Models for predicting non-sentinel lymph node positivity in sentinel node positive breast cancer: the importance of scoring system

Prediction of negative axillary node clearance by sentinel node-positive to total node ratio: a retrospective cohort study

Introduction

Increasing evidence suggests that de-escalation of axillary surgery is safe, without significantly impacting patient outcome. Obtaining positive lymph nodes at a sentinel lymph node biopsy (SNB) can guide decisions toward the requirement of axillary nodal clearance (ANC). However, methods to predict how many further nodes will be positive are not available. This study investigates the feasibility of predicting the likelihood of a negative ANC based on the ratio between positive nodes and the total number of lymph nodes excised at SNB.

Methods

Retrospective data from January 2017 to March 2022 was collected from electronic medical records. Patients with oestrogen receptor (ER) positive and HER2 negative receptor disease were included in the study. ER-negative and HER2-positive disease was excluded, alongside patients who had chemotherapy before ANC.

Results

Of 102 patients, 58.8% (n=60) had no macrometastasis at ANC. On average, 2.76 lymph nodes were removed at SNB. A higher SNB ratio of positive to total nodes [OR 11.09 (CI 95% 2.33-52.72), P=0.002] had a significant association with positive nodes during ANC. SNB ratio less than or equal to 0.33 (1/3) had a specificity of 79.2% in identifying cases that later had a negative completion ANC, with a 95.8% specificity of no further upgrade of nodal staging.

Conclusion

A low SNB ratio of less than 0.33 (1/3) has a high specificity in excluding the upgradation of nodal staging on completion of ANC, with a false-negative rate of less than 5%. This may be used to identify patients with a low risk of axillary metastasis, who can avoid ANC.

A nomogram based on genotypic and clinicopathologic factors to predict the non-sentinel lymph node metastasis in Chinese women breast cancer patients

Background

Sentinel lymph node biopsy (SLNB) is the standard treatment for breast cancer patients with clinically negative axilla. However, axillary lymph node dissection (ALND) is still the standard care for sentinel lymph node (SLN) positive patients. Clinical data reveals about 40-75% of patients without non-sentinel lymph node (NSLN) metastasis after ALND. Unnecessary ALND increases the risk of complications and detracts from quality of life. In this study, we expect to develop a nomogram based on genotypic and clinicopathologic factors to predict the risk of NSLN metastasis in SLN-positive Chinese women breast cancer patients.

Methods

This retrospective study collected data from 1,879 women breast cancer patients enrolled from multiple centers. Genotypic features contain 96 single nucleotide polymorphisms (SNPs) associated with breast cancer susceptibility, therapy and prognosis. SNP genotyping was identified by the quantitative PCR detection platform. The genetic features were divided into two clusters by the mutational stability. The normalized polygenic risk score (PRS) was used to evaluate the combined effect of each SNP cluster. Recursive feature elimination (RFE) based on linear discriminant analysis (LDA) was adopted to select the most useful predictive features, and RFE based on support vector machine (SVM) was used to reduce the number of SNPs. Multivariable logistic regression models (i.e., nomogram) were built for predicting NSLN metastasis. The predictive abilities of three types of model (based on only clinicopathologic information, the integrated clinicopathologic and all SNPs information, and integrated clinicopathologic and significant SNPs information) were compared. Internal and external validations were performed and the area under ROC curves (AUCs) as well as a series of evaluation indicators were assessed.

Results

229 patients underwent SLNB followed by ALND and without any neo-adjuvant therapy, 79 among them (34%) had a positive axillary NSLN metastasis. The LDA-RFE identified the characteristics including lymphovascular invasion, number of positive SLNs, number of negative SLNs and two SNP clusters as significant predictors of NSLN metastasis. Furthermore, the SVM-RFE selected 29 significant SNPs in the prediction of NSLN metastasis. In internal validation, the median AUCs of the clinical and all SNPs combining model, the clinical and 29 significant SNPs combining model, and the clinical model were 0.837, 0.795 and 0.708 respectively. Meanwhile, in external validation, the AUCs of the three models were 0.817, 0.815 and 0.745 respectively.

