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

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.

Issues related to sentinel lymph node assessment in the management of breast cancer-what are relevant in pathology reports?

Most cancer centers now perform sentinel node (SN) biopsies. The limited number of SNs sampled compared with an axillary dissection has allowed more comprehensive lymph node analysis resulting in increased detection of micrometastases. Many node-negative cases are now reclassified as micrometastatic. Recent research on SN biopsy focuses on whether axillary dissection is always necessary when the SN is positive. Some subgroups of patients have a higher risk of more nodal metastases when completion axillary dissections were performed. This paper summarizes the different studies and examines what are the clinically relevant items to report on SN node pathology: volume or size of nodal metastasis, location within the node, extranodal extension, number of involved SN(s) and non-SN(s), total number of SN, and total number of nodes on axillary dissection, if performed.

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.

Pathologic evaluation of axillary dissection specimens following unexpected identification of tumor within sentinel lymph nodes

CONTEXT

Axillary lymph node dissection has been the standard of care after identification of a positive sentinel lymph node for breast cancer patients.

OBJECTIVE

To determine the likelihood of non-sentinel lymph node involvement for patients with negative sentinel node by frozen section, who are subsequently found to have tumor cells in the sentinel node by permanent section levels and/or cytokeratin immunohistochemistry.

DESIGN

One hundred three patients with invasive breast cancer exhibiting negative frozen section evaluation of their sentinel node, but later found to have isolated tumor cells (n  =  46), micrometastasis (n  =  46), or metastases (n  =  11) in their sentinel node by permanent sections or immunohistochemistry, were enrolled in this prospective cohort study and underwent completion axillary dissection.

RESULTS

Six of 46 patients (13%) with isolated tumor cells in their sentinel node, 15 of 46 patients (33%) with micrometastasis in their sentinel node, and 2 of 11 patients (18%) with metastasis in their sentinel node had additional findings in the nonsentinel nodes. These findings resulted in a pathologic stage change in 2 patients. Predictors of positive nonsentinel nodes were 2 or more positive sentinel nodes (P  =  .002), sentinel nodes with micrometastasis versus isolated tumor cells (P  =  .03), and those with angiolymphatic invasion (P  =  .04).

CONCLUSIONS

Our findings lend support to axillary node dissection for patients with micrometastasis or metastasis in their sentinel nodes. However, studies with clinical follow-up are needed to determine whether axillary node dissection is necessary for patients with isolated tumor cells in sentinel nodes.

[Surgery for invasive breast cancer]

As most solid tumors, surgery is often the first step of the multidisciplinary management for breast cancers. Although mastectomy and axillar lymphadenectomy still have indications, conservative treatment and sentinel node detection are commonly used. Thanks to induction chemotherapy and oncoplastic techniques, surgery is conservative in most cases, even for important tumors without overall survival prejudice. There is no consensus about resection margins status but a limit of 2 to 3 mm seems to be reasonable while oncoplastic surgery allows large resection and good cosmetic outcomes. In this overview, we present the state of the art for breast cancer surgery including conservative and radical treatments, axillar lymphadenectomy and sentinel lymph node detection, margins status, oncoplastic techniques.

The Extent of Axillary Lymph Node Clearance Required Following Detection of Sentinel Node Micrometastases

Sentinel node (SN) micrometastases are an indication to proceed to axillary clearance. The aim of this study is to determine the extent and level of axillary clearance required for patients with SN micrometastases. All patients with SN micrometastases which were followed by axillary clearances from 1999 to 2007 were identified. Slides were reviewed by a histopathologist to detail characteristics of SN micrometastases including size and site. The SN micrometastases and primary tumor characteristics were correlated with the presence and level of non-SN micrometastases. Fifty patients who had micrometastases followed by axillary clearances were identified. Of those 18% (n = 9) had non-SN metastases.Seven patients had metastases to level I, one patient had metastases to level I and III and one patient had non-SN metastases to level III only. No patient had metastases to level II. Patients with non-SN metastases had very limited number of non-SNs involved (maximum 2 non-SNs). No variable, including site of the micrometastasis, was predictive of non-SN metastases. In patients with SN micrometastases, a limited level I axillary clearance can be justified in view of the low number of additional nodes involved and in particular, the low (4%) rate of spread to level II ⁄ III nodes.

