The diagnostic performance of sentinel lymph node biopsy in pathologically confirmed node positive breast cancer patients after neoadjuvant systemic therapy: A systematic review and meta-analysis

Long-term outcome in patients with nodal-positive breast cancer treated with sentinel lymph node biopsy alone after neoadjuvant chemotherapy

PURPOSE

Sentinel lymph node biopsy (SLNB) has yet to be accepted as the standard staging procedure in node positive (cN1) breast cancer patients who had clinical complete response in the axilla (cN0) following neoadjuvant chemotherapy (NAC), due to the presumed high false negative rate associated with SLNB in such scenario. This study aimed to determine whether there is a significant difference in the axillary recurrence rate (ARR) and long-term survival in this group of patients, receiving SLNB alone versus axillary lymph node dissection (ALND).

METHODS

A retrospective cohort of cN1 patients who were rendered cN0 by NAC from January 2014 to December 2018 were identified from the Asan Medical Center database. Patients' characteristics and outcomes were collected and analyzed.

RESULTS

902 cN1 patients treated with NAC and turned cN0 were identified. 477 (52.9%) patients achieved complete pathological response in the axilla (ypN0). At a median follow up of 65 months, ARR was 3.2% in the SLNB only group and 1.8% in the ALND group (p = 0.398). DFS and OS were significantly worse in patients with ALND as compared to patients with SLNB only (p = 0.011 and 0.047, respectively). We noted more patients in the ALND group had T3-4 tumor. In the subgroup analysis, we showed that in the T1-2 subgroup (n = 377), there was no statistically significant difference in DFS and OS (p = 0.242 and 0.671, respectively) between SLNB only and ALND group.

CONCLUSION

Our findings suggest that cN1 patients who were converted to ypN0 following NAC may be safely treated with SLNB only.

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.

"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.

Five decades of progress in surgical oncology: Breast

Surgery remains the single most effective treatment for breast cancer but coincident with a deeper understanding of tumor biology and advances in multidisciplinary care (encompassing breast imaging, systemic adjuvant therapy, radiotherapy, and genomics) continues to de-escalate, supported by strong level I data. We have moved from mastectomy to breast conservation, and from routine axillary dissection to sentinel lymph node biopsy to selective omission of axillary node staging altogether. We have further de-escalated through consensus over margin width in breast conservation, through improvements in neoadjuvant therapy, and by demonstrating no benefit for upfront surgery in patients with stage IV disease. For patients with ipsilateral breast tumor recurrence, reconservation surgery and reirradiation are promising. Cell cycle and immune checkpoint inhibitors, when added to conventional systemic therapy, have now moved beyond stage IV disease to phase III trials in the adjuvant and neoadjuvant settings, promising even further de-escalation of surgery. Finally, with genomic profiling we are moving away from the primacy of axillary node status for prognostication and into a new era allowing prediction of response to therapy.

Evaluation of Axillary Lymph Node Marking with Magseed® before and after Neoadjuvant Systemic Therapy in Breast Cancer Patients: MAGNET Study

Background. Due to the high false negative rate (FNR) associated with sentinel lymph node biopsy (SLNB) after neoadjuvant systemic therapy (NAST), the standard surgical treatment for patients with an initially positive axilla and indicated for NAST is axillary lymph node dissection (ALND). To avoid unnecessary ALND, this multicenter, prospective, observational study aimed to determine the effectiveness and ease of using magnetic seeds (Magseed®) for targeted axillary dissection (TAD) when the seeds are placed before or after NAST. Materials and Methods. We recruited 81 patients diagnosed with T1-T3 breast cancer, with clinically/radiologically positive nodal involvement (cN1, 75 patients with 1–3 nodes suspected nodes and 6 patients with up to 4 suspected nodes) prior to NAST. Positive nodes detected by fine-needle aspiration biopsy or core needle biopsy were marked with a stainless steel marker coil and after NAST with Magseed® prior to surgery (Post-NAST group), or directly with Magseed® before NAST (Pre-NAST group). The correlation between lymph nodes marked with Magseed® (MLNs) and sentinel lymph nodes (SLNs) was calculated based on pathologic assessment with the OSNA assay (Sysmex Corporation, Kobe) or conventional sectioning and staining techniques according to the standard protocols of each center. Results. All magnetic seeds were successfully identified and retrieved in just over 10 minutes of surgery, guided by the Sentimag® magnetometer system. The overall concordance rate between MLNs and SLNs was 81.5%, and the concordance between MLNs and SLNs with metastasis was 93.8%. Metastasis was detected in 54.3% of the MLNs compared with 48.1% of SLNs. In cases that presented negative MLN and negative SLN (negative TAD), the FNR was 0%. No significant differences were found between the Post-NAST and Pre-NAST groups. Conclusions. Our results validate the use of Magseed® for long-term marking of axillary lymph nodes and show that when used in combination with SLNB for TAD, a FNR of 0% can be achieved, avoiding unnecessary ALND.

Development of a novel nomogram-based online tool to predict axillary status after neoadjuvant chemotherapy in cN+ breast cancer: A multicentre study on 1,950 patients

BACKGROUND

Type of axillary surgery in breast cancer (BC) patients who convert from cN + to ycN0 after neoadjuvant chemotherapy (NAC) is still debated. The aim of the present study was to develop and validate a preoperative predictive nomogram to select those patients with a low risk of residual axillary disease after NAC, in whom axillary surgery could be minimized.

PATIENTS AND METHODS

1950 clinically node-positive BC patients from 11 Breast Units, treated by NAC and subsequent surgery, were included from 2005 to 2020. Patients were divided in two groups: those who achieved nodal pCR vs. those with residual nodal disease after NAC. The cohort was divided into training and validation set with a geographic separation criterion. The outcome was to identify independent predictors of axillary pathologic complete response (pCR).