Conclusion

We present a new nomogram by combining genotypic and clinicopathologic factors to achieve higher sensitivity and specificity comparing with traditional clinicopathologic factors to predict NSLN metastasis in Chinese women breast cancer. It is recommended that more validations are required in prospective studies among different patient populations.

Validation of Memorial Sloan Kettering Cancer Center nomogram to detect non-sentinel lymph node metastases in a United Kingdom cohort

AIM

Axillary lymph node dissection, although associated with long-term morbidity, has been the standard of treatment for all nodepositive breast cancer patients. We assessed the risk prediction ability (validity) of Memorial Sloan Kettering Cancer Center (MSKCC) nomogram for non-sentinel lymph node metastases and analysed the outcome of patients with sentinel node metastases.

PATIENTS AND METHODS

All operable early breast cancer patients with sentinel node macro metastases (size > 2mm) who underwent axillary dissection from April 2009 to March 2015 were considered eligible. The risk of non-sentinel lymph node metastases was calculated using an online MSKCC calculator, and accuracy was determined based on the area under the receiver-operating characteristic curve (AUC-ROC). Tumour characteristics and overall survival were also analysed as secondary end points.

RESULTS

Of 1745 patients who were diagnosed with operable breast cancer during the study period, 114 patients were considered eligible. The AUC-ROC was 0.66 suggestive of lesser accuracy in prediction and not statistically significant (p value = 0.7303). Seventysix (50.7%) of these patients did not have any non-sentinel node metastases. At a mean follow up of four years, the disease-free survival was 86.4% and overall survival rate was 88.4%.

CONCLUSIONS

The MSKCC nomogram was unable to accurately predict the risk in our cohort of patients with more than half of this cohort of patients not requiring axillary dissection. These findings are consistent with other European studies. This study thus highlights the need for modified prediction model for European cohorts.

Prediction of nonsentinel lymph node metastasis in breast cancer patients with one or two positive sentinel lymph nodes

OBJECTIVE

The aim of the present study was to investigate the association between non sentinel lymph node metastasis (NSLNM) and clinicopathological factors, particularly in the case of sentinel lymph node (SLN) metastasis in one or two, in clinically node negative patients with breast cancer.

METHODS

Between 10/2010 and 10/2014, 350 sentinel lymph node biopsy (SLNB) were performed in patients with histologically proven primary breast cancer in our clinic. The data collection includes the following characteristics: age, pathological tumor size, histological type, histological grade, lymphovascular invasion (LVI), number of positive SLN, size of the SLN metastasis (macrometastasis, micrometastasis, isolated tumor cells), multifocality (MF), extracapsuler invasion (ECI) of the SLN, the estrogen receptor (ER) status, the progesterone receptor (PR) status and the Her 2 receptor status, Ki 67 reseptor status. Data were collected retrospectively and then analyzed.

RESULTS

A successful SLN biopsy were performed in 345 (98.5%) cases. SLN metastases were detected in 110 (31.8%) cases. These patients then underwent axillary dissection; among these patients, 101 (91.8%) had only one to two positive SLNs. Of the 101 patients with positive SLN biopsies, 32 (31.6%) had metastases in the NSLNs. Univariate and multivariate analysis showed that lymphovascular invasion, extracapsular invasion (ECI), Her-2 receptor positive, and Ki-67 > 14% were related to NSLNM (p<.0.05).

CONCLUSION

The predicting factors of NSLNM were LVI, ECI, Ki-67 level, Her-2 reseptor positive and but should be further validated in our institutions, different institutions and different patient groups prospectively.