Analysis of predictive tools for further axillary involvement in patients with sentinel lymph node positive small (≤15 mm) invasive breast cancer

Small breast cancers often require different treatment than larger ones. The frequency and predictability of further nodal involvement was evaluated in patients with positive sentinel lymph nodes and breast cancers ≤15 mm by means of 8 different predictive tools. Of 506 patients with such small tumors 138 with positive sentinel nodes underwent axillary dissection and 39 of these had non-sentinel node involvement too. The Stanford nomogram and the micrometastatic nomogram were the predictive tools identifying a small group of patients with low probability of further axillary involvement that might not require completion axillary lymph node dissection. Our data also suggest that the Tenon score can separate subsets of patients with a low and a higher risk of non-sentinel node metastasis. Predictive tools based on multivariate models can help in omitting completion axillary dissection in patients with low risk of non-sentinel lymph node metastasis based on their small tumor size.

Intraoperative assessment of sentinel lymph nodes after neoadjuvant chemotherapy in patients with breast cancer

BACKGROUND

Sentinel lymph node (SLN) biopsy has been shown to be both accurate and feasible for women who receive neoadjuvant chemotherapy (NAC). This study was designed to evaluate the ability of intraoperative assessment to predict metastasis in the sentinel node after NAC and to compare it with patients not treated with NAC.

METHODS

Thirty-seven patients with invasive breast cancer and SLN biopsy after NAC and 461 patients with invasive breast cancer not treated with NAC were included in the study. The SLN was identified by the gamma probe and sent to pathology for frozen (FS) and H&E paraffin-sections. If the SLN was negative by H&E paraffin-sections, then immunohistochemistry was performed.

RESULTS

The sensitivity of FS in the NAC group ranged from 78.5% for micro and isolated tumor cells to 100% for macrometastasis. The sensitivity of FS in the non-NAC group ranged from 82% for micro and isolated tumor cells to 97.4% for macrometastasis. There were no statistically differences between the sensitivities of FS in the two groups. Nine (64.2%) of the 14 patients in the NAC group with metastasis to the SLN had other non-SLN metastasis.

CONCLUSIONS

After NAC, FS is an effective method for detecting macrometastasis in the SLN. As in the adjuvant setting, the sensitivity of FS is lower for SLN micro and sub-micrometastasis. Intraoperative FS of the SLN after NAC is indicated to avoid a second surgery because 60% of patients with a positive SLN will have additional positive axillary nodes.

Predicting non-sentinel lymph node status after positive sentinel biopsy in breast cancer: what model performs the best in a Czech population?

Several models have previously been proposed to predict the probability of non-sentinel lymph node (NSLN) metastases after a positive sentinel lymph node (SLN) biopsy in breast cancer. The aim of this study was to assess the accuracy of two previously published nomograms (MSKCC, Stanford) and to develop an alternative model with the best predictive accuracy in a Czech population. In the basic population of 330 SLN-positive patients from the Czech Republic, the accuracy of the MSKCC and the Stanford nomograms was tested by the area under the receiver operating characteristics curve (AUC). A new model (MOU nomogram) was proposed according to the results of multivariate analysis of relevant clinicopathologic variables. The new model was validated in an independent test population from Hungary (383 patients). In the basic population, six of 27 patients with isolated tumor cells (ITC) in the SLN harbored additional NSLN metastases. The AUCs of the MSKCC and Stanford nomograms were 0.68 and 0.66, respectively; for the MOU nomogram it reached 0.76. In the test population, the AUC of the MOU nomogram was similar to that of the basic population (0.74). The presence of only ITC in SLN does not preclude further nodal involvement. Additional variables are beneficial when considering the probability of NSLN metastases. In the basic population, the previously published nomograms (MSKCC and Stanford) showed only limited accuracy. The developed MOU nomogram proved more suitable for the basic population, such as for another independent population from a mid-European country.