RESULTS

Independent predictive factors associated to nodal pCR were axillary clinical complete response (cCR) after NAC (OR 3.11, p < 0.0001), ER-/HER2+ (OR 3.26, p < 0.0001) or ER+/HER2+ (OR 2.26, p = 0.0002) or ER-/HER2- (OR 1.89, p = 0.009) BC, breast cCR (OR 2.48, p < 0.0001), Ki67 > 14% (OR 0.52, p = 0.0005), and tumor grading G2 (OR 0.35, p = 0.002) or G3 (OR 0.29, p = 0.0003). The nomogram showed a sensitivity of 71% and a specificity of 73% (AUC 0.77, 95%CI 0.75-0.80). After external validation the accuracy of the nomogram was confirmed.

CONCLUSION

The accuracy makes this freely-available, nomogram-based online tool useful to predict nodal pCR after NAC, translating the concept of tailored axillary surgery also in this setting of patients.

Factors predicting one or two sentinel lymph nodes to be accepted for sentinel lymph node biopsy alone after neoadjuvant therapy in initially node-positive breast cancer patients

BACKGROUND

Current guidelines recommend harvesting ≥3 sentinel nodes if sentinel lymph node biopsy (SLNB) alone is considered after neoadjuvant therapy (NAT) for initially node-positive (cN+) breast cancer. We attempted to investigate factors predicting one or two sentinel lymph nodes harvested to be accepted for SLNB alone after NAT in initially cN + patients.

METHODS

Overall, 157 patients who received NAT (clinically T1-3/N1-2/M0) and underwent SLNB were identified from a prospectively maintained database. Significant factors were identified using a multiple logistic regression model.

RESULTS

The overall SLN identification rate was 83.4%. Failed SLN identification was associated with a 2-day protocol using a single tracer (odds ratio: 0.331 [95% confidence interval {CI}: 0.132-0.830], p = 0.018), age >52 years (0.345 [0.131-0.913], p = 0.032), and lobular histology (0.156 [0.026-0.944], p = 0.043). The overall false-negative SLNB rate was 14.7%. Its increased risk was associated with radioactivity count >530 for any SLN during SLNB (96.4 [4.00-2320], p = 0.005), age ≥57 years (34.2 [1.92-610], p = 0.016), and taxane use (105 [1.02-10700], p = 0.049); its decreased risk was associated with more harvested SLNs (0.191 [0.054-0.669], p = 0.01) and dual tracers (0.101 [0.012-0.843], p = 0.034). A predictive model using these factors achieved an area under the curve of 0.935 (95% CI: 0.878-0.991).

CONCLUSION

When taxane was administered during NAT, the false-negative rate was predicted at <5% for patients aged <57 years, if 1-2 SLNs were harvested using dual tracers, and when the count of every SLN was lower than 530 after NAT in cN + breast cancer.

Axillary Pathologic Complete Response After Neoadjuvant Systemic Therapy by Breast Cancer Subtype in Patients With Initially Clinically Node-Positive Disease: A Systematic Review and Meta-analysis

Importance

An overview of rates of axillary pathologic complete response (pCR) for all breast cancer subtypes, both for patients with and without pathologically proven clinically node-positive disease, is lacking.

Objective

To provide pooled data of all studies in the neoadjuvant setting on axillary pCR rates for different breast cancer subtypes in patients with initially clinically node-positive disease.

Data Sources

The electronic databases Embase and PubMed were used to conduct a systematic literature search on July 16, 2020. The references of the included studies were manually checked to identify other eligible studies.

Study Selection

Studies in the neoadjuvant therapy setting were identified regarding axillary pCR for different breast cancer subtypes in patients with initially clinically node-positive disease (ie, defined as node-positive before the initiation of neoadjuvant systemic therapy).

Data Extraction and Synthesis

Two reviewers independently selected eligible studies according to the inclusion criteria and extracted all data. All discrepant results were resolved during a consensus meeting. To identify the different subtypes, the subtype definitions as reported by the included articles were used. The random-effects model was used to calculate the overall pooled estimate of axillary pCR for each breast cancer subtype.

Main Outcomes and Measures

The main outcome of this study was the rate of axillary pCR and residual axillary lymph node disease after neoadjuvant systemic therapy for different breast cancer subtypes, differentiating studies with and without patients with pathologically proven clinically node-positive disease.

Results

This pooled analysis included 33 unique studies with 57 531 unique patients and showed the following axillary pCR rates for each of the 7 reported subtypes in decreasing order: 60% for hormone receptor (HR)-negative/ERBB2 (formerly HER2)-positive, 59% for ERBB2-positive (HR-negative or HR-positive), 48% for triple-negative, 45% for HR-positive/ERBB2-positive, 35% for luminal B, 18% for HR-positive/ERBB2-negative, and 13% for luminal A breast cancer. No major differences were found in the axillary pCR rates per subtype by analyzing separately the studies of patients with and without pathologically proven clinically node-positive disease before neoadjuvant systemic therapy.

Conclusions and Relevance

The HR-negative/ERBB2-positive subtype was associated with the highest axillary pCR rate. These data may help estimate axillary treatment response in the neoadjuvant setting and thus select patients for more or less invasive axillary procedures.

Long-term prognosis in breast cancer is associated with residual disease after neoadjuvant systemic therapy but not with initial nodal status

BACKGROUND

This follow-up analysis of a Swedish prospective multicentre trial had the primary aim to determine invasive disease-free (IDFS), breast cancer-specific (BCSS) and overall survival (OS) rates, and their association with axillary staging results before and after neoadjuvant systemic therapy for breast cancer.

METHODS

Women who underwent neoadjuvant systemic therapy for clinically node-positive (cN+) or -negative (cN0) primary breast cancer between 2010 and 2015 were included. Patients had a sentinel lymph node biopsy before and/or after neoadjuvant systemic therapy, and all underwent completion axillary lymph node dissection. Follow-up was until February 2019. The main outcome measures were IDFS, BCSS and OS. Univariable and multivariable Cox regression analyses were used to identify independent factors associated with survival.

