Oncologic Outcomes of Sentinel Lymph Node Surgery After Neoadjuvant Chemotherapy for Node-Positive Breast Cancer

Axillary de-escalation after neoadjuvant chemotherapy for advanced lymph node involvement in breast cancer

INTRODUCTION

Sentinel lymph node biopsy reduces morbidity in patients with clinically node-positive breast cancer who achieve axillary pathologic complete response following neoadjuvant therapy (NACT). De-escalation trials primarily addressed cN1 disease, with underrepresentation of cN2 disease. This study evaluates the role of de-escalation in patients with cN2 breast cancer.

METHODS

A retrospective analysis of the National Cancer Database (2013-2020) included women over 18 with T1-2 invasive breast cancer and clinical N2 disease who received NACT followed by ALND or SLNB then ALND. The primary outcome was pathologic nodal status post-NACT.

RESULTS

Of 5852 cN2 patients treated, 18.15 ​% achieved ypN0, 0.97 ​% had isolated tumor cells, 19.14 ​% were ypN1, 49.64 ​% were ypN2, and 12.20 ​% were ypN3 following NACT. Achieving ypN0 was associated with pCR in the breast, HER2-positive and triple-negative receptor status, cT2 tumors, and younger age.

CONCLUSION

Despite some patients with cN2 disease achieving ypN0, most exhibited residual axillary disease post-NACT. These findings indicate that axillary de-escalation may not be feasible for most patients with cN2 disease, underscoring the importance of meticulous patient selection and assessment.

Residual Nodal Burden After Neoadjuvant Chemotherapy in cN1 Breast Cancer Patients with Positive Nodes at Targeted Axillary Dissection

BACKGROUND

Targeted axillary dissection (TAD) facilitates nodal staging in cN1 breast cancer after neoadjuvant chemotherapy (NAC). Completion axillary node dissection (cALND) remains the standard of care for TAD-positive patients. This study investigated factors associated with additional positive nodes at cALND (cALND+) and the impact on the residual cancer burden (RCB).

METHODS

Retrospective review of cN1 breast cancer patients treated with NAC and TAD was conducted from July 2013 to June 2023. The review defined cN1 status by ultrasound (US) and biopsy. Patient, tumor, and treatment characteristics were evaluated. Multivariate analysis was performed to identify factors associated with cALND+, and RCB was calculated.

RESULTS

Of 902 patients who underwent TAD, 554 (61.4%) were TAD-positive. 457 underwent cALND, and 124 (27%) were cALND+ (average 4.1 additional +nodes). The cALND+ patients had larger primary tumors at diagnosis (4 vs 3.5 cm; p = 0.04), more than three suspicious nodes on initial US (30% vs 13%; p ≤ 0.0001), larger residual primary tumors on pathology (median, 3 vs 2.1 cm; p = 0.0004), and more positive TAD nodes (median, 2 vs 1; p ≤ 0.0001). In the multivariate analysis, the factors associated with cALND+ were more than three suspicious nodes on initial US (odds ratio [OR], 2.9; p ≤ 0.0001), more positive TAD nodes (OR, 1.1; p ≤ 0.0001), larger clipped node metastasis (OR, 1.1; p ≤ 0.0001), and larger residual tumor on pathology (OR, 1.1; p = 0.006). Of 65 cALND+ patients with RCB class I or II, 29 (45%) had an increase in RCB based on cALND.

CONCLUSION

Of cN1 breast cancer patients treated with NAC who are TAD-positive, approximately 25% will have additional nodal disease on cALND. In these patients, positive cALND is associated with greater disease burden, which has potential implications for RCB status and prognosis.

Clipping the Positive Lymph Node in Patients with Clinically Node Positive Breast Cancer Treated with Neoadjuvant Chemotherapy: Impact on Axillary Surgery in the ISPY-2 Clinical Trial

BACKGROUND

For patients with clinically node-positive (cN+) breast cancer undergoing neoadjuvant chemotherapy (NAC), retrieving previously clipped, biopsy-proven positive lymph nodes during sentinel lymph node biopsy [i.e., targeted axillary dissection (TAD)] may reduce false negative rates. However, the overall utilization and impact of clipping positive nodes remains uncertain.

PATIENTS AND METHODS

We retrospectively analyzed cN+ ISPY-2 patients (2011-2022) undergoing axillary surgery after NAC. We evaluated trends in node clipping and associations with type of axillary surgery [sentinel lymph node (SLN) only, SLN and axillary lymph node dissection (ALND), or ALND only] and event-free survival (EFS) in patients that were cN+ on a NAC trial.

RESULTS

Among 801 cN+ patients, 161 (20.1%) had pre-NAC clip placement in the positive node. The proportion of patients that were cN+ undergoing clip placement increased from 2.4 to 36.2% between 2011 and 2021. Multivariable logistic regression showed nodal clipping was independently associated with higher odds of SLN-only surgery [odds ratio (OR) 4.3, 95% confidence interval (CI) 2.8-6.8, p < 0.001]. This was also true among patients with residual pathologically node-positive (pN+) disease. Completion ALND rate did not differ based on clip retrieval success. No significant differences in EFS were observed in those with or without clip placement, both with or without successful clip retrieval [hazard ratio (HR) 0.85, 95% CI 0.4-1.7, p = 0.7; HR 1.8, 95% CI 0.5-6.0, p = 0.3, respectively].

CONCLUSION

Clip placement in the positive lymph node before NAC is increasingly common. The significant association between clip placement and omission of axillary dissection, even among patients with pN+ disease, suggests a paradigm shift toward TAD as a definitive surgical management strategy in patients with pN+ disease after NAC.

De-Escalation of Axillary Surgery in Clinically Node-Positive Breast Cancer Patients Treated with Neoadjuvant Therapy: Comparative Long-Term Outcomes of Sentinel Lymph Node Biopsy versus Axillary Lymph Node Dissection

BACKGROUNDS

This study compares the long-term outcomes of axillary lymph node dissection (ALND) versus sentinel lymph node biopsy (SLNB) in clinically node-positive (cN+) breast cancer (BC) patients treated with neoadjuvant therapy (NAT).

METHODS

We conducted a retrospective analysis of 322 cN+ BC patients who became clinically node-negative (ycN0) post-NAT. Patients were categorized based on the final type of axillary surgery performed: ALND or SLNB. Recurrence-free survival (RFS), distant disease-free survival (DDFS), overall survival (OS), and breast cancer-specific survival (BCSS) were evaluated and compared between the two groups.

RESULTS

Patients in the SLNB group had significantly better 3-, 5-, and 10-year RFS, DDFS, OS, and BCSS compared to those in the ALND group. The SLNB group also had a higher proportion of patients achieving pathologic complete response (pCR). Multivariate analysis identified pCR, ypN0 status, and SLNB as favorable prognostic factors for all survival metrics. Axillary recurrence rates were low for both groups (0.6-2.1%).

CONCLUSIONS

SLNB may be a safe and effective alternative to ALND for selected cN+ BC patients who convert to ycN0 after NAT. These findings suggest that careful patient selection is crucial, and further research is needed to validate these results in more comparable populations.

Omission of Axillary Lymph Node Dissection in Patients with Residual Nodal Disease After Neoadjuvant Chemotherapy

BACKGROUND

Axillary management after neoadjuvant chemotherapy (NAC) is evolving but axillary lymph node dissection (ALND) remains the standard of care for patients with residual nodal disease. The results of the Alliance A011202 trial evaluating the oncologic safety of ALND omission in this cohort are pending but we hypothesize that ALND omission is already increasing.

METHODS

The National Cancer Database was queried to identify patients diagnosed with cT1-3N1M0 breast cancer who underwent NAC and had residual nodal disease (ypN1mi-2) from 2012 to 2021. Temporal trends in omission of completion ALND were assessed annually. Multivariable logistic and Cox regression models were used to identify factors associated with ALND omission and overall survival (OS), respectively.

