Sentinel node micrometastasis in breast carcinoma may not be an indication for complete axillary dissection

Micrometastases in axillary lymph nodes in breast cancer, post-neoadjuvant systemic therapy

INTRODUCTION

The significance of minimal residual axillary disease, specifically micrometastases, following neoadjuvant systemic therapy (NST) remains largely unexplored. Our study aimed to elucidate the prognostic implications of micrometastases in axillary and sentinel lymph nodes following NST.

METHODS

This retrospective study analyzed primary breast cancer patients who underwent surgery after NST from September 2006 through February 2018. All patients received axillary lymph node dissection (ALND), either with or without sentinel lymph node biopsy. Recurrence-free survival (RFS)-associated variables were identified using a multivariate Cox proportional hazard model.

RESULTS

Of the 978 patients examined, 438 (44.8%) exhibited no pathologic lymph node involvement (ypN0) after NST, while 89 (9.1%) had micrometastases (ypN1mi) and 451 (46.7%) had macrometastases (ypN+). Notably, 51.1% of the patients with sentinel lymph node micrometastases (SLNmi) had additional metastases, nearly triple that of SLN-negative patients (P < 0.001), and 29.8% of SLNmi patients were upstaged with the ALND. Although ypN1mi was not associated with RFS in patients post-NST (HR, 1.02; 95% CI, 0.42-2.49; P = 0.958), SLNmi patients experienced significantly worse RFS compared to SLN-negative patients (hazard ratio [HR], 2.23; 95% confidence intervals [CI], 1.12-4.46; P = 0.023). Additional metastases in SLNmi were more prevalent in patients with larger residual breast disease greater than 20 mm, HR-positive/HER2-negative subtype, and low Ki-67 LI (< 14%).

CONCLUSIONS

SLNmi is a negative prognostic factor significantly associated with additional non-SLN metastases, while ypN1mi does not influence the prognosis compared to ypN0. Hence, additional ALND may be warranted to confirm axillary nodal status in patients with SLNmi.

Impact of Deep Learning Assistance on the Histopathologic Review of Lymph Nodes for Metastatic Breast Cancer

Supplemental Digital Content is available in the text.

Advances in the quality of whole-slide images have set the stage for the clinical use of digital images in anatomic pathology. Along with advances in computer image analysis, this raises the possibility for computer-assisted diagnostics in pathology to improve histopathologic interpretation and clinical care. To evaluate the potential impact of digital assistance on interpretation of digitized slides, we conducted a multireader multicase study utilizing our deep learning algorithm for the detection of breast cancer metastasis in lymph nodes. Six pathologists reviewed 70 digitized slides from lymph node sections in 2 reader modes, unassisted and assisted, with a wash-out period between sessions. In the assisted mode, the deep learning algorithm was used to identify and outline regions with high likelihood of containing tumor. Algorithm-assisted pathologists demonstrated higher accuracy than either the algorithm or the pathologist alone. In particular, algorithm assistance significantly increased the sensitivity of detection for micrometastases (91% vs. 83%, P=0.02). In addition, average review time per image was significantly shorter with assistance than without assistance for both micrometastases (61 vs. 116 s, P=0.002) and negative images (111 vs. 137 s, P=0.018). Lastly, pathologists were asked to provide a numeric score regarding the difficulty of each image classification. On the basis of this score, pathologists considered the image review of micrometastases to be significantly easier when interpreted with assistance (P=0.0005). Utilizing a proof of concept assistant tool, this study demonstrates the potential of a deep learning algorithm to improve pathologist accuracy and efficiency in a digital pathology workflow.

