Sentinel lymph node biopsy: strategies for pathologic examination of the specimen

MRI Findings Suggestive of Metastatic Axillary Lymph Nodes in Patients with Invasive Breast Cancer

Purpose

This study aimed to investigate the diagnostic performance of features suggestive of nodal metastasis on preoperative MRI in patients with invasive breast cancer.

Materials and Methods

We retrospectively reviewed the preoperative breast MRI of 192 consecutive patients with surgically proven invasive breast cancer. We analyzed MRI findings of axillary lymph nodes with regard to the size, long/short ratio, cortical thickness, shape and margin of the cortex, loss of hilum, asymmetry, signal intensity (SI) on T2-weighted images (T2WI), degree of enhancement in the early phase, and enhancement kinetics. Receiver operating characteristic (ROC) analysis, chi-square test, t test, and McNemar’s test were used for statistical analysis.

Results

Increased shorter diameter, uneven cortical shape, increased cortical thickness, loss of hilum, asymmetry, irregular cortical margin, and low SI on T2WI were significantly suggestive of metastasis. ROC analysis revealed the cutoff value for the shorter diameter and cortical thickness as 8.05 mm and 2.75 mm, respectively. Increased cortical thickness (> 2.75 mm) and uneven cortical shape showed significantly higher sensitivity than other findings in McNemar’s test. Irregular cortical margins showed the highest specificity (100%).

Conclusion

Cortical thickness > 2.75 mm and uneven cortical shape are more sensitive parameters than other findings, and an irregular cortical margin is the most specific parameter for predicting axillary metastasis in patients with invasive breast cancer.

Clinical effect of the pathological axillary assessment method in breast cancer without clinical nodal metastasis

BACKGROUND

This study aimed to assess the clinical effect of the pathological axillary assessment method in breast cancer without clinical lymph node metastasis.

METHODS

Data of patients with clinically node-negative breast cancer were retrospectively reviewed. The study period was divided into early (January 2000-July 2007) and late (August 2007-December 2014) periods based on the pathological assessment method used (single-sectional and detailed multi-sectional lymph node processing). In the late period, lymph nodes were evaluated at six levels including immunohistochemistry on each 1.5-2 mm interval section. The axillary diagnostic accuracy and role of chemotherapy were assessed.

RESULTS

In 1698 patients, 27 isolated tumor cells (ITCs), 39 micrometastases, and 205 macrometastases were noted. The sensitivity for pathological N0 diagnosis was dependent on clinical T stage, Tis (97.8%), T1 (83.0%), T2 (74.2%), T3 (54.5%), and T4 (63.6%). ITCs and micrometastases were detected only in the late period, and 84.7% and 91.6% of cases in the early and late period, respectively, did not have macrometastases. The 5-year disease-free interval (DFI) rates were 95.2% in node-negative cases, 98.4% in ITCs/micrometastases, and 91.4% in macrometastases (P < 0.001). In multivariate analysis, the predictor for DFI was estrogen receptor negativity (P = 0.013). Chemotherapy did not improve DFI in patients with node-positive breast cancer.

CONCLUSIONS

The detailed multi-sectional pathological assessment of axillary lymph nodes detected ITCs and micrometastases. Implementation of chemotherapy should not be based on the minimal nodal metastasis and this type of serially nodal sectioned processing had little clinical significance.

[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.

Analysis of Metastatic Involvement of Interpectoral (Rotter's) Lymph Nodes Related to Tumor Location, Size, Grade and Hormone Receptor Status in Breast Cancer

Aims and background

This study was aimed at analyzing metastatic involvement in interpectoral (Rotter's) lymph nodes in relation to tumor location, size, grade and hormone receptor status in primary breast cancer.

Methods

The study included 172 female patients undergoing surgery for breast cancer at the University Hospital for Tumors, Zagreb, Croatia from November 2001 to August 2003. In addition to the standard surgical procedure, interpectoral (Rotter's) lymph nodes were removed in all of the patients. Serum levels of the tumor marker CA 15-3 were determined before surgery and hormone receptor status after surgery.

Results

Rotter's lymph nodes were identified in 67% of the patients, with metastatic involvement being found in 20% of the Rotter's nodes. Metastatic involvement of Rotter's nodes in patients with negative and positive axillary lymph nodes was 4% and 35%, respectively. When we looked at the location of the tumor in patients with metastatic involvement of Rotter's nodes, we found that tumors located in the upper quadrants were more prone to metastasis to Rotter's nodes; there was a significant positive correlation between tumor location and positive Rotter's nodes (r = 0.953, P = 0.012). As regards tumor size, Rotter's nodes were identified in 15%, 20% and 30% of stage T1 (<2 cm), T2 (2-5 cm) and T3 (>5 cm) tumors, respectively. Hormone receptor status showed no statistically significant difference in the expression of estrogen and progesterone receptors between patients with and those without positive Rotter's nodes. Of 35 Rotter's node-positive patients, 31.4% had elevated serum levels of CA 15-3; the level was significantly higher in Rotter's-positive patients compared to those with negative (or absent) Rotter's nodes.

Conclusions

The results show that one-fifth of breast cancer patients, or even one-third of those with positive axillary lymph nodes, are discharged with positive interpectoral lymph nodes that remain undiagnosed. As the nodes can be surgically removed without additional mutilation, exploration of Rotter's lymph nodes should be introduced into routine clinical practice.

