Sentinel node biopsy in early breast cancer. A review on recent and ongoing randomized trials

Cryoablation Allows the Ultimate De-escalation of Surgical Therapy for Select Breast Cancer Patients

BACKGROUND

Widespread use of screening mammography has allowed breast cancer to be detected at earlier stages. This allows for increased customization of treatment and less aggressive management. De-escalation of therapy plays an important role in decreasing treatment burden and improving patient quality of life. This report examines cryoablation as the next step in the surgical de-escalation of breast cancer.

METHODS

Women with a diagnosis of clinically node-negative, estrogen receptor-positive (ER +), progesterone receptor-positive (PR +), human epidermal growth factor receptor 2-negative (HER2 -) infiltrating ductal carcinomas 1.5 cm or smaller underwent ultrasound-guided cryoablation. Either the Visica 2 treatment system (before 2020) or the ProSense treatment system (since 2020) was used to perform the cryoablation. Patients received mammograms and ultrasounds at a 6 months follow-up visit, and magnetic resonance images at baseline, then at 1 year follow-up intervals. Adjuvant therapy decisions and disease status were recorded.

RESULTS

This study enrolled 32 patients who underwent 33 cryoablation procedures (1 patient had bilateral cancer). One patient had a sentinel node biopsy in addition to clinical staging of the axilla. For all the patients, adjuvant endocrine therapy was recommended, and six patients (18.75%) received adjuvant radiation. Of the 32 patients, 20 (60.6%) have been followed up for 2 years or longer, with no residual or recurrent disease at the site of ablation.

CONCLUSION

Cryoablation of the primary tumor foregoing sentinel node biopsy offers an oncologically safe and feasible minimally invasive office-based procedure option in lieu of surgery for patients with early-stage, low-risk breast cancer.

Development and validation of a point-based scoring system for predicting axillary lymph node metastasis and disease outcome in breast cancer using clinicopathological and multiparametric MRI features

BACKGROUND

Axillary lymph node (ALN) metastasis is used to select treatment strategies and define the prognosis in breast cancer (BC) patients and is typically assessed using an invasive procedure. Noninvasive, simple, and reliable tools to accurately predict ALN status are desirable. We aimed to develop and validate a point-based scoring system (PSS) for stratifying the ALN metastasis risk of BC based on clinicopathological and quantitative MRI features and to explore its prognostic significance.

METHODS

A total of 219 BC patients were evaluated. The clinicopathological and quantitative MRI features of the tumors were collected. A multivariate logistic regression analysis was used to create the PSS. The performance of the models was evaluated using receiver operating characteristic curves, and the area under the curve (AUC) of the models was calculated. Kaplan-Meier curves were used to analyze the survival outcomes.

RESULTS

Clinical features, including the American Joint Committee on Cancer (AJCC) stage, T stage, human epidermal growth factor receptor-2, estrogen receptor, and quantitative MRI features, including maximum tumor diameter, K_ep, V_e, and TTP, were identified as risk factors for ALN metastasis and were assigned scores for the PSS. The PSS achieved an AUC of 0.799 in the primary cohort and 0.713 in the validation cohort. The recurrence-free survival (RFS) and overall survival (OS) of the high-risk (> 19.5 points) groups were significantly shorter than those of the low-risk (≤ 19.5 points) groups in the PSS.

CONCLUSION

PSS could predict the ALN metastasis risk of BC. A PSS greater than 19.5 was demonstrated to be a predictor of short RFS and OS.

Comparative observation of common tracers in sentinel lymph node biopsy of breast cancer and a study on simplifying its surgical procedure

Background

Many breast cancer patients have avoided axillary lymph node dissection after sentinel lymph node biopsy (SLNB). During the SLNB operation, the color of lymphatic vessels is sometimes poor and so finding them is difficult. This study observed the tracing effects of three tracer combinations and also reported our experience in simplifying the SLNB program.

Methods

In total, 123 breast cancer patients whose TNM stage was cT1-2N0M0 were retrospectively studied. According to the tracer used, the patients were divided into the carbon nanoparticle (CNP) group (38 cases), CNP combined with methylene blue (CNP + MB) group (41 cases), and indocyanine green combined with MB (ICG + MB) group (44 cases). All 123 breast cancer cases were also classified into the non-tracking group (53 cases) and tracking group (70 cases) according to the SLNB operation process. The non-tracking group looked for the stained sentinel lymph nodes directly, while the tracking group looked for the stained lymph nodes along the lymphatic vessels.