RESULTS

The study included a total of 417 women. Median follow-up was 48 (range 7-114) months. Nodal status after neoadjuvant systemic therapy, but not before, was significantly associated with crude survival: residual nodal disease (ypN+) resulted in a significantly shorter 5-year OS compared with a complete nodal response (ypN0) (83·3 versus 91·0 per cent; P = 0·017). The agreement between breast (ypT) and nodal (ypN) status after neoadjuvant systemic therapy was high, and more so in patients with cN0 tumours (64 of 66, 97 per cent) than those with cN+ disease (49 of 60, 82 per cent) (P = 0·005). In multivariable analysis, ypN0 (hazard ratio 0·41, 95 per cent c.i. 0·22 to 0·74; P = 0·003) and local radiotherapy (hazard ratio 0·23, 0·08 to 0·64; P = 0·005) were associated with improved IDFS, and triple-negative molecular subtype with worse IDFS.

CONCLUSION

The present findings underline the prognostic significance of nodal status after neoadjuvant systemic therapy. This confirms the clinical value of surgical axillary staging after neoadjuvant systemic therapy.

A nomogram for predicting axillary pathologic complete response in hormone receptor-positive breast cancer with cytologically proven axillary lymph node metastases

BACKGROUND

The objective of this study was to determine an axillary pathologic complete response (pCR) and its influencing factors in patients with hormone receptor (HR)-positive breast cancer and cytologically proven axillary lymph node metastases. A prediction nomogram was established to provide information for the de-escalation of axillary management in these patients after neoadjuvant chemotherapy.

METHODS

The authors retrospectively enrolled all patients with HR-positive breast cancer in the neoadjuvant chemotherapy data set of Fudan University Shanghai Cancer Center. All data were prospectively collected. From 2007 to 2016, 533 consecutive patients were included. Multivariate logistic regression analysis was performed, after which a nomogram was constructed and validated.

RESULTS

An axillary pCR was achieved in 168 patients (31.5%), the which was much higher than the proportion of those who achieved a breast pCR (103 patients; 19.3%). Patients who had human epidermal growth factor receptor 2-positive disease (P = .004), a better primary tumor response (P = .001), earlier clinical stage (P = .045), and lower estrogen receptor expression (P < .001) were more likely to achieve a lymph node pCR. The nomogram indicated an area under the receiver operating characteristic curve (AUC) of 0.84 (95% CI, 0.78-0.89) in the training set. The validation set showed good discrimination with an AUC of 0.75 (95% CI, 0.69-0.81). The C-index was 0.834 and 0.756 in the training and validation cohort, respectively. The nomogram was well calibrated.

CONCLUSIONS

The authors developed and validated a nomogram for predicting axillary pCR in patients with HR-positive disease accurately by using clinicopathologic factors available before surgery. The model will facilitate logical clinical decision making and clinical trial design.

Correlation between outcome and extent of residual disease in the sentinel node after neoadjuvant chemotherapy in clinically fine-needle proven node-positive breast cancer patients

BACKGROUND

Whether the extent of residual disease in the sentinel lymph node (SLN) after neoadjuvant chemotherapy (NAC) influences the prognosis in clinically node-positive breast cancer (BC) patients remains to be ascertained.

METHODS

One hundred and thirty-four consecutive cN+/BC-patients received NAC followed by SLN biopsy and axillary lymph node dissection. Cumulative incidence of overall (OS) and disease-free (DFS) survival, BC-related recurrences and death from BC were assessed using the Kaplan-Meier method both in the whole patient population and according to the SLN status. The log rank test was used for comparisons between groups.

RESULTS

The SLN was identified in 123/134 (91.8%) patients and was positive in 98/123 (79.7%) patients. Sixty-five of them (66.3%) had other axillary nodes involved. SLN sensitivity and false-negative rate were 88.0% and 2.0%, Median follow-up was 10.2 years. Ten-year cumulative incidence of axillary, breast and distant recurrences, and death from BC were 6.5%, 11.9%, 33.4% and 31.3%, respectively. Ten-year OS and DFS were 67.3% and 55.9%. When stratified by SLN status, 10-year cumulative incidence of BC-related and loco-regional events, and death from BC were similar between disease-free SLN and micrometastatic SLN subgroups (28.9% vs 30.2%, p = 0.954; 21.6% vs 13.4%, p = 0.840; 12.9 vs 24.5%, p=0.494). Likewise, 10-year OS and DFS were comparable (80.0% vs 75.5%, p=0.975 and 68.0% vs 69.8, p=0.836). Both OS and DFS were lower in patients presenting a macrometastatic SLN (60.2% and 47.5%).

CONCLUSION

Outcome of patients with micrometastatic SLN was similar to that of patients with disease-free SLN, which was more favorable as compared to that of patients with macrometastatic SLN.

Diagnostic Performance of Noninvasive Imaging for Assessment of Axillary Response After Neoadjuvant Systemic Therapy in Clinically Node-positive Breast Cancer: A Systematic Review and Meta-analysis

OBJECTIVE

The purpose of this study was to perform a systematic review and meta-analysis to determine the diagnostic performance of current noninvasive imaging modalities for assessment of axillary response after neoadjuvant systemic therapy (NST) in clinically node-positive breast cancer patients.

SUMMARY OF BACKGROUND DATA

NST can lead to downstaging of axillary lymph node disease. Imaging can potentially provide information about the axillary response to NST and, consequently, tailor the surgical management.