Comparison of models to predict nonsentinel lymph node status in breast cancer patients with metastatic sentinel lymph nodes: a prospective multicenter study

PURPOSE

Several models have been developed to predict nonsentinel lymph node (non-SN) status in patients with breast cancer with sentinel lymph node (SN) metastasis. The purpose of our investigation was to compare available models in a prospective, multicenter study.

PATIENTS AND METHODS

In a cohort of 561 positive-SN patients who underwent axillary lymph node dissection, we evaluated the areas under the receiver operating characteristic curves (AUCs), calibration, rates of false negatives (FN), and number of patients in the group at low risk for non-SN calculated from nine models. We also evaluated these parameters in the subgroup of patients with micrometastasis or isolated tumor cells (ITC) in the SN.

RESULTS

At least one non-SN was metastatic in 147 patients (26.2%). Only two of nine models had an AUC greater than 0.75. Three models were well calibrated. Two models yielded an FN rate less than 5%. Three models were able to assign more than a third of patients in the low-risk group. Overall, the Memorial Sloan-Kettering Cancer Center nomogram and Tenon score outperform other methods for all patients, including the subgroup of patients with only SN micrometastases or ITC.

CONCLUSION

Our study suggests that all models do not perform equally, especially for the subgroup of patients with only micrometastasis or ITC in the SN. We point out available evaluation methods to assess their performance and provide guidance for clinical practice.

[Sentinel node biopsy in breast cancer: pathological analysis and interpretation]

This overview examines how the introduction of sentinel lymph node biopsy (SLNB) has changed the pathological staging of breast cancer. The more intensive analysis of the sentinel lymph nodes (gross slicing, step sections, immunohistological or molecular analysis) has lead to stage shifting in breast cancer. Regarding the rate of up-staging by positive results of SLNB, there are significant differences between institutes, some method-related, some related to the interpretation of results. Methodological differences should be reduced by means of reliable guidelines with the goal of systematically identifying metastases of a particular size (a macrometastasis over 2 mm being the minimum criterion). The next review of the TNM classification should result in a reduction in interobserver variability as a result of better definitions of staging categories for isolated tumor cells and micrometastases. In addition, a staging category is expected for metastases which have been identified by calibrated quantitative molecular tests only and which are larger than isolated tumors. Even in settings where nodal staging by SLNB is based on molecular tests at least a proportion of the lymph node should be investigated histologically.

Prognostic implications of isolated tumor cells and micrometastases in sentinel nodes of patients with invasive breast cancer: 10-year analysis of patients enrolled in the prospective East Carolina University/Anne Arundel Medical Center Sentinel Node Multicenter Study

BACKGROUND

Sentinel lymph node biopsy (SLNB) is a more sensitive and accurate nodal staging procedure than axillary lymph node dissection (ALND). Because of increased pathologic evaluation in the sentinel node era, more nodal micrometastases (MIC) (> 0.2 mm to 2 mm) and isolated tumor cells (ITC; < or = 0.2 mm) have been identified. We present the 10-year analysis of our prospective SLN study, focusing on regional axillary node status and distant metastases in patients with nodal ITC and MIC.

STUDY DESIGN

From 1996 to 2005, breast cancer patients were enrolled in an Institutional Review Board-approved, multicenter study. SLNs were examined at multiple levels by hematoxylin and eosin; most (85%) hematoxylin and eosin-negative SLNs were also examined by cytokeratin immunohistochemistry. Data from 1,259 patients with invasive breast cancer and in whom an SLN was found were reviewed for this analysis.

RESULTS

Of the 1,259 patients, 893 (71%) had negative SLNs, 25 (2%) had ITCs, 57 (5%) had MIC, and 284 (23%) had positive SLNs. None of the 13 patients with ITCs who underwent an ALND had additional positive nodes, compared with 27% (11 of 41) of patients with MIC. At a mean followup of 4.9 years, the distant recurrence rates for SLN-negative, ITC, MIC, and SLN-positive groups were 6%, 8%, 14%, and 21%, respectively. The presence of MIC in the SLN was associated with a significantly shorter disease-free interval than was SLN negativity (p < 0.02 by Cox regression model).

