The feasibility and accuracy of sentinel lymph node biopsy in clinically node-negative patients after neoadjuvant chemotherapy for breast cancer--a systematic review and meta-analysis

The Feasibility and Reliability of Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Breast Cancer Patients With Negative Axillary Lymph Nodes-A Meta-analysis

Background

The application of sentinel lymph node biopsy (SLNB) has expanded from early breast cancer to locally advanced breast cancer with neoadjuvant chemotherapy (NAC). For patients with negative axillary lymph nodes, performing SLNB before or after NAC remains controversial.

Objectives

To evaluate the diagnostic feasibility and reliability of SLNB after NAC in breast cancer patients with negative axillary nodes at initial diagnosis.

Design

To calculate pooled identification rate (IR) and false negative rate (FNR) of SLNB after NAC on breast cancer patients with initially negative axillary nodes by enrolling relevant studies and perform subgroup analysis by the type of tracer and the number of biopsied sentinel lymph nodes in average.

Data sources and methods

The PubMed, Embase, Cochrane, Web of Science, and Scopus databases from January 1, 2002, to March 1, 2022, were searched for studies. The QUADAS-2 tool and MINORS item were employed to evaluate the quality of the included studies. I2 and Q tests were used to evaluate the heterogeneity among the studies. Random-effects model and fixed-effects model were employed to calculate the pooled IR, FNR, and 95% confidence interval (CI). Publication bias was evaluated, and sensitivity analysis was performed. Subgroup analysis was performed according to the type of tracer (single/double) and the number of biopsied sentinel lymph nodes in average (⩽2/>2).

Results

A total of 21 studies covering 1716 patients were enrolled in this study (IR = 93%, 95% CI = 90-96; FNR = 8%, 95% CI = 6-11).

Conclusion

The SLNB after NAC can serve as a feasible and reliable approach in breast cancer patients with negative axillary lymph node. In our study, no significant impact of tracer was found on the IR and FNR of SLNB, and the number of biopsy nodes >2 leads to the decreased FNR of SLNB.

Survival and inferential analysis in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and subsequent sentinel lymph node biopsy: prospective single-center study

BACKGROUND

The lymph node staging is the major prognostic factor in breast cancer patients. Sentinel lymph node biopsy (SLNB) allows an exactly axillar staging in patients with early disease, but not in locally advance breast cancer (LABC). Our aim was to study, the feasibility and accuracy of the SLNB technique with and without axillar lymphadenectomy (LDN) and with lymph node clipping after neoadjuvant chemotherapy (NAC), in patients with LABC.

PATIENTS AND METHODS

Patients diagnosed with LABC, scheduled for NAC and subsequent surgery and SLNB. Subsequently the patients were scheduled for adjuvant chemotherapy/hormonotherapy and radiotherapy according with the postsurgical results. Main end points were overall survival (OS) disease-free survival (DFS), mortality, SLNB identification rate (IR), sensitivity, false negative rate (FNR) of SLNB versus LDN, negative predictive value (NPV) and overall accuracy.

RESULTS

Our IR with different techniques was between 89.9 and 100%. OS was between 89 and 97%. DFS was between 89.8 and 96.8%. Sensitivity was between 75 and 100%. NPV was between 89.6 and 100%. FNR was between 0 and 25%; and accuracy was between 66 and 72%. We found that survival was lower (p < 0.05) in patients with triple negative and Luminal B/HER2 intrinsic subtype; with progression or major partial response in Magnetic Resonance Imaging (MRI) results at the end of NAC and in patients with BRCA1/2 mutation.

CONCLUSIONS

Our study presents excellent results of SLNB alone in patients with LABC with complete nodal response with an OS and DFS > 95%. The FNR is very high in partial responders, so we cannot recommend the SLNB alone in LABC. We recommend, in cN+ patients, axillar clipping, SLNB and LDN because in more than 50% of the patients with axillar clipping, this was not found, and because in 36% of the patients with negative LDN, the SLN (Sentinel Lymph Node) obtained was the only positive node, so these techniques together decrease the FNR and improve the node staging, OS and DFS. This study is the first prospective study that assess OS and DFS in patients with LABC, all submitted to SLNB.

Does Neoadjuvant Chemotherapy in Clinical T1-T2 N0 Triple-Negative Breast Cancer Increase the Extent of Axillary Surgery?

BACKGROUND

Current management strategies for early-stage triple-negative breast cancer (TNBC) include upfront surgery to determine pathologic stage to guide chemotherapy recommendations, or neoadjuvant chemotherapy (NAC) to de-escalate surgery, elucidate tumor response, and determine the role of adjuvant chemotherapy. However, patients who receive NAC with residual pathological nodal (pN) involvement require axillary lymph node dissection (ALND) as they are Z11/AMAROS ineligible. We aimed to evaluate the impact of NAC compared with upfront surgery on pN status and ALND rates in cT1-2N0 TNBC.

METHODS

The National Cancer Database (NCDB) was queried for women with operable cT1-2N0 TNBC from 2014 to 2019. Demographic, clinicopathologic, and treatment data were collected. Multivariable linear regression analysis was performed to assess the odds of pN+ disease and undergoing ALND.

RESULTS

Overall, 55,624 women were included: 26.9% (n = 14,942) underwent NAC and 73.1% (n = 40,682) underwent upfront surgery. The NAC cohort was younger (mean age 52.9 vs. 61.3 years; p < 0.001) with more cT2 tumors (71.6% vs. 31.0%; p < 0.001), and had lower ALND rates (4.3% vs. 5.5%; p < 0.001). The upfront surgery cohort was more likely to have one to three pathologically positive nodes (12.1% vs. 6.5%; odds ratio [OR] 2.37, 95% confidence interval (CI) 2.17-2.58; p < 0.001) but there was no difference in the likelihood of ALND (OR 1.1, 95% CI 0.99-1.24; p = 0.08).

CONCLUSION

Patients who underwent upfront surgery were more likely to be pN+; however, ALND rates were similar between the two cohorts. Thus, the use of NAC does not result in a higher odds of ALND and the decision for NAC should be individualized and based on modern guidelines and systemic therapy benefits.

The Role of Sentinel Lymph Node Biopsy in Breast Cancer Patients Who Become Clinically Node-Negative Following Neo-Adjuvant Chemotherapy: A Literature Review

BACKGROUND

In clinically node-positive (cN+) breast cancer (BC) patients who become clinically node-negative (cN0) following neoadjuvant chemotherapy (NACT), sentinel lymph node biopsy (SLNB) after lymphatic mapping with lymphoscintigraphy is not widely accepted; therefore, it has become a topic of international debate.

