Complete sectioning of axillary sentinel nodes in patients with breast cancer. Analysis of two different step sectioning and immunohistochemistry protocols in 246 patients

Systematic review and meta-analysis of the prognostic impact of lymph node micrometastasis and isolated tumour cells in patients with stage I-IIIA non-small cell lung cancer

Lymph node micrometastases could be one of the reasons for the high recurrence rate after complete surgical resection in stage I-IIIA non-small cell lung cancer (NSCLC). The standard evaluation of a single haematoxylin and eosin (H&E) slide of a paraffin-embedded section of a lymph node is insufficient for the detection of micrometastases, and there is a need for additional histopathological evaluation. The association of lymph node micrometastases with survival remains as yet unresolved. The aim of this systematic review and meta-analysis is to investigate if lymph node micrometastases and isolated tumour cells in patients with stage I-IIIA NSCLC, detected with multiple sectioning and/or immunohistochemistry (IHC) and/or reverse transcriptase polymerase chain reaction (RT-PCR), are associated with overall survival (OS) and disease-free survival (DFS) after surgical resection. We performed a meta-analysis of time-to-event outcomes based on 15 articles using ancillary techniques to detect micrometastases. We extracted the OS and DFS every 3-6 months after surgery, for patients with and without occult lymph node micrometastasis, from the survival curves published in each article. These data were used to reconstruct OS and DFS for 'micrometastasis' and 'no micrometastasis' groups. Based on all included studies that used IHC, serial sectioning, or RT-PCR, we found a 5-year OS of 55% (micrometastasis) vs. 75% (no micrometastasis), and a 5-year DFS of 53% (micrometastasis) vs. 75% (no micrometastasis). Patients with stage I-IIIA NSCLC with lymph node micrometastases detected by ancillary histopathological and molecular techniques have a significantly poorer OS and DFS compared to patients without lymph node micrometastases.

Contemporary approaches to the axilla in breast cancer

Over the past decade, axillary management in breast cancer has fundamentally shifted. The former notion that any degree of axillary nodal involvement warrants axillary lymph node dissection (ALND) has been challenged. Following publication of the ACOSOG Z0011 trial, national trends demonstrated significant reductions in ALND performance. Axillary radiotherapy in lieu of ALND is a consideration for select patients with a positive sentinel lymph node, while ongoing studies are investigating the role of adjuvant regional radiotherapy in women with positive nodes prior to neoadjuvant chemotherapy. Efforts toward de-escalation of axillary surgery continue to evolve, as do the indications for sentinel node biopsy omission in select subsets of patients. This review highlights the recent advances and neoteric approaches to local therapy of the axilla in breast cancer.

Near-infrared-II ratiometric fluorescence probes for non-invasive detection and precise navigation surgery of metastatic sentinel lymph nodes

Sentinel lymph node (SLN) biopsy is the key diagnostic procedure to determine tumor metastasis and treatment plan. Current SLN biopsy has considerable drawbacks in that SLNs (both malignant and normal) must be removed by navigation surgery, followed by a time-consuming pathological examination. The selective, non-invasive, and real-time diagnosis of metastatic status in SLNs is becoming essential. Methods: Here, we design two lanthanide-doped nanoparticles as a pair of NIR-II ratiometric fluorescence probes, one of which is conjugated with tumor-targeting moiety, while the other is conjugated with PEG as an internal reference. The NIR-II ratiometric fluorescence signal (I_{1060 nm}/I_{1525 nm}) from two well-separated channels were used to identify the tumor-draining SLNs. The precise navigation surgery of metastatic SLNs was performed and we further evaluated their surgery outcomes. Results: The NIR-II ratiometric fluorescence facilitates an ideal fluorescence-guided surgery with only resection of tumor-positive SLNs, thereby avoiding unnecessary removal of the normal SLNs. In addition, our system has a time-saving operation procedure and can be performed under the operation light without altering the appearance of surgical settings. Conclusion: The present study enables non-invasive and real-time detection metastatic status in SLNs with high sensitivity and selectivity. Our investigations will provide a new direction for SLN biopsy and substantially improve cancer surgery outcomes.

Multiresolution nondestructive 3D pathology of whole lymph nodes for breast cancer staging

SIGNIFICANCE

For breast cancer patients, the extent of regional lymph node (LN) metastasis influences the decision to remove all axillary LNs. Metastases are currently identified and classified with visual analysis of a few thin tissue sections with conventional histology that may underrepresent the extent of metastases.

AIM

We sought to enable nondestructive three-dimensional (3D) pathology of human axillary LNs and to develop a practical workflow for LN staging with our method. We also sought to evaluate whether 3D pathology improves staging accuracy in comparison to two-dimensional (2D) histology.