RESULTS

A total of 6101 patients were included; the majority presented with cT2 disease (57%), with 69% HER2+, 23% triple-negative, and 8% hormone receptor-positive/HER2-. Overall, 34% underwent sentinel lymph node biopsy (SLNB) alone. Rates of ALND were the lowest in the last 4 years of observation. After adjustment, treatment at community centers (vs. academic) and lower pathologic nodal burden were associated with omission of ALND. ALND omission was associated with a higher unadjusted OS (5-year OS: 86% SLNB alone vs. 84% ALND; log-rank p = 0.03), however this association was not maintained after adjustment.

CONCLUSIONS

Despite the impending release of the Alliance A011202 results, omission of ALND in patients with residual nodal disease after NAC is increasing. This practice appears more prominent in community centers and in patients with a lower burden of residual nodal disease. No association with OS was noted.

Impact of response to neoadjuvant chemotherapy on surgical modality in patients with T1-2N0-1M0 triple-negative breast cancer

PURPOSE

Many T1-2N0-1M0 triple-negative breast cancer (TNBC) patients who undergo neoadjuvant chemotherapy (NAC) do not receive breast-conserving therapy (BCT) due to concerns about non-pCR or lymph node metastasis presence.

METHODS

T1-2N0-1M0 TNBC patients who underwent NAC between 2010 and 2017 were collected from the SEER database. Factors affecting surgical modalities were analyzed by multinomial logistic regression. The overall survival (OS) and breast cancer-specific survival (BCSS) were evaluated by Kaplan-Meier curves and Cox proportional hazards models. Further stratified subgroup analyses were performed based on the response to NAC and N-stage. Adjusted-hazard ratios were also calculated to exclude potential bias.

RESULTS

A total of 1112 patients were enrolled (median follow-up: 81 months), 58.5% received BCT, 23.6% received reconstruction and 17.9% received mastectomy. Response to NAC and N-stage not only influenced the choice of surgical modality but also were independent predictors for OS and BCSS. The surgery-induced survival differences mainly affect OS. Survival analyses demonstrated that the 10-year OS of BCT was superior or equal to that of mastectomy even in patients with partial response (PR) (77.4% vs. 64.1%, P = 0.013), no response (NR) (44.9% vs. 64.2%, P = 0.33), or N1 stage (75.7% vs. 57.4%, P = 0.0021). In the N1-PR cohort, mastectomy may lead to worse OS (P = 0.0012). Besides, between reconstruction and BCT, there was no statistical difference in OS or BCSS (P > 0.05).

CONCLUSION

Our study reveals the necessity of breast surgical de-escalation. Besides, physicians should actively recommend reconstruction for individuals who strongly desire mastectomy.

Use of ultrasound and MRI to stage the axilla for breast cancer before and after neoadjuvant chemotherapy prior to targeted sentinel lymphadenectomy

PURPOSE

Prior data from this Center demonstrated that for patients who had biopsy-proven axillary metastases, were ycN0 after neoadjuvant chemotherapy (NAC), and had a wire-directed (targeted) sentinel lymphadenectomy (WD-SLND), 60% were node negative. The hypothesis of this study was that results of axillary imaging either before or after NAC would be predictive of final pathologic status after WD-SLND.

METHODS

For patients treated with NAC between 2015 and 2023, ultrasound and MRI images of the axilla were retrospectively reviewed by radiologists specializing in breast imaging, who were blinded to the surgical and pathology results.

RESULTS

Of 113 patients who fit the clinical criteria, 66 (58%) were ypN0 at WD-SLND and 34 (30%) had a pathologic complete response to NAC. There was no correlation between the number of abnormal lymph nodes on pre-NAC ultrasound or MRI imaging and the final pathologic status of the lymph nodes. The positive predictive value (PPV) of abnormal post-NAC axillary imaging was 48% for ultrasound and 53% for MRI. The negative predictive value (NPV) for normal post-NAC axillary imaging was 67% for ultrasound and 68% for MRI.

CONCLUSION

The results of axillary imaging were not adequate to identify lymph nodes after NAC that were persistently pathologically node positive or those which had become pathologically node negative.

Axillary management and long-term oncologic outcomes in breast cancer patients with clinical N1 disease treated with neoadjuvant chemotherapy

BACKGROUND

Low false negative rates can be achieved with sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) in breast cancer (BC) patients with clinical N1 (cN1) disease. We examined changes in axillary management and oncologic outcomes in BC patients with cN1 disease receiving NAC.

METHODS

BC patients with biopsy proven cN1 disease treated with NAC were selected from our institutional cancer registry (2014-2017). Patients were grouped by axillary management, axillary lymph node dissection (ALND), SLNB followed by ALND, or SLNB alone. Univariable and multivariable survival analysis for recurrence-free survival (RFS) and overall survival (OS) were performed.

RESULTS

81 patients met inclusion criteria: 31 (38%) underwent ALND, 25 (31%) SLNB + ALND, and 25 (31%) SLNB alone. A SLN was identified in 45/50 (90%) patients who had SLNB. ALND was performed in 25/50 (50%) patients who had SLNB: 18 for a + SLNB, 5 failed SLNB, and 2 insufficient SLNs. 25 patients had SLNB alone, 17 were SLN- and 8 SLN+. In the SLNB alone group, 23/25 (92%) patients received adjuvant radiation (RT). 20 (25%) patients developed BC recurrence: 14 distant (70%), 3 local (15%), 2 regional + distant (10%), and 1 contralateral (5%). In the SLNB alone group, there was 1 axillary recurrence in a patient with a negative SLNB who did not receive RT. Univariable survival analysis showed significant differences in RFS and OS between axillary management groups, ALND/SLNB + ALND vs. SLNB alone (RFS: p = 0.006, OS: p = 0.021). On multivariable survival analysis, worse RFS and OS were observed in patients with TNBC (RFS: HR 3.77, 95% CI 1.70-11.90, p = 0.023; OS: HR 8.10, 95% CI 1.84-35.60, p = 0.006).

CONCLUSIONS

SLNB alone and RT after NAC in BC patients with cN1 disease who have negative SLNs at surgery provides long-term regional disease control. This analysis provides support for the practice of axillary downstaging with NAC and SLNB alone.

Peroxiporins in Triple-Negative Breast Cancer: Biomarker Potential and Therapeutic Perspectives

Triple-negative breast cancer (TNBC) remains one of the most challenging subtypes since it is initially characterized by the absence of specific biomarkers and corresponding targeted therapies. Advances in methodology, translational informatics, genomics, and proteomics have significantly contributed to the identification of therapeutic targets. The development of innovative treatments, such as antibody-drug conjugates and immune checkpoint inhibitors, alongside chemotherapy, has now become the standard of care. However, the quest for biomarkers defining therapy outcomes is still ongoing. Peroxiporins, which comprise a subgroup of aquaporins, which are membrane pores facilitating the transport of water, glycerol, and hydrogen peroxide, have emerged as potential biomarkers for therapy response. Research on peroxiporins reveals their involvement beyond traditional channeling activities, which is also reflected in their cellular localization and roles in cellular signaling pathways. This research on peroxiporins provides fresh insights into the mechanisms of therapy resistance in tumors, offering potential avenues for predicting treatment outcomes and tailoring successful TNBC therapies.

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

New Strategies for Locally Advanced Breast Cancer: A Review of Inflammatory Breast Cancer and Nonresponders

This review explores the new strategies around the management of locally advanced breast cancer (LABC), particularly for nonresponsive tumors and/or initially unresectable tumors at diagnosis, inclusive of inflammatory breast cancer. Nonresponders to neoadjuvant systemic therapy present a unique clinical challenge. Emerging medical therapeutics as well as considerations for use of radiotherapy and/or surgery in this setting are discussed. Specifically, the use of neoadjuvant radiotherapy for LABC and lymphedema prevention with lymphatic reconstruction following axillary lymph node dissection are reviewed.

Omission of Axillary Dissection Following Nodal Downstaging With Neoadjuvant Chemotherapy

Importance

Data on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown.

Objective

To investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node.

Design, Setting, and Participants

In this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis.

Exposure

Omission of ALND after SLNB or TAD.

Main Outcomes and Measures

The primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed.

Results

A total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)-positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55).