OBJECTIVE

Our literature review aims to evaluate the current use of this surgical practice in a clinical setting and focuses on several studies published in the last six years which have contributed to the assessment of the feasibility and accuracy of this practice, highlighting its importance and oncological safety. We have considered the advantages and disadvantages of this technique compared to other suggested methods and strategies. We also evaluated the role of local irradiation therapy after SLNB and state-of-the-art SLN mapping in patients subjected to NACT.

METHODS

A comprehensive search of PubMed and Cochrane was conducted. All studies published in English from 2018 to August 2023 were evaluated.

RESULTS

Breast units are moving towards a de-escalation of axillary surgery, even in the NACT setting. The effects of these procedures on local irradiation are not very clear. Several studies have evaluated the oncological outcome of SLNB procedures. However, none of the alternative techniques proposed to lower the false negative rate (FNR) of SLNB are significant in terms of prognosis.

CONCLUSIONS

Based on these results, we can state that lymphatic mapping with SLNB in cN+ BC patients who become clinically node-negative (ycN0) following NACT is a safe procedure, with a good prognosis and low axillary failure rates.

The impact of intraoperative frozen section in patients with clinically node-negative breast cancer (cN0/ycN0) who received neoadjuvant systemic therapy

BACKGROUND

When surgical axillary staging reveals residual metastatic deposits in breast cancer (BC) patients who had received neoadjuvant chemotherapy (NACT), axillary lymphonodectomy is indicated. In this study, we investigate whether it is reasonable to perform intraoperative frozen section (FS) of the removed sentinel lymph nodes (SLNs) in cases where NACT had been administered in patients who had a clinically negative nodal status at the time of diagnosis.

PATIENTS AND METHODS

We analyzed data from 101 BCE patients with 103 carcinomas who were diagnosed between 2014 and 2021 and met the above-mentioned criteria.

RESULTS

In three cases (2.8% of the study group), histologically active tumor tissue was detected in the removed axillary LNs. Discontinuation of therapy/the use of a low-dose NACT regimen was a significant factor for positive LNs (p = 0.02) at the subsequent surgical procedure; tumor progression during therapy approached borderline significance (p = 0.058). Among patients who had completed NACT with the planned standard dose regimen, and in which the primary tumors showed a response to therapy (n = 94), only one case had histologically detected residual metastases in the SLNs.

CONCLUSIONS

Certified breast centers aim to improve the outcome of the patients. However, these specialized centers should also focus on economic aspects. This means that diagnostic and therapeutic procedures should be continuously critically reviewed in order to avoid unnecessary expenses. In BC patients with clinically node negative disease who completed NACT as planned and in which the tumor showed a good response to therapy, time consuming and costly FS of the SLNs removed should be omitted.

Sentinel Lymph Node Identification in Post Neoadjuvant Chemotherapy Breast Cancer Patients Undergoing Surgical Excision Using Lymphosonography

OBJECTIVES

This study evaluated the efficacy of lymphosonography in the identification of sentinel lymph nodes (SLNs) in post neoadjuvant chemotherapy patients with breast cancer scheduled to undergo surgical excision.

METHODS

Seventy-nine subjects scheduled for breast cancer surgery with SLN excision completed this IRB-approved study, out of which 18 (23%) underwent neoadjuvant chemotherapy before surgery. Subjects underwent percutaneous Sonazoid (GE Healthcare) injections around the tumor area for a total of 1.0 mL. Lymphosonography was performed using CPS on an S3000 HELX scanner (Siemens Healthineers) with a linear probe. Subjects received blue dye and radioactive tracer as part of their standard of care. Excised SLNs were classified as positive or negative for the presence of blue dye, radioactive tracer and Sonazoid. The results were compared between methods and pathology findings.

RESULTS

Seventy-two SLNs were surgically excised from 18 subjects, 29 were positive for blue dye, 63 were positive for radioactive tracer and 57 were positive for Sonazoid. Comparison with blue dye showed that both radioactive tracer and lymphosonography achieved an accuracy of 53% (P > .50). Comparison with radioactive tracer showed that blue dye had an accuracy of 53%, while lymphosonography achieved an accuracy of 67% (P < .01). Of the 72 SLNs, 15 were determined malignant by pathology; the detection rate was 47% for blue dye (7/15), 67% for radioactive tracer (10/15) and 100% for lymphosonography (15/15) (P < .001).

CONCLUSIONS

Lymphosonography achieved similar accuracy as radioactive tracer and higher accuracy than blue dye for identifying SLNs. The 15 SLNs positive for malignancy were all identified by lymphosonography.

Axillary lymph node dissection: Dead or still alive?

Although sentinel lymph node biopsy is now the primary method of axillary staging and is therapeutic for patients with limited nodal disease, axillary lymph node dissection (ALND) is still necessary for staging in groups where sentinel lymph node biopsy has not been proven to be accurate and to maintain local control in those with a heavy axillary tumor burden. Additionally, newer approaches to systemic therapy tailored to risk level sometimes necessitate knowledge of the number of involved axillary nodes which can only be obtained with ALND. Ongoing trials will address whether there are additional circumstances where radiotherapy can replace ALND.

Anatomy Versus Physiology: Is Breast Lymphatic Drainage to the Internal Thoracic (Internal Mammary) Lymphatic System Clinically Relevant?

Approximately 15%-25% of breast lymphatic drainage passes through the internal thoracic (internal mammary) lymphatic system, draining the inner quadrants of the breast. This study aimed to use lymphosonography to identify sentinel lymph nodes (SLNs) in the axillary and internal thoracic lymphatic systems in patients with breast cancer. Seventy-nine patients received subcutaneous ultrasound contrast agent injections around the tumor. Lymphosonography was used to identify SLNs. In 14 of the 79 patients (17.7%), the tumor was located in the inner quadrant of the breast. Lymphosonography identified 217 SLNs in 79 patients, averaging 2.7 SLNs per patient. The 217 identified SLNs in the 79 patients were located in the axillary lymphatic system; none were located in the internal thoracic (internal mammary) lymphatic system, although it was expected in two to four patients (i.e., 4-11 SLNs). These results implied that SLNs associated with breast cancer are predominantly located in the axillary lymphatic system.

Sentinel Lymph Node Biopsy in Breast Cancer Patients Undergoing Neo-Adjuvant Chemotherapy: Clinical Experience with Node-Negative and Node-Positive Disease Prior to Systemic Therapy

Background: Sentinel lymph node biopsy (SLNB) has emerged as the standard procedure to replace axillary lymph node dissection (ALND) in breast cancer (BC) patients undergoing neo-adjuvant chemotherapy (NAC). SLNB is accepted in clinically node-negative (cN0) patients; however, its role in clinically node-positive (cN+) patients is debatable. Methods: We performed a retrospective analysis of BC patients undergoing NAC and SLNB. Our aim was to evaluate the clinical significance of SLNB in the setting of NAC. This was accomplished by comparing the characteristics and oncological outcomes between cN0 and cN+ patients prior to NAC and type of axillary surgery. Results: A total of 291 patients were included in the analysis: 131 were cN0 and 160 were cN+ who became ycN0 after NAC. At a median follow-up of 43 months, axillary recurrence occurred in three cN0 (2.3%) and two cN+ (1.3%) patients. However, there were no statistically significant differences in oncological outcomes (disease-free survival, distant disease-free survival, overall survival, and breast-cancer-specific survival) between cN0 and cN+ patients nor between patients treated with SLNB only or ALND. Conclusions: SLNB in the setting of NAC is an acceptable procedure with a general good prognosis and low axillary failure rates for both cN0 and cN+ patients.

