Prediction of Additional Axillary Metastasis of Breast Cancer Following Sentinel Lymph Node Surgery

Extranodal extension, an international survey on its evaluation and reporting in breast cancer patients

Lymph node metastasis is the most important prognostic factor for breast cancer patients. In addition to the number of nodes involved and the largest metastatic focus, extranodal extension (ENE) is also used to subclassify breast cancer patients into different risk groups. More recently, pathologists are required to report the size/extent of ENE per the new CAP guideline, as it seems to be associated with more axillary nodal burden and/or a worse prognosis. Although the definition of ENE is largely understood and agreed upon among pathologists around the world, evaluation and reporting for the size of ENE are not. To understand current practice, we conducted an international survey among pathologists who are interested in breast pathology. A total of 70 pathologists responded. The results showed that (1) 98% of the participants reported the presence or absence of ENE and 61% also reported the size of ENE in millimeter (mm). (2) There was no uniform method of measuring the size of ENE; 47% measured the largest dimension regardless of orientation, while 30% measured the largest perpendicular distance from the capsule. (3) The most common factors affecting the accuracy in diagnosis of ENE are the presence of lymphovascular invasion (LVI), lack of capsule integrity, and the presence of fatty hilar or fatty replacement of a lymph node. (4) 71% felt that the H&E stain is adequate to evaluate ENE, deeper levels and IHC analysis for vascular and cytokeratin markers can be helpful if needed. (5) 75% agreed that there is an urgent need to standardize the measurement and reporting for ENE. Our survey highlights the variation in ENE evaluation and the need for its standardization in breast cancer patients with axillary node metastasis.

Update on sentinel node pathology in breast cancer

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting. Patients treated with neoadjuvant therapy, who represent a population with more extensive disease and aggressive tumor biology, were not included in Z0011 and similar trials, and thus, the evidence cannot be extrapolated to them. Recent trials have supported the safety and accuracy of sentinel lymph node biopsy (SLNB) in these patients when clinically node negative at the time of surgery. ALND remains the standard of care for any amount of residual disease in the SLNs and intraoperative evaluation of SLNs is still of value for real time surgical decision making. Given the potential prognostic significance of residual small metastases in treated lymph nodes, as well as the decreased false negative rate with the use of cytokeratin immunohistochemistry (IHC), it may be reasonable to maintain a low threshold for the use of cytokeratin IHC in post-neoadjuvant cases. Further recommendations for patients treated with neoadjuvant therapy await outcomes data from ongoing clinical trials. This review will provide an evidence-based discussion of best practices in SLN evaluation.

Pathologic Evaluation of Lymph Nodes in Breast Cancer: Contemporary Approaches and Clinical Implications

The presence of detected metastases in locoregional lymph nodes of women with breast cancer is an important prognostic variable for cancer staging, prognosis, and treatment planning. Systematic and standardized lymph node evaluation with gross and microscopic protocols designed to detect all macrometastases larger than 2.0 mm is the appropriate objective based on clinical outcomes evidence. Pathologists will detect smaller micrometastases and isolated tumor cell clusters (ITCs) by random chance but will also leave similar sized metastases undetected in paraffin blocks. Although these smaller metastases have prognostic significance, they are not predictive of recurrence for chemotherapy naïve patients. Thus, protocols to reliably detect metastases smaller than 2.0 mm are not required or recommended by guidelines. Women with T1-T2 breast cancer with a clinically negative axilla but with 1 or 2 pathologically positive sentinel nodes now have alternative options including observation and axillary irradiation and do not require completion axillary dissection.

Prevalence of extracapsular extension in metastatic sentinel lymph nodes in breast cancer

INTRODUCTION

Axillary lymph node involvement is recognized as a key prognostic factor for invasive breast cancer. Retrospective analyzes have shown that extracapsular extension (ECE) is correlated with negative prognostic factors in this neoplasia.

OBJECTIVE

to evaluate the measurement of ECE and its relationship with the number of affected non-sentinel lymph nodes, as well as to investigate the association between ECE with other clinical and pathological prognostic factors.

METHODS

This is a cross-sectional observational study carried out from January 2015 to June 2019, at the Breast Surgical Oncology service of Liga Contra o Cancer (LIGA), in Natal, Brazil. A total of 150 patients were included in the study and were divided into three groups: absence of ECE, ECE less than or equal to 2 mm and ECE greater than 2 mm.

RESULTS

The mean age was 58 years for the group with ECE and 57 years for the group without ECE. Most of the patients were mixed race (66.7%), had no family history of breast cancer (64%) and underwent quadrantectomy (64.5%). Regarding the characteristics of the disease, most presented a histological report compatible with Invasive Carcinoma of the non-special type (IC NST) (87.5%), histological grade II (52.7%), negative Lymphovascular invasion (LVI) (52.7%), Tumor Size T1 (<2.0 cm) (52%) and Luminal B molecular subtype (36.7%). Regarding sentinel lymph nodes: 103 patients (68.7%) had ECE and 1 positive sentinel lymph node was identified in most cases. There was a statistically significant association between the presence of ECE and of being mixed race (p = 0.03), between ECE and LVI (p = 0.05) and between ECE and a greater number of positive non-sentinel lymph nodes (p < 0.001).

