7%) made little or no change to their practice based on trial findings.

CONCLUSION

There is wide variability in approaches to axillary nodal evaluation, demonstrating a need for improved education and guidelines for axillary imaging in breast cancer patients.

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

AIM

The aim of this study was to assess the efficacy of preoperative axillary ultrasonography (AUS) and preoperative axillary fine-needle aspiration biopsy (FNAB) from suspicious lymph nodes in clinically node-negative breast cancer to compare with radiologically positive and sentinel lymph node biopsy (SLNB) positive involvement.

METHOD

Clinically node-negative early-stage breast cancer patients were included in the study. These patients underwent preoperative AUS examination, suspicious lymph nodes were evaluated with FNAB. AUS-FNAB results were compared with those of SLNB or axillary dissection.

RESULTS

Of 181 patients undergoing AUS, 32 were reported to have axillary metastasis, 25 suspicious, and 124 benign nodes. The suspicious group underwent FNAB examination and metastasis was found in 9 of them. The sensitivity of AUS-FNAB was found to be 64.06%, specificity 100%, positive predictive value 100%, and negative predictive value (NPV) 83.5%. The false negativity rate (FN) of this method was 16,4%. Lymphovascular invasion and tumour size were found statistically significant factors for false negativity.

CONCLUSION

It was concluded that axillary AUS-FNAB with its high NPV, low FN rate, may be a clinical alternative to SLNB for early-stage breast cancer patients.

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.

Does use of axillary ultrasound in clinically node-negative patients receiving neo-adjuvant systemic therapy for breast cancer lead to surgical overtreatment?

Increased use of neo-adjuvant chemotherapy (NAC) for breast cancer has raised uncertainty regarding staging of the axilla, particularly for patients with a clinically negative axillary physical examination (PE). We sought to determine whether axillary ultrasound (AUS) prior to NAC to identify occult nodal disease is beneficial in patients with a clinically negative examination by evaluating the difference in nodal burden on final pathology in those with abnormal vs normal AUS. A retrospective review of an institutional cancer registry identified patients who underwent NAC for breast cancer and had a pretreatment AUS. Differences in the number of positive lymph nodes (PLN) in patients with a normal axillary PE and abnormal vs normal AUS prior to NAC were determined. A total of 120 patients who received NAC had a negative axillary PE prior to treatment. Fifty-three had an abnormal AUS and biopsy-proven lymph node (LN) involvement. In patients with an abnormal AUS, median number of PLNs at surgery was 1 vs 0 for those with a normal AUS (mean difference of 2.12, P < .0001). Of those patients with an abnormal AUS and biopsy-proven LN involvement, 87% underwent axillary lymph node dissection (ALND) and nearly half had no PLN on final pathology (N = 23, 43%). Patients with a clinically negative axilla and an abnormal AUS were more likely to have PLN at the time of surgery. However, almost half of those patients had no residual LN involvement. Routine AUS prior to NAC may lead to more extensive surgical management of the axilla.

Evolution in practice patterns of axillary management following mastectomy in patients with 1-2 positive sentinel nodes

PURPOSE

The optimal management of breast cancer patients with a positive sentinel lymph node (SLN) who undergo mastectomy remains controversial. This study aimed to describe treatment patterns of patients with positive SLNs who undergo mastectomy using a large population-based database.

METHODS

The NCDB was queried for cT1-2N0 breast cancer patients treated with mastectomy between 2006 and 2014 who had 1-2 positive SLNs. Patients receiving neoadjuvant chemotherapy were excluded. Axillary management included SLN dissection (SLND) alone, axillary lymph node dissection (ALND), post-mastectomy radiation (PMRT) alone, and ALND + PMRT. Trends of axillary management and patient characteristics were examined.

RESULTS

Among 12,190 patients who met study criteria, the use of ALND dropped with a corresponding increase in other approaches. In 2006, 34% of patients had SLND alone, 47% ALND, 8% PMRT and 11% ALND + PMRT. By 2014, 37% had SLND, 23% ALND, 27% PMRT and 13% ALND + PMRT. Patients who underwent SLND alone were older (mean 60.6 years) with more comorbidities (Charlson-Deyo score > 2), smaller primary tumors (mean 2.1 cm), well-differentiated histology, hormone receptor-positive, HER2-negative tumors, without lymphovascular invasion (all P values < 0.01). Treatment with SLND alone was more likely if patients had only one positive SLN (P < 0.001) or micrometastatic disease (P < 0.001), and were treated at community centers compared with academic centers (P < 0.001).