Diagnostic accuracy of magnetic resonance imaging to evaluate axillary lymph node status in breast cancer patients receiving neoadjuvant chemotherapy

OBJECTIVES

Axillary lymph node status is an important prognostic factor for breast cancer patients. This study aimed to assess the accuracy of MRI in assessing the axillary nodal status in breast cancer patients receiving neo-adjuvant chemotherapy (NACT).

METHODS

Data were retrospectively collected for 88 patients between 2011 and 2016 from the hospital records. All patients had baseline MRI, followed by the end of neoadjuvant chemotherapy MRI. Patient demographics, cancer type, grade, stage, receptor status, and the number of positive lymph nodes identified on the baseline and preoperative MRI were recorded. The imaging results were compared to post-operative histopathological lymph node findings. The median patient age of the patients was 54 years (32-77 years).

RESULTS

There were 67 (76.1%) patients with histologically proven positive axillary lymph nodes on baseline MRI. The overall conversion from abnormal to normal axillary nodes following chemotherapy (ypN0) was 38.8% (26 patients out of 67). The sensitivity and specificity of MRI for predicting axillary status was 68.85 and 85.71%, respectively, with an overall MRI diagnostic accuracy of 73.07%.

CONCLUSION

MRI has low sensitivity and diagnostic accuracy in predicting axillary nodal status in breast cancer patients receiving neoadjuvant chemotherapy. Given the low NPV of MRI of the axilla, a negative MRI does not obviate the need for definitive axillary surgery.

ADVANCES IN KNOWLEDGE

In its current state, MRI cannot obviate the need for axillary surgery in patients receiving NACT. Long: short axis ratio (L: S) of the axillary lymph node is not a good predictor of axillary metastases.

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.

Sentinel Lymph Node Identification in Patients With Breast Cancer Using Lymphosonography

The objective of the work described here was to evaluate the efficacy of lymphosonography in identifying sentinel lymph nodes (SLNs) in patients with breast cancer undergoing surgical excision. Of the 86 individuals enrolled, 79 completed this institutional review board-approved study. Participants received subcutaneous 1.0-mL injections of ultrasound contrast agent (UCA) around the tumor. An ultrasound scanner with contrast-enhanced ultrasound (CEUS) capabilities was used to identify SLNs. Participants were administered with blue dye and radioactive tracer to guide SLN excision as standard-of-care. Excised SLNs were classified as positive or negative for the presence of blue dye, radioactive tracer and UCA, and sent for pathology. Two hundred fifty-two SLNs were excised; 158 were positive for blue dye, 222 were positive for radioactive tracer and 223 were positive for UCA. Comparison with blue dye revealed accuracies of 96.2% for radioactive tracer and 99.4% for lymphosonography (p > 0.15). Relative to radioactive tracer, blue dye had an accuracy of 68.5%, and lymphosonography achieved 86.5% (p < 0.0001). Of 252 SLNs excised, 34 were determined to be malignant by pathology; 18 were positive for blue dye (detection rate = 53%), 23 for radioactive tracer (detection rate = 68%) and 34 for UCA (detection rate = 100%) (p < 0.0001). Lymphosonography was similar in accuracy to radioactive tracer and higher in accuracy than blue dye in identifying SLNs. All 34 malignant SLNs were identified by lymphosonography.

Estimating the Benefit of Preoperative Systemic Therapy to Reduce the Extent of Breast Cancer Surgery: Current Standard and Future Directions

Once reserved for locally advanced tumors which were deemed inoperable at presentation, preoperative systemic therapy (PST) is nowadays increasingly used to treat early breast cancer. PST allows for in vivo assessment of tumor response, for tailoring of adjuvant systemic therapy and for de-escalation of breast and the axillary surgery. Increased rates of pathological complete response together with more accurate response assessment and surgical planning have led to a significant reduction in surgical morbidity. While surgical assessment remains the standard of care, ongoing studies are evaluating whether surgery can be omitted in patients who achieve a complete pathological response. In this chapter, I will review the impact of PST on surgical de-escalation and the data supporting the safety of this approach.

"This house believes that: Sentinel node biopsy alone is better than TAD after NACT for cN+ patients"

The increased use of neoadjuvant chemotherapy (NACT) has changed the approach to breast surgery. NACT allows de-escalation of surgery by both increasing breast conservation rates (up to 40%), the initial goal of this chemotherapy, and in particular it permits reduces axillary surgery. Furthermore, in relation to the molecular characteristics of the tumor we can have a pathological complete response (pCR) ranging from 20 to 80%. In clinically node positive (cN+) patients who converted to clinically node-negative (cN0) various prospective studies have demonstrated that the false negative rate (FNR) of the sentinel node biopsy (SNB) were higher than the acceptable 10% and strategies to reduce the FNR in cN + patients are being investigated. But all the effort to reduce the FNR does not have clinical prognostic significance. This has already been demonstrated in the literature in different randomized trials with long term follow up. The 10-year follow-up of our study confirmed our preliminary data that the use of standard SNB without the use of clip is acceptable in cN1/2 patients who become cN0 after NAT and will not translate into a worse outcome. In fact, the axillary recurrences were less than 2%. Similar positive data with different follow up were also confirmed by other studies that used SNB alone without TAD. All these studies, with encouraging results on the follow up, confirm that SN surgery alone for selected patients who have an excellent response to NACT is rationale and not oncologically inferior to AD during a short- and long-term follow-up.