CONCLUSION

Our study showed that ECE> 2 mm is associated with increased axillary nodal load compared to groups without ECE and ECE ≤ 2 mm in sentinel node biopsy in patients who met the Z0011 criteria.

Clinical significance of extranodal extension in sentinel lymph node positive breast cancer

The precise stage of lymph node (LN) metastasis is a strong prognostic factor in breast cancers, and sentinel lymph node (SLN) is the first station of nodal metastasis. A number of patients have extranodal extension (ENE) in SLN, whereas the clinical values of ENE in SLN in breast cancers are still in exploration. The aim of our study was to evaluate the predictive and prognostic values of ENE in SLN in breast cancers, and to investigate the feasibility of ENE to predict non-SLN metastasis, nodal burden, disease free survival (DFS) and overall survival (OS) in clinical practice. 266 cases of primary invasive breast cancer (cT1-2N0 breast cancer) underwent SLN biopsy and axillary lymph node dissection (ALND) between 2008 and 2015 were extracted from the pathology database of Fudan University Shanghai Cancer Center. ENE in SLN was defined as extension of neoplastic cells through the lymph-nodal capsule into the peri-nodal adipose tissue, and was classified as no larger than 2 mm and larger than 2 mm group. The associations between ENE and clinicopathological features, non-SLN metastasis, nodal burden, DFS, and OS were analyzed. In the 266 patients with involved SLN, 100(37.6%) were positive for ENE in SLN. 67 (25.2%) cases had ENE no larger than 2 mm in diameter, and 33(12.4%) had ENE larger than 2 mm. Among the clinicopathological characteristics, the presence of ENE in SLN was associated with higher pT and pN stages, PR status, lympho-vascular invasion. Logistic regression analysis indicated that patients with ENE in SLN had higher rate of non-SLN metastasis (OR4.80, 95% CI 2.47–9.34, P < 0.001). Meanwhile, in patients with SLN micrometastasis or 1–2 SLNs involvement, ENE positive patients had higher rate of non-SLN metastasis, comparing with ENE negative patients (P < 0.001, P = 0.004 respectively). The presence of ENE in SLN was correlated with nodal burden, including the pattern and number of involved SLN (P < 0.001, P < 0.001 respectively), the number of involved non-SLN and total positive LNs (P < 0.001, P < 0.001 respectively). Patients with ENE had significantly higher frequency of pN2 disease (P < 0.001). For the disease recurrence and survival status, Cox regression analysis showed that patients with ENE in SLN had significantly reduced DFS (HR 3.05, 95%CI 1.13–10.48, P = 0.008) and OS (HR 3.34, 95%CI 0.74–14.52, P = 0.092) in multivariate analysis. Kaplan–Meier curves and log-rank test showed that patients with ENE in SLN had lower DFS and OS (for DFS: P < 0.001; and for OS: P < 0.001 respectively). Whereas no significant difference was found in nodal burden between ENE ≤ 2 mm and > 2 mm groups, except the number of SLN metastasis was higher in patients with ENE > 2 mm. Cox regression analysis, Kaplan–Meier curves and log-rank test indicated that the size of ENE was not an independent factor of DFS and OS. Our study indicated that ENE in SLN was a predictor for non-SLN metastasis, nodal burden and prognosis in breast cancers. Patients with ENE in SLN had a higher rate of non-SLN metastasis, higher frequency of pN2 disease, and poorer prognosis. Patients with ENE in SLN may benefit from additional ALND, even in SLN micrometastasis or 1–2 SLNs involvement patients. The presence of ENE in SLN should be evaluated in clinical practice. Size of ENE which was classified by a 2 mm cutoff value had no significant predictive and prognostic values in this study. The cutoff values of ENE in SLN need further investigation.

Is completion axillary lymph node dissection necessary in patients who are underrepresented in the ACOSOG Z0011 trial?

PURPOSE

The American College of Surgeons Oncology Group trial Z0011 demonstrated that axillary node dissection (ALND) can be omitted in patients managed with breast conserving surgery and 1 to 2 positive sentinel lymph nodes (SLNs) without adverse effects on locoregional recurrence or disease-free survival (DFS). We investigated patients with breast cancer for whom clinicopathologic features were underrepresented in the Z0011 trial and analyzed radiation therapy treatment patterns and clinical outcomes.

METHODS AND MATERIALS

We retrospectively reviewed records of patients who underwent a lumpectomy and SLN biopsy with positive SLNs but not an ALND and completed adjuvant radiation therapy. Eligible patients had T3 tumors, >2 positive SLNs, invasive lobular carcinoma, estrogen receptor negative status, extranodal extension, Nottingham Grade 3, or were age <50 years.