Optical Biopsy of Lymph Node Morphology using Optical Coherence Tomography

Optical diagnostic imaging techniques are increasingly being used in the clinical environment, allowing for improved screening and diagnosis while minimizing the number of invasive procedures. Diffuse optical tomography, for example, is capable of whole-breast imaging and is being developed as an alternative to traditional X-ray mammography. While this may eventually be a very effective screening method, other optical techniques are better suited for imaging on the cellular and molecular scale. Optical Coherence Tomography (OCT), for instance, is capable of high-resolution cross-sectional imaging of tissue morphology. In a manner analogous to ultrasound imaging except using optics, pulses of near-infrared light are sent into the tissue while coherence-gated reflections are measured interferometrically to form a cross-sectional image of tissue. In this paper we apply OCT techniques for the high-resolution three-dimensional visualization of lymph node morphology. We present the first reported OCT images showing detailed morphological structure and corresponding histological features of lymph nodes from a carcinogen-induced rat mammary tumor model, as well as from a human lymph node containing late stage metastatic disease. The results illustrate the potential for OCT to visualize detailed lymph node structures on the scale of micrometastases and the potential for the detection of metastatic nodal disease intraoperatively.

Tumoral load quantification of positive sentinel lymph nodes in breast cancer to predict more than two involved nodes

AIM

One-Step Nucleic Acid Amplification (OSNA) can detect isolated tumour loads in axillary lymph nodes of breast cancer patients. We investigated the predictability of the non-sentinel lymph node (SLN) metastatic involvement (MI) based on the OSNA SLN assessment in surgical invasive breast cancer.

METHODS

We studied surgical breast invasive carcinoma patients, not taking neoadjuvant chemotherapy, having SLN positive by OSNA and having received axillary lymphadenectomy. Age, basic histopathological, immunohistochemical, SLN biopsy and lymphadenectomy data were compared between patients with or without MI of more than 2 non-SLN in both univariate and multivariate analyses. The discriminating capacity of the multivariate model was characterized by the ROC AUC.

RESULTS

726 patients from 23 centers in Spain aged 55.3 ± 12.2 years were analysed. The univariate analysis comparing patients with or without MI of more than 2 non-SLN detected statistically significant differences in primary tumour size, multifocality, presence of lymphovascular infiltration, positive proliferation index with ki67, immunophenotype and logTTL (Tumour Total Load). The multivariate logistic analyses (OR (95% CI)) confirmed multifocality (2.16 (1.13-4.13), p = 0.019), lymphovascular infiltration (4.36 (2.43-7.82), p < 0.001) and logTTL (1.22 (1.10-1.35), p < 0.001) as independent predictors, and exhibit an AUC (95% CI) of 0.78 (0.72-0.83) with an overall fit (Hosmer-Lemeshow test) of 0.359. A change in the slope of both sensitivity and specificity is observed at about 10,000 copies/μL, without relevant changes in the Negative Predictive Values.

CONCLUSIONS

Using OSNA technique, the MI of more than 2 non-SLN can be reliably predicted.

Axillary Lymph Node Status in Early-Stage Breast Cancer Patients with Sentinel Node Micrometastases (0.2-2 mm)

BACKGROUND

Omission of axillary lymph node dissection (ALND) is increasingly becoming the new standard of care for patients with sentinel lymph node micrometastases (SNMMs). However, a formidable proportion of patients is afflicted with non-sentinel node (NSN) macrometastatic tumor burden.

METHODS

Over 1 decade 5,000 patients underwent sentinel node biopsies (SNB) at 2 certified breast cancer centers in Austria. All available cases of SNMM during this time period were reviewed. Clinical, tumor and lymph node parameters were analyzed using univariate and multivariate analysis to retrieve predictors for further NSN involvement.

RESULTS

We identified 216 patients with SNMMs, of whom 181 subsequently underwent ALND. Of the latter patients, 16% (n = 29/181) presented with NSN axillary metastases. ALND revealed NSN macrometastases in 10.5% (n = 19/181) of all the investigated patients, and 66% of the NSN-positive patients (n = 19/29). In 28% (n = 8/29) of the NSN-positive patients, more than 1 macrometastasis was detected. The number of removed sentinel nodes was found to be a significant predictor (p = 0.007) for NSN involvement.