METHODS

PubMed and Embase were searched for studies that compared noninvasive imaging after NST with axillary surgery outcome to identify axillary response in patients with initial pathologically proven axillary lymph node metastasis. Two reviewers independently screened the studies and extracted the data. A meta-analysis was performed by computing the pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

Thirteen studies describing 2380 patients were included for final analysis. Of these patients, 1322 had undergone axillary ultrasound, 849 breast MRI, and 209 whole-body 18F-FDG PET-CT. The overall axillary pathologic complete response rate was 39.5% (941/2380). For axillary ultrasound, the pooled sensitivity, specificity, PPV, and NPV were 65%, 69%, 77%, 50%, respectively. For breast MRI, the pooled sensitivity, specificity, PPV, and NPV were 60%, 76%, 78%, 58%, respectively. For whole-body 18F-FDG PET-CT, the pooled sensitivity, specificity, PPV, and NPV were 38%, 86%, 78%, 49%, respectively.

CONCLUSIONS

The diagnostic performance of current noninvasive imaging modalities is limited to accurately assess axillary response after NST in clinically node-positive breast cancer patients.

Advantages of preoperative localization and surgical resection of metastatic axillary lymph nodes using magnetic seeds after neoadjuvant chemotherapy in breast cancer

PURPOSE

To assess the safety and effectiveness of magnetic seeds in preoperative localization and surgical dissection of metastatic axillary lymph nodes (LN+) in breast cancer patients with axillary involvement, after neoadjuvant chemotherapy (NAC). In addition, to assess the impact of targeted axillary dissection (TAD) in reducing the rate of false negatives (FN) in sentinel lymph node biopsy (SLNB).

MATERIALS AND METHODS

A cross-sectional prospective cohort study was conducted from April 2017 to September 2019, including breast cancer patients with axillary lymph node involvement treated with NAC. Prior to NAC, the LN+ were marked by ultrasound-guided clip insertion. After NAC, a magnetic seed (Magseed®) was inserted in the clip-marked lymph node (MLN). During surgery, the MLN was located and removed with the aid of a magnetic detection probe (Sentimag®) and the sentinel lymph node was removed. Axillary lymph node dissection (ALND) was used to determine the rate of FN for SLNB alone and the combination of SLNB and MLN dissection, called TAD.

RESULTS

The study included 29 patients (mean age, 55; range, 30-78 years). Selective preoperative localization and surgical dissection were successful for all 30 MLNs (100%). The MLN corresponded to the SLN in 50% of cases. After ALND, there were 21.4% (3/14) FN with SLNB alone and 5.9% (1/17) with TAD.

CONCLUSIONS

Following NAC, selective surgical removal of MLN by preoperative localization using magnetic seeds is a safe and effective procedure with a success rate of 100%. Adding TAD reduces the rate of FN associated with SLNB alone.

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.

Extended Sentinel Node Biopsy in Breast Cancer Patients who Achieve Complete Nodal Response with Neoadjuvant Chemotherapy

Neoadjuvant chemotherapy (NAC) can eradicate axillary disease in breast cancer (BC) patients. Sentinel node biopsy (SNB) in patients with positive axilla who accomplish complete clinical response after NAC is a new opportunity for changing paradigms and decreasing the extension and the morbidity of axillary surgery. The aim of this article is to review the limits of SNB in this setting and present the current status of an expanded modification of this technique. False-negative rates (FNRs) of conventional SNB exceed the threshold of 10%, and are not acceptable. The extended SNB (ESNB) entails the removal of at least 3 lymph nodes (LNs) including the sentinel node (SN) mapped by dual tracers and a marked lymph node (LN) that was found previously metastatic. This node by node removal procedure greatly reduces the FNRs of the procedure. Despite that axillary lymph node dissection (ALND) is still the standard of care for patients with involved LNs before NAC, the ESNB is a valid option for selected patients in whom axillary positive disease is converted to negative. When ESNB is negative in such cases (immunohistochemistry included), the omission of ALND seems to be safe.

De-escalation of axillary surgery in breast cancer patients treated in the neoadjuvant setting: a Dutch population-based study

PURPOSE

An overall trend is observed towards de-escalation of axillary surgery in patients with breast cancer. The objective of this study was to evaluate this trend in patients treated with neoadjuvant systemic therapy (NST).

METHODS

Patients with cT1-4N0-3 breast cancer treated with NST (2006-2016) were selected from the Netherlands Cancer Registry. Patients were classified by clinical node status (cN) and type of axillary surgery. Uni- and multivariable logistic regression analyses were performed to determine the clinicopathological factors associated with performing ALND in cN+ patients.

RESULTS

A total of 12,461 patients treated with NST were identified [5830 cN0 patients (46.8%), 6631 cN+ patients (53.2%)]. In cN0 patients, an overall increase in sentinel lymph node biopsy (SLNB) only (not followed by ALND) was seen from 11% in 2006 to 94% in 2016 (p < 0.001). SLNB performed post-NST increased from 33 to 62% (p < 0.001). In cN+ patients, an overall decrease in ALND was seen from 99% in 2006 to 53% in 2016 (p < 0.001). Age (OR 1.01, CI 1.00-1.02), year of diagnosis (OR 0.47, CI 0.44-0.50), HER2-positive disease (OR 0.62, CI 0.52-0.75), clinical tumor stage (T2 vs. T1 OR 1.32, CI 1.06-1.65, T3 vs. T1 OR 2.04, CI 1.58-2.63, T4 vs. T1 OR 6.37, CI 4.26-9.50), and clinical nodal stage (N3 vs. N1 OR 1.65, CI 1.28-2.12) were correlated with performing ALND in cN+ patients.

CONCLUSIONS

ALND decreased substantially over the past decade in patients treated with NST. Assessment of long-term prognosis of patients in whom ALND is omitted after NST is urgently needed.

Diagnostic Accuracy of Different Surgical Procedures for Axillary Staging After Neoadjuvant Systemic Therapy in Node-positive Breast Cancer: A Systematic Review and Meta-analysis

Objective:

The aim of this study was to perform a systematic review and meta-analysis to assess the accuracy of different surgical axillary staging procedures compared with ALND.