RESULTS

We identified 105 women treated between July 2011 and July 2016 with a median follow-up time of 48.5 months (Range, 11-83 months). There were 40 women with an extranodal extension (38.9%) and 42 women with grade 3 disease (40.0%). Nineteen patients received whole breast irradiation alone (18.1%) and 86 patients were treated with modified tangent fields including the superior axilla level I/II (81.9%). Thirty-three patients (31.4%) also received a 3rd supraclavicular, nodal-directed field. Among the 86 patients who received axillary nodal irradiation, nodal volume contouring was performed in 77 patients (89.5%). Fifty-one patients (48.6%) also received adjuvant chemotherapy. The overall rates of 4-year DFS and locoregional control (LRC) were 94.3% and 98.1%, respectively. Off all patients, 1 patient experienced an internal mammary nodal recurrence, another patient a contralateral breast tumor, and two patients distant metastases. There were no axillary or ipsilateral breast tumor recurrences.

CONCLUSIONS

This retrospective analysis of women who were underrepresented or excluded from the Z11 trial and underwent a lumpectomy and SLN biopsy with positive SLNs demonstrated comparable rates of LRC and DFS. The high rates of LRC and DFS suggest that completion ALND may be safely omitted in this patient population but larger data sets and longer follow-up times are needed to confirm this finding.

A quantitative analysis of tumour characteristics in breast cancer patients with extranodal extension in non-sentinel nodes

BACKGROUND

The presence of extranodal extension (ENE) is well documented as a predictor of non-sentinel lymph node (NSLN) metastasis. The ACOSOG Z0011 trial (2011) concluded that patients who satisfy criteria including the absence of sentinel lymph node (SLN) ENE can forgo axillary clearance (AC). Currently there are no studies analysing the rate of ENE in NSLN metastasis in which the sentinel node was positive but had no ENE. Determining this incidence will help determine if current paradigms are resulting in residual ENE in NSLN metastasis by forgoing AC based on the Z0011 trial..

METHODS

This study determined incidence of ENE at NSLN metastasis in patients with a positive SLN biopsy without ENE in 162 symptomatic breast cancer patients who underwent AC between 2009 and 2014 at Cork University Hospital Breast Cancer Service, a teaching hospital of University College Cork.

RESULTS

Of 965 sentinel node biopsies performed 251 were identified as SLN positive, 162 (64.5%) underwent further AC. Of the 162 patients, 56.8% (92/162) were positive for ENE at SLN, of these 57.6% (53/92) had NSLN metastasis versus 17.1% (12/70) in the ENE-negative group (χ² test; P < 0.001). On adjusted analysis, ENE at the SLN was a significant predictor of NSLN metastasis (odds ratio [OR] 8.63; 95% confidence interval [CI] 3.26-22.86; P < 0.001). The incidence of NSLN-ENE in patients without SLN-ENE was 1/70 (1.4%) compared with 33.7% (31/92) in patients who had ENE at the SLN (χ² test; P < 0.001).

CONCLUSION

ENE at the SLN is an independent predictor of NSLN involvement; its absence significantly reduces the likelihood of ENE in NSLN metastasis..

Extra-nodal extension of sentinel lymph node metastasis is a marker of poor prognosis in breast cancer patients: A systematic review and an exploratory meta-analysis

Invasive breast cancer is the most common malignancy in women. Its most common site of metastasis is represented by the lymph nodes of axilla, and the sentinel lymph node (SLN) is the first station of nodal metastasis. Axillary SLN biopsy accurately predicts axillary lymph node status and has been accepted as standard of care for nodal staging in breast cancer. To date, the morphologic aspects of SLN metastasis have not been considered by the oncologic staging system. Extranodal extension (ENE) of nodal metastasis, defined as extension of neoplastic cells through the nodal capsule into the peri-nodal adipose tissue, has recently emerged as an important prognostic factor in several types of malignancies. It has also been considered as a possible predictor of non-sentinel node tumor burden in SLN-positive breast cancer patients. We sought out to clarify the prognostic role of ENE in SLN-positive breast cancer patients in terms of overall and disease-free survival by conducting a systematic review and meta-analysis. Among 172 screened articles, 5 were eligible for the meta-analysis; they globally include 624 patients (163 ENE+ and 461 ENE-) with a median follow-up of 58 months. ENE was associated with a higher risk of both mortality (RR = 2.51; 95% CI: 1.66-3.79, p < 0.0001, I(2) = 0%) and recurrence of disease (RR = 2.07, 95% CI: 1.38-3.10, p < 0.0001, I(2) = 0%). These findings recommend the consideration of ENE from the gross sampling to the histopathological evaluation, in perspectives to be validated and included in the oncologic staging.

Extranodal Extension on Sentinel Lymph Node Dissection: Why should we Treat it Differently?