Conclusions and Relevance

The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

Clipping a Positive Lymph Node Improves Accuracy of Nodal Staging After Neoadjuvant Chemotherapy for Breast Cancer Patients, but Does It Drive Management Changes?

BACKGROUND

Sentinel lymph node (SLN) biopsy for cN+ breast cancer patients after neoadjuvant chemotherapy (NAC) is controversial because the false-negative rate (FNR) is high. Identification of three or more SLNs with a dual tracer improves these results, and inclusion of a clipped lymph node (CLN) (targeted axillary dissection [TAD]) may be even more effective.

METHODS

A retrospective, single-institution analysis of consecutive cN+ patients undergoing NAC from 2019 to 2021 was performed. Patients routinely underwent placement of a clip in the positive lymph node before NAC, and TAD was performed after completion of therapy.

RESULTS

The study analyzed 73 patients, and the identification rate for CLN was 98.6% (72/73). A complete response in the lymph nodes was achieved for 43 (59%) of the 73 patients. Overall, the CLN was not a SLN in 18 (25%) of 73 cases, and for women who had one or two and those who had three or more SLNs identified, this occurred in 11 (32%) and 7 (21%) of 34 cases, respectively. Failure of SLN or TAD to identify a positive residual lymph node status after NAC occurred in 10 (15%) of 69 and 2 (3%) of 73 cases, respectively (p = 0.01). In four cases, a SLN was not retrieved (5.5%), and two of these cases had a positive CLN. In three cases, the CLN was the only positive node and did not match with a SLN, directing lymphadenectomy and oncologic management change in two cases. Therefore, 7 (10%) of 73 cases had a change in surgical or oncologic management with TAD.

CONCLUSIONS

For a conservative axillary treatment in this setting, TAD is an effective method. It is more accurate than SLN alone and allows management changes. Further studies are warranted.

Axillary Surgery for Breast Cancer in 2024

Axillary surgery for patients with breast cancer (BC) in 2024 is becoming increasingly specific, moving away from the previous 'one size fits all' radical approach. The goal is to spare morbidity whilst maintaining oncologic safety. In the upfront surgery setting, a first landmark randomized controlled trial (RCT) on the omission of any surgical axillary staging in patients with unremarkable clinical examination and axillary ultrasound showed non-inferiority to sentinel lymph node (SLN) biopsy (SLNB). The study population consisted of 87.8% postmenopausal patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative BC. Patients with clinically node-negative breast cancer and up to two positive SLNs can safely be spared axillary dissection (ALND) even in the context of mastectomy or extranodal extension. In patients enrolled in the TAXIS trial, adjuvant systemic treatment was shown to be similar with or without ALND despite the loss of staging information. After neoadjuvant chemotherapy (NACT), targeted lymph node removal with or without SLNB showed a lower false-negative rate to determine nodal pathological complete response (pCR) compared to SLNB alone. However, oncologic outcomes do not appear to differ in patients with nodal pCR determined by either one of the two concepts, according to a recently published global, retrospective, real-world study. Real-world studies generally have a lower level of evidence than RCTs, but they are feasible quickly and with a large sample size. Another global real-world study provides evidence that even patients with residual isolated tumor cells can be safely spared from ALND. In general, few indications for ALND remain. Three randomized controlled trials are ongoing for patients with clinically node-positive BC in the upfront surgery setting and residual disease after NACT. Pending the results of these trials, ALND remains indicated in these patients.

Outcomes of sentinel node biopsy according to MRI response in an association with the subtypes in cN1-3 breast cancer after neoadjuvant systemic therapy, multicenter cohort study

BACKGROUND

This study investigated the feasibility of sentinel lymph node biopsy (SLNB) after neoadjuvant systemic therapy (NAST) in patients with initially high nodal burden.

METHODS

In the multicenter retrospective cohort, 388 individuals with cN1-3 breast cancer who underwent NAST and had SLNB followed by completion axillary lymph node dissection were included. In an external validation cohort, 267 patients with HER2+ or triple-negative breast cancer (TNBC) meeting similar inclusion criteria were included. Primary outcome was the false-negative rates (FNRs) of SLNB according to the MRI response and subtypes. We defined complete MRI responders as patients who experienced disappearance of suspicious features in the breast and axilla after NAST.

RESULTS

In the multicenter retrospective cohort, 130 (33.5%) of 388 patients were of cN2-3, and 55 (14.2%) of 388 patients showed complete MRI responses. In hormone receptor-positive HER2- (n = 207), complete and non-complete responders had a high FNRs (31.3% [95% CI 8.6-54.0] and 20.9% [95% CI 14.1-27.6], respectively). However, in HER2+ or TNBC (n = 181), the FNR of complete MRI responders was 0% (95% CI 0-0), whereas that of non-complete responders was 33.3% (95% CI 20.8-45.9). When we validated our findings in the external cohort with HER2+ or TNBC (n = 267), of which 34.2% were cN2-3, the FNRs of complete were 7.1% (95% CI 0-16.7).

CONCLUSIONS

Our findings suggest that SLNB can be a reliable option for nodal status evaluation in selected patients who have responded well to NAST, especially in HER2+ and TNBC patients who show a complete MRI response.

Targeted axillary dissection: worldwide variations in clinical practice

PURPOSE

Targeted axillary dissection (TAD) for the axillary staging of clinically node-positive (cN +) breast cancer patients converting to clinically node negative post neoadjuvant chemotherapy (NAC), has gained popularity due to its minimal false negative rate and low arm morbidity. The aim of this study is to shed more light on the variation in the clinical practice globally in terms of indications and perceived limitations of TAD.

METHODS

A panel of expert breast surgeons constructed a structured questionnaire comprising of 18 questions and asked surgeons worldwide for their opinions and routine practice on TAD. The questionnaire was electronically distributed and answers were collected between May 1st and August 1st 2022.

RESULTS

Responses included 137 entries from 36 countries. Of them, 73.7% consider TAD for cN + patients planned to receive NAC. Among them, the greatest number of respondents (45%) perform the procedure for tumours up to T3, whereas 27% regardless of T-stage. The majority (42%) perform TAD on patients with 1-3 positive nodes and only 30% consider TAD when matted nodes are present. HER2 positive and Triple Negative subtypes are more likely to undergo TAD than Luminal A and B (86%, 79.1%, 39.5%, and 62.8%, respectively). Maximum acceptable lymph node burden is median 3 nodes for any subtype with a tendency to accept more positive nodes for Triple Negative.

CONCLUSION

This study demonstrates the differences in current practice regarding TAD as well as the fact that the biology of the tumour heavily affects the method of axillary staging.

Axillary management in breast cancer after neoadjuvant chemotherapy in the modern era: A national cancer database analysis

BACKGROUND

Axillary management for node-positive breast cancer continues to evolve. Data further supporting targeted axillary dissection after neoadjuvant chemotherapy was published in 2016 and may have induced changes in practice.

METHODS

Patients included in the National Cancer Database from 2014 to 2017 with clinical T1 to T4 and node-positive disease who underwent neoadjuvant chemotherapy before surgical axillary management were evaluated. Patients were divided into the following 3 groups: selective axillary dissection, minimal axillary dissection, and maximal axillary dissection, according to surgical axillary management and pathological node status.

RESULTS

Patients who underwent selective axillary dissection were younger (52.4 years ± 12.4, P < .0001) compared to maximal axillary dissection (55.1 ± 12.7) and minimal axillary dissection (54.6 ± 12.7). Patients with higher clinical stage more frequently underwent maximal axillary dissection, and those with lower tumor grade more frequently underwent minimal axillary dissection (P < .0001). Community cancer programs were more likely to perform maximal axillary dissection compared to all other types of programs and had the slowest rate of adoption of selective axillary dissection. Integrated Network Cancer Programs had the lowest proportion of maximal axillary dissection performed and the highest proportion of selective axillary dissection. Uninsured patients were more likely to receive maximal axillary dissection, and those with private insurance were more likely to undergo selective axillary dissection (P < .0001). Selective axillary dissection rates increased from 29.8% of procedures in 2016 to 41.5% in 2017, and MaxAD rates decreased from 62.4% in 2016 to 47.9% in 2017.