Immunohistochemistry and Reverse Transcriptase Polymerase Chain Reaction on Sentinel Lymph Nodes can Improve the Accuracy of Nodal Staging in Breast Cancer Patients

In this study the nodal staging sensitivity of sentinel lymph node biopsy (SLNB) with detailed pathological and molecular biological examination has been investigated and compared to that of axillary lymph node dissection (ALND) with routine histological evaluation. Sentinel lymph nodes (SLNs) were removed by the dual-agent injection technique in 68 patients with primary, clinically node-negative breast cancer. Forty-seven patients had negative SLNs according to hematoxylin and eosin (H&E) staining. These H&E-negative SLNs were serially sectioned and examined at 250 μm levels by anticytokeratin immunohistochemistry (IHC). In 14 patients the SLNs were also investigated by cytokeratin 20 (CK20) reverse transcriptase polymerase chain reaction (RT-PCR). SLNB with IHC increased the node-positive rate by 26% (by 40% in tumors less than or equal to 2 cm in size (pT1) and by 9% in tumors more than 2 cm but less than or equal to 5 cm in size (pT2)). The sensitivity of SLNB with IHC was superior to that of ALND with routine histology in pT1 tumors and identical in pT2 tumors. The concordance between histology and RT-PCR was only 21%, and in two of three cases with positive histological results RT-PCR was negative. In conclusion, SLNB with detailed pathological and/or molecular biological evaluation can improve the sensitivity of regional staging. ALND can probably be abandoned in patients with pT1 SLN-negative breast cancer. Further prospective studies are required to determine the clinical significance of these detailed SLN evaluation techniques, but at present these methods are still investigational.

A pilot study to assess near infrared laparoscopy with indocyanine green (ICG) for intraoperative sentinel lymph node mapping in early colon cancer

BACKGROUND

Previous attempts at sentinel lymph node (SLN) mapping in colon cancer have been compromised by ineffective tracers and the inclusion of advanced disease. This study evaluated the feasibility of fluorescence detection of SLNs with indocyanine green (ICG) for lymphatic mapping in T1/T2 clinically staged colonic malignancy.

METHODS

Consecutive patients with clinical T1/T2 stage colon cancer underwent endoscopic peritumoral submucosal injection of indocyanine green (ICG) for fluorescence detection of SLN using a near-infrared (NIR) camera. All patients underwent laparoscopic complete mesocolic excision surgery. Detection rate and sensitivity of the NIR-ICG technique were the study endpoints.

RESULTS

Thirty patients mean age = 68 years [range = 38-80], mean BMI = 26.2 (IQR = 24.7-28.6) were studied. Mesocolic sentinel nodes (median = 3/patient) were detected by fluorescence within the standard resection field in 27/30 patients. Overall, ten patients had lymph node metastases, with one of these patients having a failed SLN procedure. Of the 27 patients with completed SLN mapping, nine patients had histologically positive lymph nodes containing malignancy. 3/9 had positive SLNs with 6 false negatives. In five of these false negative patients, tumours were larger than 35 mm with four also being T3/T4.

CONCLUSION

ICG mapping with NIR fluorescence allowed mesenteric detection of SLNs in clinical T1/T2 stage colonic cancer. CLINICALTRIALS.GOV: ID: NCT01662752.

A Wearable Goggle Navigation System for Dual-Mode Optical and Ultrasound Localization of Suspicious Lesions: Validation Studies Using Tissue-Simulating Phantoms and an Ex Vivo Human Breast Tissue Model

Surgical resection remains the primary curative treatment for many early-stage cancers, including breast cancer. The development of intraoperative guidance systems for identifying all sites of disease and improving the likelihood of complete surgical resection is an area of active ongoing research, as this can lead to a decrease in the need of subsequent additional surgical procedures. We develop a wearable goggle navigation system for dual-mode optical and ultrasound imaging of suspicious lesions. The system consists of a light source module, a monochromatic CCD camera, an ultrasound system, a Google Glass, and a host computer. It is tested in tissue-simulating phantoms and an ex vivo human breast tissue model. Our experiments demonstrate that the surgical navigation system provides useful guidance for localization and core needle biopsy of simulated tumor within the tissue-simulating phantom, as well as a core needle biopsy and subsequent excision of Indocyanine Green (ICG)—fluorescing sentinel lymph nodes. Our experiments support the contention that this wearable goggle navigation system can be potentially very useful and fully integrated by the surgeon for optimizing many aspects of oncologic surgery. Further engineering optimization and additional in vivo clinical validation work is necessary before such a surgical navigation system can be fully realized in the everyday clinical setting.

Potential applications of quantum dots in mapping sentinel lymph node and detection of micrometastases in breast carcinoma

Breast cancer cure aims at complete elimination of malignant cells and essentially requires detection and treatment of any micrometastases. Here, we present a review of the current methods in use and the potential role of the quantum dots (QDs) in detection and visualization of sentinel lymph node and micrometastases in breast cancer patients. The traditional histopathological, immunohistochemical, and reverse transcriptase polymerase chain reaction procedures being used for micrometastases detection had serious drawbacks of high false negativity, specificity variations and false positivity of the results. Photon emission fluorescence multiplexing characteristics of the quantum dots make them potentially ideal probes for studying the dynamics of cellular processes over time such as continuous tracking of cell migration, differentiation, and metastases. In breast cancer, QDs based molecular and genomic detections had an unparallel high sensitivity and specificity.