American College of Surgeons Oncology Group Z0011 concluded that axillary lymph node dissection (ALND) may be avoided in selected patients with breast cancer with limited axillary nodal metastasis on sentinel lymph node dissection (SLND). However, patients with extranodal extension (ENE) were excluded to the follow existing standard of care, which is completion ALND. The significance of ENE detected on SLND is not well defined. Our objective was to determine the impact of ENE found on SLND on nonsentinel lymph node (NSLN) metastasis, recurrence, and overall mortality. We evaluated patients with breast cancer treated at a tertiary cancer center from 2005 to 2012. SLND was performed in 655 patients. Of those, 478 of 655 (73.0%) patients had no SLN metastases, 124 of 655 (18.9%) had SLN metastases without ENE (SLN-ENE), and 53 of 655 (8.1%) had SLN metastases with ENE (SLN1ENE). Of patients undergoing ALND, NSLN metastasis was detected in 37 of 84 (44.0%) of patients in the SLN-ENE group and 26 of 45 (57.8%) patients in the SLN1ENE group ( P = 0.14). On adjusted analyses, ENE was associated with increased disease recurrence (odds ratio [OR], 5.48; 95% confidence interval [CI], 1.23 to 24.48; P = 0.03) as well as increased overall mortality (OR, 8.16; 95% CI, 1.72 to 38.63; P = 0.01). In conclusion, ENE is associated with increased overall axillary nodal burden, disease recurrence, and overall mortality.

Quantitation of sentinel node metastatic burden and Her-2/neu over-expression accurately predicts residual axillary nodal involvement and extranodal disease in breast cancer

BACKGROUND DATA

Recent literature has suggested that completion axillary lymph node dissection (ALND) in breast carcinoma patients with positive SLN may not be necessary. However, a method for determining the risk of non-SLN or extranodal disease remains to be established.

AIMS

To determine if pathological variables from primary tumors and sentinel lymph node (SLN) metastases could predict the probability of non-sentinel lymph node (NSLN) metastases and extranodal disease in patients with breast carcinoma and SLN metastases.

METHODS

84 women with T1-3 breast cancer and clinically-negative axillae underwent completion ALND. Maximum diameter and width of SLN metastases were measured to calculate metastatic area. When multiple SLNs contained metastases, areas were summed to calculate the Total Metastatic Area (TMA). Multiple linear regression models were used to identify predictive factors.

RESULTS

Her-2/neu over-expression increased the odds of NSLN metastases (OR 4.3, p = 0.01) and extranodal disease (OR 7.9, p < 0.001). Independent SLN predictors were ≥1 positive SLN (OR, 7.35), maximum diameter and area of SLN metastases (OR 2.26, 1.85 respectively) and TMA (OR, 2.12). Maximum metastatic diameter/SLN diameter (OR 3.71, p = 0.04) and the area of metastases/SLN area (OR 3.4, p = 0.04) were predictive. For every 1 mm increase in diameter of SLN metastases, the odds of NSLN extranodal disease increased by 8.5% (p = 0.02). TMA >0.40 cm(2) was an independent predictor for NSLN metastases and extranodal disease.

CONCLUSION

Her-2/neu over-expression and parameters assessing metastatic burden in the SLN, particularly TMA, predicted the presence of NSLN involvement and extranodal disease in patients with breast carcinoma and SLN metastases.

GITR-expressing regulatory T-cell subsets are increased in tumor-positive lymph nodes from advanced breast cancer patients as compared to tumor-negative lymph nodes

Lymph node (LN) infiltration by neoplastic process involves important changes in lymph node immune microenvironment. In particular, regulatory T cells (Treg) seem to have a key role in altering the immunoediting function of the immune system which leads to the elusion of the tumor from immune surveillance. In this study, we evaluated the expression of T-cell markers in CD4+ and CD8+ subsets from tumor-positive and tumor-negative lymph nodes from the same, advanced stage breast cancer patient. The study was carried out on 3 patients and similar results were obtained. Flow cytometric analysis of CD8+ cells demonstrated a significant difference in the expression of CD25, CD45RA, CD45RO, and GITRL (Glucocorticoid-Induced TNF receptor-Related ligand). Flowcytometric analysis of CD4+ cells demonstrated a significant difference in the expression of GITR (Glucocorticoid-Induced TNF receptor-Related), CD25, FoxP3 (Forkhead box P3), CD28, and CD45RA. Multiple staining allowed the identification of two Treg subpopulations, CD4+ CD25 highGITR+ CD127-/low and CD4+ CD25 low GITR+ CD127+ cells, proving that both are increased in the positive nodes in comparison with the negative nodes from the same patient. We identified for the first time the CD4+ CD25 low GITR+ CD127+ Treg subpopulation in cancer, and the 2.6 fold increase in positive LN suggests that this Treg subpopulation could be a key player in metastasis. We also found GITRL expression in the CD8 lymphocytes, which may also contribute to the changes of metastatic lymph node microenvironment. These findings make both GITR and GITRL good possible co-candidates for future therapeutical intervention against metastasis and perhaps also as disease evolution biomarkers.