Breast cancer: an up-to-date review and future perspectives

Breast cancer is the most common cancer worldwide. The occurrence of breast cancer is associated with many risk factors, including genetic and hereditary predisposition. Breast cancers are highly heterogeneous. Treatment strategies for breast cancer vary by molecular features, including activation of human epidermal growth factor receptor 2 (HER2), hormonal receptors (estrogen receptor [ER] and progesterone receptor [PR]), gene mutations (e.g., mutations of breast cancer 1/2 [BRCA1/2] and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha [PIK3CA]) and markers of the immune microenvironment (e.g., tumor-infiltrating lymphocyte [TIL] and programmed death-ligand 1 [PD-L1]). Early-stage breast cancer is considered curable, for which local-regional therapies (surgery and radiotherapy) are the cornerstone, with systemic therapy given before or after surgery when necessary. Preoperative or neoadjuvant therapy, including targeted drugs or immune checkpoint inhibitors, has become the standard of care for most early-stage HER2-positive and triple-negative breast cancer, followed by risk-adapted post-surgical strategies. For ER-positive early breast cancer, endocrine therapy for 5-10 years is essential. Advanced breast cancer with distant metastases is currently considered incurable. Systemic therapies in this setting include endocrine therapy with targeted agents, such as CDK4/6 inhibitors and phosphoinositide 3-kinase (PI3K) inhibitors for hormone receptor-positive disease, anti-HER2 targeted therapy for HER2-positive disease, poly(ADP-ribose) polymerase inhibitors for BRCA1/2 mutation carriers and immunotherapy currently for part of triple-negative disease. Innovation technologies of precision medicine may guide individualized treatment escalation or de-escalation in the future. In this review, we summarized the latest scientific information and discussed the future perspectives on breast cancer.

Sentinel lymph node biopsy with carbon nanoparticle suspension after neoadjuvant chemotherapy for breast cancer patients

INTRODUCTION

The aim of the study was to explore the feasibility of performing sentinel lymph node biopsy (SLNB) using a carbon nanoparticle suspension (CNPS) after neoadjuvant chemotherapy in breast cancer patients.

METHODS

Some 152 patients diagnosed with primary breast cancer (cT1-3N0-2M0) were recruited. Patients were divided into two groups according to axillary lymph node (ALN) status after four to six cycles of neoadjuvant chemotherapy. All patients received a CNPS injection, after which SLNB and axillary lymph node dissection (ALND) were performed.

RESULTS

Sentinel lymph nodes (SLN) of 143 patients were identified; with an accuracy rate of 94.4% and a false-negative rate of 9.9%. Group A included 67 patients, and the detection, accuracy and false-negative rates within this group were 95.5%, 96.9% and 6.7%, respectively. The corresponding rates for group B (85 patients) were 92.9%, 92.4% and 11.8%, respectively.

CONCLUSIONS

CNPS is an ideal tracer for improving the detection rate of SLN and can be used to determine SLN status following neoadjuvant chemotherapy.

Ten-year outcome results of cT4 breast cancer after neoadjuvant treatment

BACKGROUND AND OBJECTIVES

cT4 breast cancer (BC) is classified as noninflammatory breast cancer (non-IBC) or inflammatory breast cancer (IBC). The outcome often is considered worse. The purpose of this study was to determine recurrence and outcomes in overall survival (OS), invasive disease-free survival (IDFS), distant disease-free survival (DDFS) according to pathological complete response (pCR), and inflammatory status.

METHODS

From 2000 to 2015 we selected 634 nonmetastatic cT4 BC patients treated with neoadjuvant therapy followed by surgery at the European Institute of Oncology. OS, IDFS, and DDFS were estimated with the Kaplan-Meier method.

RESULTS

The median follow-up was 9.0 years. Twenty patients underwent only sentinel node biopsy (SNB), 13 SNB + AD, and 601 only AD. Considering the 614 patients with AD, only 2.5% of non-IBC patients reported pCR compared to 15% of IBC cases. Only two axillary recurrences were reported. Ten-year results were 52.3% (95% confidence interval [CI]: 47.8-56.5) for OS, 37.0% (95% CI: 32.6-41.3) for IDFS, and 49.8% (95% CI: 45.0-54.4) for DDFS. OS, IDFS, and DDFS were better in all BC with pCR (irrespective of inflammatory status).

CONCLUSION

Our long-term results demonstrated that pCR significantly improves survival, reducing locoregional and distant recurrence risk in cT4 tumors with respect to patients with no pCR and according to inflammatory status of cT4 BC.

Feasibility and reliability of sentinel lymph node biopsy after neoadjuvant chemotherapy in breast cancer patients with positive axillary nodes at initial diagnosis: An up-to date meta-analysis of 3,578 patients

Purpose

Neoadjuvant chemotherapy (NACT) is increasingly adopted in the therapy of breast cancer (BC) patients with positive axillary nodes (cN+), but the reliability and feasibility of sentinel lymph node biopsy (SLNB) following NACT are still controversial. The objective of the present study is to conduct an updated meta-analysis on this issue.

Methods

A literature search was performed using PubMed, Cochrane, Embase, and Web of Science to identify papers published from January 1, 2000 to October 22, 2020 to research SLNB after NACT in BC patients. Studies that met the quality standard were enrolled for this meta-analysis.

Results

A total of 3578 participants from 27 trials were included in this meta-analysis. The pooled estimate of the identification rate (IR) for SLNB was 91 %, and the false negative rate (FNR) was 15 %. The pooled negative prediction value (NPV), accuracy, specificity, and sensitivity were 82 %, 89 %, 97 %, and 85 %, respectively. In subgroup analysis, the application of dual mapping could clearly decrease the FNR. The FNR was significantly high in the luminal types, and it declined as more sentinel lymph nodes (SLNs) were removed.

Conclusion

SLNB following NACT is now technically feasible for BC with cN+. However, it must be emphasized that the FNR is unacceptable high.

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We performed a meta-analysis to provide a consensus regarding the application of SLNB post-NACT in cN + patients.

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One comprehensive database search yielded 27 studies (3578 patients).

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The pooled estimate of IR for SLNB was 91 %, and FNR was 15 %.

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The application of dual mapping could clearly decrease the FNR.

New horizons in imaging and surgical assessment of breast cancer lymph node metastasis

Axillary nodal status is one of the most important prognostic factors in breast cancer. While sentinel lymph node biopsy (SLNB) is a safe and validated procedure for clinically node-negative patients, axillary management of clinically node-positive patients has been more controversial. Patients with clinically detected axillary metastases often benefit from neoadjuvant chemotherapy (NAC). Those who convert to node-negative disease following NAC are important to identify, since they can often be spared significant morbidity from axillary dissection. SLNB has shown widely varying false-negative rates (FNR) but with the use of dual mapping and surgical biopsy of 3 or more nodes, it is considered an acceptable method to stage the axilla in clinically node-positive patients who receive NAC. Various methods including targeted axillary dissection (TAD) have been shown to decrease the FNR of SLNB. We will review appropriate methods to identify a metastatic node and subsequent ultrasound-guided biopsy with tissue marking techniques. We underscore key points in monitoring axillary response, techniques to accurately localize the biopsied and clipped known metastatic node for surgical excision and the effect of various methods in reducing the FNR of SLNB, including the emerging concept of TAD on patient care.