CONCLUSION

In this retrospective investigation of breast cancer patients with SNMMs, a substantial proportion exhibited involvement of NSNs. Macrometastases accounted for the largest fraction of NSN tumor burden. Refraining from ALND in the face of SNMMs may entail substantial micro- and macrometastatic tumor burden in the remaining axillary lymph node basin.

Molecular and clinicopathological markers of prognosis in breast cancer

A vast body of research in breast cancer prognostication has accumulated. Yet despite this, patients within current prognostic categories may have significantly different outcomes. There is a need to more accurately divide those cancer types associated with an excellent prognosis from those requiring more aggressive therapy. Gene expression array studies have revealed the numerous molecular breast cancer subtypes that are associated with differing outcomes. Furthermore, as next generation technologies evolve and further reveal the complexities of breast cancer, it is likely that existing prognostic approaches will become progressively refined. Future prognostication in breast cancer requires a morphomolecular, multifaceted approach involving the assessment of anatomical disease extent and levels of protein, DNA and RNA expression. One of the major challenges in prognostication will be the integration of potential assays into existing clinical systems and identification of appropriate patient subgroups for analysis.

Clinical significance and management of sentinel node micrometastasis in invasive breast cancer

Axillary node status is one of the most important prognostic indicators in patients with invasive breast cancer. Sentinel node biopsy allows an exhaustive examination of the lymph node and has led to an increased detection rate of small tumor deposits. Patients with micrometastatic deposits can have nonsentinel node involvement, including macrometastatic deposits. Sentinel node micrometastases are associated with an adverse impact on disease recurrence and survival. Axillary dissection does not offer an advantage in reducing the incidence of disease recurrence or survival. However, the long-term outcomes can be improved with the use of adjuvant chemotherapy, and it would be reasonable to consider systemic treatment in these patients.

Factors predicting the non-sentinel lymph node involvement in breast cancer patients with sentinel lymph node metastases

OBJECTIVE

In a significant proportion of patients, the sentinel lymph node (SLN) is the only involved axillary node. The goal of the present study was to identify predictive factors associated with a positive SLN and with a positive non-SLN in patients in whom axillary lymph node dissection (ALND) was performed.

METHODS

Data was reviewed for patients with T1-2 invasive breast cancer who underwent SLN biopsy with or without axillary dissection in a single institution between July 2000 and May 2010. The SLNs were examined by serial sectioning and H&E staining, and by cytokeratin immunostaining in suspicious cases.

RESULTS

Of 332 patients with SLNB, 134 had SLN positivity, and 116 of them further underwent completion axillary dissection. Patients with T2 tumors (OR=3.2; 95% CI, 1.74-5.58), or tumors with lymphovascular invasion (OR=8.0; 95% CI, 4.44-14.27), or invasive ductal cancer (OR=2.92; 95% CI, 1.1-8.0) were more likely to have a positive SLN. In patients with ALND, the non-SLN involvement rates were 10%, 11.5% and 50% in patients with isolated tumor cells (ITC), micrometastasis and macrometastasis, respectively. Finding of ITC or micrometastasis in SLNs (OR=0.28; 95% CI, 0.08-0.99) or presence of extracapsular invasion (ECI) in SLN (OR=0.24; 95% CI, 0.09-0.67) were the predictive factors of not having a non-SLN metastasis in logistic regression analysis.

CONCLUSIONS

These findings suggest further axillary surgery can be best omitted in patients with micrometastasis while validation of nomograms including factors such as ECI are still needed to be studied in patients with macrometastasis.

Sentinel lymph node micrometastasis in human breast cancer: an update

INTRODUCTION

The advent of sentinel lymph node biopsy (SLNB) and advances in histopathological and molecular analysis techniques have been associated with an increase in micrometastasis (MM) detection rate. However, the clinical significance of sentinel lymph node micrometastasis (SLN MM) continues to be a subject of much debate. In this article we review the literature concerning SLN MM, with particular emphasis on the prognostic significance of SLN MM. The controversies regarding histopathological assessment, clinical relevance and management implications are also discussed.