CONCLUSION

Utilization of selective axillary dissection has increased since 2016; however, discrepancies in surgical axillary management after neoadjuvant chemotherapy still exist.

The use of blue dye alone for sentinel lymph node biopsy after neoadjuvant chemotherapy in patients with initially node-positive breast cancer

INTRODUCTION

False-negative sentinel lymph node biopsy (SLNB) rates following neoadjuvant chemotherapy (NACT) in initially node-positive (cN1/2) breast cancer patients are high, but decrease when lymph nodes are clipped, ≥3 sentinel lymph nodes (SLN) are removed or dual-tracer localization (radioisotope and blue dye) is used. Radiotracer, however, is often unavailable and outcomes with blue dye alone are unknown.

MATERIALS AND METHODS

Initially cT1-4, cN1/2 patients treated with NACT in 2013-2023 who underwent SLNB using blue dye alone were evaluated regarding SLN identification, axillary recurrence, disease-free and overall survival rates.

RESULTS

Of 119 patients included, 19 remained cN1/2 after NACT. SLNB was performed using blue dye alone in 100 ycN0 cases (84%), with an identification rate of 96%. The SLN was negative in 70/119 cases (i.e. 59% avoided axillary dissection). The number of SLN detected was ≥3 in 55/70 cases (78%) (median 3.1; 1-6). Median age was 49 years (25-84). Most were T2 (n = 40, 57.1%), N1 (n = 64, 91.4%). Predominant subtypes were ERBB2 (52.9%) and triple-negative (20%). No axillary recurrence occurred over a median 36-month period. Five-year disease-free and overall survival were, respectively, 85.9% (95%CI: 74-99.8) and 96.3% (95%CI: 89.4-100). The ERBB2 subtype (1.99, 95%CI: 1.02-3.85, p = 0.04) and N1 lymph node status (2.58, 95%CI: 1.54-9.10, p = 0.03) were associated with a greater likelihood of undergoing SLNB alone without axillary dissection.

CONCLUSIONS

SLNB with blue dye alone following NACT in initially cN1/2 patients avoided axillary dissection in almost 60% of cases, with no recurrences during the period evaluated. Longer follow-up studies are necessary.

Prognostic analysis of cT1-3N1M0 breast cancer patients who have responded to neoadjuvant therapy undergoing various axillary surgery and breast surgery based on propensity score matching and competitive risk model

Background

Sentinel lymph node biopsy (SLNB) in breast cancer patients with positive clinical axillary lymph nodes (cN1+) remains a topic of controversy. The aim of this study is to assess the influence of various axillary and breast surgery approaches on the survival of cN1+ breast cancer patients who have responded positively to neoadjuvant therapy (NAT).

Methods

Patients diagnosed with pathologically confirmed invasive ductal carcinoma of breast between 2010 and 2020 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. To mitigate confounding bias, propensity score matching (PSM) analysis was employed. Prognostic factors for both overall survival (OS) and breast cancer-specific survival (BCSS) were evaluated through COX regression risk analysis. Survival curves were generated using the Kaplan-Meier method. Furthermore, cumulative incidence and independent prognostic factors were assessed using a competing risk model.

Results

The PSM analysis matched 4,890 patients. Overall survival (OS) and BCSS were slightly worse in the axillary lymph node dissection (ALND) group (HR = 1.10, 95% CI 0.91-1.31, p = 0.322 vs. HR = 1.06, 95% CI 0.87-1.29, p = 0.545). The mastectomy (MAST) group exhibited significantly worse OS and BCSS outcomes (HR = 1.25, 95% CI 1.04-1.50, p = 0.018 vs. HR = 1.37, 95% CI 1.12-1.68, p = 0.002). The combination of different axillary and breast surgery did not significantly affect OS (p = 0.083) but did have a significant impact on BCSS (p = 0.019). Competing risk model analysis revealed no significant difference in the cumulative incidence of breast cancer-specific death (BCSD) in the axillary surgery group (Grey's test, p = 0.232), but it showed a higher cumulative incidence of BCSD in the MAST group (Grey's test, p = 0.001). Multivariate analysis demonstrated that age ≥ 70 years, black race, T3 stage, ER-negative expression, HER2-negative expression, and MAST were independent prognostic risk factors for both OS and BCSS (all p < 0.05).

Conclusion

For cN1+ breast cancer patients who respond positive to NAT, the optimal surgical approach is combining breast-conserving surgery (BCS) with SLNB. This procedure improves quality of life and long-term survival outcomes.

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.

Performance and oncologic safety of sentinel lymph node biopsy after neoadjuvant chemotherapy: Results from a tertiary care center in Lebanon

BACKGROUND

The feasibility of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) in initially node-positive patients is still controversial. We aim to evaluate the oncologic outcomes of SLNB after NACT and further compare the results between those who were initially node-negative and node-positive.

METHODS

This is a retrospective cohort that included patients diagnosed with invasive breast cancer and had surgical management between January 2010 and December 2016. Survival and recurrence data after 3-5 years were collected from patients' records. We divided patients into Group A who were initially node-negative and had SLNB ± axillary lymph node dissection (ALND) and Group B who were node-positive and had SLNB ± ALND.

RESULTS

Among initially node-negative patients, 43 out of 63 patients did SLNB (Group A). However, among initially node-positive patients only 28 out of 123 patients did SLNB (Group B). Out of the 71 patients who did SLNB after NACT, 26 patients had positive SLNs with only 14 patients who further underwent ALND. The identification rate of SLNB was 100% in Group A and 96.4% in Group B. The survival curves by nodal status showed no significant difference between overall survival and recurrence-free survival at 5 years between patients in Group A versus Group.

CONCLUSION

The results suggest that in properly selected patients, SLNB can be feasible after NACT. Our results resemble the reported literature on accuracy of SLNB after NACT and adds to the growing pool of data on this topic.

What's new in surgical oncology breast

It is on the backdrop of advances in tumor biology and systemic therapy for breast cancer, that progress in locoregional treatment has focused on management of the breast for invasive cancer, imaging for staging and therapeutic decision-making, and de-escalation in the management of the axilla.

Absence of post-treatment changes in sentinel lymph nodes does not translate into increased regional recurrence rate in initially node-positive breast cancer patients

PURPOSE

To determine whether the absence of post-treatment changes in the negative sentinel lymph nodes (SLN) in the neoadjuvant setting for biopsy-proven cN + disease results in an increased regional recurrence (RR) rate in patients after SLN biopsy (SLNB) only.

METHODS

Breast cancer patients with biopsy-proven cN + disease who converted to node-negative disease after neoadjuvant systemic treatment (NAST) and underwent SLNB only were included. Retrospective analysis was performed for patients diagnosed between 2008 and 2021. Pathohistological specimens were reviewed for the presence of post-treatment changes in the SLNs. Patients with negative SLNs (ypN0) were divided into two groups: (i) with post-treatment changes, (ii) without post-treatment changes. Patients' characteristics were compared between groups. Crude RR rates were compared using the log-rank test. Recurrence-free (RFS) and overall survival (OS) for the entire cohort were calculated using Kaplan-Meier.

RESULTS

Of 437 patients with cN + disease, 95 underwent SLNB only. 82 were ypN0, 57 with post-treatment changes (group 1), 25 without post-treatment changes (group 2). During the median follow-up of 37 months (range 6-148), 1 isolated regional recurrence occurred in group 2 (RR rate 0% for group 1 vs. 4% for group 2, p = 0.149). There were no differences in 3-year RFS and OS between groups.

CONCLUSION

Absent post-treatment changes in negative SLNs for biopsy-proven cN + disease that covert to node-negative after NAST did not result in increased regional recurrence rates in our cohort. Multidisciplinary input is essential to determine whether additional treatment is needed in these patients.