Breast cancer

Breast cancer is still the most common cancer worldwide. But the way breast cancer is viewed has changed drastically since its molecular hallmarks were extensively characterised, now including immunohistochemical markers (eg, ER, PR, HER2 [ERBB2], and proliferation marker protein Ki-67 [MKI67]), genomic markers (eg, BRCA1, BRCA2, and PIK3CA), and immunomarkers (eg, tumour-infiltrating lymphocytes and PD-L1). New biomarker combinations are the basis for increasingly complex diagnostic algorithms. Neoadjuvant combination therapy, often including targeted agents, is a standard of care (especially in HER2-positive and triple-negative breast cancer), and the basis for de-escalation of surgery in the breast and axilla and for risk-adapted post-neoadjuvant strategies. Radiotherapy remains an important cornerstone of breast cancer therapy, but de-escalation schemes have become the standard of care. ER-positive tumours are treated with 5-10 years of endocrine therapy and chemotherapy, based on an individual risk assessment. For metastatic breast cancer, standard therapy options include targeted approaches such as CDK4 and CDK6 inhibitors, PI3K inhibitors, PARP inhibitors, and anti-PD-L1 immunotherapy, depending on tumour type and molecular profile. This range of treatment options reflects the complexity of breast cancer therapy today.

Lymph nodal radiotherapy in breast cancer: what are the unresolved issues?

Introduction: Sentinel lymph node biopsy (SLNB) is the gold standard in invasive breast cancer. Axillary dissection (ALND) is controversial in some presentations.Areas covered: Key questions were formulated and explored focused on four different scenarios in adjuvant axillary radiation management in early and locally advanced breast cancer. Answers to these questions were searched in MEDLINE, PubMed from June 1946 to August 2020. Clinical trials, retrospective studies, international guidelines, meta-analysis, and reviews were explored.Expert opinion: Analysis according to biological disease characteristics is necessary to establish the impact of ALND avoidance in unexpectedly positive SLNB (pN1) in cN0 patients. A low-risk probability of axillary recurrence was observed if axillary radiotherapy (ART) or ALND were offered without impact on outcomes. Adjuvant RNI in pT1-3 pN1 treated with mastectomy or BCS should be proposed in unfavorable disease and risk factors. In ycN0 after NACT, SLNB can be offered in selected cases or ALND should be performed. After SLNB post-NACT (ypN1), ALND and adjuvant radiotherapy are mandatory.

Sentinel Node Biopsy after Neoadjuvant Chemotherapy for Breast Cancer: Preliminary Experience with Clinically Node Negative Patients after Systemic Treatment

Sentinel lymph node biopsy (SLNB) following neoadjuvant treatment (NACT) has been questioned by many studies that reported heterogeneous identification (IR) and false negative rates (FNR). As a result, some patients receive axillary lymph node dissection (ALND) regardless of response to NACT, leading to a potential overtreatment. To better assess reliability and clinical significance of SLNB status on ycN0 patients, we retrospectively analyzed oncological outcomes of 399 patients treated between January 2016 and December 2019 that were either cN0-ycN0 (219 patients) or cN1/2-ycN0 (180 patients). The Endpoints of our study were to assess, furthermore than IR: oncological outcomes as Overall Survival (OS); Distant Disease Free Survival (DDFS); and Regional Disease Free Survival (RDFS) according to SLNB status. SLN identification rate was 96.8% (98.2% in patients cN0-ycN0 and 95.2% in patients cN+-ycN0). A median number of three lymph nodes were identified and removed. Among cN0-ycN0 patients, 149 (68%) were confirmed ypN0(sn), whereas regarding cN1/2-ycN0 cases 86 (47.8%) confirmed an effective downstaging to ypN0. Three year OS, DDFS and RDFS were significantly related to SLNB positivity. Our data seemed to confirm SLNB feasibility following NACT in ycN0 patients, furthermore reinforcing its predictive role in a short observation timing.

Association between tumor molecular subtype, clinical stage and axillary pathological response in breast cancer patients undergoing complete pathological remission after neoadjuvant chemotherapy: potential implications for de-escalation of axillary surgery

Background

Axillary node status is used in clinical practice to guide the selection of axillary surgery in breast cancer patients. However, to date, the optimal axillary management following neoadjuvant therapy (NAT) for breast cancer remains controversial. Our study aimed to investigate the association of molecular subtype, clinical stage, and ypN status after NAT in breast cancer patients, especially those achieving breast pathological complete remission (pCR).

Patients and methods

Patients receiving ⩾4 cycles of NAT were retrospectively included between January 2009 and January 2020. ypN status was compared among patients with different breast pCR statuses, clinical stages, and molecular subtypes in univariate and multivariate analyses.

Results

A total of 1999 patients were included: 457 (22.86%), 884 (44.22%), and 658 (32.92%) patients with cT1-2N0, cT1-2N1, and locally advanced breast cancer (LABC), respectively. Altogether, 435 (21.8%) patients achieved breast pCR: 331 with ypN- and 104 with ypN+ status. Patients achieving breast pCR had a significantly lower ypN+ rate than those without pCR [23.9% versus 62.5%, odds ratio (OR) = 0.14, 95% confidence interval (CI) = 0.09-0.21]. For patients with breast pCR, the ypN+ rate was 6.4%, 25.7%, and 33.9% in cT1-2N0, cT1-2N1, and LABC patients, respectively (p < 0.001). Furthermore, the ypN+ rate was 30.8%, 16.8%, 17.5%, 29.6%, and 27.6% in breast pCR patients with the Luminal A, Luminal B (HER2+), HER2-amplified, Luminal B (HER2-), and triple-negative subtype, respectively. Luminal B (HER2+) (OR = 0.20, 95% CI = 0.05-0.82) and HER2-amplified (OR = 0.19, 95% CI = 0.05-0.83) tumors were associated with lower ypN+ rates. Moreover, 100% of breast pCR patients with cT1-2N0 and HER2-positive disease achieved pathological pN0.

Conclusion

In breast pCR patients after NAT, clinical stage and molecular subtype were significantly associated with ypN status. Patients with cT1-2N0 and HER2-positive disease who achieved breast pCR had a very low ypN+ rate, possibly indicating the possibility for de-escalation of axillary surgery in this patient subgroup.

Axillary management after neoadjuvant treatment

Since its introduction nearly 30 years ago, sentinel lymph node biopsy (SLNB) has become the standard technique to stage the axilla for the great majority of patients with early breast cancer. While the accuracy of SLNB in clinically node-negative patients who undergo neoadjuvant chemotherapy (NAC) is similar to the upfront surgery setting, modifications of the technique to improve the false negative rate are necessary in node-positive patients at presentation. Currently, patients who present with matted nodes, cN1 patients who fail to downstage to cN0 with NAC and those with pathological residual disease have an indication to undergo axillary lymph node dissection. Ongoing trials will confirm if extensive nodal irradiation can replace surgery in patients with residual nodal disease after NAC and if nodal radiotherapy can be omitted in patients who achieve nodal pathological complete response. The aim of this review was to focus on the open questions on the management of the axilla after NAC.