APPROACH

We developed a method to fluorescently stain and optically clear LN specimens for comprehensive imaging with multiresolution open-top light-sheet microscopy. We present an efficient imaging and data-processing workflow for rapid evaluation of H&E-like datasets in 3D, with low-resolution screening to identify potential metastases followed by high-resolution localized imaging to confirm malignancy.

RESULTS

We simulate LN staging with 3D and 2D pathology datasets from 10 metastatic nodes, showing that 2D pathology consistently underestimates metastasis size, including instances in which 3D pathology would lead to upstaging of the metastasis with important implications on clinical treatment.

CONCLUSIONS

Our 3D pathology method may improve clinical management for breast cancer patients by improving staging accuracy of LN metastases.

[Pathological process for sentinel lymph node]

Sentinel node is defined as the first node to receive drainage from a primary tumor and seems to reflect the nodal status in the lymphatic drainage of the tumor. Sentinel node technique has modified the pathological examination of lymph nodes, with intraoperative evaluation of sentinel node, allowing immediate lymph node dissection in case of positive sentinel node, and histological ultrastratification to detect occult metastases. This is a literature review of different histological protocols of sentinel node according to different organs. Except for sentinel node in breast cancer and melanoma, intraoperative examination of sentinel node is helpful using frozen section, more sensitive than touch imprint cytology. Sentinel node should be embedded in paraffin block entirely after gross sectioning at two millimeters intervals parallel to the long axis of the node. Histological ultrastaging with serial sections can be helpful, but the number of sections and the interval between them is not codified. Three sections at 200-250 microns can identify the majority of micrometastases (<2mm and >200 microns). Systematic immunohistochemistry of sentinel node is not necessary for breast cancers, since isolated tumor cells do not modify the therapeutic strategy, but remains useful in other organs.

Lymph Node Radiotherapy Instead of Extended Axillary Surgery - the New Standard?

Breast cancer treatment has undergone major changes in the last 20 years. Specifically, the role of axillary lymph node dissection has changed from radical axillary dissection with excision of a high number of lymph nodes to sentinel lymph node biopsy (SLNB). This paradigm shift is associated with a controversial debate regarding the significance of axillary staging, the need for surgery, and the role of radiotherapy. Looking ahead, lymph node staging and axillary treatment might shift from SLNB and/or axillary dissection to ultrasound-guided needle biopsy and irradiation of regional lymph nodes in order to reduce treatment-related sequelae in early-stage breast cancer.

De-escalation of axillary surgery in early breast cancer

With the advent of sentinel lymph node biopsy, surgical methods for accurately staging the axilla in patients with early-stage breast cancer have become progressively less extensive, with formal axillary lymph node dissection confined to a dwindling group of patients. Although details of methods for sentinel lymph node biopsy have yet to be standardised, this technique is now widely practised and accepted as standard of care worldwide. In the past 5 years, attention has focused on minimisation of surgical morbidity by restricting further axillary surgery or considering radiotherapy in patients with a small tumour burden in their sentinel nodes. This change in approach to patients with positive sentinel lymph node biopsies has increased the complexity of axillary management, and any policy of de-escalation and avoidance of morbidity must not compromise patient outcomes. This trend for de-escalation has accompanied a shift in understanding of how any residual tumour burden can be adequately managed without surgical extirpation and reliance on effective adjuvant therapies. Indications for omission of completion axillary lymph node dissection in patients with two or fewer nodes containing macrometastases demand further clarification, together with the roles of preoperative imaging in defining axillary nodal burden, deselection of patients for sentinel lymph node biopsy, and provision of radiotherapy. Downstaging of biopsy-proven node-positive patients with neoadjuvant chemotherapy could safely permit sentinel lymph node biopsy alone when the index node has been successfully retrieved at surgery, while nodal deposits of any size continue to mandate completion axillary lymph node dissection. Developments in molecular imaging technologies and percutaneous biopsy techniques could potentially render sentinel lymph node biopsy redundant in the future.