CONCLUSIONS

This prospective breast cancer study found that sentinel node MIC, but not ITCs, were associated with additional positive nodes and with distant recurrence. These data suggest that ALND may be unnecessary in patients with ITCs. But ALND and more aggressive adjuvant therapy should be considered in patients with SLN micrometastases.

A nomogram predictive of non-sentinel lymph node involvement in breast cancer patients with a sentinel lymph node micrometastasis

PURPOSE

Predictive factors of non-sentinel lymph node (NSN) involvement at axillary lymph node dissection (ALND) have been studied in the case of sentinel node (SN) involvement, with validation of a nomogram. This nomogram is not accurate for SN micrometastasis. The purpose of our study was to determine a nomogram for predicting the likelihood of NSN involvement in breast cancer patients with a SN micrometastasis.

METHODS

We collated 909 observations of SN micrometastases with additional ALND. Characteristics of the patients, tumours and SN were analysed.

RESULTS

Involvement of SN was diagnosed 490 times (53.9%) with standard staining (HES) and 419 times solely on immunohistochemical analysis (IHC) (46.1%). NSN invasion was observed in 114 patients (12.5%), whereas 62.3% (71) had only one NSN involved and 37.7% (43) two or more NSN involved. In multivariate analysis, significant predictive factors were: tumour size (pT stage < or = 10 mm or >11 and < or = 20 or >20 mm [odds ratio (OR) 2.1 and 3.43], micrometastases detected by HES or IHC [OR 1.64], presence or absence of lymphovascular invasion (LVI) [OR 1.76], tumour histological type mixed or not [OR 2.64]. The rate and probability of NSN involvement with the model are given for 24 groups, with a representation by a nomogram.

CONCLUSION

One group, corresponding to 10.1% of the patients, was associated with a risk of NSN involvement of less than 5%, and five groups, corresponding to 29.8% of the patients, were associated with a risk < or = 10%. Omission of ALND could be proposed with minimal risk for a low probability of NSN involvement.

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.

Variations in sentinel node isolated tumour cells/micrometastasis and non-sentinel node involvement rates according to different interpretations of the TNM definitions

Breast cancers with nodal isolated tumour cells (ITC) and micrometastases are categorised as node-negative and node-positive, respectively, in the tumour node metastasis (TNM) classification. Two recently published interpretations of the TNM definitions were applied to cases of low-volume sentinel lymph node (SLN) involvement and their corresponding non-SLNs for reclassification as micrometastasis or ITC. Of the 517 cases reviewed, 82 had ITC and 435 had micrometastasis on the basis of one classification, and the number of ITC increased to 207 with 310 micrometastases on the basis of the other. Approximately 24% of the cases were discordantly categorised. The rates of non-SLN metastases associated with SLN ITCs were 8.5% and 13.5%, respectively. Although the second interpretation of low-volume nodal stage categories has better reproducibility, it may underestimate the rate of non-SLN involvement. The TNM definitions of low-volume nodal metastases need to be better formulated and supplemented with visual information in the form of multiple sample images.

Minimal disease in sentinel nodes

Isolated tumor cells and micrometastases represent low-volume or minimal disease in the regional lymph nodes of breast cancer patients as compared to macrometastases. Sentinel lymph node biopsy is a functional selection and removal of the most likely site of regional metastasis, and gives pathologists the opportunity to concentrate detection techniques on a limited number of lymph nodes. Consequently, more lesions belonging in the two mentioned staging categories are discovered in sentinel lymph nodes. Despite some publications contradicting stochastic models of breast cancer, micrometastases seem to reflect a prognosis intermediate between the node-negative and macrometastatic nodal status, and they also reflect a risk of non-sentinel node involvement slightly higher than that associated with a node-negative status. Data are more contradictory as concerns isolated tumor cells. This minireview summarizes the definitions, their inconsistencies, pathological protocols aiming at the detection of minimal nodal disease, the prognostic impact and non-sentinel node involvement related risk of such nodal lesions, and their therapeutic consequences.