Comparison of five different popular scoring systems to predict nonsentinel lymph node status in patients with metastatic sentinel lymph nodes: a tertiary care center experience

Sentinel lymph node biopsy (SLNB) is the current standard of care for breast cancers with no clinically palpable axillary lymph nodes. Almost 50 % of sentinel lymph node positive patients have negative non-sentinel nodes and undergo non-therapeutic axillary dissection. Five different scoring systems, reported in the literature, were compared for their predictive ability of non-SLN involvement in patients with SLN positive breast cancer. 242 patients who underwent breast surgery and SLNB were included in the study. Of these, 70 who were confirmed to have SLN metastasis and received complementary ALND and constituted the final study population. The nomograms (MSKCC, M.D. Anderson Cancer Center, Tenon model, Stanford and Turkish) were statistically compared for their prediction of non-SLN metastasis (95 % confidence interval). We have determined only two clinicopathologic (multifocality and size of the primary tumor) situations which have a statistically significant association between SLN metastasis with using a multivariate logistic regression analysis. Multifocality (P = 0.001) and size of the primary tumor (P = 0.001) were associated with a higher probability of-SLN metastasis. No predictive model was constructed that showed good area under the curve (AUC) discrimination in the validation series. Currently published predictive models lack accuracy when applied to a different population. Multi-institutional heterogenic population studies are important to determine the exact combination of scoring systems and/or nomograms.

Validation of Six Nomograms for Predicting Non-sentinel Lymph Node Metastases in a Dutch Breast Cancer Population

Background

The usefulness of axillary lymph node dissection (ALND) in patients with positive sentinel nodes (SN) is still an ongoing debate. Several nomograms have been developed for predicting non-sentinel lymph node metastases (NSLNM). We validated six nomograms using data from 10 years of breast cancer surgery in our hospital.

Methods

We retrospectively analyzed all patients with a proven breast malignancy and a SN procedure between 2001 and 2011 in our hospital.

Results

Data from 1084 patients were reviewed; 260 (24 %) had a positive SN. No patients with isolated tumor cells, 6 patients (8 %) with micrometastases, and 65 patients (41 %) with macrometastases had additional axillary NSLNM. In 2 patients (3 %) with micrometastases, the ALND influenced postoperative treatment. In the group of patients with macrometastases tumor size >2 cm, extranodal growth and having no negative SNs were predictors of NSLNM. The revised MD Anderson Cancer Center and Helsinki nomograms performed the best, with an area under the curve value of 0.78.

Conclusions

ALND could probably be safely omitted in most patients with micrometastases but is still indicated in patients with macrometastases, especially in patients with tumor size >2 cm, extranodal growth, and no negative SNs. The revised MD Anderson Cancer Center and Helsinki nomograms were the most predictive in our patient group.

An independent assessment of the 7 nomograms for predicting the probability of additional axillary nodal metastases after positive sentinel lymph node biopsy in a cohort of British patients with breast cancer

INTRODUCTION

Axillary lymph node dissection (ALND) is currently the recommended procedure in patients with tumor-positive sentinel lymph node biopsy (SLNB). A significant proportion of patients with positive SLNs will not have any additional metastases in nonsentinel lymph nodes (NSLNs). Predictive nomograms could identify a subgroup of patients with low or high risk of further disease in whom completion ALND can be avoided or recommended. The aim of this study was to assess the accuracy of the currently available 7 nomograms in a cohort of British patients with breast cancer.

PATIENTS AND METHODS

A total of 138 patients with positive SLNs who underwent completion ALND were identified. Data were then used to calculate the probability of further metastases in NSLNs predicted by the 7 nomograms that are currently in use: the MSKCC (Memorial Sloan Kettering Cancer Center), Cambridge, Turkish, Stanford, MDACC (University of Texas MD Anderson Cancer Center), Tenon, and MOU (Masarykuv onkologický ústav, Masaryk Memorial Cancer Institute) models. The area under the receiver operating characteristic (ROC) curve (AUC) was calculated for each nomogram.

RESULTS

Of the 138 patients, 54 (41%) had additional metastases in NSLNs. AUC values for the MSKCC, Cambridge, Turkish, Stanford, MDACC, Tenon, and MOU models are 0.68, 0.68, 0.70, 0.69, 0.56, 0.63, and 0.74, respectively.

CONCLUSION

The MOU nomogram was more predictive than the other nomograms, with a better AUC value and false-negative rate. None of the models were able to achieve AUC value ≥ 0.80 in a cohort of British patients with breast cancer.