Detailed Lymph Node Sectioning of Papillary Thyroid Carcinoma Specimen Increases the Number of pN1a Patients

Papillary thyroid carcinoma (PTC) is a common endocrine malignancy, frequently presenting with lymph node metastasis at the time of diagnosis. Lymph node staging (N) partly determines treatment, follow-up, and prognosis. Since 2011, our institution has employed a more comprehensive histopathological work-up of lymph nodes in patients with PTC. We sought to retrospectively determine the value of serial lymph node level sectioning in PTCs with negative preoperative lymph node status (pN0) as a method to increase the sensitivity of detecting metastatic disease. We included all patients that underwent thyroidectomy and central neck dissection and subsequent comprehensive lymph node level sectioning due to PTC with an initial pN0 status between the years 2011 and 2015 at our institution. Sixty-seven cases of PTC with a median of 10 metastatic free lymph nodes identified per case were included. After serial lymph node sectioning of the central compartment, 11 cases (16 %) revealed lymph node metastasis, six of which (55 %) presented with a small primary tumor (<20 mm, T1). Of all T1 tumors with initial pN0 status, 18 % (T1a) and 9 % (T1b) reached a pN1 stage after comprehensive lymph node sectioning. Cases with altered lymph node status had a median of 15 identified lymph nodes as compared to ten in cases that remained negative. We conclude that comprehensive lymph node sectioning increased the sensitivity of detecting metastases in PTC and altered the pathological TNM staging (pTNM) for a significant number of patients. Although of limited prognostic significance, the method should be considered as an adjunct tool when assessing lymph node status of PTC as a part of the routine histological work-up to ensure an accurate cancer staging.

What Is a False Negative Sentinel Node Biopsy: Definition, Reasons and Ways to Minimize It?

Sentinel node biopsy helps in assessing the involvement of axillary lymph node without the morbidity of full axillary lymph node dissection, namely arm and shoulder pain, paraesthesia and lymphoedema. The various methods described in the literature identify the sentinel lymph nodes in approximately 96 % of cases and associated with a false negativity rate of 5 to 10 %. A false negative sentinel node is defined as the proportion of cases in whom sentinel node biopsy is reported as negative, but the rest of axillary lymph node(s) harbours cancer cells. The possible causes of a false negative sentinel lymph node may be because of blocked lymphatics either by cancer cells or following fibrosis of previous surgery/radiotherapy, and an alternative pathway opens draining the blue dye or isotope to another uninvolved node. The other reasons may be two lymphatic pathways for a tumour area, the one opening to a superficial node and the other in deep nodes. Sometimes, lymphatics do not relay into a node but traverse it going to a higher node. In some patients, the microscopic focus of metastasis inside a lymph node is so small-micrometastasis (i.e. between 0.2 and 2 mm) or isolated tumour cells (i.e. less than 0.2 mm) that is missed by the pathologist. The purpose of this review is to clear some fears lurking in the mind of most surgeons about the false negative sentinel lymph node (FNSLN).

Internal Mammary Sentinel Node Biopsy in Breast Cancer. Is it Indicated?

Axillary sentinel node (A-SN) biopsy is a standard procedure in breast cancer surgery. Sampling of intenal mammary sentinel nodes (IM-SN) is not performed routinly, although it is also considered an important prognostic factor of breast cancer. The role of this latter procedure was investigated in cases of IM-SN visualized on lymphoscintigraphy. Between January 2001 and June 2012 1542 patients with clinically node negative operable primary breast cancer had sentinel node biopsy (SNB). Both axillary and IM-SN were sampled (whenever detected), based on lymphoscintigraphy, intraoperative gamma probe detection and blu dye mapping. Lymphoscintigraphy showed IM-SN in 83 cases. IM-SN biopsy (IM-SNB) was succesfull in 77 patients (93%). A total of 86 IM-SNs were removed. IM-SN involvement was identified in 14 cases, representing 18% of patients who underwent IM-SNB. This included macrometastases (MAC) in 5 cases, micrometastases (MIC) in 2 cases, isolated tumor cells (ITC) in 7 cases. No significant differences were found between patients with and without IM-SN involvement in terms of age, tumor location, tumor size, axillary involvement, tumor grade or estrogen receptor status. The IM-SN involvement has lead to new therapeutic indications in 2 cases (2.6%), both of them due to MAC in the IM-SN: in 1 case change in chemotherapy and in 1 case change in radiotherapy, with the addition of iradiation of the internal mammary chain. Based on this series and information from the literature, we conclude that the indication for an IM-SNB procedure is very limited and its routine use should not be recommended.

Implementation of step sectioning in the examination of sentinel lymph nodes to improve the detection of micrometastases in breast cancer patients

The object of this study was to examine whether a new protocol for examination of sentinel lymph nodes (SLNs) would lead to the detection of more metastases. Sections of 1 mm would identify most SLN macrometastases, and step sections at intervals of 200-250 μm would identify most micrometastases. A total of 111 breast cancer patients who underwent the SLN procedure at St. Olavs University Hospital in Trondheim, Norway in 2008 were included in the study group. Their SLNs were processed according to a new standardized protocol with sections of 2-3 mm being step sectioned at intervals of 200-250 μm. A total of 109 breast cancer patients undergoing the SLN procedure in 2007 were used as a reference group. Metastases were found in 29% of the cases, compared with 26% in the reference group. Step sectioning of SLNs revealed metastases in five cases initially found to be negative. The metastases of the study group were smaller, with a median value of 1.25 mm compared with 4.25 mm in the reference group. Step sectioning led to the detection of metastases in SLNs initially found to be negative. The median size of the metastases was considerably smaller in the study group than in the reference group.