METHODS

Literature review facilitated by Medline and PubMed databases. Cross referencing of the obtained articles was used to identify other relevant studies.

RESULTS

Published studies have reported divergent and rather conflicting results regarding the clinical significance and implications of axillary lymph node (ALN) MM in general and SLN MM in particular. Some earlier studies demonstrated no associations, however most recent studies have found SLN MM to be an indicator of poorer prognosis and to be associated with non-SLN involvement. The use of adjuvant chemotherapy and/or hormonal manipulation therapy is associated with an improved survival in patients with SLN MM. Complete ALND may be safely omitted provided that adjuvant systemic therapy recommendations are equal to patients with node-positive disease. However, optimal management of SLN MM is yet to conclude. Furthermore, the identification of MM remains largely dependent on the analytical technique employed and the use of immunohistochemistry (IHC) increases the detection rate of SLN MM. Discrepancies in the histopathological interpretation of TNM classification of SLN tumour burden do exist. Published studies were non-randomized and have significant limitations including a small sample size, limited follow-up period, and lack of standardization and reproducibility of pathological examination of the SLN.

CONCLUSION

Patients with SLN MM have a poorer prognosis than those who are SLN negative. Therapeutic recommendations regarding patients with SLN MM should be taken in the context of multidisciplinary team setting and in selected cases of SLN MM, complete ALND may be safely omitted. A better reproducibility of pathological interpretation of the TNM classification is required so that future therapeutic guidelines can be applied without confusion.

Intraoperative assessment of sentinel lymph nodes in breast cancer

Background

Sentinel lymph node biopsy (SLNB) reduces the morbidity of axillary clearance and is the standard of care for patients with clinically node-negative breast cancer. The ability to analyse the sentinel node during surgery enables a decision to be made whether to proceed to full axillary clearance during primary surgery, thus avoiding a second procedure in node-positive patients.

Methods

Current evidence for intraoperative sentinel node analysis following SLNB in breast cancer was reviewed and evaluated, based on articles obtained from a MEDLINE search using the terms ‘sentinel node’, ‘intra-operative’ and ‘breast cancer’.

Results and conclusion

Current methods for evaluating the sentinel node during surgery include cytological and histological techniques. Newer quantitative molecular assays have been the subject of much recent clinical research. Pathological techniques of intraoperative SLNB analysis such as touch imprint cytology and frozen section have a high specificity, but a lower and more variably reported sensitivity. Molecular techniques are potentially able to sample a greater proportion of the sentinel node, and could have higher sensitivity.

Recent advances in the surgical care of breast cancer patients

A tremendous improvement in every aspect of breast cancer management has occurred in the last two decades. Surgeons, once solely interested in the extipartion of the primary tumor, are now faced with the need to incorporate a great deal of information, and to manage increasingly complex tasks.

As a comprehensive assessment of all aspects of breast cancer care is beyond the scope of the present paper, the current review will point out some of these innovations, evidence some controversies, and stress the need for the surgeon to specialize in the various aspects of treatment and to be integrated into the multisciplinary breast unit team.

Sentinel lymph node biopsy in breast cancer patients undergoing skin/nipple-sparing mastectomy and immediate autologous reconstruction

Immediate breast reconstruction following mastectomy is an effective treatment for breast cancer patients. Among several implant options, a latissimus dorsi myocutaneous (LDM) flap is used mainly due to the ease and minimal invasiveness of the procedure. The role of sentinel lymph node (SLN) biopsy with total mastectomy is evolving. Since SLN biopsy is not included in health insurance coverage in the treatment of patients in Japan, it is not generally performed as a separate procedure due to its cost. The present study reviewed the results of seven patients who underwent initial-staged SLN biopsy followed by planned mastectomy and LDM flap reconstruction. Two patients with positive SLNs showed macrometastases and underwent modified radical mastectomy with immediate reconstruction. In contrast, cases showing negative results for sentinel lymph nodes underwent total mastectomy. There were no false-negative cases among the SLN biopsy-negative cases. When an SLN is found to be positive on final pathology, the patient with reconstruction by LDM flap generally requires a potentially difficult reoperation on the remaining axillary nodes. When initial SLN biopsy is generally performed as a separate procedure in Japan, it will be an effective method for screening the axilla for patients who wish to undergo LDM flap reconstruction.