This house believes that: MARI/TAD is better than sentinel node biopsy after PST for cN+ patients

The increasing use and effectiveness of primary systemic treatment (PST) enables tailored locoregional treatment. About one third of clinically node positive (cN+) breast cancer patients achieve pathologic complete response (pCR) of the axilla, with higher rates observed in Human Epidermal growth factor Receptor (HER)2-positive or triple negative (TN) breast cancer subtypes. Tailoring axillary treatment for patients with axillary pCR is necessary, as they are unlikely to benefit from axillary lymph node dissection (ALND), but may suffer complications and long-term morbidity such as lymphedema and impaired shoulder motion. By combining pre-PST and post-PST axillary staging techniques, ALND can be omitted in most cN + patients with pCR. Different post-PST staging techniques (MARI/TAD/SN) show low or ultra-low false negative rates for detection of residual disease. More importantly, trials using the MARI (Marking Axillary lymph nodes with Radioactive Iodine seeds) procedure or sentinel lymph node biopsy (SLNB) as axillary staging technique post-PST have already shown the safety of tailoring axillary treatment in patients with an excellent response. Tailored axillary treatment using the MARI procedure in stage I-III breast cancer resulted in 80% reduction of ALND and excellent five-year axillary recurrence free interval (aRFI) of 97%. Similar oncologic outcomes were seen for post-SLNB in stage I-II patients. The MARI technique requires only one invasive procedure pre-NST and a median of one node is removed post-PST, whereas for the SLNB and TAD techniques two to four nodes are removed. A disadvantage of the MARI technique is its use of radioactive iodine, which is subject to extensive regulations.

Changes in Surgical Management of the Axilla Over 11 Years - Report on More Than 1500 Breast Cancer Patients Treated with Neoadjuvant Chemotherapy on the Prospective I-SPY2 Trial

BACKGROUND

Axillary surgery after neoadjuvant chemotherapy (NAC) is becoming less extensive. We evaluated the evolution of axillary surgery after NAC on the multi-institutional I-SPY2 prospective trial.

METHODS

We examined annual rates of sentinel lymph node (SLN) surgery with resection of clipped node, if present), axillary lymph node dissection (ALND), and SLN and ALND in patients enrolled in I-SPY2 from January 1, 2011 to December 31, 2021 by clinical N status at diagnosis and pathologic N status at surgery. Cochran-Armitage trend tests were calculated to evaluate patterns over time.

RESULTS

Of 1578 patients, 973 patients (61.7%) had SLN-only, 136 (8.6%) had SLN and ALND, and 469 (29.7%) had ALND-only. In the cN0 group, ALND-only decreased from 20% in 2011 to 6.25% in 2021 (p = 0.0078) and SLN-only increased from 70.0% to 87.5% (p = 0.0020). This was even more striking in patients with clinically node-positive (cN+) disease at diagnosis, where ALND-only decreased from 70.7% to 29.4% (p < 0.0001) and SLN-only significantly increased from 14.6% to 56.5% (p < 0.0001). This change was significant across subtypes (HR-/HER2-, HR+/HER2-, and HER2+). Among pathologically node-positive (pN+) patients after NAC (n = 525) ALND-only decreased from 69.0% to 39.2% (p < 0.0001) and SLN-only increased from 6.9% to 39.2% (p < 0.0001).

CONCLUSIONS

Use of ALND after NAC has significantly decreased over the past decade. This is most pronounced in cN+ disease at diagnosis with an increase in the use of SLN surgery after NAC. Additionally, in pN+ disease after NAC, there has been a decrease in use of completion ALND, a practice pattern change that precedes results from clinical trials.

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.

Axillary ultrasound for predicting response to neoadjuvant treatment in breast cancer patients-a single institution experience

BACKGROUND

In node-positive breast cancer patients at diagnosis (cN +) that render node-negative after neoadjuvant systemic treatment (NAST), axillary lymph node dissection (ALND) can be avoided in selected cases. Axillary ultrasound (AUS) is most often used for re-staging after NAST. We aimed to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of AUS after NAST for predicting nodal response at the Institute of Oncology, Ljubljana.

METHODS

Biopsy-confirmed cN + patients consecutively diagnosed at our institution between 2008 and 2021, who received NAST, followed by surgery were identified retrospectively. Only patients that underwent AUS after NAST were included. AUS results were compared to definite nodal histopathology results. We calculated sensitivity, specificity, PPV and NPV of AUS. We also calculated the proportion of patients with false-positive AUS that results in surgical overtreatment (unnecessary ALND).

RESULTS

We identified 437 cN + patients. In 244 (55.8%) AUS after NAST was performed. Among those, 42/244 (17.2%) were triple negative (TN), 78/244 (32.0%) Her-2 positive (Her-2 +), and 124/244 (50,8%) luminal Her-2 negative cancers. AUS was negative in 179/244 (73.4%), suspicious/positive in 65/244 (26.6%) (11/42 (26.2%) TN, 19/78 (24.4%) Her-2 + , and 35/124 (28.2%) luminal Her-2 negative cancers). On definite histopathology, nodal complete response (pCR) was observed in 89/244 (36.5%) (19/42 (45.2%) TN, 55/78 (70.5%) Her-2 + , and 15/124 (12.1%) luminal Her-2 negative cancers). Among patients with suspicious/positive AUS, pCR was observed in 20/65 (30.8%) (6/11 (54.5%) TN, 13/19 (68.4%) Her-2 + and 1/35 (2.9%) luminal Her-2 negative cancers). Sensitivity was 29.0%, specificity 77,5%, PPV 69.2%, NPV 38.5%. Specificity and PPV in TN was 68.4% and 45.4%, in Her-2 + 76.4% and 31.6%, in luminal Her-2 negative 93,3% and 97,1%, respectively.

CONCLUSION

In approximately half of the patients, AUS falsely predicts nodal response after NAST and may lead to overtreatment in 30% of the cases (ALND). However, AUS has to be interpreted in context with tumor subtype. In luminal Her-2 negative cancers, it has a high PPV and is therefore useful.

Regional radiotherapy after primary systemic treatment for cN+ breast cancer patients

Pathologic complete response (pCR) after Primary Systemic Treatment (PST) for breast cancer is associated with excellent long-term outcomes. With increasing use of PST, the indication for regional nodal irradiation (RNI) has been challenged. The aim of this paper is to review the literature on de-escalation of RNI in patients treated with PST. We found no level 1 evidence on de-escalation of RNI after PST, but several randomized trials are ongoing. Consequently, current de-escalation strategies are based on cohort studies. These studies showed that in patients with low nodal tumour burden (LNTB) (≤3 suspicious nodes at imaging) prior to PST, and ypN0 based on Axillary Lymph Node Dissection (ALND), omission of RNI resulted in very low regional recurrences (RR) without compromising survival. In patients with LNTB and ypN0 based on Sentinel Lymph Node Biopsy (SLNB), omission of axillary treatment also resulted in low RR; the majority of these patients received local radiotherapy. Similarly, in patients with ypN1 (ALND) disease, omission of RNI resulted in low 5-year RR rates. Low RR-rates were also found in the few studies replacing ALND by RNI, in patients with ypN1 (SLNB) disease. In patients with high nodal tumour burden prior to PST and ypN0 (SLNB), replacing ALND by RNI also resulted in low RR. Due to the limited number of patients, these data should be interpreted with caution. We conclude that although level 1 evidence is lacking, de-escalation of RNI after PST can be considered in selected cases.

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.

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.

Axillary ultrasound after neoadjuvant therapy reduces the false-negative rate of sentinel lymph node biopsy in patients with cytologically node-positive breast cancer

OBJECTIVES

This study aimed to determine whether post-neoadjuvant therapy (NAT) axillary ultrasound (AUS) could reduce the false-negative rate (FNR) of sentinel lymph node biopsy (SLNB). We also performed subgroup analyses to identify the appropriate patient for SLNB.

METHODS

A total of 220 patients with cytologically proven axillary node-positive breast cancer who underwent both SLNB and axillary lymph node dissection (ALND) after NAT were included. We calculated the FNR of SLNB. In the case of post-NAT AUS results available, AUS was classified as negative or positive. Then the FNR of post-NAT AUS combined with SLNB was evaluated. Subgroup analyses based on the number of sentinel lymph nodes removed, molecular subtypes, and the clinical N stage were also performed.