Results

The SLN identification rates in the CNP, CNP + MB, and ICG + MB groups were 97.4%, 97.6%, and 95.5% respectively (P > 0.05). The average number of SLNs detected was 4.92 ± 2.06, 5.12 ± 2.18, and 4.57 ± 1.90, respectively (P > 0.05). The ideal display rates of lymphatic vessels in the three groups were 86.8%, 87.8%, and 93.2%, respectively (P > 0.05). The SLN identification rates in the non-tracking and tracking groups were 96.2% and 97.1%, respectively (P > 0.05). The average number of SLNs detected were 5.73 ± 1.76 and 5.70 ± 1.93, respectively (P > 0.05), and the average operation time was 16.47 ± 5.78 and 27.53 ± 7.75 min, respectively (P < 0.05).

Conclusion

This is the first study to observe the application effect of CNP combined with MB and ICG combined with MB tracers in SLNB of breast cancer patients. No significant difference was observed among the patients in SLN identification and lymphatic vessel display. Omitting the step of searching for lymphatic vessels in SLNB surgery does not reduce the surgical effect, but the reduced operating steps can reduce the surgical time and theoretically reduce postoperative complications.

The value of sentinel lymph-node biopsy in women with node-positive breast cancer at diagnosis and node-negative tumour after neoadjuvant therapy: a systematic review

PURPOSE

To conduct a systematic review to analyse the performance of the sentinel lymph-node biopsy (SLNB) in women with node-positive breast cancer at diagnosis and node-negative tumour after neoadjuvant therapy, compared to axillary lymph-node dissection.

METHODS

The more relevant databases were searched. Main outcomes were false-negative rate (FNR), sentinel lymph-node identification rate (SLNIR), negative predictive value (NPV), and accuracy. We conducted meta-analyses when appropriate.

RESULTS

Twenty studies were included. The pooled FNR was 0.14 (95% CI 0.11-0.17), the pooled SLNIR was 0.89 (95% CI 0.86-0.92), NPV was 0.83 (95% CI 0.79-0.87), and summary accuracy was 0.92 (95% CI 0.90-0.94). SLNB performed better when more than one node was removed and double mapping was used.

CONCLUSIONS

SLNB can be performed in women with a node-negative tumour after neoadjuvant therapy. It has a better performance when used with previous marking of the affected node and with double tracer.

Iodine map histogram metrics in early-stage breast cancer: prediction of axillary lymph node metastasis status

BACKGROUND

Variations in axillary lymph node (ALN) metastatic potential between different breast cancers lead to microscopical alterations in tumor perfusion heterogeneity. This study investigated the usefulness of histogram metrics from iodine maps in the preoperative diagnosis of metastatic ALNs in patients with early-stage breast cancer.

METHODS

Between October 2020 and November 2021 enhanced spectral computed tomography (CT) was performed in female patients with breast cancer. Quantitative spectral CT parameters and histogram parameters (mean, median, maximum, minimum, 10th percentiles, 90th percentiles, kurtosis, skewness, energy, range, and variance) from iodine maps were compared between patients with metastatic and nonmetastatic ALNs. Continuous variables were compared using Student's t-test or Mann-Whitney U test. Categorical variables were compared using Pearson's chi-square tests or Fisher's exact tests. Associations between ALN status and imaging features were evaluated using Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis.

RESULTS

This study included 113 female patients (62 and 51 in the ALN-negative and ALN-positive groups, respectively). Tumor size, molecular subtypes, and location differed significantly between the ALN-negative and ALN-positive groups (P<0.05). None of the quantitative spectral CT parameters of mass between metastatic and nonmetastatic ALN groups were significantly different (P>0.05). Histogram parameters of iodine maps for breast cancers, including maximum, 10th percentile, range, and energy, were significantly higher in the metastatic ALNs group compared with the nonmetastatic ALNs group (P<0.05). Multivariable logistic regression analyses showed that tumor location and energy were independent predictors of metastatic ALNs in breast cancers. The combination of independent predictors yielded an area under the curve (AUC) of 0.824 (sensitivity 72.5%; specificity 74.2%).

CONCLUSIONS

Whole-lesion histogram parameters derived from spectral CT iodine maps may be used as a complementary noninvasive means for the preoperative identification of ALN metastases in patients with early-stage breast cancer.