Intraoperative cytologic evaluation of sentinel lymph nodes in patients with breast carcinoma by scrape preparation

Intraoperative evaluation of sentinel lymph nodes (SLNs) in patients with breast carcinoma allows surgeons to complete axillary lymph node dissection in one procedure if any SLN shows metastasis. The accuracy of intraoperative pathological diagnosis is critical for decision-making. The purpose of this study was to evaluate our rapid intraoperative cytologic diagnosis of SLN through comparing with the final surgical pathologic diagnosis of the corresponding lymph nodes. A total of 454 SLNs from 159 consecutive female patients with a preoperative diagnosis of breast carcinoma over 3-year period were included in this study. After gross examination of each bisected lymph node, a scrape preparation was prepared for each submitted lymph node and was stained by the rapid Papanicolaou method. The intraoperative cytologic diagnosis was compared with the final surgical pathologic diagnoses. The overall sensitivity of intraoperative cytology was 52.5% with specificity of 100%. There were 17 false-negative cases. Of them, six nodes had isolated tumor cells, seven nodes had micrometastasis (0.2-2 mm), and four nodes had macrometastasis (>2 mm). There were no interpretive errors identified. The size of metastasis and tumor grade appeared to be significant factors in detecting metastasis by cytology. In addition, subsequent non-SLN involvement was 9% in patients with micrometastasis versus 50% in patients with macrometastasis (P < 0.05). Our study shows that the intraoperative cytologic evaluation of SLNs in breast carcinoma is a reasonably accurate method. The majority of false-negative cases were due to micrometastasis and isolated tumor cells.

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.

The location of small tumor deposits in the SLN predicts Non-SLN macrometastases in breast cancer patients

AIMS

The extent to which the location of micrometastases (MIC) or isolated tumor cells (ITC) in sentinel lymph nodes (SLNs) is correlated with the risk of downstream metastases is still unknown. This study examined this issue and compared the impact of MIC/ITC location with other established risk factors.

METHODS

Paraffin slides of SLNs with MIC/ITC-involvement obtained from 68 breast cancer patients were evaluated for MIC/ITC location, lesion size, and various SLN morphologic features. These parameters, together with demographic data and primary tumor characteristics, were analyzed using univariate and multivariate analysis to determine their association with the presence of downstream macrometastases in Non-SLN.

RESULTS

Eighteen of 68 patients with MIC (n=37) or ITC (n=31) had Non-SLN metastases. After multivariate analysis, the location of MIC/ITC in the SLN (parenchyma vs. sinus/vessel) had the strongest association with the presence of Non-SLN macrometastases (p<0.0001), followed by the pT-category (p=0.008). Sixteen of 18 patients with parenchymal involvement but only 2 of 31 without parenchymal involvement had Non-SLN macrometastases. The metric size of the primary tumor and the estrogen receptor status were significantly associated only on univariate analysis (p=0.041, 0.034), whereas the correlation to the size classification for tumor cell deposits (MIC vs. ITC) was not significant (p=0.077).

CONCLUSIONS

The results indicate that lesion location is an important predictor of Non-SLN-macrometastases. This finding may simplify the decision for axillary treatment in patients with small tumor deposits in the SLN.

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.

The Critical Role of Axillary Ultrasound and Aspiration Biopsy in the Management of Breast Cancer Patients with Clinically Negative Axilla

BACKGROUND

Sonographic evaluation of the axilla can predict node status in a significant proportion of clinically node-negative patients. This review focuses on the value of ultrasound followed by ultrasound-guided cytology in assessing the need for sentinel node mapping and conservative versus complete axillary dissections.