Clinical significance of sentinel lymph node isolated tumour cells in breast cancer

The advent of sentinel lymph node biopsy (SLNB) and improvements in histopathological and molecular analysis have increased the rate at which isolated tumour cells (ITC) are identified. However, their biological and clinical significance has been the subject of much debate. In this article we review the literature concerning SLNB with particular reference to ITC. The controversies regarding histopathological assessment, clinical relevance and management implications are explored. The literature review was facilitated by Medline, PubMed, Embase and Cochrane databases. Published studies have reported divergent results regarding the biological significance and clinical implications of ITC in general and SLN ITC in particular. Some studies demonstrate no associations, whilst others have found these to be indicators of poor prognosis, associated with non-SLN involvement, in addition to local recurrence and distant disease. Absolute consensus regarding the optimal analytical technique for SLN has yet to be reached, particularly concerning immunohistochemical (IHC) techniques targeting cytokeratins and contemporary molecular analysis. The clinical relevance of ITC within the SLN should be primarily determined by the magnitude of their impact on patient management and outcome measures. The modest up-staging within current classification systems is justified and reflects the marginally poorer prognosis for women with SLN ITC. Management need not be altered where further axillary treatment with surgical clearance or radiotherapy and systemic adjuvant treatment are already indicated. However, in the absence of level-1 guidance, each case requires discussion with regard to other tumour and patient related factors in the context of the multidisciplinary team. The identification of ITC remains highly dependent on the analytical technique employed and there exists potential for stage migration and impact on management decisions. Evidence supporting the routine analysis of deeper tissue sections by IHC is lacking and molecular technologies should be restricted to research purposes at present.

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.

Implication of extracapsular invasion of sentinel lymph nodes in breast cancer: prediction of nonsentinel lymph node metastasis

BACKGROUND

Accurate intraoperative diagnosis of sentinel lymph node (SLN) metastases enables the selection of patients who require axillary lymph node dissection (ALND). However, many patients with positive SLN do not show metastasis to other axillary lymph nodes. In this study, we investigated the factors that may determine the likelihood of additional positive nodes in the axilla when metastasis is found in the SLN.

METHODS

SLN biopsy was performed on 276 patients with breast cancer with clinically negative nodes, of which 46 (16.6%) had positive SLNs and underwent ALND. Eleven (23.9%) of these 46 cases had additional metastasis in nonsentinel lymph nodes (NSLN). The clinical and pathological features of these cases were reviewed and statistical analysis was performed.

RESULTS

All cases of positive nodes in NSLN in our series had extracapsular invasion (ECI) at the metastatic SLNs. Furthermore, the absence of ECI of SLN was significantly associated with the absence of metastasis in the NSLN (P < 0.001). As contributing factors, the absence of lymphatic invasion at the primary tumor, primary tumor size (<2 cm) and foci size in the metastatic SLN fell short of reaching statistical significance. Other factors, including histological type, pathological grade, estrogen receptor status, HER2 status, and age, were not significantly associated with metastatic involvement of NSLN.

CONCLUSIONS

Our results suggest that the presence of ECI at metastatic SLNs is a strong predictor for residual disease in the axilla. These findings imply the possibility that ALND might be foregone in the treatment of patients with breast cancer without ECI at metastatic SLNs.

Assessment of the performance of the Stanford Online Calculator for the prediction of nonsentinel lymph node metastasis in sentinel lymph node-positive breast cancer patients

BACKGROUND

Several models for the prediction of nonsentinel lymph node (NSLN) metastasis in sentinel lymph node (SLN)-positive breast cancer patients have been proposed. In this study, the authors evaluate the Stanford Online Calculator (SOC), which was designed to predict the likelihood of NSLN metastasis using only 3 variables: primary tumor size, SLN metastasis size, and angiolymphatic invasion status. They compared it with the Mayo and Memorial Sloan-Kettering Cancer Center (MSKCC) nomograms.

METHODS

The SOC was used to calculate the probability of NSLN metastasis in 464 breast cancer patients with SLN metastasis who underwent completion axillary lymph node dissection at the Mayo Clinic. The area under the receiver operating characteristic curve (AUC) was calculated for each model. Mean probabilities of patients with and without NSLN metastasis were compared. Patients with <or=5%, <or=10%, and 100% NSLN metastasis probabilities were examined.

RESULTS

The AUCs of the Stanford, MSKCC, and Mayo models were 0.72, 0.74, and 0.77, respectively (P=.13). The mean Stanford probabilities for patients with and without NSLN metastasis were 0.75 (range, 0.06-1.0) and 0.50 (range, 0.05-1.0), respectively (P<.0001). The false-negative rates for patients with a Stanford probability of <or=5% and <or=10% were 0% and 13%, respectively. Of the patients with a Stanford probability of 100%, 26% did not have NSLN metastasis.

CONCLUSIONS

Despite using only 3 variables, the Stanford nomogram appears to perform on a par with, but not better than, the MSKCC and Mayo nomograms. Further validation in other patient populations is needed.

Non-sentinel lymph node metastases associated with isolated breast cancer cells in the sentinel node