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.

Ultrastaging of colon cancer by sentinel node biopsy using fluorescence navigation with indocyanine green

PURPOSE

Lymph node status is the most important prognostic factor in colon cancer, but the role of sentinel lymph node biopsy (SLNB) as a tool for identification of micrometastatic disease and extraanatomical lymph nodes for adjuvant strategies and a tailored approach still remains unclear. Indocyanine green (ICG) fluorescence detection is a new method for SLNB allowing real-time lymphography and lymph node detection. This study was designed to evaluate the feasibility of fluorescence-guided sentinel lymph node detection in colon carcinoma.

METHODS

Twenty six patients with colon adenocarcinoma were prospectively included in this study. Intraoperatively, a peritumorous injection with a mean of 2.0 ml ICG was performed, followed by lymphatic mapping and SLNB. Clinical feasibility, detection rate, and sensitivity of the method were analyzed.

RESULTS

No adverse reactions occurred due to the injection of ICG. Overall, ICG fluorescence imaging identified 1.7 sentinel lymph node (SLN) in average in 25 out of 26 patients (detection rate, 96%). Metastatic involvement of the SLN was found in nine out of 11 nodal positive patients by conventional histopathology. The sensitivity of the method was 82% for colon carcinoma, respectively.

CONCLUSION

ICG fluorescence imaging is a new, feasible method for SLNB of colon carcinoma and enables ultrastaging with improved accuracy but with limited validity due to the small number of cases. One advantage of this technique is real-time visualization of lymphatic vessels and SLNB without radiation exposure. Further, larger series are necessary to analyze the role of fluorescence-guided SLNB for colon cancer.

Longitudinal 3.0T MRI analysis of changes in lymph node volume and apparent diffusion coefficient in an experimental animal model of metastatic and hyperplastic lymph nodes

PURPOSE

To perform a longitudinal analysis of changes in lymph node volume and apparent diffusion coefficient (ADC) in healthy, metastatic, and hyperplastic lymph nodes.

MATERIALS AND METHODS

Three groups of four female Copenhagen rats were studied. Metastasis was induced by injecting cells with a high metastatic potential in their left hind footpad. Reactive nodes were induced by injecting Complete Freund Adjuvant (CFA). Imaging was performed at baseline and at 2, 5, 8, 11, and 14 days after tumor cell injection. Finally, lymph nodes were examined histopathologically.

RESULTS

The model was highly efficient in inducing lymphadenopathy: subcutaneous cell or CFA inoculation resulted in ipsilateral metastatic or reactive popliteal lymph nodes in all rats. Metastatic nodal volumes increased exponentially from 5-7 mm(3) at baseline to 25 mm(3) at day 14, while the control node remained 5 mm(3). The hyperplastic nodes showed a rapid volume increase reaching a plateau at day 6. The ADC of metastatic nodes significantly decreased (range 13%-32%), but this decrease was also seen in reactive nodes.

CONCLUSION

Metastatic and hyperplastic lymph nodes differed in terms of enlargement patterns and ADC changes. Enlarged reactive or malignant nodes could not be differentiated based on their ADC values.

Sentinel node biopsy by indocyanine green retention fluorescence detection for inguinal lymph node staging of anal cancer: preliminary experience

BACKGROUND

There is some evidence that sentinel lymph node (SLN) biopsy guided by dye injection and/or radioisotopes can improve staging of inguinal lymph nodes (LNs) in anal cancer. This study was performed to investigate the feasibility of fluorescence detection of SLN and lymphatic mapping in anal cancer.

METHODS

Twelve patients with anal cancer without evidence for inguinal LN involvement were included in the study. Intraoperatively, all patients received a peritumorous injection of 25 mg indocyanine green (ICG) for fluorescence imaging of the SLN with a near-infrared camera. For comparison, conventional SLN detection by technetium-(99)m-sulfur radiocolloid injection in combination with blue dye was also performed in all patients. The results of both techniques and the effect on the therapeutic regimen were analyzed.

RESULTS

Overall, ICG fluorescence imaging identified at least one SLN in 10 of 12 patients (detection rate, 83%). With the combination of radionuclide and blue dye, SLN were detected in 9 of 12 patients (detection rate, 75%). Metastatic involvement of the SLN was found in 2 of 10 patients versus 2 of 9 patients. Patients with metastatic involvement of the SLN received extended radiation field with inguinal boost.

CONCLUSIONS

ICG fluorescence imaging allows intraoperative lymphatic mapping and transcutaneous SLN detection for selective biopsy of inguinal SLN in anal cancer. This technique should be further evaluated in comparative studies with larger patient numbers.

ICG fluorescence-guided sentinel node biopsy for axillary nodal staging in breast cancer

BACKGROUND

Sentinel lymph node (SLN) biopsy is a selective approach to axillary staging of breast cancer with reduced morbidity. Current detection methods including radioisotope and blue dye show good results but some drawbacks are remaining. Indocyanine green (ICG) fluorescence detection was evaluated as a new method for SLN biopsy in breast cancer allowing both transcutaneous visualization of lymphatic vessels and intraoperative identification of SLN.

