Sentinel lymph node biopsy after neoadjuvant chemotherapy for breast cancer: retrospective comparative evaluation of clinically axillary lymph node positive and negative patients, including those with axillary lymph node metastases confirmed by fine needle aspiration

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

Background

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

Objectives

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

Design

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

Data sources and methods

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

Results

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

Conclusion

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

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.

Study protocol: Randomized, open-label, non-inferiority clinical trial for evaluating the clinical and pathological response rates to neoadjuvant hormone therapy and chemotherapy in patients with luminal-subtype breast tumors

Background

Despite neoadjuvant hormone therapy (NHT) is being underused, it is an effective treatment for luminal tumors at a lower cost and with fewer side effects compared to those associated with neoadjuvant chemotherapy (NCT). The lack of robust comparative data between NHT and NCT is a factor that limits its use in clinical practice.

Methods

This study will be a randomized, open-label, non-inferiority clinical trial. Patients diagnosed with HER2-negative luminal-subtype breast cancer will be identified at the time of diagnosis. Menopausal patients randomized for NHT should receive anastrozole for at least six months. Premenopausal women should receive anastrozole associated with subcutaneous goserelin acetate every 12 weeks for at least six months. Patients randomized for NCT will receive a standard institutional regimen based on anthracyclines and taxanes. Sample size was calculated considering the CPS + EG as a method for evaluating response and prognosis, where a score <3 was defined as good. The non-inferiority margin for NHT was set at 15%. The study considered a power of 80%, a significance level of 5%, and an outcome proportion in each group of 69%, resulting in 118 patients in each group. We estimated at 10% of losses, resulting in a sample of 130 patients in each group.

Conclusion

The non-inferiority of NHT in relation to NCT will provide further evidence that replacing NCT with NHT is safe and effective in eligible patients, which is particularly relevant for populations with limited access to health services and for institutions with few available resources.

Outcomes of Sentinel Node Biopsy for Women with Breast Cancer After Neoadjuvant Therapy: Systematic Review and Meta-Analysis of Real-World Data

BACKGROUND

Evidence on the accuracy of sentinel lymph node biopsy (SLNB) after neoadjuvant therapy (NAT) for patients with breast cancer is inconclusive. This study reviewed the real-world data to determine the acceptability of SLNB after NAT.

METHODS

The study searched for articles in the PubMed, EMBASE, and Cochrane Library databases. The primary outcomes were the identification rate for sentinel lymph nodes (SLNs) and the false-negative rate (FNR) for SLNB. The study also evaluated the FNR in subgroups defined by tumor stage, nodal stage, hormone receptor status, human epidermal growth factor receptor-2 status, tumor response, mapping technique, and number of SLNs removed.

RESULTS

The study retrieved 61 prospective and 18 retrospective studies with 10,680 initially cN± patients. The pooled estimate of the identification rate was 0.906 (95 % confidence interval [CI], 0.891-0.922), and the pooled FNR was 0.118 (95 % CI, 0.103-0.133). In subgroup analysis, the FNR was significantly higher for the patients with estrogen receptor (ER)-negative status and fewer than three SLNs removed. The FNR did not differ significantly between the patients with and those without complete tumor response. Among the patients with initial clinical negative axillary lymph nodes, the incidence of node metastasis was 26.8 % (275/1041) after NAT.

CONCLUSION

Real-world evidence indicates that the FNR of SLNB after NAT in breast cancer is 11.8 %, exceeding only slightly the commonly adopted threshold of 10 %. The FNR is significantly higher for patients with ER-negative status and removal of fewer than three SLNs. Using a dual tracer and removing at least three SLNs may increase the accuracy of SLNB after NAT.

After neoadjuvant therapy, axillary sentinel lymph node frozen sections from breast cancer patients are accurately diagnosed using telepathology

Context

Telepathology is a digital, microscope-independent method of diagnosing pathology from scanned slides. Frozen sections (FS) can be performed and read by a pathologist at any site. At our institution, telepathology is used for diagnosis of frozen sections of sentinel lymph nodes (SLN) in patients who have undergone neoadjuvant chemotherapy and are enrolled in a clinical trial.