DESIGN

Breast primaries from 168 sentinel node candidates were prospectively assessed for clinicopathologic variables associated with increased incidence of axillary metastases. Patients were classified accordingly, and those at a higher risk underwent ultrasound of their axillae, followed by aspiration biopsy if needed. Sentinel node mapping was performed in all low-risk patients, and in high-risk patients with normal axillary ultrasounds or negative cytology. Final axillary status was compared in terms of nodal stage, number of positive nodes, and size of metastasis.

RESULTS

112 patients were at high risk for nodal disease (67%), with a statistically significant lower probability for remaining node-negative and a statistical significantly higher risk for having more than one positive node. All patients with more than three positive nodes were detected by ultrasound-guided cytology. High-risk patients with final positive axillae missed by ultrasound or ultrasound guided cytology had tumor deposits measuring </=5 mm.

CONCLUSION

Extent of axillary dissections can be decided based on the risk for axillary metastases: sentinel node mapping for low-risk patients; less-aggressive axillary dissections for high-risk patients with negative ultrasound and/or negative cytology; and a standard dissection for high-risk patients with positive cytology.

Size of Sentinel Node Tumor Deposits and Extent of Axillary Lymph Node Involvement: Which Breast Cancer Patients May Benefit From Less Aggressive Axillary Dissections?

BACKGROUND

In most breast cancer series, nearly 30% to 40% of all patients are sentinel node positive; however, in a large proportion of these, the disease is limited to three or fewer positive nodes. On the basis of these observations, the object of this study is to identify a subset of patients who might benefit from a less aggressive axillary dissection, without compromising staging or local disease control. We reviewed known clinicopathologic variables associated with a higher risk for axillary metastasis in 467 patients who underwent sentinel node mapping at our institution. We then compared the incidence of these variables in patients with N1a versus N2-3 stage disease.

RESULTS

Although the presence of lymphvascular invasion in the primary tumor and extracapsular extension of tumor in the sentinel node were statistically significantly different between N1a and N2-3 patients (P < .025 and P < .01, respectively), the variable that most reliably separated N1a from N2-3 patients was the size of the tumor deposits in the sentinel node (P < .001). All patients with sentinel node tumor deposits <or=5 mm had three or fewer positive nodes; 95% were sentinel node-positive only, and 91% had single-node involvement.

CONCLUSIONS

Patients at low risk for extensive axillary nonsentinel node involvement may benefit from a more conservative surgical approach to their axillae, perhaps limited to sentinel node biopsy only or to axillary procedures restricted to the group of axillary nodes in close proximity to those designated as sentinel nodes.

Pathologic examination of sentinel lymph nodes in breast cancer by a single haematoxylin-eosin slide versus serial sectioning and immunocytokeratin staining: clinical implications

BACKGROUND

The objective was to determine the additional value of pathologic examination using three-level sectioning and immunocytokeratin (ICK) staining of sentinel lymph node (SN) biopsies in cT1-2N0M0 breast carcinoma patients regarding lymph node staging and eligibility of systemic therapy taking primary tumor characteristics in account.

METHODS

SN slides of 277 patients out of a total group of 961 patients known to have tumor-positive SNs detected by three-level sectioning and ICK staining were re-examined. Haematoxylin-eosin (HE) slide level three was scanned for tumor deposits, and when present, extra capsular extension, maximum tumor diameter and number of positive SNs was noted. In addition, slides of the axillary dissection of non-SNs were reviewed, with determination of metastasis size and number of positive non-SNs. Primary tumor characteristics (grade, diameter, estrogen receptor) were recorded.

RESULTS

In the single-HE examination, 26 cases SN micrometastasis and 6 macrometastasis were missed, 3 cases of micrometastasis were incorrectly classified as isolated tumor cells, and 9 patients with macrometastasis were misclassified as micrometastasis. In addition, in the tumor-negative single-HE examination, additional axillary lymph node dissection (ALND) revealed 6 cases of non-SN metastasis. Taking primary tumor factors into account for adjuvant systemic therapy, 21 patients would have been denied the choice for systemic therapy if single-HE examination was carried out only.