METHODS

Forty-three women with clinically node negative breast cancer received subareolar injection of ICG for fluorescence detection of SLN. All patients underwent either planned axillary lymph node dissection (ALND) with SLN biopsy or selective SLN biopsy to determine need for ALND. Clinical feasibility, detection rate, sensitivity, and axillary recurrence after isolated SLN biopsy were analyzed.

RESULTS

Overall ICG fluorescence imaging identified 2.0 SLN in average in 42 of 43 patients (detection rate: 97.7%). Metastatic involvement of the SLN was found in 17 of 18 nodal positive patients by conventional histopathology (sensitivity: 94.4%). Immunohistochemistry revealed isolated tumor cells in five further cases. There was only one false-negative case in 43 patients (5.6%). In 17 of 23 overall nodal positive patients, the SLN was the only positive lymph node. After a median follow-up of 4.7 years none of the patients presented with axillary recurrence.

CONCLUSION

ICG fluorescence imaging is a new method for SLN biopsy in breast cancer with acceptable sensitivity and specificity comparable to conventional methods. One advantage of this technique is that it allows transcutaneous visualization of lymphatic vessels and intraoperative lymph node detection without radioisotope.

Sentinel lymph node biopsy in breast cancer guided by indocyanine green fluorescence

BACKGROUND

Sentinel lymph node (SLN) biopsy with radioisotope and blue dye has been used successfully for axillary staging in breast cancer. This study evaluated the feasibility of fluorescence detection of SLNs with indocyanine green (ICG) for lymphatic mapping and SLN biopsy.

METHODS

Thirty women with breast cancer had a periareolar injection of ICG for fluorescence detection of SLN using a near-infrared camera. Twenty also received (99m)Tc-labelled sulphur radiocolloid for SLN scintigraphy. All patients underwent axillary lymph node dissection. Detection rate and sensitivity of both methods were the study endpoints.

RESULTS

Visualization of lymphatic vessels by fluorescence detection depended on the dose of ICG. ICG imaging identified SLNs in 29 of 30 women (detection rate 97 per cent). Nineteen of 21 patients had metastatic SLN involvement (sensitivity 90 per cent) with false-negative results in two. Among the 20 patients who had both methods, ICG fluorescence and radiocolloid identified SLNs in 20 and 17 patients respectively. Metastatic lymph nodes were diagnosed in 12 and ten of 13 patients (sensitivity 92 and 77 per cent). False-negative rates were 8 and 23 per cent respectively.

CONCLUSION

ICG fluorescence allowed transcutaneous imaging of lymphatic vessels and SLN detection, thus combining the advantages of radioisotope and blue dye methods.

Identification and biologic significance of micrometastases in axillary lymph nodes in patients with invasive breast cancer

CONTEXT

The presence or absence of metastases in axillary lymph nodes is one of the most important prognostic factors for patients with breast cancer. During the past decade sentinel lymph node (SLN) biopsy has been increasingly adopted as a minimally invasive staging alternative to complete axillary node dissection.

OBJECTIVE

Sentinel lymph nodes are more likely to contain metastases than non-SLNs. In routine clinical practice SLNs are assessed by diverse methodologies including multiple sectioning, immunohistochemical staining, and molecular diagnostic tests. Despite the lack of standard histopathologic protocols during the years detailed evaluation of SLNs has resulted in an increased detection of small (micro) metastases.

DATA SOURCES

Breast cancer with micrometastases constitutes a heterogenous group of tumors with variable clinical outcome regarding the risk of additional metastases in the remaining axillary lymph nodes and to patients' survival.

CONCLUSION

The clinical significance of micrometastases has been subject to great controversy in patients with breast cancer. In this review we highlight controversies regarding micrometastases especially in relation to SLNs.

Technique and clinical consequences of sentinel lymph node biopsy in colorectal cancer

Sentinel lymph node biopsy (SLNB) in colorectal cancer (CRC) is a controversial issue. Different detection techniques, various protocols for the histopathological work-up of the SLN and a greatly differing experience between the investigators make the comparison of the available studies problematic. Nevertheless, it is clear, that the successful clinical application of SLNB in breast cancer and melanoma cannot simply be transferred into colorectal cancer treatment. In this paper we try to define the current status of clinical application of this technique in CRC by means of a literature review and our own experience. Moreover, the background and the potential clinical implications of additionally small tumor deposits in the SLN (so-called "upstaging") is critically reviewed. Summarizing the results, it is clear, that the value of SLNB in CRC is still unclear. If current techniques are to be applied outside a study protocol and no patient selection is performed the correct identification of macrometastases needs further investigation. Although still under debate, there is otherwise growing evidence, that -at least if RT-PCR-techniques are used- the detection of small tumor deposits in the SLN may be of prognostic and therefore clinical value. Future studies should focus on two subjects: First, alternative detection techniques and careful patient selection may clarify, if an improvement of the sensitivity to detect macrometastases is feasible. Second, large prospective trials using a standardized histopathological lymph node assessment should compare SLN and Non-SLN for its incidence to bear small tumor deposits. If SLNB proves to be sensitive, the prognostic and predictive value of these additional findings should be clarified.

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.

Presence of mature DC-Lamp+ dendritic cells in sentinel and non-sentinel lymph nodes of breast cancer patients

AIM

Our study examined differences in the presence of mature, DC-Lamp+ DC in the SLN and non-SLN according to the extent of metastatic involvement.