Summary of Background Data:

Optimal axillary staging after neoadjuvant systemic therapy (NST) in node-positive breast cancer is an area of controversy. Several less invasive procedures, such as sentinel lymph node biopsy (SLNB), marking axillary lymph node with radioactive iodine seed (MARI), and targeted axillary dissection (a combination of SLNB and a MARI-like procedure), have been proposed to replace the conventional axillary lymph node dissection (ALND) with its concomitant morbidity.

Methods:

PubMed and Embase were searched for studies comparing less invasive surgical axillary staging procedures to ALND to identify axillary burden after NST in patients with pathologically confirmed node-positive breast cancer (cN+). A meta-analysis was performed to compare identification rate (IFR), false-negative rate (FNR), and negative predictive value (NPV).

Results:

Of 1132 records, 20 unique studies with 2217 patients were included in quantitative analysis: 17 studies on SLNB, 1 study on MARI, and 2 studies on a combination procedure. Overall axillary pathologic complete response rate was 37%. For SLNB, pooled rates of IFR and FNR were 89% and 17%. NPV ranged from 57% to 86%. For MARI, IFR was 97%, FNR 7%, and NPV 83%. For the combination procedure, IFR was 100%, FNR ranged from 2% to 4%, and NPV from 92% to 97%.

Conclusion:

Axillary staging by a combination procedure consisting of SLNB with excision of a pre-NST marked positive lymph node appears to be most accurate for axillary staging after NST. More evidence from prospective multicenter trials is needed to confirm this.

Diagnostic performance of axillary ultrasound and standard breast MRI for differentiation between limited and advanced axillary nodal disease in clinically node-positive breast cancer patients

Preoperative differentiation between limited (pN1; 1–3 axillary metastases) and advanced (pN2–3; ≥4 axillary metastases) nodal disease can provide relevant information regarding surgical planning and guiding adjuvant radiation therapy. The aim was to evaluate the diagnostic performance of preoperative axillary ultrasound (US) and breast MRI for differentiation between pN1 and pN2–3 in clinically node-positive breast cancer. A total of 49 patients were included with axillary metastasis confirmed by US-guided tissue sampling. All had undergone breast MRI between 2008–2014 and subsequent axillary lymph node dissection. Unenhanced T2-weighted MRI exams were reviewed by two radiologists independently. Each lymph node on the MRI exams was scored using a confidence scale (0–4) and compared with histopathology. Diagnostic performance parameters were calculated for differentiation between pN1 and pN2–3. Interobserver agreement was determined using Cohen’s kappa coefficient. At final histopathology, 67.3% (33/49) and 32.7% (16/49) of patients were pN1 and pN2–3, respectively. Breast MRI was comparable to US in terms of accuracy (MRI reader 1 vs US, 71.4% vs 69.4%, p = 0.99; MRI reader 2 vs US, 73.5% vs 69.4%, p = 0.77). In the case of 1–3 suspicious lymph nodes, pN2–3 was observed in 30.4% on US (positive predictive value (PPV) 69.6%) and in 22.2–24.3% on MRI (PPV 75.7–77.8%). In the case of ≥4 suspicious lymph nodes, pN1 was observed in 33.3% on US (negative predictive value (NPV) 66.7%) and in 38.5–41.7% on MRI (NPV 58.3–61.5%). Interobserver agreement was considered good (k = 0.73). In clinically node-positive patients, the diagnostic performance of axillary US and breast MRI is comparable and limited for accurate differentiation between pN1 and pN2–3. Therefore, there seems no added clinical value of preoperative breast MRI regarding nodal staging in patients with positive axillary US.

Management of the axilla after neoadjuvant chemotherapy for breast cancer

Minor international differences

Excision of both pretreatment marked positive nodes and sentinel nodes improves axillary staging after neoadjuvant systemic therapy in breast cancer

BACKGROUND

Marking the axilla with radioactive iodine seed and sentinel lymph node (SLN) biopsy have been proposed for axillary staging after neoadjuvant systemic therapy in clinically node-positive breast cancer. This study evaluated the identification rate and detection of residual disease with combined excision of pretreatment-positive marked lymph nodes (MLNs) together with SLNs.

METHODS

This was a multicentre retrospective analysis of patients with clinically node-positive breast cancer undergoing neoadjuvant systemic therapy and the combination procedure (with or without axillary lymph node dissection). The identification rate and detection of axillary residual disease were calculated for the combination procedure, and for MLNs and SLNs separately.

RESULTS

At least one MLN and/or SLN(s) were identified by the combination procedure in 138 of 139 patients (identification rate 99·3 per cent). The identification rate was 92·8 per cent for MLNs alone and 87·8 per cent for SLNs alone. In 88 of 139 patients (63·3 per cent) residual axillary disease was detected by the combination procedure. Residual disease was shown only in the MLN in 20 of 88 patients (23 per cent) and only in the SLN in ten of 88 (11 per cent), whereas both the MLN and SLN contained residual disease in the remainder (58 of 88, 66 per cent).

CONCLUSION

Excision of the pretreatment-positive MLN together with SLNs after neoadjuvant systemic therapy in patients with clinically node-positive disease resulted in a higher identification rate and improved detection of residual axillary disease.

The Loss of Lymph Node Metastases After Neoadjuvant Chemotherapy in Patients With Cytology-proven Axillary Node-positive Primary Breast Cancer

BACKGROUND

Axillary lymph node (LN) dissection after neoadjuvant chemotherapy (NAC) still remains a standard treatment of initially LN-positive primary breast cancer because of the difficulty of assessment of LN status. The aim of this study was to assess the LN status after NAC in initially LN-positive primary breast cancer patients who were assessed as clinically LN-negative after NAC (ycN0) and identify factors associated with loss of LN metastasis.