There are many reports on the frequency of non-sentinel lymph node involvement when isolated tumor cells are found in the sentinel node, but results and recommendations for the use of an axillary lymph node dissection differ among studies. This systematic review was conducted to give an overview of this issue and to provide recommendations for the use of an axillary lymph node dissection in these patients. We searched Medline, Embase, and Cochrane databases from January 1, 2002, through November 27, 2007, for articles on patients with invasive breast cancer who had isolated tumor cells in the sentinel lymph node (according to the sixth edition of the Cancer Staging Manual of the American Joint Committee on Cancer) and who also underwent axillary lymph node dissection. Of 411 selected articles, 29 (including 836 patients) were included in this review. These 29 studies were heterogeneous, reporting a wide range of non-sentinel lymph node involvement (defined as the presence of isolated tumor cells or micro- or macrometastases) associated with isolated tumor cells in the sentinel lymph node, with an overall pooled risk for such involvement of 12.3% (95% confidence interval = 9.5% to 15.7%). This pooled risk estimate was marginally higher than the risk of a false-negative sentinel lymph node biopsy examination (ie, 7%-8%) but marginally lower than the risk of non-sentinel lymph node metastases in patients with micrometastases (ie, approximately 20%) who are currently eligible for an axillary lymph node dissection. Because 36 (64%) of the 56 patients with isolated tumor cells in their sentinel lymph node also had non-sentinel lymph node macrometastases, those patients with isolated tumor cells in the sentinel lymph node without other indications for adjuvant systemic therapy might be candidates for axillary lymph node dissection.

A model for predicting non-sentinel lymph node metastatic disease when the sentinel lymph node is positive

BACKGROUND

Women with axillary sentinel lymph node (SLN)-positive breast cancer usually undergo completion axillary lymph node dissection (ALND). However, not all patients with positive SLNs have further axillary nodal disease. Therefore, in the patients with low risk of further disease, completion ALND could be avoided. The Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram to estimate the risk of non-SLN disease. This study critically appraised the nomogram and refined the model to improve predictive accuracy.

METHODS

The MSKCC nomogram was applied to 118 patients with a positive axillary SLN biopsy who subsequently had completion ALND. Predictive accuracy was assessed by calculating the area under the receiver-operator characteristic (ROC) curve. A further predictive model was developed using more detailed pathological information. Backward stepwise multiple logistic regression was used to develop the predictive model for further axillary lymph node disease. This was then converted to a probability score. After k-fold cross-validation within the data, an inverse variance weighted mean ROC curve and area below the ROC curve was calculated.

RESULTS

The MSKCC nomogram had an area under the ROC curve of 68 per cent. The revised predictive model showed the weighted mean area under the ROC curve to be 84 per cent.

CONCLUSION

The modified predictive model, which incorporated size of SLN metastasis, improved predictive accuracy, although further testing on an independent data set is desirable.

Increased Sentinel Lymph Node Lymphangiogenesis is Associated with Nonsentinel Axillary Lymph Node Involvement in Breast Cancer Patients with a Positive Sentinel Node

PURPOSE

Lymph node (LN) lymphangiogenesis has recently been shown to be important in the premetastatic niche of sentinel LNs. To study its role in the further metastatic spread of human breast cancer, we investigated the association of angiogenesis and lymphangiogenesis in sentinel LN metastases with the presence of nonsentinel LN metastases in breast cancer patients with a positive sentinel LN.

EXPERIMENTAL DESIGN

Angiogenesis and lymphangiogenesis--quantified as endothelial cell proliferation fraction (ECP%) and lymphatic ECP fraction (LECP%)--were assessed in sentinel LN metastases of 65 T(1)/T(2) patients with breast cancer using CD34/Ki67 and D2-40/Ki67 immunohistochemical double stains. Correlations were analyzed between nonsentinel LN status, LECP%, and other clinicopathologic variables (number of involved sentinel LNs, size of the primary tumor and LN metastasis, presence of lymphovascular invasion in the primary tumor, and of extracapsular growth in the sentinel LN metastasis).

RESULTS

Thirty seven out of 65 patients (56.9%) had at least one involved nonsentinel LN. Size of the sentinel LN metastasis (P = 0.001), lymphovascular invasion (P = 0.02), extracapsular growth (P = 0.02), and LECP% (P = 0.01) were correlated with a positive nonsentinel LN status. The multivariate logistic regression model retained high LECP% (odds ratios = 4.2, P = 0.01) and the presence of extracapsular growth (odds ratios = 3.38, P = 0.04) as independently associated with the presence of nonsentinel LN metastases.

CONCLUSIONS

Increased sentinel LN metastasis lymphangiogenesis is associated with metastatic involvement of nonsentinel axillary LNs. These are the first data sustaining the hypothesis that sentinel LN lymphangiogenesis is involved in further metastatic spread of human breast cancer.

Detection of circulating tumor cells in early-stage breast cancer metastasis to axillary lymph nodes

PURPOSE

Clinical and pathologic prognostic factors do not always accurately predict disease outcome. Patients with early-stage breast cancer may harbor clinically significant but undetected systemic disease. We hypothesized that a multimarker quantitative real-time reverse transcription-PCR (qRT) assay could detect circulating tumor cells (CTC) in patients with early-stage breast cancer and correlate with sentinel lymph node (SLN) and non-SLN metastasis status.

EXPERIMENTAL DESIGN

Blood samples from 90 women with the American Joint Committee on Cancer stages I to III breast cancer and 39 age-matched normal healthy volunteers were assessed by qRT for mRNA expression of three markers: stanniocalcin-1 (STC-1), N-acetylgalactosaminyltransferase (GalNacT), and melanoma antigen gene family-A3 (MAGE-A3). CTC biomarker detection was correlated with overall axillary LN (ALN), SLN, and non-SLN histopathology status.