Sentinel node biopsy in breast cancer revisited

The axilla has long been a focus of clinicians' attention in the management of breast cancer. The approach to the axilla has undergone dramatic changes over the last century, from radical and extended radical excisions, through the introduction of sentinel node biopsy for node negative patients to the current situation where selective management of those with nodal involvement is being introduced. The introduction of lymphatic mapping and sentinel node biopsy in the 1990's has been key to the major changes that have occurred. In less than 20 years it has moved from a hypothesis to a situation where it is the default approach to almost all clinically node negative patients and is being considered in other situations where axillary clearance was previously considered standard. This article reviews the development and introduction of sentinel node biopsy, its current uncertainties and limitations, and possible future developments.

Predicting the likelihood of additional lymph node metastasis in sentinel lymph node positive breast cancer: validation of the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram

AIM

To identify important clinicopathological parameters that are most helpful in predicting additional non-sentinel lymph node (SLN) metastasis among patients with a positive SLN biopsy in the Singapore breast cancer population.

METHODS

A total of 1409 patients who underwent SLN biopsy were reviewed over a 5 year period from July 2004 to October 2009. A Singapore General Hospital (SGH) nomogram was developed from predictors in the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram using 266 patients with primary invasive breast cancer and a positive SLN biopsy who subsequently had an axillary lymph node dissection. The SGH nomogram was calibrated using bootstrapped data, while the MSKCC nomogram was calibrated using SGH data. The performance of these two nomograms was compared with the calculation of the area under the receiver-operator characteristics curve and adequacy indices.

RESULTS

The MSKCC nomogram achieved an area under the curve (AUC) of 0.716 (range 0.653-0.779) in our study population, while the SGH nomogram, which used only three pathological parameters, lymphovascular invasion, number of positive and negative SLN biopsies, achieved an AUC of 0.750 (range 0.691-0.808). The SGH nomogram with a higher adequacy index (0.969) provided better estimates compared with the MSKCC nomogram (0.689).

CONCLUSIONS

The use of the MSKCC nomogram was validated in our local patient population. The SGH nomogram showed promise to be equally, if not, more predictive as a model in our own population, while using only three pathological parameters.

The use of one step nucleic-acid amplification (OSNA) in clinical practice: a single-centre study

BACKGROUND

The development of intraoperative sentinel node biopsy (SLNB) analysis methods, such as One-Step Nucleic Acid Amplification (OSNA), has made single-stage procedures possible.

AIMS

We investigated the incidence of OSNA-detected lymph node positivity, comparing it to conventional histopathology, the incidence of non-SLNB node disease for the OSNA positive patients, and the breast re-operation rate, to assess the benefit from single-stage procedures.

METHODS

This was a single-centre series of 573 consecutive patients undergoing SLNB (173 histopathology and 400 OSNA).

RESULTS

OSNA-detected SLNB macrometastasis was similar to routine histopathology, with more micrometastasis detected (p < 0.001). Non-SLNB involvement in the OSNA group was similar to documented histopathological series. 27.6% of OSNA patients avoided further surgery because of OSNA. The median time for OSNA results was 42 min.

CONCLUSIONS

OSNA is an effective method for detecting SLNB-metastasis. It is easily used in clinical practice, providing reliable results and negating the need for a second axillary operation.

Validation of three breast cancer nomograms and a new formula for predicting non-sentinel lymph node status

BACKGROUND

The aim of the study was to evaluate the available breast nomograms (MSKCC, Stanford, Tenon) to predict non-sentinel lymph node metastasis (NSLNM) and to determine variables for NSLNM in SLN positive breast cancer patients in our population.

MATERIALS AND METHODS

We retrospectively reviewed 170 patients who underwent completion axillary lymph node dissection between Jul 2008 and Aug 2010 in our hospital. We validated three nomograms (MSKCC, Stanford, Tenon). The likelihood of having positive NSLNM based on various factors was evaluated by use of univariate analysis. Stepwise multivariate analysis was applied to estimate a predictive model for NSLNM. Four factors were found to contribute significantly to the logistic regression model, allowing design of a new formula to predict non-sentinel lymph node metastasis. The AUCs of the ROCs were used to describe the performance of the diagnostic value of MSKCC, Stanford, Tenon nomograms and our new nomogram.