Prognostic value of lymph node micrometastases in breast cancer: a multicenter cohort study

Background

To evaluate the prognostic meaning of lymph node micrometastases in breast cancer patients.

Methods

Between January 2000 and January 2003, 1411 patients with a cT_1-2N₀ invasive breast carcinoma underwent surgery in 7 hospitals in the Netherlands. Sentinel lymph node biopsy was done in all patients. Based on lymph node status, patients were divided into 4 groups: _pN₀ (n = 922), _pN_1micro (n = 103), _pN_1a (n = 285), and _pN_≥1b (n = 101). Median follow-up was 6.4 years.

Results

At the end of follow-up, 1121 women were still alive (79.4%), 184 had died (13.0%), and 106 were lost to follow-up (7.5%). Breast cancer recurred in 244 patients: distant metastasis (n = 165), locoregional relapse (n = 83), and contralateral breast cancer (n = 44). Following adjustment for possible confounding characteristics and for adjuvant systemic treatment, overall survival (OS) remained comparable for _pN₀ and _pN_1micro and was significantly worse for _pN_1a and _pN_≥1b (hazard ratio [HR] 1.18; 95% confidence interval [95% CI] 0.58–2.39, HR 2.47; 95% CI 1.69–3.63, HR 4.36; 95% CI 2.70–7.04, respectively). Disease-free survival (DFS) was similar too in the _pN₀ and _pN_1micro group, and worse for _pN_1a and _pN_≥1b (HR 0.96; 95% CI 0.56–1.67 vs HR 1.64; 95% CI 1.19–2.27, HR 2.95; CI 1.98–4.42). The distant metastases rate also did not differ significantly between the _pN₀ and _pN_1micro group and was worse for _pN_1a and _pN_≥1b (HR 1.22; 95% CI 0.60–2.49, HR 2.26; 95% CI 1.49–3.40, HR 3.49; CI 2.12–5.77).

Conclusions

In breast cancer patients survival is not affected by the presence of micrometastatic lymph node involvement.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-010-1451-z) contains supplementary material, which is available to authorized users.

Accuracy of sentinel node biopsy for breast cancer using blue dye alone

Blue dye alone (BDA), lymphoscintigraphy alone, or, a combination of the two techniques are used for sentinel node biopsy (SNB) in breast cancer. This study reviews the effectiveness of the SNB technique using BDA by measuring the node identification rate and comparing the cohort node positivity with expected rates from established nomograms. A consecutive case series was examined from the database. This included the learning experience of six surgeons. Patients with unifocal tumors estimated at less than 31 mm were eligible. The tumor and axillary nodal histology was recorded. Published data were then used to calculate and predict node positivity rates in the study according to the size and grade of the tumors. There were 332 SNB procedures from 2001 to 2008. BDA successfully identified nodes in 94.6% (314/332) of the cases. The identification rate improved with experience. In patients with invasive cancer, 28.4% (85/299) of SNB were found to be positive for metastases or micrometastases. The node identification rate and the node positivity rate were found to be within published predicted ranges for the size and grade of the study tumors. The SNB with BDA was found to be effective in identifying sentinel nodes (SLN) in breast cancer. Surgeon experience was a factor in the success of the technique. Rates of detecting metastases were consistent with internationally published data, suggesting that BDA may perform as well as other techniques in experienced hands.

Breast cancer prognosis and occult lymph node metastases, isolated tumor cells, and micrometastases

BACKGROUND

The prognostic relevance of isolated tumor cells and micrometastases in lymph nodes from patients with breast cancer has become a major issue since the introduction of the sentinel lymph node procedure. We conducted a systematic review of this issue.

METHODS

Studies published from January 1, 1977, until August 11, 2008, were identified by use of MEDLINE, EMBASE, and the Cochrane Library. A total of 58 studies (total number of patients = 297,533) were included and divided into three categories according to the method for pathological assessment of the lymph nodes: cohort studies with single-section pathological examination of axillary lymph nodes (n = 285,638 patients), occult metastases studies with retrospective examination of negative lymph nodes by step sectioning and/or immunohistochemistry (n = 7740 patients), and sentinel lymph node biopsy studies with intensified work-up of the sentinel but not of the nonsentinel lymph nodes (n = 4155 patients). We used random-effects meta-analyses to calculate pooled estimates of the relative risks (RRs) of 5- and 10-year disease recurrence and death and the multivariably corrected pooled hazard ratio (HR) of overall survival of the cohort studies.