PATIENTS AND METHODS

Paraffin blocks of the SLN and non-SLN from patients with primary breast cancer who had undergone SLN biopsy and axillary dissection were separated into three groups: (Group A) no tumor cell involvement in the SLN and non-SLN; (Group B) isolated tumor cells or micrometastases in the SLN, and tumor cell-free non-SLN; and (Group C) macrometastases in the SLN. One section of all the SLN and non-SLN was examined with immunohistochemistry using an anti-DC-Lamp-antibody. The densest area occupied by the DC-Lamp+ cells on each slide was quantified and recorded by an electronic imaging system. In this regard, the SLN and non-SLN were compared within the patients of each group using the Wilcoxon signed rank-test (p<0.05).

RESULTS

One hundred and fourteen SLN and 1258 non-SLN from 79 patients were examined. A significantly larger area was occupied by the DC-Lamp(+) cells in the SLN compared to the non-SLN in Groups A (p=0.024) and B (p=0.009), whereas no significant difference was found within Group C (p=0.107).

CONCLUSIONS

This study suggests that the DC-dependent immune response is altered during the process of metastasis formation and is primarily activated before and during formation of micrometastasis.

Sentinel node biopsy: interpretation and management of patients with immunohistochemistry-positive sentinel nodes and those with micrometastases

The sentinel node procedure is an adequate tool to identify lymph node metastasis in breast cancer. Sentinel nodes are generally examined with greater attention mainly to exclude, as reliably as possible, lymph node metastasis. To achieve this, many protocols are used, resulting in different rates of micrometastasis or isolated tumor cells encountered. Since the prognostic significance of isolated tumor cells or micrometastasis in the sentinel nodes, and the risk of further axillary lymph node involvement in patients with isolated tumor cells, is uncertain and at most limited, these findings may pose difficulties for clinicians in clinical decision making. Protocols that identify lymph node metastasis, from which the clinical relevance is known, are warranted. Unnecessary lymph node dissections should be avoided.

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.

Sentinel lymph node biopsy in colon cancer: a prospective multicenter trial

INTRODUCTION

The clinical impact of sentinel lymph node biopsy (SLNB) in colon cancer is still controversial. The purpose of this prospective multicenter trial was to evaluate its clinical value to predict the nodal status and identify factors that influence these results.

METHODS

Colon cancer patients without prior colorectal surgery or irradiation were eligible. The sentinel lymph node (SLN) was identified intraoperatively by subserosal blue dye injection around the tumor. The SLN underwent step sections and immunohistochemistry (IHC), if classified free of metastases after routine hematoxylin and eosin examination.

RESULTS

At least one SLN (median, n = 2) was identified in 268 of 315 enrolled patients (detection rate, 85%). Center experience, lymphovascular invasion, body mass index (BMI), and learning curve were positively associated with the detection rate. The false-negative rate to identify pN+ patients by SLNB was 46% (38 of 82). BMI showed a significant association to the false-negative rate (P < 0.0001), the number of tumor-involved lymph nodes was inversely associated. If only slim patients (BMI < or =24) were investigated in experienced centers (>22 patients enrolled), the sensitivity increased to 88% (14 of 16). Moreover, 21% (30 of 141) of the patients, classified as pN0 by routine histopathology, revealed micrometastases or isolated tumor cells (MM/ITC) in the SLN.

CONCLUSIONS

The contribution of SLNB to conventional nodal staging of colon cancer patients is still unspecified. Technical problems have to be resolved before a definite conclusion can be drawn in this regard. However, SLNB identifies about one fourth of stage II patients to reveal MM/ITC in lymph nodes. Further studies must clarify the clinical impact of these findings in terms of prognosis and the indication of adjuvant therapy.

Efficacy of different technical procedures for sentinel lymph node biopsy in gastric cancer staging

BACKGROUND

The clinical impact of sentinel lymph node biopsy (SLNB) in gastric cancer is controversial. We performed a prospective trial to compare different methods: radiocolloid method (RM), dye method (DM), and both methods simultaneously (dual method, or DUM) for reliability and therapeutic consequences.

METHODS

RM and DM were applied in 35 gastric cancer patients. After endoscopic peritumoral injection of (99m)Tc-colloid and Patent Blue V, the positions of all blue sentinel lymph nodes (SLNs) were recorded, and the SLNs microscopically examined by hematoxylin and eosin, step sections, and immunohistochemistry.

RESULTS

RM, DM, and DUM identified the SLNs in 34 (97%) of 35 patients. The sensitivity for the prediction of positive lymph node status for RM was 22 (92%) of 24, for DM 16 (66%) of 24, and for DUM 22 (92%) of 24. In 7 of 17 (RM), 5 of 15 (DM), and 7 of 17 (DUM) patients classified as N0 by routine hematoxylin and eosin staining, micrometastases or isolated tumor cells were found in the SLN (upstaging) after focused examination. If only a limited lymph node dissection of the SLN basins would have been performed in patients, residual lymph node metastases were left in 9 of 24 (RM), in 7 of 34 (DM), and in 5 of 24 (DUM) of patients with node-positive disease.

CONCLUSIONS

Use of RM was superior. DUM did not further increase the sensitivity. A limited lymph node dissection-i.e., lymphatic basin in patients with SLN-positive disease-is associated with a high risk of residual metastases. Patients with negative SLNs may be selected for a limited surgical procedure if they meet certain criteria.