RESULTS

After stepwise multiple logistic regression analysis, multifocality, proportion of positive SLN to total SLN, LVI, SLN extracapsular extention were found to be statistically significant. AUC results were MSKCC: 0.713/Tenon: 0.671/Stanford: 0.534/DEU: 0.814.

CONCLUSIONS

The MSKCC nomogram proved to be a good discriminator of NSLN metastasis in SLN positive BC patients for our population. Stanford and Tenon nomograms were not as predictive of NSLN metastasis. Our newly created formula was the best prediction tool for discriminate of NSLN metastasis in SLN positive BC patients for our population. We recommend that nomograms be validated before use in specific populations, and more than one validated nomogram may be used together while consulting patients.

Assessing second echelon lymph nodes during sentinel lymph node biopsy: can we have more accurate axillary treatment for breast cancer patients?

Sentinel lymph node biopsy (SLNB) is the standard treatment for breast cancer patients with clinically negative axilla. For patients with positive sentinel lymph nodes, axillary lymph node dissection (ALND) was required. However, approximately a half of the SLNs-positive patients were found to have clear axillary lymph nodes after ALND, indicating that they had received unnecessary ALND without therapeutic benefit. Therefore, we propose a hypothesis for solution of this clinical problem. We defined the second echelon lymph nodes (SELNs) as those nodes receiving lymphatic drainage directly from the SLNs. For patients with positive-SLNs, SELNs can be biopsy and assessed. If SELNs are negative, no more ALND was needed in these patients even if their SLNs are positive. If our hypothesis were confirmed to be true, we can tailored our axillary treatment to more breast cancer patients, avoiding unnecessary ALND and its complications.

Axillary dissection in breast cancer patients with metastatic sentinel node: to do or not to do? Suggestions from our series

Several studies have put to question and evaluated the indication and prognosis of sentinel lymph node biopsy (SNLB) as sole treatment in human breast cancer. We reviewed 1588 patients who underwent axillary surgery. In 239 patients, axillary lymph node dissection (ALND) was performed following positive fine needle aspiration cytology (FNAC), and, in 299 cases, ALND was executed after positive SNLB. The most dramatic result from our data is that patients with either micrometastasis of the sentinel lymph node (SLN) or only metastatic SLN have, respectively, an 84.5% and a 75.0% chance of having no other nodal involvement. We believe a more refined patient selection is neccessary when considering ALND. Where the primary tumor is larger than 5 cm, where radio or adjuvant therapies are not indicated, in cases of FNAC+ nodes, and in cases presenting more than one metastatic sentinel node, we prefer to carry out ALND. Having thus said, however, our data suggests that it is wise not to perform ALND in almost all cases presenting positive SLNs.

Meta-analysis of predictive factors for non-sentinel lymph node metastases in breast cancer patients with a positive SLN

AIMS

A meta-analysis was performed to identify the clinicopathological variables most predictive of non-sentinel node (NSN) metastases when the sentinel node is positive.

METHODS

A Medline search was conducted that ultimately identified 56 candidate studies. Original data were abstracted from each study and used to calculate odds ratios. The random-effects model was used to combine odds ratios to determine the strength of the associations.

FINDINGS

The 8 individual characteristics found to be significantly associated with the highest likelihood (odds ratio >2) of NSN metastases are SLN metastases >2mm in size, extracapsular extension in the SLN, >1 positive SLN, ≤1 negative SLN, tumour size >2cm, ratio of positive sentinel nodes >50% and lymphovascular invasion in the primary tumour. The histological method of detection, which is associated with the size of metastases, had a correspondingly high odds ratio.

CONCLUSIONS

We identified 8 factors predictive of NSN metastases that should be recorded and evaluated routinely in SLN databases. These factors should be included in a predictive model that is generally applicable among different populations.

Sentinel lymph node biopsy in breast cancer: a comprehensive literature review

Sentinel lymph node biopsy has emerged as the new standard of care for nodal staging in early-stage breast disease. In the this review, the procedure of SLNB in breast cancer will be examined in greater detail with the aim of understanding techniques that may improve results and of identifying future research questions in this field.