A prospective, blinded trial of touch prep analysis versus frozen section for intraoperative evaluation of sentinel lymph nodes in breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) has largely replaced axillary dissection (ALND) for axillary staging in early breast cancer. However, intense pathologic evaluation is not routinely available intraoperatively; therefore, patients with SLN metastasis may require a second surgery for completion ALND. We hypothesized that a single-section approach (by either frozen section [FS] or touch preparation analysis [TPA]) could be accurate for intraoperative SLN evaluation.

METHODS

We performed a prospective, blinded study of patients undergoing SLNB for breast cancer from September 2004 to July 2006. SLNs were bivalved along the long axis, underwent FS and TPA of the facing halves, followed by routine sentinel node processing (serial sectioning with hematoxylin/eosin staining). A single pathologist reviewed all study slides and was blinded to the permanent section interpretation.

RESULTS

We analyzed 233 nodes from 118 patients. Overall, 21% of patients (N = 25) had SLN metastasis by serial-section histopathology. Single-section FS and TPA had similar sensitivities (0.67 and 0.66, P = .82) and specificities (0.995 and 0.995, P = 1.0) for detection of SLN metastasis, yielding equivalent accuracies (95%). All micrometastases (<2 mm; N = 4) were missed by both techniques. False positives were rare-only one in each group (2% overall).

CONCLUSION

Single-section TPA and FS have similar accuracies and can be safely used to identify the majority of patients with SLN metastasis, sparing these patients a delayed ALND. False-negative results from TPA or FS occur in patients with micrometastatic disease, for which the role of completion ALND remains controversial.

Sentinel lymph node biopsy in women with pT1a or "microinvasive" breast cancer

The role of sentinel lymph node biopsy (SLNB) in pT1a and "microinvasive" breast cancer has not been extensively studied. We report our experience with SLNB in patients with "minimal" breast cancer to determine the incidence and type of SLN metastases, and to study the potential impact on their surgical or oncological management. Among some 3387 women operated upon for primary breast cancer who underwent sentinel lymph node biopsy at nine institutions participating in the Rome Breast Cancer Study Group, 251 were staged pT1a or pT1mic (7.4%). There were 13 cases of sentinel lymph node metastases identified in this group of patients (5.2%), seven macrometastases and six micrometastases. Additionally, ITC were diagnosed by immunohistochemistry in four cases (1.6%). The incidence of SLN metastases was 7/174 (4%) and 6/77 (7.8%) in patients with pT1a and pT1mic tumors, respectively (p=0.2). Age and histological grade were predictive factors for SLN metastases. Chemotherapy was seldom directed by axillary node status (8/38 patients). As the incidence of SLN metastases in these patients is very small, particularly in the pT1a group, the indications for even a minimally invasive procedure, such as sentinel lymph node biopsy, should be probably individualized.

The clinical significance of sentinel lymph node micrometastasis in breast cancer

INTRODUCTION

The advent of sentinel lymph node biopsy (SLNB) and improvements in histopathological and molecular analysis have increased the rate at which micrometastases (MM) are identified. However, their significance has been the subject of much debate. In this article we review the literature concerning axillary lymph node (ALN) MM, with particular reference to SLNB. The controversies regarding histopathological assessment, clinical relevance and management implications are discussed.

METHODS

Literature review facilitated by Medline and PubMed databases.

RESULTS

Published studies have reported divergent results regarding the significance and implications of ALN MM in general and sentinel lymph node (SLN) MM 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 and distant failure. Absolute consensus regarding the optimal analytical technique for SLNs has yet to be reached, particularly concerning immunohistochemical (IHC) techniques targeting cytokeratins and the utility of contemporary molecular analysis.