Long-term standard sentinel node biopsy after neoadjuvant treatment in breast cancer: a single institution ten-year follow-up

INTRODUCTION

In patients with positive lymph nodes (cN+) prior to neoadjuvant treatment (NAT), which convert to a clinically negative axilla (cN0) after treatment, the use of sentinel node biopsy (SNB) is still debatable, since the false-negative rate (FNR) is significantly high (12.6-14.2%). The objective of this retrospective mono-institutional study, with a long follow-up, aimed to evaluate the outcome in patients undergoing NAT who remained or converted to cN0 and received SNB independent of target axillary dissection (TAD) or the removal of at least 3 sentinel nodes (SNs).

METHODS

This study analyzed 688 consecutive cT1-3, cN0/1/2 patients, operated at the European Institute of Oncology, Milan, from 2000 to 2015 who became or remained cN0 after NAT and underwent SNB with a least one SN found. Axillary dissection (AD) was not performed if the SN was negative. Nodal radiotherapy (RT) was not mandatory.

RESULTS

Axillary failure occurred in 1.8% of the initially cN1/2 patients and in 1.5% of the initially cN0 patients. After a median follow-up of 9.2 years (IQR 5.3-12.3), the 5- and 10-year overall survival (OS) were 91.3% (95% CI, 88.8-93.2) and 81.0% (95% CI, 77.2-84.2) in the whole cohort, 92.0% (95% CI, 89.0-94.2) and 81.5% (95% CI, 76.9-85.2) in those initially cN0, 89.8% (95% CI, 85.0-93.2) and 80.1% (95% CI, 72.8-85.7) in those initially cN1/2.

CONCLUSION

The 10-year follow-up confirmed our preliminary data that the use of standard SNB is acceptable in cN1/2 patients who become cN0 after NAT and will not translate into a worse outcome.

Leveraging the increased rates of pathologic complete response after neoadjuvant treatment in breast cancer to de-escalate surgical treatments

INTRODUCTION

Breast conservative surgery (BCS) and sentinel lymph node biopsy (SLNB) after neoadjuvant treatment (NAT) is safe and effective for selected patients. This aim of this study is to evaluate the impact of anatomic site of response on outcomes and to assess the real population who may benefit from nonsurgical approaches after NAT.

MATERIAL AND METHODS

From a prospectively maintained database, patients with T1-4 N0-2 breast cancer undergoing NAT were identified. Clinicopathological and survival rates were compared in relation to response and anatomic site of response.

RESULTS

Six hundred and forty-six patients were included in the study. Pathologic complete response (pCR) was an independent factor for BCS and SLN. HER2 positive and TN tumors with cN0 achieving a breast pCR remain ypN0 (p = .002). Residual axillary disease was associated with breast residual tumor (p = .05) and subtype (p = .001). With a median follow up of 35.25 months, patients with any pCR had improved survival when compared with partial response, but not significant differences between pCR, axillary pCR, or breast pCR.

CONCLUSION

Achieving a pCR increases BCS and SLN. In selected subgroups, sparing any axillary surgery after NAT maybe feasible. In cN+ patients, any pCR was associated with survival, but not the anatomic site of response.

Sentinel Lymph Node Removal After Neoadjuvant Chemotherapy in Clinically Node-Negative Patients: When to Stop?

BACKGROUND

The maximum number of sentinel lymph nodes (SLN) to be resected to accurately stage the axilla in patients undergoing neoadjuvant chemotherapy (NAC) for the treatment of clinically node-negative (cN0) breast cancer has not been determined. We sought to determine the sequence of removal of the positive SLNs in this patient population.

METHODS

All patients aged ≥ 18 years diagnosed with cN0 invasive breast cancer who received NAC and underwent SLN surgery at Mayo Clinic Rochester between September 2008 and September 2018 were identified. Univariate analysis was performed to compare factors associated with positive nodes and where the first positive node was in the sequence of removal of the SLNs.

RESULTS

We identified 446 cancers among 440 patients with a median age of 51 (IQR: 43, 61) years. At surgery, 381 (85.4%) cancers were pathologically node (ypN) negative and 65 (14.6%) were pN + . The number of nodes removed was similar for both patients with ypN0 and ypN + disease, with a median number of SLNs removed of 2.0 (IQR: 2.0, 3.0). Of all patients with a positive node, the first positive node was most commonly the 1st node removed (75.4%), and was identified by the 3rd SLN removed in all cases.

CONCLUSIONS

Among cN0 patients treated with NAC, if a positive SLN is present, it is most commonly identified as the 1st sentinel node removed by the surgeon, and was identified by the 3rd sentinel node in our series. This suggests that once 3 SLNs have been resected, removal of additional sentinel lymph nodes does not add diagnostic value.

Sentinel Lymph Node Biopsy is a Reliable Method for Lymph Node Evaluation in Neoadjuvant Chemotherapy-treated Patients with Breast Cancer

Sentinel lymph node (SLN) mapping in patients with breast cancer treated with neoadjuvant chemotherapy has been debated by surgeons as a result of potential compromise of lymphatic drainage. Whether clinicopathologic variables traditionally associated with SLN positivity differ in patients who have been treated with neoadjuvant chemotherapy has not been well studied. Patients diagnosed with breast carcinoma who underwent neoadjuvant chemotherapy, definitive breast surgery, sentinel node biopsy (SNB), and axillary lymph node dissection (ALND) were retrospectively identified over a 75-month period. Clinicopathologic parameters including age, clinical tumor and node stage, neoadjuvant chemotherapy regimen, pathological tumor and node stage, lymphovascular invasion (LVI), SLN and non-SLN involvement, and extranodal extension were recorded. Ninety-seven patients met inclusion criteria. Ninety-eight per cent had successful SLN mapping. Eight patients with negative SLNs had positive ALND (false-negative rate, 8.3%). Clinicopathological variables associated with SLN status included clinical axillary status ( P = 0.038), pathologic tumor size, and nodal status and LVI ( P < 0.001). Extranodal extension was significantly associated with non-SLN status ( P = 0.004). In patients achieving a pathologic complete response (PCR), SNB remained feasible and accurate (false-negative rate, 11.6%). Successful SLN mapping in patients who have undergone neoadjuvant chemotherapy is highly accurate with a low false-negative rate even in patients who have a PCR.

Does 'fast - track' axillary node clearance following positive core biopsy lead to overtreatment of axilla?