Objective

We investigated the accuracy of diagnosing SLN frozen sections in the neoadjuvant setting using telepathology.

Design

SLN were entirely submitted for frozen section. A pathology assistant prepared the frozen and scanned the slides using VisionTek M6 digital microscope ecosystem (East Dundee, IL). Cases were interpreted by trained, board-certified pathologists. All frozen sections remnants were submitted for formalin-fixed paraffin-embedded permanent sections. Frozen section diagnoses using telepathology were compared to final pathology. Turn-around time from specimen collection to frozen section diagnosis was recorded.

Results

54 SLN from 22 breast neoadjuvant cases were diagnosed via telepathology from March 2017 to July 2019. 95% of SLNs interpreted as negative on frozen section and on permanents. A definitive diagnosis could not be rendered on six SLNs; diagnosed “atypical” at frozen. Sensitivity and specificity were 80% and 100% respectively with accuracy of 95.8%. The false-negative rate was 5%. There were no false positives. The average turn-around time was over an hour.

Conclusions

Telepathology is an accurate method of diagnosing SLN frozen sections in the neoadjuvant setting, but lobular carcinomas and treatment effect pose diagnostic challenges and the time to report results is increased compared to standard microscopy.

Sentinel lymph node mapping in breast cancer patients following neoadjuvant chemotherapy: systematic review and meta-analysis about head to head comparison of cN0 and cN + patients

PURPOSE

The effectiveness of sentinel lymph node (SLN) mapping and biopsy following neoadjuvant chemotherapy (NAC) in axillary lymph node staging of breast cancer (BCa) patients with initial clinical node positive status (cN +) compared to clinical node negative status (cN0) is not yet known. The aim of this meta-analysis was to compare the accuracy of SLN mapping following NAC in cN + and cN0 BCa patients.

METHODS

PubMed and Scopus were comprehensively reviewed to retrieve all the studies that performed SLN mapping/biopsy and standard axillary lymph node dissection on cN0 and cN + BCa patients following NAC. Pooled detection and false negative rates for N0 and N + patients including 95% confidence interval values (95% CI) were evaluated. Odds ratio (OR) and risk difference (RD) of SLN detection failure and false negative results were compared between two groups.

RESULTS

A total of 27 articles were included for SLN detection rate evaluation and 17 for false negative assessment. The OR and RD of detection failure in N + group compared with N0 group following NAC were 2.22 (p = 0.00, 95% CI 1.4-3.4) and 4% (p = 0.00, 95% CI 2-6%), respectively. The OR and RD of false negative rate were 1.6 (p = 0.01, 95% CI 1-2.6) and 8% (p = 0.02, 95% CI 1-14%), respectively.

CONCLUSION

SLN mapping in BCa patients following NAC shows high risk of detection failure and high false negative rate of SLN biopsy in cN + patients. In comparison with cN0 BCa patients, SLN mapping and biopsy after NAC was associated with almost two times higher odds of detection failure and false negative results in cN + patients; therefore, this method should not be recommended in this group of patients.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

•

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

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

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

•

The application of dual mapping could clearly decrease the FNR.

Breast and axillary surgery in malignant breast disease: a review focused on literature of 2018 and 2019

PURPOSE OF REVIEW

There have been fundamental changes in the surgical approach to breast cancer management over the last decades. The primary objective of achieving locoregional control, however, remains unchanged.