RESULTS

The overall axillary lymph node pathological complete response rate was 45.5% (100/220). The FNR of SLNB alone was 15.8% (95%CI: 9.2 to 22.5%). Post-NAT AUS results were available for 181 patients. When combined negative post-NAT AUS results and SLNB, the FNR was reduced to 7.5% (95%CI: 2.4 to 12.7%). Subgroup analyses of the FNR for SLNB alone and negative post-NAT AUS combined with SLNB were shown as follows: in cases patients with less than three sentinel lymph nodes (SLNs) and at least three SLNs removed, the FNR was decreased from 24.5 to 13.2%, and 9.0 to 5.0%, respectively. The FNR was decreased from 20.8 to 10.5% in HR+/HER2+subgroup, 21.4 to 16.7% in HR-/HER2+subgroup, 15.9 to 7.0% in HR+/HER2- subgroup, and 0% in HR-/HER2- subgroup, respectively. For cN1 patients, the FNR was decreased from 18.1 to 12.1% while 17.1 to 3.6% for cN2 patients and 0% for cN3 patients.

CONCLUSION

Using negative post-NAT AUS may help to decrease the FNR and improve patient selection for SLNB.

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.

Axillary management in patients with breast cancer and positive axilla at diagnosis. Experience in a Spanish university hospital with a 5-year follow-up

Background

Axillary lymph node dissection (ALND) was the standard in breast cancer with axillary involvement until recently. Along with the number of metastatic nodes, axillary positivity was considered a main prognostic factor and scientific evidence shows that the administration of radiotherapy on ganglion areas decreases the risk of recurrence even in positive axilla. The objective of this study was to evaluate the axillary treatment in patients with positive axilla at diagnosis, the evolution of them over time, and to assess patient's follow-up with the aim of avoiding the morbidity associated with axillary dissection.

Methods

A retrospective observational study of breast cancer patients diagnosed between 2010 and 2017 was performed. In total, 1,100 patients were studied, out of which 168 were women with clinically and histologically positive axilla at diagnosis. Seventy-six percent received primary chemotherapy and subsequent treatment with sentinel node biopsy, axillary dissection, or both. Patients with positive sentinel lymph node biopsy received either radiotherapy or lymphadenectomy depending on the year time they were diagnosed.

Results

For 60 patients out of 168, neoadjuvant chemotherapy resulted in a complete pathological axillary response. Axillary recurrence was registered for six patients. No recurrence was detected in the biopsy group associated with radiotherapy. These results support the benefit of lymph node radiotherapy for patients with positive sentinel node biopsy after receiving primary chemotherapy.

Conclusion

Sentinel node biopsy provides useful and reliable information about cancer staging and might prevent lymphadenectomy, leading to a decrease in morbidity. Pathological response to systemic treatment came out as the most important predictive factor of disease-free survival of breast cancer.

Axillary staging and management of cN + breast cancer patients treated with neoadjuvant chemotherapy: results of a survey among breast cancer surgeons in Spain

INTRODUCTION

Given the high rate of complete nodal response, the role of axillary lymph node dissection on staging the axilla has been questioned. This survey, addressed to breast cancer surgeons in Spain, has the objective of assessing current clinical trends on axillary staging of cN + patients treated with NAC.

METHODS

An online survey was conducted among breast surgeons from the Spanish Society of Surgery (AEC), Spanish Surgical Oncology Society (SEOQ), Spanish Breast Cancer Surgeons Society (AECIMA) and Spanish Gynecology and Obstetrics Society (SEGO). It was structured in 5 sections: general information and clinical practice, knowledge of clinical trials, diagnosis work-up and nodal marking, axillary staging, and axillary treatment.

RESULTS

150 breast cancer surgeons completed the full survey (96.7%). 81.8% of respondents performed SLNB or targeted axillary dissection in cN1 patients treated with NAC. Radiological axillary response was the preferred parameter guiding the surgical strategy. The excision of the clipped node (92.0%), use of dual tracer (73.2%), and axillary US (65.9%) after treatment were the most important variables considered by respondents, to increase the accuracy of SLNB in cN + patients.

CONCLUSION

This survey confirms a trend toward a less invasive approach for axillary staging in cN + patients treated with NAC among breast cancer surgeons in Spain. While there is widespread agreement in less invasive approaches to axillary staging, there is, however, a lack of consensus around treatment strategy. Further, it shows a wide heterogeneity in their clinical practice. This study highlights the need for clear evidence concerning less invasive staging procedures and their oncological safety, to ensure consistent recommendations in surgical practice.

Is Nodal Clipping Beneficial for Node-Positive Breast Cancer Patients Receiving Neoadjuvant Chemotherapy?

BACKGROUND

In cN1 patients rendered cN0 with neoadjuvant chemotherapy, the false-negative rate of sentinel lymph node biopsy (SLNB) is < 10% when ≥ 3 sentinel lymph nodes (SLNs) are removed. The added value of nodal clipping in this scenario is unknown. Here we determine how often the clipped node is a sentinel node when ≥ 3 SLNs are retrieved.

METHODS

We identified cT1-3N1 patients treated between 02/2018 and 10/2021 with a clipped lymph node at presentation. SLNB was performed with a standardized approach of dual-tracer mapping and retrieval of ≥ 3 SLNs. Clipped nodes were not localized; SLNs were X-rayed intraoperatively to determine clip location. Axillary lymph node dissection (ALND) was performed for any residual disease or retrieval of < 3 SLNs.

RESULTS

Of 269 patients, 251 (93%) had ≥ 3 SLNs. Median age was 51 years; the majority (92%) had ductal histology; 46% were HR+/HER2-. The median number of SLNs removed was 4 (IQR 3,5). The clipped node was an SLN in 88% (220/251) of cases. Of the 31 where the clipped node was not, 13 had a positive SLN mandating ALND, and the clip was identified in the ALND specimen. In the remaining 18, where ≥ 3 negative SLNs were retrieved and an ALND was not performed, the clip was not retrieved, with no axillary failures in this group (median follow-up: 55 months).

CONCLUSION

When the SLNB procedure is optimized with dual tracer and retrieval of ≥ 3 SLNs, the clipped node is an SLN in the majority of cases, suggesting that failure to retrieve the clipped node should not be an indication for ALND.

Factors Influencing Non-sentinel Lymph Node Involvement in Patients with Positive Sentinel Lymph Node(s) After Neoadjuvant Chemotherapy for Breast Cancer

BACKGROUND

When a positive sentinel lymph node (SLN) is identified after neoadjuvant chemotherapy (NAC), completion axillary lymph node dissection (cALND) is generally recommended. We sought to evaluate the rate of non-SLN positivity and factors influencing this in patients with a positive SLN following NAC.

METHODS

We identified all patients at our hospital between 2006 and 2021 with a positive SLN (> 0.2 mm) following NAC who underwent cALND. Rates of positive non-SLN (NSLN) on cALND were compared by nodal status. Chi-square tests and multivariable logistic regression were used to assess factors predictive of positive NSLN and overall nodal burden.

RESULTS

Overall, 229 cases (177 cN+, 52 cN0 prior to NAC) with positive SLN(s) after NAC underwent cALND. Additional NSLN involvement was found in 129/229 (56.3%) patients, including 24/52 (46.2%) cN0 and 105/177 (59.3%) cN+ patients (p = 0.09). There was a trend for patients with SLN micrometastases to be less likely to have positive NSLN(s) than those with SLN macrometastases (38.5% vs. 58.6%; p = 0.05). Subgroup analyses showed no clinicopathologic factors significantly associated with additional axillary involvement for initially cN0 patients. Factors found to significantly influence NSLN positivity in the initially cN+ subgroup were HER2 status, multicentricity/multifocality, number of positive SLNs, and size of SLN metastasis. SLN metastasis size > 5 mm and three or more positive SLNs exerted the greatest influence on NSLN positivity.

CONCLUSION

Rates of nodal positivity on cALND in the setting of positive SLN after NAC are high, supporting the current standard of routine cALND. In cN+ disease, NSLN positivity varies by tumor biology, multicentricity/multifocality, number of positive SLNs, and SLN metastasis size.