CONCLUSIONS

The management of breast cancer patients undergoing mastectomy with positive SLNs has evolved over time with decreased use of ALND and increased use of radiation. Some patient subsets are underrepresented in recent clinical trials, and therefore, future trials should focus on these patients.

Value of ultrasound-guided fine needle aspiration in diagnosing axillary lymph node recurrence after breast cancer surgery

BACKGROUND

This article aims to assess the diagnostic performance of ultrasound-guided fine needle aspiration (US-FNA) in diagnosing axillary lymph node (ALN) recurrence in patients with a history of breast cancer.

METHODS

From January 2005 to June 2015, 231 US-FNA examinations performed for suspicious axillary lesions in 218 patients with a history of breast cancer were included. Diagnostic performance of US-FNA for ALN recurrence were evaluated.

RESULTS

Of the 231 US-FNA examinations, 172 (74.5%) obtained negative and 59 (25.5%) obtained positive cytological results. All US-FNA-negative axillary lesions were considered imaging-cytology concordant and underwent follow-up, with one false-negative result (false negative rate, 1.6% [1/60]). The overall sensitivity, specificity, PPV and NPV of US-FNA for diagnosing ALN recurrence/metastasis per examination were 98.3% (59/60), 100% (171/171), 100% (59/59) and 99.4% (171/172). When excluding nine patients with newly developed contralateral breast cancer, the sensitivity, specificity, PPV and NPV of US-FNA for diagnosing ALN recurrence was 98.1% (51/52),100% (170/170),100% (51/51) and 99.4% (170/171).

CONCLUSIONS

US-FNA is a reliable method for diagnosing axillary recurrence in patients with a history of breast cancer.

Expanding Implementation of ACOSOG Z0011 in Surgeon Practice

BACKGROUND

After publication of American College of Surgeons Oncology Group (ACOSOG) Z0011, surgeons at our institution limited axillary surgery to sentinel lymph node dissection (SLND) in 76% of patients meeting trial eligibility criteria. Our study objective was to assess incorporation of the trial data into practice 5 years later.

PATIENTS AND METHODS

Patients with clinical T1-2, N0 invasive breast cancer undergoing breast conserving surgery were included. Comparisons were made between patients who underwent axillary lymph node dissection (ALND) and those that had no further surgery.

RESULTS

A total of 396 patients were included. Twelve percent (48/396) had positive SLNs; ALND was performed in 8% (4/48). Patients who underwent ALND were more likely to have 2 positive SLNs (50%, 2/4 vs. 2%, 1/44; P = .02) and microscopic extranodal extension (75%, 3/4 vs. 18%, 8/44; P = .03) than those that did not undergo ALND. Patients who underwent ALND also had a higher nomogram-predicted probability of having additional positive non-SLNs (53%) than those who had SLND alone (22%) (P = .0002). No patients had intraoperative assessment of SLNs performed.

CONCLUSIONS

The practice of omitting ALND in ACOSOG Z0011-eligible patients has expanded over 5 years. Clinicopathologic features continue to impact this decision. Intraoperative SLN assessment is no longer performed.

Positive Ultrasound-guided Lymph Node Needle Biopsy in Breast Cancer may not Mandate Axillary Lymph Node Dissection

BACKGROUND

The ACOSOG Z0011 (Z11) trial demonstrated that in patients with nonpalpable axillary lymph nodes (LN) and one to two positive sentinel LN (SLN), axillary LN dissection (ALND) is unnecessary.JAMA 305:569-575, [2011], Ann Surg 264:413-42, [2016] The Z11 trial did not require preoperative axillary ultrasound (axUS). In many centers, preoperative axUS is part of the standard workup of a newly diagnosed breast cancer patient, but in light of the Z11 results, its role is now questioned.

METHODS

We retrospectively analyzed newly diagnosed breast cancer patients at two institutions. Inclusion criteria were patients with (1) no palpable lymphadenopathy, (2) abnormal axUS, (3) axillary LN metastasis confirmed preoperatively by axUS-lymph node needle biopsy, (4) no neoadjuvant therapy, and (5) ALND. LN disease burden was dichotomized as N1 versus N2-3. We examined relationships between clinicopathologic factors, including axUS characteristics, and LN disease burden.