PATIENTS AND METHODS

The study cohort comprised 279 patients with cytology-proven LN-positivity before NAC. LN status was assessed by ultrasonography. Regional recurrence-free survival and overall survival according to pathologic LN after NAC (ypN) status were assessed in patients with ycN0.

RESULTS

Of the 279 patients, 179 patients (64.2%) had ycN0. High nuclear grade, estrogen receptor-negative (ER^-), and human epidermal growth factor receptor 2-positive (HER2⁺), were significant predictors of ycN0/ypN0 (P < .001, .007, and .046, respectively). Metastases persisted in 1 or 2 LNs for 5 (20.0%) of 25 patients with ER^-/HER2⁺ and for 4 (21.1%) of 19 patients with ER^-/HER2^-, and in 3 or more LNs for 0 (0%) of 25 patients with ER^-/HER2⁺ and for 1 (5.3%) of 19 patients with ER^-/HER2^-. Patients with ER⁺ tumors had more numerous residual LN metastases than those with ER^- tumors (P < .001). Among patients with ycN0, ypN status was not associated with regional recurrence-free survival or overall survival.

CONCLUSIONS

Three or more residual LN metastases were rare in patients with ER^- tumors if assessed as ycN0 by ultrasonography. Prospective studies are needed to confirm the prognostic impact of not performing axillary lymph node dissection in such patients.

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.

SEOM clinical guidelines in early stage breast cancer (2018)

Breast cancer is the most common cancer in women in our country and it is usually diagnosed in the early and potentially curable stages. Nevertheless, around 20-30% of patients will relapse despite appropriate locoregional and systemic therapies. A better knowledge of this disease is improving our ability to select the most appropriate therapy for each patient with a recent diagnosis of an early stage breast cancer, minimizing unnecessary toxicities and improving long-term efficacy.

Current Status and Future Perspectives of Axillary Management in the Neoadjuvant Setting

Axillary surgery has undergone considerable changes in recent years, especially in relation to patients who undergo neoadjuvant chemotherapy (NACT). Due to constantly decreasing rates of recurrence and death from breast cancer, modern surgical strategies aim at de-escalating the extent of local treatment and avoiding unnecessary procedures. This relates especially to lymph node surgery which is associated with considerable morbidity. In patients who initially present with clinically node-negative disease, sentinel lymph node biopsy (SLNB) is increasingly performed after NACT. The determination of the post-NACT nodal status does not only spare patients from additional surgery but also allows the assessment of pathologic complete response which is increasingly becoming an important tool for treatment planning. Since more than 70% of these patients have a ypN0 status after NACT, future trials will aim to identify patients who might be spared any axillary surgery after NACT. In patients who initially present with positive lymph nodes, the success rates of SLNB in terms of detection and accuracy are less favorable compared to those in patients who undergo primary surgery. The clinical significance of this is unclear. To reduce unnecessary axillary dissection in patients with cN1ycN0 status, prospective outcome data after SLNB without further lymph node removal are urgently needed. Improvements in surgical technique by localizing positive nodes at the time of diagnosis and removing them in a targeted surgical procedure (targeted axillary dissection) are under evaluation. Risk assessment and patient selection (including gene expression profiles) might be other ways of safely omitting axillary dissection.

Evolution in sentinel lymph node biopsy in breast cancer

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in clinically node-negative (cN0) breast cancer patients without neoadjuvant chemotherapy (NAC). The application of SLNB in patients receiving NAC has also been explored. Evidence supports its use after NAC in pretreatment cN0 patients. Nonetheless, its routine use in all the pretreatment node-positive patients who become cN0 after NAC is unjustified due to the unacceptably high false-negative rate, which can be improved in a subset of patients. Axillary surgery omission in selected patients with a low risk of ALN metastasis has gained more and more research interest because the SLNs are tumor-free in more than 70% of all patients. To avoid drawbacks of conventional mapping methods, novel techniques for SLN detection have been developed and shown to be highly accurate in patients with early breast cancer. This article reviews the progress in SLNB in patients with breast cancer.

Interference of Notch 1 inhibits the proliferation and invasion of breast cancer cells: Involvement of the β‑catenin signaling pathway

Breast cancer is one of the most common types of carcinoma in humans. The aim of the present study was to identify the role of Notch 1 in the proliferation and invasion of human breast cancer cells. Firstly, the levels of Notch 1 were determined by western blot analysis in breast cancer cell lines, and the results revealed that the expression levels of Notch 1 were markedly higher in MDA‑MB‑231 and MCF‑7 cells, and lower in MCF‑10A cells, compared with human mammary epithelial cells. An MTT assay was used to determine the viability of breast cancer cells. The optical density (OD)490 values were significantly decreased in Notch 1 short hairpin (sh)RNA‑transfected MCF‑7 and MDA‑MB‑231 cells, compared with the OD490 values in the negative control shRNA‑transfected cells. The MCF‑7 cells and MDA‑MB‑231 cells were also treated with increasing concentrations of MRK003, a Notch 1 inhibitor, for 24, 48 and 72 h, respectively. The inhibition rate was gradually increased in the MRK003‑treated cells in a time‑ and dose‑dependent manner. The invasive ability of the cells was determined using a Transwell migration assay. The migration ability was significantly decreased in the Notch 1‑transfected MCF‑7 cells and MDA‑MB‑231 cells. The molecular mechanism was examined, and the knockdown of Notch 1 significantly decreased the expression levels of β‑catenin, matrix metalloproteinase (MMP)‑2 and MMP‑9, and was also correlated with the downregulation of β‑catenin in the nucleus. In conclusion, Notch 1 was key in the progression of breast cancer, and knocking down the expression of Notch 1 significantly suppressed the proliferation and invasion of breast cancer cells. This provides novel clues for cancer therapy in human 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.