CONCLUSION

SLN MM are likely to represent an incremental detriment to prognosis and increased risk of non-SLN involvement, despite only modest up-staging within current classification systems. In the absence of level-1 guidance concerning the management of women with SLN MM, each case requires discussion with regard to other tumour and patient related factors in the context of the multidisciplinary team. Randomized studies are required to evaluate the prognostic significance and optimal management of each category of tumour burden within the SLN. The identification of MM remains highly dependent on the analytical technique employed and there exists potential for stage migration and impact on management decisions.

Sentinel node procedure is warranted in ductal carcinoma in situ with high risk of occult invasive carcinoma and microinvasive carcinoma treated by mastectomy

Axillary lymph node dissection in patients with ductal carcinoma in situ (DCIS) of the breast is not warranted because DCIS has no metastatic potential. However, the risk of microinvasive carcinoma (MIC) exists in large DCIS treated by mastectomy. The aim of this series is to evaluate the incidence of lymph node metastases in DCIS and DCIS-MIC. We analyzed retrospectively patients treated in six French cancer centers for pure DCIS or DCIS-MIC. Surgical procedures were lumpectomy or mastectomy associated with an axillary sentinel node (SN) procedure. We included 161 patients suffering from pure DCIS (116/161, 72%) or DCIS-MIC (45/161, 28%). Mean age was 56 years (32-78). We observed underestimation between core biopsy and histological result in 43/142 cases (30%). These data show an association between lesion size, solid subtype, high-grade DCIS, and underestimation. Forty-eight breast conservative procedures were performed and 113 mastectomies (70%). SN procedure was performed using blue dye, technetium, or both. In our series, we selected patients with a high risk of occult invasive carcinoma: high grade (55%), mean size (27 mm), and mastectomy (112). Six SN were found positive (3.7%). In the five patients treated with complete axillary dissection, the SN was the only positive node. SN in DCIS is an interesting procedure but not necessary for all patients. We need to focus on the subgroup with or a high risk of occult MIC: extensive calcifications or palpable mass, DCIS diagnosed by core biopsy and underestimation, multifocality, high grade, large tumor size, MIC, and mastectomy.

Axillary surgery in breast cancer patients

Surgeons have routinely removed ipsilateral axillary lymph nodes from women with breast cancer for over 100 years. The procedure provides important staging information, enhances regional control of the malignancy and may improve survival. As screening of breast cancer has increased, the mean size of newly diagnosed primary invasive breast cancers has steadily decreased and so has the number of women with lymph node metastases. Recognising that the therapeutic benefit of removing normal nodes may be low, alternatives to the routine level I/II axillary lymph node dissection have been sought. A decade ago sentinel lymph node biopsy (SLNB) was introduced. Because of its high accuracy and relatively low morbidity, this technique is now widely used to identify women with histologically involved nodes prior to the formal axillary node dissection. Specifically, SLNB has allowed surgeons to avoid a formal axillary lymph node biopsy in women with histologically uninvolved sentinel nodes, while identifying women with involved sentinel nodes who derive the most benefit from a completion axillary node dissection. Despite the increasing use of SLNB for initial management of the axilla in women with breast cancer, important questions remain regarding patient selection criteria and optimal surgical methods for performing the biopsy. This article discusses the evolution of axillary node surgery for women with breast cancer.

[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.

Role of lymphadenectomy in surgical treatment of solid tumors: an update on the clinical data

BACKGROUND

The role of lymphadenectomy as an adjunct of standard excision for treatment of cancer is highly debated and controversial. Standard practice for treatment of solid tumors is resection with regional lymphadenectomy. This surgical concept assumes that cancers grow and spread in an orderly manner, from primary cancer to regional lymph nodes and finally to vital organs. We reviewed randomized trials, published a description of lymphatic anatomy and physiology, and presented data that disputed the role of lymphadenectomy as standard practice. The present review updates the literature and reiterates the concept that lymphadenectomy does not increase survival in the surgical treatment of solid tumors.