Diagnostic accuracy of de-escalated surgical procedure in axilla for node-positive breast cancer patients treated with neoadjuvant systemic therapy: A systematic review and meta-analysis

BACKGROUND

More initial clinical node-positive breast cancer patients achieve axillary pathological complete response (ax-pCR) after neoadjuvant systemic therapy (NST). Restaging axillary status and performing de-escalated surgical procedures to replace routine axillary lymph nodes dissection (ALND) is urgently needed. Targeted axillary lymph node biopsy (TLNB) is a novel de-escalated surgical strategy marking metastatic axillary nodes before NST and targeted dissection and biopsy intraoperatively to tailor individual axillary management.

METHODS

This study provided a systematic review and meta-analysis to evaluate the feasibility and diagnosis accuracy of TLNB. Prospective and retrospective clinical trials on TLNB were searched from Pubmed, Embase, and Cochrane. Identification rate (IFR), false-negative rate (FNR), negative predictive value (NPV), and rate of ax-pCR were the outcomes of this meta-analysis.

RESULTS

One thousand nine hundred and twenty patients attempted TLNB, with an overall IFR of 93.5% (95% confidence interval [CI] 90.1%-96.2%). IFR of three nodal marking methods, namely iodine seeds, clips, and carbon dye, was 95.6% (95% CI 91.2%-98.7%), 91.7% (95% CI 87.3%-95.4%), and 97.1% (95% CI 89.1%-100.0%), respectively. Of them, 847 patients received ALND, with an overall FNR of 5.5% (95% CI 3.3%-8.0%), and NPV ranged from 90.1% to 96.1%. Regression analysis showed that the overlap of targeted and sentinel biopsied nodes might associate with IFRs and FNRs.

CONCLUSION

TLNB is a novel, less invasive surgical approach to distinguish initial node-positive breast cancer that achieves negative axillary conversion after NST. It yields an excellent IFR with a low FNR and a high NPV. A combination of preoperative imaging, intraoperative TLNB with SLNB, and postoperative nodal radiotherapy might affect the future treatment paradigm of primary breast cancer with nodal metastases.

Breast and axillary surgery after neoadjuvant systemic treatment - A review of clinical routine recommendations and the latest clinical research

Breast and axillary surgery after neoadjuvant systemic treatment for women with breast cancer has undergone multiple paradigm changes within the past years. In this review, we provide a state-of-the-art overview of breast and axillary surgery after neoadjuvant systemic treatment from both, a clinical routine perspective and a clinical research perspective. For axillary disease, axillary lymph node dissection, sentinel lymph node biopsy, or targeted axillary dissection are nowadays recommended depending on the lymph node status before and after neoadjuvant systemic treatment. For the primary tumor in the breast, breast conserving surgery remains the standard of care. The clinical management of exceptional responders to neoadjuvant systemic treatment is a pressing knowledge gap due to the increasing number of patients who achieve a pathologic complete response to neoadjuvant systemic treatment and for whom surgery may have no therapeutic benefit. Current clinical research evaluates whether less invasive procedures can exclude residual cancer after neoadjuvant systemic treatment as reliably as surgery to possibly omit surgery for those patients in the future.

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Breast and axillary surgery after neoadjuvant systemic treatment has evolved.

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Choice of axillary surgery depends on lymph node status before and after treatment.

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Optimal management of exceptional responders to neoadjuvant treatment is unclear.

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Clinical research aims to reliably exclude residual cancer without surgery.

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For exceptional responders, breast cancer surgery may be omitted in the future.

How Often Does Retrieval of a Clipped Lymph Node Change Adjuvant Therapy Recommendations? A Prospective, Consecutive, Patient Cohort Study

BACKGROUND

Prior studies examining sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) for cN1 patients have demonstrated that 20% of biopsied, clipped lymph nodes (cLNs) are nonsentinel lymph nodes (non-SLNs). Our goal was to determine how often the cLN was a non-SLN among both cN0 and cN1 patients and how often cLN pathology impacted management.

METHODS

Overall, 238 patients treated with NAC and surgery January 2019 to June 2020 were prospectively examined. Patients underwent routine axillary ultrasound, biopsy of suspicious nodes, and clip placement. Radioactive iodine-125 seed localization of the cLN was performed in cN1 patients only. Isolated tumor cells (ITCs) were considered node positive (ypN+) for both cN0 and cN1 cohorts. Chart review was performed to determine if cLNs were non-SLN and their ypN status.

RESULTS

Of 118 cN0 patients, 115 of 118 (97%) underwent successful SLNB, 33 of whom had a cLN present; 21 of 33 (64%) cLNs were non-SLNs. Overall, 9 of 118 (8%) were ypN+; no cLN was ypN+ without additional +SLNs. Of 120 cN1 patients, 104 of 120 (87%) converted to cN0, 98 of 104 (94%) of which had attempted SLNB, and 95 of 98 (97%) successfully mapped. The cLN was a non-SLN in 18 of 95 (19%). Overall, 58 of 104 (56%) cN1 patients were ypN+. One patient had a positive cLN in the absence of +SLNs. This patient underwent axillary lymph node dissection (ALND); adjuvant treatment recommendations were unchanged.

CONCLUSIONS

The cLN was a non-SLN in 19% of cN1 patients. cLN pathology did not impact adjuvant therapy recommendations, calling into question the utility of routinely clipping biopsied lymph nodes.

De-escalating axillary surgery in early-stage breast cancer

The role of axillary surgery has evolved over the last three decades from routine axillary lymph node dissection (ALND) to sentinel lymph node biopsy to omission of axillary surgery altogether in select patients. This evolution has been achieved through the design and conduct of multiple clinical trials demonstrating that ALND does not impact survival and is not necessary for local control in patients with early-stage breast cancer and limited nodal involvement. Importantly, this practice-changing shift mirrored the trend towards earlier stage at diagnosis and the recognition of the interplay between local and systemic therapies in maintaining local control. There are numerous clinical scenarios today in which axillary staging can be safely avoided, including (1) DCIS treated with lumpectomy, (2) at the time of contralateral prophylactic mastectomy, and (3) in elderly patients with early-stage, HR+/HER2-clinically node-negative (cN0) disease. Ongoing clinical trials seek to expand the cohorts in which surgical nodal staging can be omitted. These populations include a broader range of early-stage, cN0 patients undergoing upfront surgery, as seen in the SOUND, INSEMA, BOOG 2013-08, SOAPET and NAUTILUS trials. Omission of axillary surgery in cN0 patients with HER2+ or triple-negative disease treated with neoadjuvant chemotherapy is also being tested in the ASICS and EUBREAST-01 trials. Continued advances in imaging and the growing role of genomic assays in selecting patients for systemic therapy are likely to further minimize the need for axillary surgery; thereby further reducing the morbidity of local therapy for women with breast cancer.

Tailored axillary surgery in patients with clinically node-positive breast cancer: Pre-planned feasibility substudy of TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101)

AIM

We developed tailored axillary surgery (TAS) to reduce the axillary tumor volume in patients with clinically node-positive breast cancer to the point where radiotherapy can control it. The aim of this study was to quantify the extent of tumor load reduction achieved by TAS.

METHODS

International multicenter prospective study embedded in a randomized trial. TAS is a novel pragmatic concept for axillary surgery de-escalation that combines palpation-guided removal of suspicious nodes with the sentinel procedure and, optionally, imaging-guided localization. Pre-specified study endpoints quantified surgical extent and reduction of tumor load.

RESULTS

A total of 296 patients were included at 28 sites in four European countries, 125 (42.2%) of whom underwent neoadjuvant chemotherapy (NACT) and 71 (24.0%) achieved nodal pathologic complete response. Axillary metastases were detectable only by imaging in 145 (49.0%) patients. They were palpable in 151 (51.0%) patients, of whom 63 underwent NACT and 21 had residual palpable disease after NACT. TAS removed the biopsied and clipped node in 279 (94.3%) patients. In 225 patients with nodal disease at the time of surgery, TAS removed a median of five (IQR 3-7) nodes, two (IQR 1-4) of which were positive. Of these 225 patients, 100 underwent ALND after TAS, which removed a median of 14 (IQR 10-17) additional nodes and revealed additional positive nodes in 70/100 (70%) of patients. False-negative rate of TAS in patients who underwent subsequent ALND was 2.6%.