Impact of Patient- and Disease-Specific Factors on SLNB in Breast Cancer Patients. Are Current Guidelines Justified?

BACKGROUND

The evidence on which to base guidelines for sentinel lymph node biopsy (SLNB) in breast cancer is still limited. In order to facilitate the further implementation of renewed guidelines, we evaluated patient- and disease-specific factors for their impact on the results of SLNB.

MATERIALS AND METHODS

Prospective data acquisition from patients undergoing surgery for primary invasive breast cancer was performed. All patients underwent SLNB using the radiocolloid or the combined technique. The association of patient- and disease-specific factors to detection rate and false-negative rate was calculated using univariate and multivariate analyses (P < 0.05 considered as significant). Calculation of the false-negative rate was based on patients who underwent a backup axillary dissection.

RESULTS

Among 455 consecutively enrolled patients, a significant inverse association to the detection rate was found for extracapsular extension of non-SLN metastases, body mass index (BMI), number of involved lymph nodes, pT category, tumor size, and age. A significant association to the false-negative rate to identify macrometastases was found for pT category, tumor size, and grading. Other factors, such as prior surgery, multicentric tumor growth, or vascular invasion, showed no influence. A cut-point analysis revealed that a tumor size of 2 cm separated the collective of patients with the highest significance in regard to the false-negative rate (9% vs. 25%).

CONCLUSION

Our results indicate that SLNB can be safely used in elderly and obese patients with multicentric tumors and those having undergone prior surgery for benign breast disease. However, the method should be applied with caution in patients with tumors larger than 2 cm.

[Minimal residual tumor in gastrointestinal carcinoma. Relevance to prognosis and oncologic surgical consequences]

Isolated tumor cells as a consequence of minimal residual disease are often not detectable by routine diagnostic procedures. However, before or after surgery, isolated tumor cells in lymph nodes, the peritoneal cavity, blood, or bone marrow can frequently be identified by immunohistochemical or molecular methods. Failure to reveal the presence of such cells results in under-staging of tumor patients and may constitute the source of unexpected tumor recurrence after radical surgery. These facts emphasize the importance of isolated tumor cells at least as a surrogate marker. The frequency of appearance of isolated tumor cells in different organ systems also depends on the type of primary tumor. Developments in modern detection methods have led to increasing sensitivity but at the expense of specificity. Isolated tumor cells demonstrate remarkable heterogeneity with respect to proliferative potential and tumorigenicity. This characteristic is also reflected by a striking variability in the expression of various genes conditioning the aforementioned biological behavior. Unfortunately there is also remarkable heterogeneity in methods used for sampling and processing patient material as well as for the enrichment and detection of isolated tumor cells. Despite the ongoing controversies concerning detection methods and biological significance of isolated tumor cells, several clinical trials providing data supporting the prognostic relevance of minimal residual disease should also be considered for gastrointestinal carcinoma. In future this finding should be integrated in the planning of trials in surgical oncology, and "minimal residual disease" should receive stronger attention as a stratification criterion in such clinical studies.

Detection of lymph node micrometastases and isolated tumor cells in sentinel and nonsentinel lymph nodes of colon cancer patients

About 20% to 30% of colon cancer patients classified as node negative by routine hematoxylin-eosin (H&E) staining are found to have micrometastases (MM) or isolated tumor cells (ITC) in sentinel lymph nodes (SLNs) if analyzed by step sections and immunohistochemistry (IHC). Whether SLNs are in this respect representative for all lymph nodes was addressed in this study. SLNs were identified using the intraoperative blue dye detection technique. If all lymph nodes (SLNs and non-SLNs) of a patient were negative by routine H&E staining, they were step-sectioned and analyzed by IHC using pancytokeratin antibodies. We identified at least one SLN in 47 of the 55 patients (85%) and examined a median of 26 lymph nodes per patient (range 10-59). By routine H&E staining, 14 of the 47 patients showed lymph node metastases (30%); the remaining 33 were classified as node-negative. In this group (33 patients), 1011 lymph nodes were analyzed by step sections and IHC: 14 of 70 SLNs. (20%) but only 37 of 941 non-SLNs (4%) had MM/ITC (p < 0.001). Furthermore, 13 of the 33 H&E-negative patients were found to have MM/ITC (39%). In 11 of the 13 patients, MM/ITC were identified in both SLNs and non-SLNs in 1 patient in the SLN only, and in 1 patient in a non-SLN only (sensitivity for the identification of MM/ITC: 92%; negative predictive value: 95%). The SLN biopsy is a valid tool to detect, as well as exclude, the presence of MM/ITC in colon cancer patients. Our results may be of prognostic relevance and influence patient stratification for adjuvant therapy trials.