METHODS

We reviewed the English-language literature (Medline) for prospective randomized trials and nonrandomized reports, as well as retrospective studies addressing the role of lymphadenectomy in cancers of the esophagus, lung, stomach, pancreas, breast, and skin (melanoma) reported between 2000 and 2006.

RESULTS

This extensive review demonstrates that there are few prospective randomized trials assessing patient survival with solid tumors that contrast resection with or without lymphadenectomy. However, there was at least one, and for some cancers more than one, prospective randomized trial for each organ site studied, and the data demonstrate no statistically significant difference in overall survival of patients treated with or without lymphadenectomy. Most nonrandomized and retrospective studies, with a few exceptions, support the conclusions of randomized trials; lymphadenectomy does not improve overall survival in solid tumors. Overall survival is primarily a function of the biological nature of the primary tumor, as evidenced by lymphovascular invasion, lymph node involvement, and other prognostic features.

CONCLUSIONS

This extensive literature review of recent reports indicates that lymphadenectomy does not improve overall survival. Lymph node resection should be conceived in terms of staging, prognosis, and regional control only.

[Sentinel node detection applied to breast cancer: 2007 update]

The technique of detection and resection of the sentinel lymph node applied to early breast cancer management aims to spare the patient with a low risk of lymph node involvement an unnecessary axillary lymphadenectomy. This innovating technique lies on the double hypothesis of an accuracy to predict non sentinel lymph node status and to induce a lower morbidity when compared with axillary lymphadenectomy. This multidisciplinary technique depends on surgeons, nuclear physicians and pathologists. In practice sentinel lymph nodes are detected thanks to two types of tracers, the Blue and the colloids marked with technetium, harvested by the surgeon guided by the blue lymphatic channel and the use of a gamma probe detection, analyzed by the pathologist according to a particular procedure with the concept of serial slices, and possibly immuno histo chemistry. The objectives of this review are to specify the state of knowledge concerning the different steps: detection, surgical resection and the pathological analysis of the sentinels lymph nodes and to focus on validated and controversial indications, and on the main ongoing trials.

Cancer canalaire in situ du sein avec micro-invasion. Place du ganglion sentinelle

OBJECTIVES

To investigate the role of sentinel lymph node biopsy for microinvasive ductal carcinoma in situ of the breast.

PATIENTS AND METHODS

From January 2001 to January 2006, lymphatic mapping was performed using radiocolloid and/or blue dye technique. Full axillary lymph node dissection was accomplished systematically in 10 instances at the beginning of the study, and furthermore when the sentinel node was involved (macrometastatic or micrometastatic disease).

RESULTS

Identification rate was 98% (40/41), the unsuccessful procedure occurred after incisional biopsy for diagnosis. The number of sentinel nodes removed was 2 in average (1-5). Sentinel node involvement was found in 10% of cases (4/40): 1 sentinel node macrometastasis pN1, 2 sentinel node micrometastases determined by hematoxylin and eosin staining pN1 (mi), 1 sentinel node micrometastasis detected only by immunohistochemical staining pN0 (mi).

DISCUSSION AND CONCLUSION

Sentinel lymph node sampling should not be currently applied for management of every ductal carcinoma in situ of the breast but a selective utilization is proposed in documented high risk subset of patients according to clinical, mammographic, and histologic features obtained by percutaneous biopsies. Ductal carcinoma in situ (DCIS) with proved or suspected microinvasion could be scheduled for sentinel node procedure a fortiori in cases undergoing mastectomy because of extensive DCIS before the occurrence of disturbances of lymphatic drainage induced by surgical breast dissection.

What is a positive sentinel lymph node in a breast cancer patient? A practical approach

Sentinel lymph node (SN) biopsy has become increasingly used for the staging of breast carcinoma, resulting in the upstaging of this disease, and this has led to concerns with regard to what should be considered a positive SN. Factors influencing the positive staging of an SN include metastasis size, the method used for metastasis detection, the definition of metastasis and the individual pathologist. Until evidence to the contrary emerges, an SN should be considered positive if metastases (nodal involvement >0.2mm in the largest dimension) are detected in it by histology. A target size should be identified, and SNs, as the most likely sites of nodal metastases, should be searched systematically to find (nearly) all of the targeted metastases. The European guidelines for SN assessment have set two such target sizes: as a minimum, all metastases >2mm should be identified, and optimally all micrometastases should also be sought.