CONCLUSIONS

TAS selectively reduced the tumor load in the axilla and remained much less radical than ALND.

To Look or Not to Look? Axillary Imaging: Less May Be More

Axillary lymph node status in patients with breast cancer is an important prognostic indicator and often guides vital treatment decisions. Although in many cases imaging plays a crucial role in the assessment of the axilla, it is essential that targeted axillary US and/or image-guided biopsy of an axillary lymph node be performed by the radiologist only when clinically appropriate. This decision-making process requires multidisciplinary communication and collaboration among radiologists, surgeons, medical oncologists, and radiation oncologists. Our goal is to review axillary imaging for patients with breast cancer in two distinct clinical settings, the patient with newly diagnosed breast cancer who meets American College of Surgeons Oncology Group Z0011 criteria and patients undergoing neoadjuvant chemotherapy, with a specific focus on potential reasons to not perform axillary US and/or image-guided biopsy in these settings.

Nodal Recurrence in Patients With Node-Positive Breast Cancer Treated With Sentinel Node Biopsy Alone After Neoadjuvant Chemotherapy-A Rare Event

Importance

Prospective trials have demonstrated sentinel lymph node (SLN) false-negative rates of less than 10% when 3 or more SLNs are retrieved in patients with clinically node-positive breast cancer rendered clinically node-negative with neoadjuvant chemotherapy (NAC). However, rates of nodal recurrence in such patients treated with SLN biopsy (SLNB) alone are unknown because axillary lymph node dissection (ALND) was performed in all patients, limiting adoption of this approach.

Objective

To evaluate nodal recurrence rates in a consecutive cohort of patients with clinically node-positive (cN1) breast cancer receiving NAC, followed by a negative SLNB using a standardized technique, and no further axillary surgery.

Design, Setting, and Participants

From November 2013 to February 2019, a cohort of consecutively identified patients with cT1 to cT3 biopsy-proven N1 breast cancer rendered cN0 by NAC underwent SLNB with dual tracer mapping and omission of ALND if 3 or more SLNs were identified and all were pathologically negative. Metastatic nodes were not routinely clipped, and localization of clipped nodes was not performed. The study was performed in a single tertiary cancer center.

Intervention

Omission of ALND in patients with cN1 breast cancer after NAC if 3 or more SLNs were pathologically negative.

Main Outcome and Measures

The primary outcome was the rate of nodal recurrence among patients with cN1 breast cancer treated with SLNB alone after NAC.

Results

Of 610 patients with cN1 breast cancer treated with NAC (median [IQR] age, 49 [40-58] years), 555 (91%) converted to cN0 and underwent SLNB; 234 (42%) had 3 or more negative SLNs and had SLNB alone. Median age was 49 years. Median tumor size was 3 cm; 144 (62%) were ERBB2 (formerly HER2)-positive, and 43 (18%) were triple negative. Most (212 [91%]) received doxorubicin-based NAC, 205 (88%) received adjuvant radiotherapy (RT), and 164 (70%) also received nodal RT. At a median follow-up of 40 months, there was 1 axillary nodal recurrence synchronous with local recurrence in a patient who refused RT. Among patients who received RT (n = 205), there were no nodal recurrences.

Conclusions and Relevance

This cohort study found that in patients with cN1 disease rendered cN0 with NAC, with 3 or more negative SLNs with SLNB alone, nodal recurrence rates were low, without routine nodal clipping. These findings potentially support omitting ALND in such patients.

Is Residual Nodal Disease at Axillary Dissection Associated with Tumor Subtype in Patients with Low Volume Sentinel Node Metastasis After Neoadjuvant Chemotherapy?

BACKGROUND

In patients with a positive sentinel lymph node (SLN) after neoadjuvant chemotherapy (NAC), the likelihood of residual nodal disease at axillary dissection (ALND) is high. Whether non-SLN metastasis frequency varies based on tumor subtype and SLN metastasis size is uncertain. We examined the association between tumor subtype and frequency of non-SLN metastases in patients with SLN micro- vs macrometastases after NAC.

METHODS

Patients with invasive breast cancer and a positive SLN biopsy after NAC between July 2008 and July 2019 were identified. Associations between tumor subtype, SLN disease volume, and frequency of non-SLN metastases were examined.

RESULTS

Among 273 patients with ≥ 1 positive SLN and a completion ALND, mean age was 51 years, 87% of tumors were ductal, 80% were clinically node-positive at presentation, and 85% were cT2-3. The frequency of non-SLN metastases was non-significantly higher in HR+/HER2- (61%) vs. HER2+ (52%) and triple negative tumors (45%) (p = 0.09). Frequency of SLN micrometastasis was 9% for triple negative tumors compared with 17% for HR+/HER2- and 34% for HER2+ tumors (p = 0.015). Size of SLN metastasis (micro- vs. macrometastases) was not associated with non-SLN metastasis frequency or number within any subtype.

CONCLUSIONS

In patients with a positive SLN after NAC, the likelihood of non-SLN metastasis at ALND was high across all tumor subtypes and did not vary significantly for SLN micro- versus macrometastases. ALND is recommended for SLN micro- and macrometastases after NAC, irrespective of tumor subtype.

Customizing local and systemic therapies for women with early breast cancer: the St. Gallen International Consensus Guidelines for treatment of early breast cancer 2021

The 17th St Gallen International Breast Cancer Consensus Conference in 2021 was held virtually, owing to the global COVID-19 pandemic. More than 3300 participants took part in this important bi-annual critical review of the 'state of the art' in the multidisciplinary care of early-stage breast cancer. Seventy-four expert panelists (see Appendix 1) from all continents discussed and commented on the previously elaborated consensus questions, as well as many key questions on early breast cancer diagnosis and treatment asked by the audience. The theme of this year's conference was 'Customizing local and systemic therapies.' A well-organized program of pre-recorded symposia, live panel discussions and real-time panel voting results drew a worldwide audience of thousands, reflecting the far-reaching impact of breast cancer on every continent. The interactive technology platform allowed, for the first time, audience members to ask direct questions to panelists, and to weigh in with their own vote on several key panel questions. A hallmark of this meeting was to focus on customized recommendations for treatment of early-stage breast cancer. There is increasing recognition that the care of a breast cancer patient depends on highly individualized clinical features, including the stage at presentation, the biological subset of breast cancer, the genetic factors that may underlie breast cancer risk, the genomic signatures that inform treatment recommendations, the extent of response before surgery in patients who receive neoadjuvant therapy, and patient preferences. This customized approach to treatment requires integration of clinical care between patients and radiology, pathology, genetics, and surgical, medical and radiation oncology providers. It also requires a dynamic response from clinicians as they encounter accumulating clinical information at the time of diagnosis and then serially with each step in the treatment plan and follow-up, reflecting patient experiences and treatment response.

Axillary surgery in node-positive breast cancer

Long-term follow-up data from multicenter phase III non-inferiority trials confirmed the safety of omission of axillary dissection in selected patients with clinically node-negative, sentinel node-positive breast cancer. Several ongoing trials investigate extended eligibility of the Z0011 protocol in the adjuvant setting. De-escalation of axillary surgery in patients with clinically node-positive breast cancer is currently limited to the neoadjuvant setting, where the sentinel procedure is used to determine nodal pathological complete response. Targeted axillary dissection lowers the false-negative rate of the sentinel procedure, which, however, is consistently associated with a very low risk of axillary recurrence in several recent single-center series. Axillary dissection remains standard care in patients with residual disease after neoadjuvant chemotherapy while the results of Alliance A011202 are pending. The TAXIS trial investigates the role of tailored axillary surgery in patients with clinically node-positive breast cancer, a novel concept designed to selectively remove positive nodes in the adjuvant and neoadjuvant setting.