RESULTS

In the cohort studies, the presence (vs the absence) of metastases of 2 mm or less in diameter in axillary lymph nodes was associated with poorer overall survival (pooled HR of death = 1.44, 95% confidence interval [CI] = 1.29 to 1.62). In the occult metastases studies, the presence (vs the absence) of occult metastases was associated with poorer 5-year disease-free survival (pooled RR = 1.55, 95% CI = 1.32 to 1.82) and overall survival (pooled RR = 1.45, 95% CI = 1.11 to 1.88), although these endpoints were not consistently assessed in multivariable analyses. Sentinel lymph node biopsy studies were limited by small patient groups and short follow-up.

CONCLUSION

The presence (vs the absence) of metastases of 2 mm or less in diameter in axillary lymph nodes detected on single-section examination was associated with poorer disease-free and overall survival.

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.

Comparability of different pathologic protocols in sentinel lymph node evaluation: an analysis of two step-sectioning methods for the same patients with breast cancer

CONTEXT

The pathologic protocol for sentinel lymph node evaluation has yet to be standardized. Results from previous studies are troublesome to compare because they have been conducted on different sets of subjects with cancer.

OBJECTIVE

To compare the detection of sentinel lymph node metastases by using step-sectioning methods at 20-microm and 150-microm intervals for the same patient with primary breast cancer.

DESIGN

A total of 186, initially tumor-negative sentinel lymph nodes from a group of 80 patients with breast cancer were included. For all nodes, each paraffin block was cut serially to produce a total of 10 levels: 5 consecutive levels of sections for each of the 20-microm and 150-microm intervals. The nodal findings obtained at these intervals on hematoxylin-eosin and cytokeratin slides were compared by using the McNemar test.

RESULTS

The overall detection rate for sentinel lymph node metastasis at intervals of 20 microm and 150 microm was 27.5% (22/80) and 20% (16/80), respectively. The overall agreement between the 20-microm and 150-microm sections was 82.5%. No macrometastasis was missed by either method. At the 20-microm interval, 2 cases of micrometastasis were missed, while 10 cases of isolated tumor cells were missed at the 150-microm interval. However, no statistical difference was observed for the final sentinel lymph node results with either method. (McNemar test, P = .18 for case-based results and P = .052 for nodal-based results).

CONCLUSIONS

The 20-microm and 150-microm interval step-sectioning methods produce comparable results for detection of metastatic deposits in sentinel lymph 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.

Strategies for optimizing pathologic staging of sentinel lymph nodes in breast cancer patients

Due to the extensive pathologic evaluation of the sentinel lymph node (SLN), micrometastases are frequently observed. If micrometastases are clinically relevant, the histopathologic examination of SLNs should be sensitive enough to detect them. The probability of detecting micrometastases was calculated when examining the SLN according to the current Dutch pathology protocol and strategies evaluated to optimize the chance of detection. The dimensions of 20 consecutive axillary SLNs in patients with cT1-2N0 breast cancer were measured. In a mathematical model, the probability of detecting micrometastases in a SLN was calculated. Similarly, strategies to optimize the probability of detecting micrometastases were explored. When applying the pathology guidelines, the calculated probability to detect a micrometastasis was 18% for a 200-microm micrometastasis and 69% for a 2.0-mm metastasis in a median sized SLN. To detect the smallest micrometastasis in a median-sized SLN with a 95% probability, the interval between the sections must be decreased to 200 microm, and 20 levels from both halves must be examined. Given a prognostic significance of micrometastases, our current pathology guidelines are not sensitive enough. The number of sections should be increased, while the interval between cuts should be no more than 200 microm.

Sentinel node staging for breast cancer: intraoperative molecular pathology overcomes conventional histologic sampling errors

BACKGROUND

When sentinel node dissection reveals breast cancer metastasis, completion axillary lymph node dissection is ideally performed during the same operation. Intraoperative histologic techniques have low and variable sensitivity. A new intraoperative molecular assay (GeneSearch BLN Assay; Veridex, LLC, Warren, NJ) was evaluated to determine its efficiency in identifying significant sentinel lymph node metastases (>.2 mm).

METHODS

Positive or negative BLN Assay results generated from fresh 2-mm node slabs were compared with results from conventional histologic evaluation of adjacent fixed tissue slabs.