RESULTS

CTCs were detected in 39 of 90 (43%) patients, but not in normal volunteers. At least one CTC biomarker was detected in 10 of 35 (29%) stage I patients, 19 of 42 (45%) stage II patients, and 10 of 13 (77%) stage III patients. In multivariate analysis, only lymphovascular invasion and >or=2 CTC biomarkers detected significantly correlated with ALN metastasis [odds ratio (OR), 12.42; 95% confidence interval (95% CI), 3.52-43.77, P<0.0001; and OR, 3.88; 95% CI, 1.69-8.89, P=0.001, respectively]. The number of CTC biomarkers detected similarly correlated with SLN and non-SLN metastasis status (P=0.0004). At least one CTC biomarker was detected in 10 of 11 (91%) patients with non-SLN metastases.

CONCLUSION

The detection of CTCs offers a novel means to assess the presence of systemic disease spreading relative to SLN and ALN histopathology status.

[Sentinel node biopsy in invasive breast cancer in 2007]

Sentinel lymph node (SN) biopsy for breast cancer has been introduced in the mid-1990s and it has now been performed on thousands of patients. This procedure has been rapidly adopted around the world by surgical specialists in clinical practice as a diagnostic procedure instead of the axillary lymph node dissection. The diffusion of the SN mapping in routine must be careful by respecting some principles of methodology and especially of training, in order to maintain its irreversible development. However, the advent of this mini-invasive technique revealed new questions, which the concept of the SN procedure raises: can we increase the current indications? Could axillary lymph node dissection be avoided in patients with metastatic SN? What is the morbidity of the biopsy of the SN? Which is the prognostic value of micrometastatis discovered by the diffusion of the ultra-stadification of the SNs? The GS procedure is a diagnostic method the reliability of which is now on accepted in its usual indications (tumours in place, small size breast tumour without palpable adenopathy). The value of the axillary dissection after metastatic SN is the subject of debates and controversies although axillary dissection remains recommended. So the use of scores or predictive nomograms is currently developed to select the patients being able not to justify of complementary axillary dissection, and seems promising.

Proteomic Profiling of Primary Breast Cancer Predicts Axillary Lymph Node Metastasis

To determine if protein expression in primary breast cancers can predict axillary lymph node (ALN) metastasis, we assessed differences in protein expression between primary breast cancers with and without ALN metastasis using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Laser capture microdissection was performed on invasive breast cancer frozen sections from 65 patients undergoing resection with sentinel lymph node (SLN) or level I and II ALN dissection. Isolated proteins from these tumors were applied to immobilized metal affinity capture (IMAC-3) ProteinChip arrays and analyzed by SELDI-TOF-MS to generate unique protein profiles. Correlations between unique protein peaks and histologically confirmed ALN status and other known clinicopathologic factors were examined using ANOVA and multivariate logistic regression. Two metal-binding polypeptides at 4,871 and 8,596 Da were identified as significant risk factors for nodal metastasis (P = 0.034 and 0.015, respectively) in a multivariate analysis. Lymphovascular invasion (LVI) was the only clinicopathologic factor predictive of ALN metastasis (P = 0.0038). In a logistic regression model combining the 4,871 and 8,596 Da peaks with LVI, the area under the receiver operating characteristic curve was 0.87. Compared with patients with negative ALN, those with > or =2 positive ALN or non-SLN metastases were significantly more likely to have an increased peak at 4,871 Da (P = 0.016 and 0.0083, respectively). ProteinChip array analysis identified differential protein peaks in primary breast cancers that predict the presence and number of ALN metastases and non-SLN status.

Micrometastases in Sentinel Lymph Node in a Multicentric Study: Predictive Factors of Nonsentinel Lymph Node Involvement—Groupe Des Chirurgiens De La Federation Des Centres De Lutte Contre Le Cancer

Purpose

To determine the rate of nonsentinel lymph node (NSN) involvement at axillary lymph node dissection (ALND) and predictive factors of this involvement following detection of micrometastasis in sentinel nodes (SN).

Methods

We analyzed 700 observations of SN micrometastases with additional ALND with the characteristics of the patients, tumors, and SN.

Results

Involvement of SN was diagnosed 388 times by serial sections (55.4%) with standard hemoxylin and eosin staining (HES) and 312 times solely on immunohistochemical analysis (IHC; 44.6%). The accurate size of the micrometastases was indicated in 488 cases: 301 larger than 0.2 mm (61.7%) and 187 ≤ 0.2 mm (38.3%). Ninety-four patients (13.4%) presented an NSN involvement with only one NSN involved in 62 cases (66%). Predictive factors of NSN involvement were in univariate analysis (pT stage [P < .000], menopausal status [P = .048], T stage [P = .006], grade [P = .013], lymphovascular invasion [LVI; P = .013], histologic tumor type [P = .017], and method of micrometastasis detection, by HES or IHC [P = .015]) and in multivariate analysis (pT stage ≤ or > 20 mm [odds ratio, 2.54], micrometastases detected by HES or IHC [odds ratio,1.734], presence or absence of LVI [odds ratio, 1.706]). Micrometastasis size ≤ or greater than 0.2 mm was not predictive.