Sentinel lymph node biopsy in staging small (up to 15 mm) breast carcinomas. Results from a European multi-institutional study

Sentinel lymph node (SLN) biopsy has become the preferred method for the nodal staging of early breast cancer, but controversy exists regarding its universal use and consequences in small tumors. 2929 cases of breast carcinomas not larger than 15 mm and staged with SLN biopsy with or without axillary dissection were collected from the authors' institutions. The pathology of the SLNs included multilevel hematoxylin and eosin (HE) staining. Cytokeratin immunohistochemistry (IHC) was commonly used for cases negative with HE staining. Variables influencing SLN involvement and non-SLN involvement were studied with logistic regression. Factors that influenced SLN involvement included tumor size, multifocality, grade and age. Small tumors up to 4 mm (including in situ and microinvasive carcinomas) seem to have SLN involvement in less than 10%. Non-SLN metastases were associated with tumor grade, the ratio of involved SLNs and SLN involvement type. Isolated tumor cells were not likely to be associated with further nodal load, whereas micrometastases had some subsets with low risk of non-SLN involvement and subsets with higher proportion of further nodal spread. In situ and microinvasive carcinomas have a very low risk of SLN involvement, therefore, these tumors might not need SLN biopsy for staging, and this may be the approach used for very small invasive carcinomas. If an SLN is involved, isolated tumor cells are rarely if ever associated with non-SLN metastases, and subsets of micrometastatic SLN involvement may be approached similarly. With macrometastases the risk of non-SLN involvement increases, and further axillary treatment should be generally indicated.

The Utility of Intraoperative Evaluation of Sentinel Lymph Nodes in Breast Cancer

BACKGROUND

In breast cancer treatment, intraoperative sentinel lymph node (SLN) evaluation is used to identify patients who may potentially benefit from immediate completion of axillary lymph node dissection.

METHODS

Prospectively collected breast cancer registry data identified 516 SLN biopsies between January 2003 and December 2005. Intraoperative evaluation (IE) of the SLNs was performed in 479 axillae. Final pathology by hematoxylin and eosin and, for negative nodes, by immunohistochemical stains was compared with the IE result. The effect of IE and final pathology on surgical treatment was examined.

RESULTS

The sensitivities for IE of N0(i+) (n = 39), N1mi (n = 41), and N1a-3a (n = 89) metastases were 0%, 5%, and 63%, respectively. The specificity was 99.7%. IE identified 57 (44%) of SLN-positive (N1mi and N1a-3a) axillae, thus resulting in synchronous axillary lymph node dissection for those patients. Reoperation for false-negative IEs (N1mi or N1a-3a with negative IE) occurred in only 27 axillae (39%).

CONCLUSIONS

IE of SLNs has adequate sensitivity and excellent specificity. In addition to allowing patients to benefit from synchronous surgery, IE helped patients to receive care in concordance with recommended practice guidelines. The false-negative IE of SLNs highlights uncertainty with the clinical significance of axillary nodal staging when only small amounts of metastatic disease are identified in the axilla.

Maladie micrométastatique et maladie résiduelle axillaire. Exemple du cancer du sein

The knowledge of the axillary involvement is a major prognosis factor for breast cancer and an important parameter for treatment decision. Nevertheless, two recent current medical situations have occurred in breast cancer, changing our management. First, with the development of mass screening and sentinel lymph nodes biopsies, we have to take treatment decisions based upon minimal lymph node involvement, with a clinical significance still poorly understood. Second, for the large tumors, potentially with lymph node involvement, we have to deal with tumor and lymph node under staging, after induction chemotherapy. We have to learn how to evaluate accurately those new parameters to treat the best way our patients.