RESULTS

In a prospective study of 416 patients at 11 clinical sites, the assay detected 98% of metastases >2 mm and 88% of metastasis greater >.2 mm, results superior to frozen section. Micrometastases were less frequently detected (57%) and assay positive results in nodes found negative by histology were rare (4%).

CONCLUSIONS

The BLN Assay is properly calibrated for use as a stand alone intraoperative molecular test.

Sentinel lymph nodes in cancer of the oral cavity: is central step-sectioning enough?

BACKGROUND

Extended histopathologic work-up has increased the detection of micrometastasis in sentinel lymph nodes in malignant melanoma and breast cancer. The aim of this study was to examine if (A) step-sectioning of the central 1000 microM at 250 microM levels with immunostaining were accurate when compared with (B) step-sectioning and immunostaining of the entire sentinel lymph node at 250 microM levels.

METHODS

Forty patients with T1/T2 cN0 oral cancer were enrolled. Three patients were excluded. In one patient no sentinel lymph node was identified. The remaining two had unidentified sentinel lymph nodes due to lymphoscintigraphic and surgical sampling error. The central 1000 microM of 147 sentinel lymph nodes were step-sectioned in 250-microm intervals and stained with hematoxylin and eosin and CK-KL1. All lymph nodes were recorded as negative or positive for macrometastases or micrometastases. After inclusion of the last patient the residual tissue of the lymph nodes was totally step-sectioned at 250-microm intervals and re-classified. The tumor deposits were divided into macrometastases and micrometastases and ITC.

RESULTS

Method (A) upstaged 17 lymph nodes and 11 patients compared with method (B), which upstaged 22 lymph nodes and 11 patients. Seven of the patients with positive lymph nodes did not change stage. However, four lymph nodes changed from micrometastases to macrometastases. One patient changed from a micrometastasis to four micrometastases. One pN2c patient with bilateral micrometastases did not change stage, but an additional ipsilateral lymph node with a micrometastasis was identified.

CONCLUSION

Larger tumor deposits and more metastases are identified by more extensive sectioning of the sentinel lymph nodes. None of the patients was false-negative due to histopathologic sampling error, but the results indicate that central step-sectioning of the central 1000 microM cannot completely be relied upon for accurate staging of the patients.

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.

Pathological Evaluation of Sentinel Lymph Nodes

The sentinel lymph nodes are the most likely site of nodal metastasis. Their focused analysis results in upstaging cancers, although the extra yield from a more intensive work-up is generally dominated by micrometastases and isolated tumor cells. Nodal staging is generally done to reflect systemic spread of solid tumors and guide treatment accordingly. However, in general, the two processes of haematogenous and lymphogenic spread are not causally interrelated, and the extrapolation from low-volume nodal involvement to systemic involvement and therapeutic consequences of this extrapolation are still under investigation.

Axillary Lymph Node Nanometastases Are Prognostic Factors for Disease-Free Survival and Metastatic Relapse in Breast Cancer Patients

PURPOSE

Early breast cancer presents with a remarkable heterogeneity of outcomes. Undetected, microscopic lymph node tumor deposits may account for a significant fraction of this prognostic diversity. Thus, we systematically evaluated the presence of lymph node tumor cell deposits<or=0.2 mm in diameter [pN0(i+), nanometastases] and analyzed their prognostic effect.

EXPERIMENTAL DESIGN

Single-institution, consecutive patients with 8 years of median follow-up (n=702) were studied. To maximize chances of detecting micrometastases and nanometastases, whole-axilla dissections were analyzed. pN0 cases (n=377) were systematically reevaluated by lymph node (n=6676) step-sectioning and anticytokeratin immunohistochemical analysis. The risk of first adverse events and of distant relapse of bona fide pN0 patients was compared with that of pN0(i+), pN1mi, and pN1 cases.

RESULTS

Minimal lymph node deposits were revealed in 13% of pN0 patients. The hazard ratio for all adverse events of pN0(i+) versus pN0(i-) was 2.51 (P=0.00019). Hazards of pN1mi and pN0(i+) cases were not significantly different. A multivariate Cox model showed a hazard ratio of 2.16 for grouped pN0(i+)/pN1mi versus pN0(i-) (P=0.0005). Crude cumulative incidence curves for metastatic relapse were also significantly different (Gray's test chi2=5.54, P=0.019).

CONCLUSION

Nanometastases are a strong risk factor for disease-free survival and for metastatic relapse. These findings support the inclusion of procedures for nanometastasis detection in tumor-node-metastasis staging.