RESULTS

Of 129 included cases, 67 had N1 disease (51.9%) and 62 had N2-3 disease (48.1%). Factors significantly associated with N1 disease were tumor size ≤2 cm (p = 0.012), nonlobular histology (p = 0.013), and one suspicious LN on axUS (p = 0.008). For patients with both tumor size on imaging ≤2 cm and one abnormal LN on axUS, only 27% had N2-3 disease (p = 0.007).

CONCLUSIONS

More than half of patients without palpable adenopathy but with preoperative US-guided biopsy proven axillary LN metastases had N1 disease. For patients with both tumor size ≤2 cm and only 1 abnormal LN on axUS, 73% had N1 disease. This suggests that such patients, if they are otherwise analogous to Z11 patients, may undergo attempt at SLNB.

Axillary ultrasound and Fine-Needle Aspiration Cytology in the preoperative staging of axillary node metastasis in breast cancer patients

OBJECTIVE

A prospective observational clinical study was undertaken to assess the accuracy of preoperative Axillary Ultrasound (AUS) plus Fine-Needle Aspiration Cytology (FNAC) as well as and its clinical utility, that is the capacity of the information supplied by the test to guide the clinical decision-making.

MATERIALS AND METHODS

from January 2013 to August 2015, 400 female patients with pT1-3 cN0 operable breast cancer underwent AUS with FNAC at the Breast Unit of the "IRCCS San Martino-IST" in Genoa (Italy).

RESULTS

127 out of 400 patients (31.7%) had axillary lymph node metastases; in 69 out of 127 node-positive patients (54.3%) AUS detected at least one abnormal lymph node, and in 56 out of 127 patients (44.1%) the abnormal sonographic pattern of the lymph node was coupled with a positive FNAC finding. No false-positive finding by both AUS-alone or combined AUS/FNAC was observed. AUS-alone had sensitivity of 54.3% (69/127), specificity of 100% (273/273), PPV of 100% (69/69), NPV of 82.5% (273/331), and accuracy of 85.5% (342/400). Combined AUS/FNAC had sensitivity of 44.1% (56/127), specificity of 100% (273/273), PPV of 100% (56/56), NPV of 79.4% (273/344), and accuracy of 82.2% (329/400).

CONCLUSIONS

AUS-alone or combined AUS/FNAC had a high accuracy rate coupled with a more than satisfactory efficiency due to their low costs and easy access for the preoperative staging of the axilla. Notably, AUS-alone might be suggested for the preoperative staging of patients with early stage breast cancer because FNAC did not increased the specificity but reduced the sensitivity of the technique. Patients with negative findings might undergo either SLNB or close observation while waiting for the definitive results of ongoing SOUND randomized clinical trial.

Is ultrasound-guided fine-needle aspiration cytology of adequate value in detecting breast cancer patients with three or more positive axillary lymph nodes?

This study evaluated the accuracy of ultrasound-guided fine-needle aspiration cytology of the sonographically most suspicious axillary lymph node (US/FNAC) to select early breast cancer patients with three or more tumour-positive axillary lymph nodes. Between 2004 and 2014, a total of 2130 patients with histologically proven early breast cancer were evaluated and treated in the Noordwest Clinics Alkmaar. US/FNAC was performed preoperatively in all these patients. We analysed the results of US/FNAC retrospectively. Pathological axillary node status (sentinel node biopsy and/or axillary lymph node dissection) was used as reference standard. A total of 634 (29.8 %) of 2130 patients had axillary lymph node metastases on final histology. 248 node positive patients (11.6 %) had three or more positive lymph nodes. The accuracy of US/FNAC to detect three or more positive lymph nodes was 89.8 %, sensitivity was 44.8 %, specificity was 95.7 %, PPV was 58.1 %, and NPV was 92.9 %. This study shows a more than adequate accuracy of preoperative US/FNAC to detect three or more positive lymph nodes (89.8 %). However, when US/FNAC was chosen as the only axillary staging method, 6.4 % of all patients (false negative group) would have been undertreated and 3.8 % of all patients (false positive group) would have been overtreated according to the ACOSOG Z0011 criteria.