The value of whole-lesion histogram analysis based on field‑of‑view optimized and constrained undistorted single shot (FOCUS) DWI for predicting axillary lymph node status in early-stage breast cancer

Background

This study aims to estimate the amount of axillary lymph node (ALN) involvement in early-stage breast cancer utilizing a field of view (FOV) optimized and constrained undistorted single-shot (FOCUS) diffusion-weighted imaging (DWI) approach, as well as a whole-lesion histogram analysis.

Methods

This retrospective analysis involved 81 individuals with invasive breast cancer. The patients were divided into three groups: N0 (negative ALN metastasis), N1–2 (low metastatic burden with 1–2 ALNs), and N≥3 (heavy metastatic burden with ≥ 3 ALNs) based on their sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND). Histogram parameters of apparent diffusion coefficient (ADC) depending basically on FOCUS DWI were performed using 3D-Slicer software for whole lesions. The typical histogram characteristics for N0, N1–2, and N≥ 3 were compared to identify the significantly different parameters. To determine the diagnostic efficacy of significantly different factors, the area under their receiver operating characteristic (ROC) curves was examined.

Results

There were significant differences in the energy, maximum, 90 percentile, range, and lesion size among N0, N1–2, and N≥ 3 groups (P < 0.05). The energy differed significantly between N0 and N1–2 groups (P < 0.05), and some certain ADC histogram parameters and lesion sizes differed significantly between N0 and N≥3, or N1–2 and N≥3 groups. For ROC analysis, the energy yielded the best diagnostic performance in distinguishing N0 and N1–2 groups from N≥3 group with an AUC value of0.853. All parameters revealed excellent inter-observer agreement with inter-reader consistencies data ranging from0.919 to 0.982.

Conclusion

By employing FOCUS DWI method, the analysis of whole-lesion ADC histogram quantitatively provides a non-invasive way to evaluate the degree of ALN metastatic spread in early-stage breast cancer.

Axillary management for early invasive breast cancer patients: Who will truly benefit?

Background

The implementation of sentinel lymph node biopsy (SLNB) and further completion axillary lymph node dissection (cALND) after positive sentinel lymph nodes (SLNs) on early invasive breast cancer patients should be cautiously tailored. Identifying predictors for SLN and non-sentinel lymph node (nSLN) metastases can help surgeons make better surgical decisions.

Methods

A retrospective case-control study was designed and a total of 560 eligible patients were enrolled consecutively. They were all diagnosed in our center and received appropriate medical care. According to the metastasis of SLN and nSLN, they were divided into metastatic and non-metastatic groups on two successive occasions to investigate the relationship between clinical factors, pathological factors, hematological factors and lymph node metastasis.

Results

In total, 101 (18.04%) patients developed SLN metastases, including 98 patients with macro-metastases and 3 patients with micro-metastases. Out of 97 patients receiving further cALND, 20 patients (20.62%) developed nSLN metastases. Multivariate analysis revealed that “high expression of Ki-67” and “lymphatic invasion” predicted a higher risk of SLN metastasis; and “increased number of positive SLNs” and “increased systemic inflammation index (SII)” predicted a higher risk of nSLN metastasis.

Conclusion

Surgery for early invasive breast cancer patients should be more customized and precise. Appropriate axillary management is necessary for patients with the associated predictors.

The value of preoperative sentinel lymph node contrast-enhanced ultrasound for breast cancer: a large, multicenter trial

Objective

The study conducted a multicenter study in China to explore the learning curve of contrast enhanced ultrasound (CEUS) for sentinel lymph nodes (SLNs), the feasibility of using this technique for the localization of SLNs and lymphatic channels (LCs) and its diagnostic performance for lymph node metastasis.

Method

Nine hundred two patients with early invasive breast cancer from six tertiary class hospitals in China were enrolled between December 2016 and December 2019. Each patient received general ultrasound scanning and SLN-CEUS before surgery. The locations and sizes of LCs and SLNs were marked on the body surface based on observations from SLN-CEUS. These body surface markers were then compared with intraoperative blue staining in terms of their locations. The first 40 patients from each center were included in determining the learning curve of SLN-CEUS across sites. The remaining patients were used to investigate the diagnostic efficacy of this technique in comparison with intraoperative blue staining and pathology respectively.

Result

The ultrasound doctor can master SLN-CEUS after 25 cases, and the mean operating time is 22.5 min. The sensitivity, specificity, negative predictive value, and positive predictive value of SLN-CEUS in diagnosing lymph node metastases were 86.47, 89.81, 74.90, and 94.97% respectively.