Feasibility of Charcoal Tattooing of Cytology-Proven Metastatic Axillary Lymph Node at Diagnosis and Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer Patients

Purpose

Sentinel lymph node biopsy (SLNB) can be performed when node-positive disease is converted to node-negative status after neoadjuvant chemotherapy (NCT). Tattooing nodes might improve accuracy but supportive data are limited. This study aimed to investigate the feasibility of charcoal tattooing metastatic axillary lymph node (ALN) at presentation followed by SLNB after NCT in breast cancers.

Materials and Methods

Twenty patientswith cytology-proven node metastases prospectively underwent charcoal tattooing at diagnosis. SLNB using dual tracers and axillary surgery after NCT were then performed. The detection rate of tattooed node and diagnostic performance of SLNB were analyzed.

Results

All patients underwent charcoal tattooingwithout significant morbidity. Sentinel and tattooed nodes could be detected during surgery after NCT. Nodal pathologic complete response was achieved in 10 patients. Overall sensitivity, false-negative rate (FNR), negative predictive value, and accuracy of hot/blue SLNB were 80.0%, 20.0%, 83.3%, and 90.0%, respectively. Retrieving more nodes and favorable nodal response were associated with improved performance. The best accuracy was observed when excised tattooed node was calculated together (FNR, 0.0%). Cold/non-blue tattooed nodes of five patients were removed during non-sentinel axillary surgery but clinicopathological parameters did not differ compared to patients with hot/blue tattooed node detected during SLNB, suggesting the importance of the tattooing procedure itself to improve performance.

Conclusion

Charcoal tattooing of cytology-confirmed metastatic ALN at presentation is technically feasible and does not limit SLNB after NCT. The tattooing procedure without additional preoperative localization is advantageous for improving the diagnostic performance of SLNB in this setting.

Sentinel node biopsy for axillary management after neoadjuvant therapy for breast cancer: a single-center retrospective analysis with long follow-up

PURPOSE

Sentinel node biopsy (SNB) after neoadjuvant therapy (NAT) for breast cancer remains controversial. We conducted a retrospective study of patients who underwent SNB after NAT to evaluate the effectiveness of this procedure.

METHODS

A consecutive 105 women with locally advanced breast cancer (cT1-4, cN0-3, M0) were treated with NAT between 2006 and 2015. The subjects were 80 of these patients who became or remained clinically node-negative after NAT, 53 of whom had axillary management determined by SNB (group A) and the other 27 underwent axillary lymph node dissection (ALND) without SNB (group B). SNB was performed using a modified dye method.

RESULTS

The sentinel node (SN) identification rate was 94.3% and the mean number of removed SNs was 2.4. ALND was avoided in 33 patients, who were confirmed as SN-negative. There was no difference in recurrence-free and overall survival rates between groups A and B (p = 0.71 and p = 0.46, respectively) during the median follow-up time of 63 months. Of the 33 patients who did not undergo ALND, 10 suffered recurrence (33%). One patient (3%) had recurrence in an axillary lymph node and four had recurrence in a supraclavicular lymph node.

CONCLUSION

Axillary SNB after NAT did not affect the axillary failure rate or the prognosis. SNB may be a reliable procedure, even after NAT.

Combined PET-CT and axillary lymph node marking with radioactive iodine seeds (MARI procedure) for tailored axillary treatment in node-positive breast cancer after neoadjuvant therapy

BACKGROUND

The treatment of axillary lymph node metastases after neoadjuvant systemic therapy (NST) remains debatable and axillary lymph node dissection (ALND) is still the standard of care. Marking axillary lymph nodes with radioactive iodine seeds (MARI procedure) is accurate in restaging the axilla after NST (false-negative rate 7 per cent). Here, the potential of tailored axillary treatment, determined by combining the results of PET-CT before NST with those of the MARI procedure after NST, was analysed.

METHODS

A cohort of axillary node-positive patients was used to construct a hypothetical treatment algorithm based on a combination of PET-CT and the MARI procedure. In the algorithm, the number of fluorodeoxyglucose (FDG)-avid axillary lymph nodes (1-3 versus 4 or more) before NST and the tumour status of the MARI node (positive versus negative) after NST were used to tailor axillary treatment. All patients in the cohort underwent ALND, allowing estimation of potential overtreatment and undertreatment.

RESULTS

A total of 93 patients were included in the study. Between one and three FDG-avid axillary lymph nodes were observed in 59 patients, and four or more in 34 patients. The MARI node was tumour-negative in 32 patients and showed residual disease in 61. Treatment according to the constructed algorithm would have resulted in 74 per cent of patients avoiding an ALND, with potential undertreatment in three patients (3 per cent) and overtreatment in 16 (17 per cent).

CONCLUSION

Tailored axillary treatment after NST in node-positive patients, by combining PET-CT before NST and the MARI procedure after NST, has the potential for ALND to be avoided in 74 per cent of patients.

Prognosis of residual axillary disease after neoadjuvant chemotherapy in clinically node-positive breast cancer patients: isolated tumor cells and micrometastases carry a better prognosis than macrometastases

PURPOSE

The aim of this study was to compare disease-free survival (DFS) and overall survival (OS) between clinically node-positive breast cancer patients, treated with neoadjuvant chemotherapy (NAC), with axillary pathologic complete response (ypN0), residual axillary isolated tumor cells or micrometastases (ypNitc/mi), and residual axillary macrometastases (ypN1-3).

METHODS

All patients diagnosed with clinically node-positive primary invasive breast cancer treated with NAC and subsequent axillary lymph node dissection between 2005 and 2008 were retrospectively analyzed. Data were obtained from the Netherlands Cancer Registry. Patients were stratified by final pathological axillary status: ypN0, ypNitc/mi, or ypN1-3. The main outcome measures DFS and OS were analyzed using Kaplan-Meier survival analysis. Uni- and multivariable cox regression analyses were used to determine independent predictors for DFS and OS.