The value of immunohistochemistry in sentinel lymph node histopathology in breast cancer

The optimal protocol for the histopathological examination of sentinel lymph nodes (SLNs) in breast cancer has not been determined. The value of more detailed examination using immunohistochemistry (IHC) is controversial. A total of 476 SLNs from 216 patients were reviewed. Sentinel lymph nodes were sectioned at three levels at 100 μm intervals and stained with haematoxylin and eosin (H&E). If the H&E sections showed no evidence of metastasis, then the three serial sections were stained with a murine monoclonal anti-cytokeratin antibody (CAM 5.2). Metastatic deposits were classified as macrometastasis (>2.0 mm), micrometastasis (0.2–2.0 mm) or isolated tumour cells (ITC, <0.2 mm). Of the 216 patients, 56 (26%) had metastasis as identified by H&E. Immunohistochemistry detected metastatic deposits in a further nine patients (4%), of whom four (2%) had micrometastasis and five (2%) had ITC only. Those cases with micrometastases were all, on review, visible on the H&E sections. Immunohistochemistry detects only a small proportion of metastasis in SLNs. All metastatic deposits identified by IHC were either micrometastasis or ITC. Until the prognostic significance of these deposits has been determined, IHC may be of limited value in the histopathological examination of SLNs.

[Optimization of staging in colon cancer using sentinel lymph node biopsy]

Routine determination of the nodal status in colon cancer is strongly dependent on the individual quality and technique of histopathological assessment and surgical lymph node dissection. We evaluated whether sentinel lymph node biopsy (SLNB) could contribute to an improvement in staging. At least one SLN (median n=2) was detected (detection rate 84%) in each of 38 of 45 patients with primary colon cancer. Ten of these 38 were found to have lymph node metastases by HE staining (26%), six of them in the SLN. Nine of the 28 patients that were initially nodal-negative by HE revealed one micrometastasis and eight cases of isolated tumor cells by immunohistochemical (IHC) staining (32% upstaging response). Including the IHC-positive cases, 19 of the 38 patients were nodal-positive (50%), 15 of them with tumor-infiltrated SLN (overall sensitivity of SLNB 79%). Using the dye method, SLNB is clinically practicable and leads in the majority of the patients to the detection of SLN. The selective, intensified histopathological assessment of SLN identifies small tumor cell deposits in a relevant percentage of patients with little and clinically practicable effort.

Alternative Lymphatic Pathway After Previous Axillary Node Dissection in Recurrent/Primary Breast Cancer

OBJECTIVES

The sentinel lymph node approach has almost become the standard procedure of choice in the management of patients with early breast cancer. The status of sentinel nodes, whether or not pathologically involved by cancer cells, represents those of the axillary nodes with a negative predictive value of almost 100%. If the axillary lymphatic nodal drainage is altered, alternative lymphatic pathways and accordingly sentinel node location will be changed.

METHODS

In this article, 4 patients are presented, 3 with recurrent breast cancer who had already undergone lumpectomy, axillary node dissection, and radiotherapy in the past and 1 with primary breast cancer after surgical removal of a malignant melanoma on her back and had axillary node dissection on the same side as the breast cancer. These patients underwent lymphoscintigraphy followed by sentinel node localization using the gamma probe and also blue dye injection during surgery.

RESULTS

All patients showed alternate lymphatic pathways, 1 had an ipsilateral internal mammary node and crossed lymphatics to a contralateral axillary node, 2 had intramammary sentinel nodes, and 1 had an internal mammary on the same side. Pathologic examination of the intramammary and contralateral sentinel nodes were negative for metastases. Internal mammary sentinel nodes were not biopsied.

CONCLUSION

We feel that sentinel node lymphoscintigraphy should be done even in patients who have altered lymphatic pathways resulting from previous axillary node dissection. It allows identifying and biopsy of the sentinel node at its new unpredicted location.

Sentinel Lymph Node Biopsy or Detection of Micrometastasis in Bone Marrow: Which Might Be an Alternative to Axillary Lymph Node Dissection in Breast Cancer Patients?

Axillary lymph node status has limited prognostic significance in breast cancer patients and much improvement can be made. Sentinel lymph node biopsy is emerging as an alternative to axillary lymph node dissection for staging, but its prognostic relevance is still uncertain. Detection of micrometastases in sentinel nodes and bone marrow may provide more information, but the clinical significance still needs to be confirmed by ongoing large trials. In this review, we focus on the possibility of sentinel lymph node biopsy or detection of bone marrow micrometastasis replacing traditional axillary lymph node dissection.

Refined staging by sentinel lymph node biopsy to individualize therapy in anal cancer

We evaluated the feasibility of the sentinel lymph node technique to refine staging and potentially individualize therapy for anal cancer. Seventeen patients with cancer of the anal canal underwent peritumoral injection of 99mTc-colloid, followed 17 hours later by lymphoscintigraphy. A selective lymph node biopsy (SLNB) was attempted in 12 of 13 cases with scintigraphically detected SLNs. Lymph node metastases were present in 5 of 12 cases (42%); in 2 of these 5 cases, micrometastases were detected only by immunohistochemical staining. Hence, SLNB refines the diagnostic workup for anal cancer and provides an accurate basis for individualized therapy.

Sentinel lymph node biopsy in rectal cancer--not yet ready for routine clinical use

BACKGROUND

The value of sentinel node biopsy in visceral cancers is uncertain. We evaluated the feasibility and utility of radiocolloid lymphatic mapping and selective lymph node sampling in patients with rectal cancer.

METHODS

Forty-eight patients with rectal cancer were investigated. Thirty-seven patients had already undergone preoperative radiochemotherapy for locally advanced tumors. Eleven patients underwent primary surgery. An endoscopic injection of 1 mL technetium 99m-sulfur-colloid into the peritumoral submucosa was performed 15 to 17 hours before surgery. Ex vivo identification of the nuclide-enriched "sentinel lymph nodes" (SLNs) was performed using a hand-held gamma-probe. The selected SLNs were then carefully and systematically examined using serial sections and immunohistochemistry.