Conclusion

This study confirms the value of serial sections and the vital role played by IHC in screening for small micrometastases. Omission of additional ALND may be envisaged with minimal risk for pT1a and pT1b tumors, and pT1a-b-c tumors corresponding to tubular, colloidal, or medullar cancers.

Factors predicting the sentinel and non-sentinel lymph node metastases in breast cancer

The sentinel lymph node (SLN) is the only focus of axillary metastasis in a significant proportion of patients. In this single institutional study, clinicopathologic characteristics were investigated to determine the factors predicting the status of a SLN biopsy and the metastatic involvement of non-SLNs. Data were retrospectively reveiwed for 400 consecutive patients with clinical T1/T2 N0 breast cancer who underwent a SLN biopsy including axillary and/or internal mammary lymph nodes. The SLNs were evaluated by using the new AJCC staging criteria following multiple sectioning and immunohistochemical (IHC) analyses of nodes. The SLN contained metastases in 148 patients (38.5%) including 18 patients (12.2%) with micrometastases (<or=0.2 mm) and 130 patients (87.8%) with macrometastases (>0.2 cm). Five patients had isolated tumor cells detected by IHC (<or=0.2 mm, N(0i)). Patients with tumor size more than 2 cm (T1, 29.8% versus T2, 51.6%; OR=2.31, 95% CI, 1.50-3.56) and lymphovascular invasion (LVI-, 30.3% versus LVI+, 51.3%; OR=2.07, 95% CI, 1.34-3.19) were more likely to have positive SLNs in both univariate and multivariate analyses. Among patients with a positive SLN biopsy, those with T2 tumors (versus T1; 63.1% versus 36.9; OR=2.93, 95% CI, 1.43-6.04), macrometastases in SLNs (versus micrometastases; 88.9% versus 11.1%; OR=8.83; 95% CI, 1.82-42.87) and extracapsular node extension (versus without extracapsular node extension; 65.4% versus 34.6%; OR, 2.23; 95% CI, 1.05-4.72) were more likely to have non-SLN metastases in both univariate and multivarite analyses. These results indicate that clinicopathologic factors might be helpful to select patients who were less likely to have negative SLN or non-SLNs. However, additional factors are still needed to be identified to omit surgical axillary staging.

Evaluation of a breast cancer nomogram for prediction of non-sentinel lymph node positivity

AIMS

This study evaluates the breast cancer nomogram (BCN), an online tool developed by Memorial Sloan-Kettering Cancer Center to determine the rate of non-SLN positivity, in an independent cohort of SLN positive patients.

MATERIAL AND METHODS

Available data between 02/2000 and 06/2004 in two prospective databases, 749 cases had successful SLN biopsy including 149 axillary-SLN metastases study cases. These cases had accurately graded tumours up to 9 cm in size and CAD with a minimum total 10 nodes removed. Histopathological assessment of nodes included hematoxylin and eosin staining and/or immunohistochemistry. Computerized BCN was used to estimate probability of non-SLN positivity and compared with actual probability after grouping into deciles.

RESULTS

The trend of actual probability in various decile groups was comparable to the predicted probability. An area under the receiver operating characteristic curve was 0.75 as compared to 0.76 in the original study.

CONCLUSION

Although this study is small, the results are encouraging and suggest the nomogram is a useful tool to estimate the likelihood of positive axillary non-SLN. However, variations in pathological assessment between centres are the major impediment to widespread application of BCN. If SLN positive patients decline the standard recommendation of CAD or entry into clinical trials evaluating the significance of CAD then the BCN could help in decision making.

Sentinel lymph nodes and breast carcinoma: analysis of 70 cases by frozen section

BACKGROUND

The sentinal node biopsy (SNB) is a reliable method for determining the status of the regional lymph nodes in patients with breast cancer. SNB technology is evolving rapidly, but no standardization has yet been accomplished. The aim of this study is to discuss the accuracy of this procedure and the optimal method for identifying micrometastases.

METHODS

We collected data from 70 women with primary invasive breast carcinoma who underwent SNB for breast cancer. We examined two frozen sections levels from each half of each lymph node, as well as a cytology imprint before arriving at the frozen section diagnosis. Immunohistochemistry with pancytokeratin (AE1/AE3) was done on the paraffin sections. For the association between the lymph node size and the possibility of metastases, Student's t test was used and a P value of less than 0.05 was regarded as significant.

RESULTS

The number of patients with metastases in SNB was 19, from which 15 cases were correctly diagnosed in frozen sections/imprints and four cases were false negative. The axillary toilet from all cases with SNB metastases smaller than 2 mm showed no additional positive nodes. Lymph node diameter showed a significant association with sentinel node status (P<0.0001).

CONCLUSION

Frozen section examination of SNB from patients with breast carcinoma is both specific (100%) and sensitive (79%). Diagnosis of lobular carcinoma can be difficult, and may require immunohistochemistry with cytokeratin for diagnosis. Small metastases in a non-optimal frozen section may be difficult to discern. Cytology imprints add nothing to the diagnosis.