Histopathologic Examination of the Sentinel Lymph Nodes

Sentinel lymph nodes (SLNs) are the most likely site of regional metastasis. Their step sectioning and cytokeratin immunohistochemistry (IHC) result in the upstaging of breast cancer. The heterogeneity of histologic methods is partially responsible for differences in nodal upstaging of the disease in different reports. Intraoperative assessment might be done by both frozen sections and imprint cytology; both methods have advantages and disadvantages. Several guidelines relating to the histopathology of sentinel nodes, including the recent European Working Group for Breast Screening Pathology guidelines, are briefly summarized. These latter advocate multilevel assessment of grossly or intraoperatively negative sentinel nodes with levels separated by a maximum of 1 mm and allow IHC in their assessment, although this latter method is not mandatory. Both methods of intraoperative evaluation are allowable. There are also minimum requirements for the reports on sentinel node histology. For example, the reports should include the extent of nodal involvement, the method used for their identification, and preferably the method used for investigating the sentinel nodes, even if the results are negative. These guidelines are intended to form the basis for national guidelines in European countries.

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.

Local recurrence after mastectomy for breast cancer: analysis of clinicopathological, biological and prognostic characteristics

BACKGROUND

Despite the increasing use of breast-conserving therapy, modified radical mastectomy retains an important role in primary as well as in salvage treatment of breast cancer. Nevertheless, a significant number of patients will eventually develop a local recurrence (LR).

AIMS

To identify the potential prognostic factors at the time of the first isolated LR, and to compare the expression of several parameters of the molecular biology of breast carcinomas by primary tumors and paired isolated LRs.

METHODS

We analyzed the medical records from 1,087 women who underwent mastectomy for breast cancer, out of which 98 developed LRs as the first manifestation of tumor progression. We investigated the prognostic value of various classical prognostic factors, at the time of mastectomy as well as when the diagnosis of LR was made. In addition, by using tissue microarrays and immunohistochemical techniques, we analyzed the expression of estrogen (ER), progesterone (PR) and androgen receptors (AR), ki67, p53, c-erbB-2 and apolipoprotein D in primary tumors and paired isolated LRs from a subset of patients (n = 25).

RESULTS

Patients who developed distant metastases as well as patients with local recurrent disease showed a significantly higher percentage of larger tumors, node-positive status and higher tumoral grade than patients without evidence of tumoral recurrence. Furthermore, patients with LR had a better outcome compared with those with distant metastases, although the former received less frequently adjuvant systemic therapy and/or radiotherapy. Tumor size, histological grade, ER and PR status, and a shorter disease-free interval (<12 months) were significantly associated with overall survival amongst mastectomized patients that developed isolated LR. There was a significant concordance between primary tumors and LRs regarding the expression of the following factors: ER, PR and p53. However, we were not able to demonstrate similar findings for AR, c-erbB-2 and ki67. In addition, ER, PR and p53 status in the LRs were significantly associated with a poorer overall survival.

CONCLUSIONS

Based on classical clinicopathological factors as well as on some new biological parameters we have been able to identify subgroups of mastectomized patients with LR differing in their prognosis. Thus, at the present time it would be possible to select group of patients candidates for further and individualized therapeutic strategies.

The importance of accurate pathological assessment of lymph node involvement in colorectal cancer

This review presents an up-to-date analysis of the importance of accurate pathological lymph node staging in colorectal cancer. Lymph node staging is reliant on the technique of the surgeon and the pathologist as well as methods employed in the histopathology laboratory, and is vital for determining appropriate therapy. The significance of micrometastatic nodal disease is evaluated and new techniques for pathological evaluation are discussed. Recommendations for evaluation of lymph node status in colorectal cancer are provided based on current scientific evidence, and standardization of pathological dissection and laboratory handling is advocated.

Discriminating between micrometastases and isolated tumor cells in a regional and institutional setting

The reproducibility of diagnosing isolated tumor cells (ITC) and micrometastases has been recently tested by expert breast pathologists, but might be different in a community setting. Digital images of 50 cases of low volume nodal involvement were circulated among pathologists from the Piedmont region (Italy) and from the Helios Medical Center in Berlin. Participants were asked to categorize the lesions into micrometastasis, ITC or others. The test was performed on the basis of a previous consensus statement. Kappa statistics were used for the assessment of interobserver variability. The kappa values for the consistency of categorizing cases were 0.47 and 0.57 for the regional and the institutional tests, respectively. Our study suggests that the reproducibility of diagnosing micrometastases and ITC in a community setting may reach that of experts, but is in the moderate range, and this may interfere with studies trying to solve the prognostic significance of these diagnostic categories.