RESULTS

A total of 1347 patients were included. Pathologic nodal status was ypN0 in 22.2%, ypNitc/mi in 3.8%, and ypN1-3 in 74.0% of patients. Overall, 5-year DFS was 57.8% and mean OS was 7.4 years. DFS and OS were comparable between ypN0 and ypNitc/mi (HR 1.38 (0.40-4.79, p = 0.613) and HR 0.92 (0.27-3.09, p = 0.889), respectively), but significantly different between ypN0 and ypN1-3 (HR 1.78 (1.06-3.00, p = 0.031) and HR 1.70 (1.07-2.71, p = 0.026), respectively).

CONCLUSIONS

Clinically node-positive patients, treated with NAC, with axillary nodal status ypN0 or ypNitc/mi carry similar prognosis regarding DFS and OS. Axillary nodal status ypN1-3 is associated with a less favorable prognosis. Future studies should consider ypN0 and ypNitc/mi as one entity.

Swedish prospective multicenter trial evaluating sentinel lymph node biopsy after neoadjuvant systemic therapy in clinically node-positive breast cancer

Purpose

Patients with clinically node-positive breast cancer planned for neoadjuvant systemic therapy (NAST) may draw advantages from the nodal downstaging effect and reduce the extent of axillary surgery with sentinel lymph node biopsy (SLNB) performed after NAST. Since there are concerns about lower sentinel lymph node (SLN) detection and higher false-negative rates (FNR) in this setting, our aim was to define the accuracy of SLNB after NAST.

Methods

This Swedish national multicenter trial prospectively recruited 195 breast cancer patients from ten hospitals with T1–T4d biopsy-proven node-positive disease planned for NAST between October 1, 2010 and December 31, 2015. Clinically node-negative axillary status after NAST was not mandatory. SLNB was always attempted and followed by a completion axillary lymph node dissection (ALND).

Results

The SLN identification rate was 77.9% (152/195) but improved to 80.7% (138/171) with dual mapping. The median number of SLNs was two (range 1–5). A positive SLNB was found in 52% (79/152), almost 66% (52/79) of whom had additional positive non-sentinel lymph nodes. The overall pathologic nodal response rate was 33.3% (66/195). The overall FNR was 14.1% (13/92) but decreased to 4% (2/50) when only patients with two or more sentinel nodes were analyzed.

Conclusions

In biopsy-proven node-positive breast cancer, SLNB after NAST is feasible even though the identification rate is lower than in clinically node-negative patients. Since the overall FNR is unacceptably high, the omission of ALND should only be considered if two or more SLNs are identified.

The Feasibility and Accuracy of Sentinel Lymph Node Biopsy in Initially Clinically Node-Negative Breast Cancer after Neoadjuvant Chemotherapy: A Systematic Review and Meta-Analysis

Background

With the increased use of neoadjuvant chemotherapy (NAC) in breast cancer, the timing of sentinel lymph node biopsy (SLNB) has become increasingly important. In this study, we aimed to evaluate the feasibility and accuracy of SLNB for initially clinically node-negative breast cancer after NAC by conducting a systematic review and meta-analysis.

Methods

We searched PubMed, Embase, and the Cochrane Library from January 1, 1993 to November 30, 2015 for studies on initially clinically node-negative breast cancer patients who underwent SLNB after NAC followed by axillary lymph node dissection (ALND).

Results

A total of 1,456 patients from 16 studies were included in this review. The pooled identification rate (IR) for SLNB was 96% [95% confidence interval (CI): 95%-97%], and the false negative rate (FNR) was 6% (95% CI: 3%-8%). The pooled sensitivity, negative predictive value (NPV) and accuracy rate (AR) were 94% (95% CI: 92%-97%, I² = 27.5%), 98% (95% CI: 98%-99%, I² = 42.7%) and 99% (95% CI: 99%-100%, I² = 32.6%), respectively. In the subgroup analysis, no significant differences were found in either the IR of an SLNB when different mapping methods were used (P = 0.180) or in the FNR between studies with and without immunohistochemistry (IHC) staining (P = 0.241).

Conclusion

Based on current evidence, SLNB is technically feasible and accurate enough for axillary staging in initially clinically node-negative breast cancer patients after NAC.

[Not Available]

THERAPEUTIC DE-ESCALATION IN BREAST CANCER SURGERY

CONS: Therapeutic de-escalation in breast cancer surgery is not recommanded for all patients. Concerning the axillary management, there are still some contraindications for practicing sentinel node, and avoiding axillary dissection is not safe for more than 3 positive sentinel nodes and in the absence of adjuvant treatment. Mastectomy can also be preferred by patients rather than conservative surgery, especially in case of genetic mutation, or for oncological reasons. Larger glandular resections, known as oncoplasties, should also be chosen in case of associated ductal carcinoma in situ and risky subgroups of local recurrence after neoadjuvant therapy. Finally, all patients will not benefit from ambulatory surgery.

Sentinel lymph node biopsy after neoadjuvant treatment in breast cancer: Work in progress

Sentinel lymph node biopsy has replaced axillary lymph node dissection (ALND) in those patients with clinically node negative axilla and nowadays, patients with low burden disease in the SLNs may spare an ALND without compromising their oncologic outcomes. In the last decade, indications of neoadjuvant treatment (NAT) have been extended to patients with operable disease and with the use of targeted therapies, rates of pathologic complete response (pCR) after NAT have increased. In the neoadjuvant setting, SLN after NAT is feasible and accurate in clinically node negative patients and it has been explored in different randomized prospective studies in patients with clinically positive axilla in the continuous effort to avoid the morbidity of ALND. The importance of identifying patients with residual axillary disease may serve not only as indicator for selecting patients with pCR to be spared an ALND but also for selecting patients for additional therapy. Future research is needed to more accurately identify residual axillary disease and the SLN after NAT is the driver for this achievement.