AIMS

Sentinel lymph node biopsy (SLNB) is the preferred axillary staging procedure, although axillary node clearance (ANC) is still indicated in subgroups of patients. This study aims to review our practice of axillary treatment in node positive cancer, to determine the proportion of patients requiring ANC and to identify if this can be avoided in some patients.

METHODS

Retrospective data for all breast cancer patients who underwent surgery between 1 January 2017 and 31 December 2018 were included in this study. The histopathology results of ANC were correlated with axillary ultrasound findings, axillary biopsy or SLNB results and effect of neoadjuvant treatment. These were analysed against the available guidelines to evaluate the current practice.

RESULTS

82 patients out of 520 had ANC (15.7%). Four groups were identified: Group A included 45 patients with nodal infiltration on preoperative biopsy; Group B included 24 patients with nodal infiltration who had neoadjuvant chemotherapy (NACT); Group C included 11 patients with involved nodes on SLNB; Group D included 2 patients with axillary recurrence. 35.5% of patients in Group A had only 1-2 positive nodes following ANC. Complete pathological response was observed in 37.5% patients following NACT. No further nodes were subsequently found in a majority of patients who underwent ANC following positive SLNB (63.6%).

CONCLUSIONS

15.7% of breast cancer patients required ANC. Few patients now require ANC following positive SLNB. The practice of direct (fast-track) ANC after axillary biopsy may lead to overtreatment of the axilla, which needs re-evaluation. Targeted axillary dissection could avoid unnecessary axillary dissection in patients with abnormal nodes and in patients who have received NACT.

Assessment of sentinel lymph node biopsy after neoadjuvant chemotherapy for breast cancer in two subgroups: Initially node negative and node positive converted to node negative - A systemic review and meta-analysis

Background:

Neoadjuvant chemotherapy (NAC) is increasingly used to treat patients with breast cancer, but the reliability of sentinel lymph node biopsy (SLNB) following chemotherapy is in doubt. In this meta-analysis, we aimed to evaluate studies that examine the results of SLNB after NAC to assess identification rate (IR) and false-negative rate (FNR).

Materials and Methods:

Systemic searches were performed in the PubMed, ISI Web of Sciences, Scopus, and Cochrane databases from January 1, 2000, to November 30, 2016, for studies of SLNB after NAC for breast cancer and followed by axillary lymph node (LN) dissection in two subgroups: initially node negative and node positive converted to node negative. Two reviewers independently review quality of included studies. A random-effects model was used to pool IR and FNR with 95% confidence intervals (CI), and heterogeneity among studies was assessed by I² and Q-test.

Results:

A total of 23 studies with 1521 patients in the initially node-negative subgroup and 13 studies with 1088 patients in the node-positive converted to node-negative subgroup, were included in this meta-analysis with IR and FNR of 94% (95% CI: 92–96) and 7% (95% CI: 5–9) in the initially node-negative subgroup and 89% (95% CI: 85–94) and 13% (95% CI: 7–18) in the node-positive converted to node-negative subgroup, respectively.

Conclusion:

Our meta-analysis showed acceptable IR and FNR in initially node-negative group and it seems feasible in these patients, but these parameters did not reach to predefined value in node-positive converted to node-negative group, and thus, it is not recommended in these patients.

Axillary Lymph Node Tattooing and Targeted Axillary Dissection in Breast Cancer Patients Who Presented as cN+ Before Neoadjuvant Chemotherapy and Became cN0 After Treatment

INTRODUCTION

Targeted axillary dissection (TAD) is an alternative to axillary dissection for breast cancer patients who presented as cN+ before neoadjuvant chemotherapy (NAC) and became cN0 after treatment. TAD is defined as the removal of sentinel lymph nodes (SLNs) along with the pre-NAC marked positive nodes. Tattooing is an option to mark positive nodes. In this study we aimed to investigate the identification rate of tattooed nodes during surgery, correspondence between tattooed nodes and SLNs, and difficulties and pitfalls of the method.

PATIENTS AND METHODS

In 75 patients who were cN+, with axillary lymph nodes known to have or suspected to have disease were tattooed pre-NAC with a sterile carbon suspension (Spot). After NAC completion all patients became cN0 and underwent TAD as an axillary staging procedure.

RESULTS

SLNs were identified successfully in 70 of 75 patients (93.3%). All tattooed nodes were identified successfully intraoperatively in 71 of 75 patients (94.6%). Retrieval of all tattooed nodes in surgical specimens was achieved in 74 patients (98.6%). Correspondence between tattooed nodes and SLNs was observed in 53 of 70 patients (75.3%). In 34 patients (45.3%) the number of pigmented nodes in pathological examination was greater than the number of initially tattooed nodes, indicating the possibility of tattoo ink migration.

CONCLUSION

Tattoo of axillary lymph nodes is a feasible, accurate, and low-cost method of positive node marking pre-NAC. Pathological confirmation of black pigment in the lymph nodes excised is not by itself warranty of retrieval of all marked node because of tattoo ink migration from one node to another. Intraoperative identification using visual inspection is essential.

[Risk of axillary recurrence after sentinel lymph node biopsy before neoadjuvant chemotherapy in breast cancer]

OBJECTIVES

In case of large breast cancer, neoadjuvant chemotherapy (NAC) can be performed to reduce the size of the tumor and thus perform a conservative surgery. The place of the sentinel lymph node biopsy (SLNB) in case of NAC is still debated. The main aim of this study is to assess the risk of axillary recurrence after negative SLNB before NAC.

METHODS

It is a retrospective, observational and uni-centric study. We included 18 to 80-year-old patients with unilateral breast cancer requiring a NAC and with a negative SLNB before NAC. Our primary endpoint was axillary recurrence.

RESULTS

Between August 2006 and October 2016, 64 patients had a negative GS performing before a NAC and did not benefit from axillary dissection after NAC. The average duration of follow-up was 37 months. During our follow-up, we did not find any cases of axillary recurrence.

CONCLUSION

This study supports the reliability of lymph node status assessment using the SLNB before CNA.

Surgical Management of Breast Cancer Treated with Neoadjuvant Therapy

Neoadjuvant therapy (NAT) allows downstaging in some cases of breast cancer. By consequence, it may enable a more conservative surgical approach or make surgery possible in cases ineligible for surgery before NAT. In this article, we review the evidence and management recommendations for optimal surgical treatment in this setting.

Predicting Post Neoadjuvant Axillary Response Using a Novel Convolutional Neural Network Algorithm

OBJECTIVES

In the postneoadjuvant chemotherapy (NAC) setting, conventional radiographic complete response (rCR) is a poor predictor of pathologic complete response (pCR) of the axilla. We developed a convolutional neural network (CNN) algorithm to better predict post-NAC axillary response using a breast MRI dataset.