CONCLUSIONS

Single-HE examination of SN may result in a reduction of locoregional and systemic treatment according to treatment guidelines then current in the Netherlands.

Ultrasound-Guided Fine-Needle Aspiration of Clinically Negative Lymph Nodes Versus Sentinel Node Mapping in Patients at High Risk for Axillary Metastasis

BACKGROUND

Sonographically directed fine-needle aspiration is a less invasive and less costly alternative to sentinel node (SN) mapping in breast cancer patients at high risk for metastatic disease but with clinically negative axillae.

METHODS

Radiographic, cytological, and histological diagnostic data on breast primary tumors from 114 consecutive SN candidates were prospectively assessed for clinicopathologic variables associated with an increased incidence of axillary metastases. Patients in whom these variables were identified underwent sonographic examination of their axillae followed by fine-needle aspiration when abnormal nodes were detected. SN mapping was performed in patients with normal axillary sonogram results or negative cytological results. Patients with positive cytological results proceeded to complete axillary dissection. Final axillary histological outcomes from patients not meeting the high-risk criteria were recorded. Additionally, a cost analysis was performed in which the costs of ultrasonography and ultrasound-guided fine-needle aspiration of the axilla were compared with those of SN mapping.

RESULTS

According to our selection criteria, a third of the patients with clinically negative axillae (37 of 114; 32%) were considered at high risk for axillary metastases. Fifty-nine percent of these patients (22 of 37) had metastatic disease on final histological analysis. Forty percent (15 of 37) of high-risk patients were spared SN mapping, with a reduction in health care costs of 20% in this patient population. Eighty-seven percent of patients not meeting high-risk criteria were SN negative.

CONCLUSIONS

This study suggests that in patients at increased risk for axillary metastases, the use of sonographic evaluation of the axilla in combination with fine-needle aspiration is not only clinically justified, but also cost-effective.

Sentinel lymph nodes in breast cancer after 10 years: rethinking basic principles

New techniques and treatments in medicine occasionally take on a life of their own. Sometimes, an idea's use is inherently obvious from the outset, sometimes not, in which case it becomes technology in search of an application. Identification of sentinel lymph nodes in breast cancer is a combination of these two options: to some extent the technique has been overused and its results overinterpreted. 10 years after the procedure's introduction and general acceptance, a few issues still deserve further discussion despite much published work on this topic. Use of sentinel-lymph-node identification has been extended to other organ systems, yet not all the lessons learned in the breast might apply to other sites. Review of the theory behind the technique and breast cancer experience to date is important. Many of the published controversies about sentinel lymph nodes in breast cancer can be resolved by consideration of the basic ideas underlying the procedure, which is the aim of this Essay.

Intraoperative touch imprint cytology for the diagnosis of sentinel lymph node metastases in breast cancer

Background

Intraoperative detection of sentinel lymph node (SLN) metastases enables the surgeon to take an immediate decision to proceed to completion axillary lymph node dissection (ALND). The aim of this study was to determine the accuracy of touch imprint cytology (TIC) for the diagnosis of SLN metastases in sentinel nodes from women with breast cancer.

Methods

Touch imprints from 235 sentinel nodes in 133 women with breast cancer were diagnosed by cytopathology and compared with definitive histopathology results. After a feasibility study, a real-time study was performed with the surgeon proceeding to ALND based on the TIC diagnosis. The clinical opinion of the operating surgeon as to whether the SLN appeared to contain metastases was recorded, as was the time taken for the result to be available.

Results

TIC detected metastases with a sensitivity of 81·1 per cent and a specificity of 100 per cent. False-negative TIC diagnoses were associated with micrometastases and lobular carcinoma. The majority of false-negative diagnoses were due to sampling rather than interpretation errors. Clinical assessment of sentinel nodes had a sensitivity of 64·3 per cent and a specificity of 87·6 per cent.

Conclusion

TIC is feasible and enables the rapid diagnosis of SLN metastases with an acceptable accuracy for clinical use in ductal carcinoma of the breast.