Conclusion

Ultrasound doctors can master SLN-CEUS with a suitable learning curve. SLN-CEUS is a feasible and useful approach to locate SLNs and LCs before surgery and it is helpful for diagnosing LN metastases.

The value of sentinel lymph-node biopsy after neoadjuvant therapy: an overview

PURPOSE

We conducted a systematic review to analyse the performance of the sentinel lymph-node biopsy (SLNB) after the neoadjuvant chemotherapy, compared to axillary lymph-node dissection, in terms of false-negative rate (FNR) and sentinel lymph-node identification rate (SLNIR), sensitivity, negative predictive value (NPV), need for axillary lymph-node dissection (ALND), morbidity, preferences, and costs.

METHODS

MEDLINE, Embase, Scopus, and The Cochrane Library were searched. We assessed the quality of the included systematic reviews using AMSTAR2 tool, and estimated the degree of overlapping of the individual studies on the included reviews.

RESULTS

Six systematic reviews with variable quality were selected. We observed a very high overlapping degree across the included reviews. The FNR and the SLNIR were quite consistent (FNR 13-14%; SLNIR ~ 90% or higher). In women with initially clinically node-negative breast cancer, the FNR was better (6%), with similar SLNIR (96%). The included reviews did not consider the other prespecified outcomes.

CONCLUSIONS

It would be reasonable to suggest performing an SLNB in patients treated with NACT, adjusting the procedure to the previous marking of the affected lymph node, using double tracer, and biopsy of at least three sentinel lymph nodes. More well-designed research is needed. PROSPERO registration number: CRD42020114403.

Misclassification of nodal stage in gastric cancer: 16 lymph nodes is not enough

Background

In gastric cancer, nodal stage plays an important role. Insufficient lymph node harvesting or incomplete examination may lead to misclassification and affect postoperative strategy and group survival. This study’s objective was to determine the minimum number of examined lymph nodes needed in gastric cancer and compare this to the minimum lymph node count according to the current Union for International Cancer Control (UICC) classification using real world data.

Methods

Based on anatomical data, expected mean lymph node counts and their 95% confidence intervals for complete D2 lymphadenectomy were calculated. Using stochastic analysis, a threshold for correct classification in 95% of cases was determined. Survival data of nodal negative gastric cancer patients was extracted from the Surveillance, Epidemiology, and End Results (SEER)-Database for 2010–2017. Patients reaching at least the calculated theoretical threshold were compared to the minimum threshold according to the current UICC classification.

Results

The expected lymph node count was 30 (95% CI: 28–32; range 17–52), corresponding to a 27 lymph nodes. In nodal negative patients with exactly 16 and at least 27 examined lymph nodes, relative 5 year survival was 79 and 89% in T1/T2 and 39 and 64% T3/T4 gastric cancer, respectively. Theoretically, when only 16 lymph nodes are analyzed, nodal negative staging may be incorrect in up to 47% of cases.

Conclusions

A minimum threshold of 16 examined lymph nodes cannot be justified. Retrospective analysis confirmed systematic misclassification of patients with insufficient lymphadenectomy in nodal negative gastric cancer patients. Correct lymphadenectomy and thorough examination of the surgical specimen is mandatory.

Controversies in Breast Cancer Surgery

Breast surgical oncology is a rapidly evolving field with significant advances shaped by practice-changing research. Three areas of ongoing controversy are (1) high rates of contralateral prophylactic mastectomy (CPM) in the United States despite uncertain benefit, (2) indications for and use of neoadjuvant chemotherapy (NACT) and endocrine therapy (NET), and (3) staging and treatment of the axilla, particularly after neoadjuvant systemic therapy. We discuss the patient populations for whom CPM may or may not be beneficial, indications for NACT and NET, and the trend toward de-escalation of locoregional axillary treatment.

Evaluation of whole axillary status with lymphatic contrast-enhanced ultrasound in patients with breast cancer

OBJECTIVES

This study aims to evaluate the whole axillary status of patients with breast cancer by lymphatic contrast-enhanced ultrasound (LCEUS).

METHODS

LCEUS was applied for 169 patients with suspected breast cancer. Abnormal patterns in lymphatic channels, sentinel lymph nodes (SLNs), and non-enhanced but abnormal lymph nodes were investigated. The signs of distorted, attenuated, netted, or interrupted lymphatic channels, defective-filling or no-filling SLNs, and the appearance of non-enhanced but abnormal lymph nodes were designated as features of axillary metastasis. A positive outcome was given when any of the abnormal patterns was found in the LCEUS. The diagnostic efficiencies were calculated to differentiate the axillary lymphatic status using LCEUS for the whole axilla, compared with conventional ultrasound (US) and LCEUS for SLNs.