METHODS

An institutional review board-approved retrospective study from January 2009 to June 2016 identified 127 breast cancer patients who: (1) underwent breast MRI before the initiation of NAC; (2) successfully completed Adriamycin/Taxane-based NAC; and (3) underwent surgery, including sentinel lymph node evaluation/axillary lymph node dissection with final surgical pathology data. Patients were classified into pathologic complete response (pCR) of the axilla group and non-pCR group based on surgical pathology. Breast MRI performed before NAC was used. Tumor was identified on first T1 postcontrast images underwent 3D segmentation. A total of 2811 volumetric slices of 127 tumors were evaluated. CNN consisted of 10 convolutional layers, 4 max-pooling layers. Dropout, augmentation and L2 regularization were implemented to prevent overfitting of data.

RESULTS

On final surgical pathology, 38.6% (49/127) of the patients achieved pCR of the axilla (group 1), and 61.4% (78/127) of the patients did not with residual metastasis detected (group 2). For predicting axillary pCR, our CNN algorithm achieved an overall accuracy of 83% (95% confidence interval [CI] ± 5) with sensitivity of 93% (95% CI ± 6) and specificity of 77% (95% CI ± 4). Area under the ROC curve (0.93, 95% CI ± 0.04).

CONCLUSIONS

It is feasible to use CNN architecture to predict post NAC axillary pCR. Larger data set will likely improve our prediction model.

The Optimal Treatment Plan to Avoid Axillary Lymph Node Dissection in Early-Stage Breast Cancer Patients Differs by Surgical Strategy and Tumor Subtype

BACKGROUND

Strategies to reduce the likelihood of axillary lymph node dissection (ALND) include application of Z0011 or use of neoadjuvant chemotherapy (NAC). Indications for ALND differ by treatment plan, and nodal pathologic complete response rates after NAC vary by tumor subtype. This study compared ALND rates for cT1-2N0 tumors treated with upfront surgery versus those treated with NAC.

METHODS

The ALND rates for cT1-2N0 breast cancer patients were compared by tumor subtype among women undergoing upfront surgery to NAC. Multivariable analysis with control for age, cT stage, and lymphovascular invasion, and stratification by subtype was performed.

RESULTS

The study identified 1944 cancers in 1907 women who underwent sentinel lymph node (SLN) biopsy with or without ALND (669 upfront breast-conserving surgeries [BCSs], 1004 upfront mastectomies, 271 NACs). Compared with the NAC group, the ALND rates in the BCS group were lower for estrogen receptor (ER), progesterone receptor-positive (PR+), human epidermal growth factor 2-negative (HER2-) tumors (15 vs 34%; p < 0.001). The ALND rates in the upfront mastectomy group were higher than in the NAC group for HER2+ or TN tumors. In the multivariable analysis, receipt of NAC compared with upfront BCS remained significantly associated with higher odds of ALND in the ER/PR+ HER2- subtype (hazard ratio [HR], 3.35; p < 0.001), whereas NAC versus upfront mastectomy remained significantly associated with lower odds of ALND in the HER2+ and TN subtypes (HR for HER2+, 0.19, p < 0.001; HR for TN, 0.25, p = 0.007).

CONCLUSION

The study showed that ALND rates differ according to surgery type and tumor subtype secondary to differing ALND indications and nodal response to NAC. These factors can be used to personalize treatment planning to minimize ALND risk for patients with early-stage breast cancer.

Sentinel Lymph Node Biopsy in Breast Cancer: A Clinical Review and Update

Sentinel lymph node biopsy has become a standard staging tool in the surgical management of breast cancer. The positive impact of sentinel lymph node biopsy on postoperative negative outcomes in breast cancer patients, without compromising the oncological outcomes, is its major advantage. It has evolved over the last few decades and has proven its utility beyond early breast cancer. Its applicability and efficacy in patients with clinically positive axilla who have had a complete clinical response after neoadjuvant chemotherapy is being aggressively evaluated at present. This article discusses how sentinel lymph node biopsy has evolved and is becoming a useful tool in new clinical scenarios of breast cancer management.

Current approach of the axilla in patients with early-stage breast cancer

The surgical approach of the axilla in patients with early-stage breast cancer has witnessed considerable evolution during the past 25 years. The previously undisputed gold standard of axillary-lymph-node dissection for staging has now been replaced by sentinel-lymph-node biopsy for patients with clinically negative axilla. For selected patients with limited sentinel-lymph-node involvement, completion axillary-lymph-node dissection can be omitted or replaced by axillary radiotherapy, reducing morbidity. The clinical interest of axillary staging after neoadjuvant chemotherapy is increasing and this approach might contribute to morbidity reduction, and to the further tailoring of future systemic and locoregional treatment decisions by response assessment. Refinement of the sentinel-lymph-node biopsy technique might overcome the slightly impaired success rates in this setting. New techniques for lymphatic mapping attempt to further simplify the procedure. In view of the declining influence of axillary nodal status on adjuvant therapy decision-making, ongoing clinical trials will evaluate whether sentinel-lymph-node biopsy can be avoided altogether in selected patients.

The intraoperative assessment of sentinel nodes - Standards and controversies

Intraoperative assessment of sentinel lymph nodes (SLNs) has the advantage of allowing breast cancer patients with tumor-positive SLNs to avoid a second surgery by immediately proceeding to axillary lymph node dissection (ALND). However, there are several reasons why the use of intraoperative assessment should be questioned. Whereas ALND was traditionally advised for all breast cancer patients with tumor-positive lymph nodes for axillary staging and locoregional control, more recent studies have demonstrated safety of omitting ALND in a substantial number of patients. In addition, there are concerns about the accuracy of intraoperative assessment methods including frozen section analysis, touch preparation cytology and one-step nucleic acid amplification. Moreover, intraoperative assessment of SLNs denies patients the opportunity to contribute to their treatment planning. In our opinion, intraoperative assessment of axillary lymph nodes should be reserved for patients who still have a strict indication for ALND. Patients with clinical node negative disease (cN0) and one or two positive SLNs can be safely treated with breast conserving surgery and radiotherapy. There has been more controversy for cN0 patients who are treated with mastectomy since radiotherapy is not routinely administered in these patients. However, there is increasing evidence that ALND may be omitted in patients undergoing mastectomy who have a low tumor-burden in their SLNs. Therefore, we defend the position that in cN0 patients undergoing mastectomy, SLNB should be performed and full pathologic evaluation of the SLN should be awaited. In cN0 patients undergoing neoadjuvant systemic therapy (NST) intraoperative assessment of SLNs can be omitted since ALND will not provide therapeutic benefit. It is being hypothesized that patients with limited axillary disease prior to NST who remain node-positive after NST could be treated safely with axillary radiotherapy instead of ALND. In these patients, omitting intraoperative assessment might be a reasonable option. In patients with extensive nodal disease prior to NST intraoperative assessment of axillary lymph nodes should be performed.