The value of cytokeratin immunohistochemistry in the evaluation of axillary sentinel lymph nodes in patients with lobular breast carcinoma

BACKGROUND

Cytokeratin immunohistochemistry (IHC) reveals a higher rate of occult lymph node metastases among lobular carcinomas than among ductal breast cancers. IHC is widely used but is seldom recommended for the evaluation of sentinel lymph nodes in breast cancer patients.

OBJECTIVE

To assess the value of cytokeratin IHC for the detection of metastases in sentinel lymph nodes of patients with invasive lobular carcinoma.

METHODS

The value of IHC, the types of metastasis found by this method, and the involvement of non-sentinel lymph nodes were analysed in a multi-institutional cohort of 449 patients with lobular breast carcinoma, staged by sentinel lymph node biopsy and routine assessment of the sentinel lymph nodes by IHC when multilevel haematoxylin and eosin staining revealed no metastasis.

RESULTS

189 patients (42%) had some type of sentinel node involvement, the frequency of this increasing with increasing tumour size. IHC was needed for identification of 65 of these cases: 17 of 19 isolated tumour cells, 40 of 64 micrometastases, and 8 of 106 larger metastases were detected by this means. Non-sentinel-node involvement was noted in 66 of 161 cases undergoing axillary dissection. Although isolated tumour cells were not associated with further lymph node involvement, sentinel node positivity detected by IHC was associated with further nodal metastases in 12 of 50 cases (0.24), a proportion that is higher than previously reported for breast cancer in general.

CONCLUSIONS

IHC is recommended for the evaluation of sentinel nodes from patients with lobular breast carcinoma, as the micrometastases or larger metastases demonstrated by this method are often associated with a further metastatic nodal load.

Comprehensive examination of sentinel lymph node in breast cancer: a solution without a problem?

Although several methods have been devised to examine sentinel lymph node (SLN) specimens in breast cancer, the extent of examination and whether it should routinely include multilevel sectioning to detect micrometastases (MM) (<2.0 mm) is still debated. In this study all "positive'' SLN biopsies from 67 consecutive patients with breast carcinoma and evaluated by means of an extended protocol were reviewed. Abnormal findings included micrometastases (MM) between 0.2 and 1.0 mm (14 cases), (MM) between 1.0 and 2.0 mm (8 cases), metastases>2.0 mm (22 cases), and isolated tumor cells (ITCs) (23 cases). The likelihood of finding metastatic deposits was comparable if sections were carried out at 100-, 150-, 200-, 250-, and 500-microm intervals. No metastatic foci>2.0 mm would have been missed. 1 MM (1.1 mm focus) was missed within the 250- and 500-microm levels on hematoxylin-eosin, but not complementary cytokeratin staining. Our data show that SLN step sectioning does not add significant yield if compared to standard examination carried on initial levels, if the minimal target of 1.0 mm micrometastatic deposit is sought.

Axillary sentinel lymph nodes can be falsely positive due to iatrogenic displacement and transport of benign epithelial cells in patients with breast carcinoma

PURPOSE

Immunohistochemical (IHC) staining for cytokeratins (CK) is common practice in evaluating sentinel lymph nodes (SLNs) in patients with breast carcinoma. IHC positivity typically indicates metastasis. SLN procedures are increasingly common in patients with pure intraductal carcinoma (DCIS). Iatrogenic epithelial cell displacement and benign transport of breast epithelial cells into axillary lymph nodes are recently described phenomena. We report 25 cases in which these factors probably resulted in benign epithelial cells in axillary SLNs (ie, false positivity).

METHODS

We reviewed 25 cases of CK-positive SLNs in which the epithelial cells had histologic and IHC characteristics different from their respective patients' underlying breast carcinomas.

RESULTS

In all cases, the cytologic features of the epithelial cells in the SLNs were benign, and 22 matched those of corresponding intraductal papillomas that were involved by or were separate from the DCIS in the original cores or surgical biopsies. Fifteen cases were pure DCIS; most invasive tumors were smaller than 1.0 cm. In six carcinomas (DCIS) showing strong Her-2/neu staining, the corresponding epithelial cells in the SLNs were negative. In 13 tumors that were strongly and uniformly positive for estrogen receptor (ER), the cytokeratin-positive cells in the SLNs were negative for ER. Nineteen cases showed benign epithelial cell displacement at the biopsy site.

CONCLUSION

Epithelial cells in SLNs may result from transport of displaced cells, usually originating in intraductal papillomas. Positive immunohistochemical results in SLNs should be interpreted with extreme caution to avoid automatically concluding that such cells represent metastasis. Sentinel lymph nodes in breast carcinoma can be falsely positive.