RESULTS

The LCEUS procedure was successfully performed for 157 breast cancer patients with axillary dissection. Compared to normal axillae, abnormal patterns had a significantly higher frequency in metastatic axillae (p = 0.000). Using conventional US to evaluate the whole axillae, the diagnostic sensitivity, specificity, and accuracy were 69.1%, 71.9%, and 70.7%, respectively. When LCEUS was used for SLN evaluation to predict the whole axilla, the diagnostic sensitivity, specificity, and accuracy were 66.2%, 89.9%, and 79.6%, respectively. When LCEUS was used as the whole axillary evaluation method, the diagnostic sensitivity, specificity, and accuracy were 76.5%, 86.5%, and 82.2%, respectively.

CONCLUSION

LCEUS can be an accurate method to observe the whole axillae in breast cancer patients. Lymphatic channels, SLNs, and non-enhanced but abnormal lymph nodes constitute the LCEUS for whole axillary evaluation.

KEY POINTS

• LCEUS can be an accurate method to observe the whole axillae in breast cancer patients. • Three aspects in the LCEUS for whole axillary evaluation are the lymphatic channels, sentinel lymph nodes (SLNs), and non-enhanced but abnormal lymph nodes. • Signs of distorted, attenuated, netted, or interrupted lymphatic channels, defective-filling or no-filling SLNs, and the appearance of non-enhanced but abnormal lymph nodes were considered as features of axillary metastasis.

Axillary observation alone versus sentinel node biopsy: past, present and future perspectives

The evolution of axillary surgery in breast cancer has led from complete axillary dissection (AD) to sentinel node biopsy (SNB). It has not stopped yet but continues with a progressive de-escalation of surgical procedures aiming at axillary conservation. In parallel, the meaning of axillary surgery has changed as well. Over time, the dual role of both a therapeutic and a staging procedure has decreased leaving room to other modalities to treat and stage breast cancer. Although, the gold standard for axillary staging in early breast cancer remains SNB, the idea that axillary surgery could be even omitted has been proposed. The concept of abandoning axillary surgery is revolutionary but not new. Historical literature provides interesting data on patients who did not receive any axillary treatment at all with no impact on their survival. Starting from this, several ongoing trials are working to demonstrate that in selected breast cancer cohorts the information deriving from axillary surgery is superfluous and "axillary observation" alone is as effective as SNB. Whilst surgery has been de-escalated to less invasive procedures, systemic treatment, radiotherapy, multigene assays and advanced imaging modalities have gained ground in the management of breast cancer. New research is expected to help select the subgroups of patients for whom axillary surgery is not necessary anymore. This is a qualitative review reporting the most relevant literature data from historical trials on the omission of axillary surgery to the most recent and ongoing ones.

Lymphoscintigraphy in the Time of COVID-19: Effect of Molybdenum-99 Shortage on Feasibility of Sentinel Node Mapping

Background: In the current study, we reported our experience on sentinel node mapping of breast cancer patients during the extreme shortage of Mo99-Tc99m generators using Tc-99m phytate. Methods and Results: During the period from March 7, 2019, to April 18, 2020, due to disruption of molybdenum supply chain, we used low specific activity Tc-99m pertechnetate elute (0.5-2 mCi of ^99mTcO₄ in 5 mL) for each kit preparation. Two or three intradermal periareolar injections were done for each patient (0.02-0.1 mCi/0.2 mL for each injection). Immediately following injection, dynamic lymphoscintigraphy was done. Surgery was done the same day of injection and the axillary sentinel node was sought using a gamma probe. Overall, 35 patients were included in the study. The specific activity of the Tc-99m elute (in 5 mL) used for kit preparation was 2 mCi/10 mg in four, 1.5 mCi/10 mg in eight, 1.25 mCi/10 mg in eight, 1 mCi/10 mg in three, 0.75 mCi/10 mg in five, and 0.5 mCi/10 mg of ^99mTc-Phytate in seven patients. For the first four groups of patients, we used two 0.2 mL injections, while in the latter two groups, three 0.2 mL injections were used. At least one sentinel node was detected in all patients but three in whom axilla was involved. Conclusion: Sentinel node biopsy can be achieved with low specific activity of Tc-99m elute at the time of Mo99-Tc-99m generator shortage. If special personal protection is used, sentinel node mapping can be done in nuclear medicine departments with excellent results despite the COVID-19 pandemic and disruption of generator shipment.