RECENT FINDINGS

In addition to strategies optimizing systemic treatment and radiotherapy, current discussions focus on improving the surgical approach to breast cancer. Especially in view of the increasingly pivotal role of neoadjuvant chemotherapy NAT/NAC (NACT), gauging the extent of tissue removal in the breast and the width of resection margins in breast-conserving surgery is highly important, as is the extent of axillary surgery. Although sentinel lymph node (SLN)-positive patients always underwent axillary lymph node dissection in the past, this paradigm has been challenged in recent years. Targeted axillary dissection (TAD) has emerged as a new staging option in biopsy-proven node-positive patients who convert to clinical node negativity (cN0) after NACT. TAD combines the removal of the SLN and of the target lymph node marked prior to NACT. The accuracy of axillary staging both before and after NACT plays an important role for prognostication and multidisciplinary treatment plans, while its extent has significant effects on patients' arm morbidity and quality of life.

SUMMARY

The current review focuses on recent evidence regarding surgical management of the breast and axilla in patients with primary breast cancer based on a PubMed and EMBASE literature search for publication years 2018 and 2019.

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

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

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

Objective:

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

Summary of Background Data:

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

Methods:

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

Results:

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

Conclusion:

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

Clinical-grade computational pathology using weakly supervised deep learning on whole slide images

The development of decision support systems for pathology and their deployment in clinical practice have been hindered by the need for large manually annotated datasets. To overcome this problem, we present a multiple instance learning-based deep learning system that uses only the reported diagnoses as labels for training, thereby avoiding expensive and time-consuming pixel-wise manual annotations. We evaluated this framework at scale on a dataset of 44,732 whole slide images from 15,187 patients without any form of data curation. Tests on prostate cancer, basal cell carcinoma and breast cancer metastases to axillary lymph nodes resulted in areas under the curve above 0.98 for all cancer types. Its clinical application would allow pathologists to exclude 65-75% of slides while retaining 100% sensitivity. Our results show that this system has the ability to train accurate classification models at unprecedented scale, laying the foundation for the deployment of computational decision support systems in clinical practice.

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Intraoperative Assessment of Sentinel Lymph Nodes in Breast Cancer Patients Post-Neoadjuvant Therapy

BACKGROUND

Shift toward minimizing axillary lymph node dissection in patients with breast cancer post neoadjuvant therapy has led to the assessment of sentinel lymph nodes by frozen section intraoperatively to determine the need for axillary lymph node dissection. However, few studies have examined the accuracy of sentinel lymph node frozen section after neoadjuvant therapy. Our objective is to compare the accuracy of sentinel lymph node frozen section in patients with breast cancer with and without neoadjuvant therapy and to identify features that may influence accuracy.

DESIGN

We identified 161 sentinel lymph node frozen section from 77 neoadjuvant therapy patients and 255 sentinel lymph node frozen section from 88 non-neoadjuvant therapy patients diagnosed between 2010 and 2016 in 2 institutions. The frozen section diagnoses were compared to the final diagnoses, and clinicopathologic data were analyzed.

RESULTS

The sensitivity, specificity, and accuracy of frozen section analysis were comparable between neoadjuvant therapy patients and non-neoadjuvant therapy patients (71.9% vs 50%, 100% vs 100%, and 88.3% vs 81.8%). Nine (11.7%) of 77 neoadjuvant therapy patients had discordant results, most often due to undersampling (tumor absent on frozen section slide). Four of these patients subsequently underwent axillary lymph node dissection. Discordant results (all false negatives) were significantly more likely in neoadjuvant therapy patients with Estrogen Receptor-positive/HER2-negative status, and in sentinel lymph node with pN1mic and pN0i+ deposits; age, preneoadjuvant therapy lymph node status, histotype, nuclear grade, tumor size, and response to neoadjuvant therapy showed no significant differences. For non-neoadjuvant therapy cases, large tumor size, lobular histotype, and sentinel lymph node with pN1mic and pN0i+ were associated with false-negative frozen section assessment.

CONCLUSION

Sentinel lymph node frozen section diagnosis post-neoadjuvant therapy has comparable sensitivity, specificity, and accuracy to the sentinel lymph node frozen section diagnosis in the non-neoadjuvant therapy setting.