Is the frozen section examination for sentinel lymph node necessary in early breast cancer patients?

Purpose

Sentinel lymph node (SLN) biopsy (SLNB) is widely performed for axillary staging in patients with breast cancer. Based on the results of frozen section examination (FSE), surgeons can decide to continue further axillary dissections. This study aimed to verify the accuracy of FSE for SLNs.

Methods

We reviewed the records of 4,219 patients who underwent SLNB for primary invasive breast cancer between 2007 and 2016 at the Severance Hospital. We evaluated factors associated with the false-negative results of FSE for SLNs using the Generalized Estimating Equations model.

Results

A total of 1,397 SLNs from 908 patients were confirmed to be metastatic. Seventy-one patients (1.7%) had confirmed pathologic N2 or N3 stage. Among metastatic SLNs, micrometastasis was found in 234 (16.8%). The overall accuracy of SLNB was 98.5%. The sensitivity and false-negative rate of FSE were 86.4% and 13.6%, respectively. Several clinicopathological factors, including the size of SLN metastases, suspicious preoperative axillary lymph nodes, and luminal B subtype, were associated with a higher rate of false-negative results.

Conclusion

Most patients were not indicated for axillary lymph node dissection. Some patients may show transition in their permanent pathology due to the size of the metastatic node. However, the false-negative results of FSE for SLNs based on the size of the metastatic node did not change our practice. Therefore, intraoperative FSE for SLN should not be routinely performed for all breast cancer patients.

Patterns of lymphatic drainage after axillary node dissection impact arm lymphoedema severity: A review of animal and clinical imaging studies

Upper extremity lymphoedema after axillary node dissection is an iatrogenic disease particularly associated with treatment for breast or skin cancer. Anatomical studies and lymphangiography in healthy subjects identified that axillary node dissection removes a segment of the lymphatic drainage pathway running from the upper limb to the sub-clavicular vein, creating a surgical break. It is reasonable to infer that different patterns of lymphatic drainage may occur in the upper limb following surgery and contribute to the various presentations of lymphoedema from none to severe. Firstly, we reviewed animal imaging studies that investigated the repair of lymphatic drainage pathways from the limb after lymph node dissection. Secondly, we examined clinical imaging studies of lymphatic drainage pathways after axillary node dissection, including lymphangiography, lymphoscintigraphy and indocyanine green fluorescence lymphography. Finally, based on the gathered data, we devised a set of general principles for the restoration of lymphatic pathways after surgery. Lymphoscintigraphy shows that restoration of the original lymphatic pathway to the axilla after its initial disruption by nodal dissection was not uncommon and may prevent lymphoedema. We found that regenerated lymphatic vessels and dermal backflow (the reflux of lymph to the skin) contributed to either restoration of the original pathway or rerouting of the lymphatic pathway to other regional nodes. Variation in the lymphatic drainage pathway and the mechanisms of fluid drainage itself are the foundation of new lymphatic drainage patterns considered to be significant in determining the severity with which lymphoedema develops.

What Is the Best Management of cN0pN1(sn) Breast Cancer Patients?

Although the majority of breast cancer patients are clinically node-negative (cN0) at diagnosis, 15-20% will have a metastatic sentinel lymph node (SLN, pN1(sn)). While a less radical approach regarding axillary surgery in cN0 patients with a positive SLN biopsy is advocated, the limitations of 5 published trials on axillary management in pN1(sn) are discussed intensely in the literature and support the performance of ongoing validation and extension trials, especially considering the lack of data in the setting of mastectomy. As locoregional radiotherapy has a significant effect on both recurrence and survival, a standardization of locoregional radiotherapy in the situation of SLN biopsy alone in pN1(sn) patients has to be defined in the future, and de-escalation trials should embrace a truly multidisciplinary approach. This is also of utmost importance considering the fact that high-volume nodal disease requires an intensified adjuvant chemotherapy strategy to which patients omitting axillary dissection cannot be stratified. Finally, there is mounting evidence that the therapeutic role of extensive axillary surgery in low-volume nodal disease is negligible, and multidisciplinary and translational efforts must be undertaken to individualize treatment in order to gain a reasonable balance between necessary staging information and unnecessary treatment-related morbidity.