RESULTS

One or more SLNs were found in 46 of the 48 patients. The SLN detection rate was 96%. Sixteen of the 48 patients had lymph node metastases (35%). In 7 of the 16 patients, the SLNs correctly represented the nodal status. In 9 of the 16 patients, the SLN was tumor-free whereas non-SLN harbored metastases. This result represents a sensitivity of only 44%, and a false-negative rate of 56%. Further analysis showed that the method correctly predicted the nodal status only in the small subgroup of 5 patients with early cancer without preoperative radiation. In 4 patients, juxtaregional lymph nodes were excised on the basis of intraoperative radiocolloid detection, leading to upward staging in 1 patient.

CONCLUSIONS

Sentinel lymph node biopsy using the radiocolloid technique with ex vivo lymph node identification shows a relatively high detection rate; however, the sensitivity in patients with locally advanced/irradiated rectal cancer is low. Nevertheless, the detection of juxtaregional metastases can improve staging in some patients. Further studies should focus on patients with early rectal cancers where the data were more promising.

A model for determining the optimum histology of sentinel lymph nodes in breast cancer

AIMS

To create and use a geometrical model for sentinel lymph node (SLN) histopathology in breast cancer.

METHODS

The model involves a spherical metastasis randomly situated in an SLN. Two extreme situations are taken as the starting points. In one of these, the metastasis is seen in its largest dimension, whereas in the other it is only just visible, approximating 0 mm in size. Intermediate positions are analysed, with different metastasis sizes and different distances between the levels assessed by histology.

RESULTS

The findings suggest that sections taken 1 mm apart afford a reasonable means of identifying almost all metastases measuring > 2 mm (referred to as macrometastases here). For nearly all micrometastases to be identified correctly according to the current TNM definitions (that is, metastases > 0.2 mm), a step sectioning protocol with levels of 250 microm or 200 microm would be adequate.

CONCLUSIONS

SLNs are the most likely sites of nodal metastasis. Macrometastases are of recognised prognostic relevance so that all should be identified, preferably correctly as macrometastases; an assessment of levels 1 mm apart appears satisfactory and sufficient for this aim. SLNs also offer an ideal method for the study of the significance of micrometastases; for this, step sections separated by 200 or 250 microm are a good choice.

La technique du ganglion sentinelle et ses applications cliniques

INTRODUCTION

The sentinel lymph node (SLN) procedure consists of finding the first lymph node encountered by lymphatic vessels draining a tumor. This technique identifies the SLN histological status, which is representative of all the other draining area lymph nodes' status.

EXEGESIS

SLN identification requires the injection of a lymphatic tracer, which could be either a blue dye or radiolabeled particles, or both. Performing a lymphoscintigraphy, which identifies and quantitates SLNs is a possibility provided by the use of radiolabeled particles before a gamma probe guided search is performed intraoperatively. Finally, a specific histopathological methodology involving serial sections of the entire SLN and immunohistochemistry is also required.

CONCLUSION

This technique is applicable to melanoma in which the SLN status might be a stronger prognostic factor than Breslow's thickness; to breast cancer in order to avoid full axillary lymph node dissection in patients with small tumors; and potentially to other carcinomas.

Is it necessary to perform prospective randomized studies before sentinel node biopsy can replace routine axillary dissection?

BACKGROUND AND METHODS

Sentinel lymph node (SLN) biopsy is a useful way of assessing axillary nodal status in breast cancer patients. Recently, several surgeons have begun to abandon routine axillary dissection on the basis of negative SLN biopsy results. However, there is no long-term data comparing outcomes of SLN biopsy alone with those of axillary dissection. This paper reviews and discusses the significance of ongoing prospective randomized clinical trials aiming at the elimination of axillary dissection.

RESULTS

SLN biopsy is known to have a false-negative rate. It can thus be assumed that SLN biopsy alone may fail to remove the disease completely from the axilla in some patients. As a result, it is not known whether SLN biopsy alone will increase the axillary recurrence rate, particularly in patients with a high risk of axillary lymph node metastasis. Recently, moreover, locoregional control appears to be important for enhancing survival in conjunction with adjuvant systemic therapy. It is therefore still unclear to what extent the benefits of SLN biopsy outweigh the risks and, if so, for which patient groups.

CONCLUSION

Before SLN biopsy can replace routine axillary dissection, research using long-term regional controls and investigation of survival in a prospective randomized trial are essential. Except for clinical research studies, routine axillary dissection should not be abandoned until and unless there is documentation of extensive experience and a low false negative rate. Even with such evidence, however, patients undergoing SLN biopsy without concomitant axillary dissection should be informed of the risk of a false-negative result.

The new TNM classification and micrometastases

The 6th Edition of the TNM classification is considered with particular reference to the evidence base for the analysis of lymph nodes. The justification for the definition of a micrometastasis is considered and in particular the problems related to describing a node deposit of less than 200 microm as NO. Such a classification in the absence of clear instructions on node examination is of limited value in terms of comparing different centres and even within the same centre. The classification does not embrace the rapid advances in the biology of breast cancer and some of these are considered as possible ways forward. TNM is meant to be pragmatic and evidence based leading to indications for treatment and a uniform approach between centres. In the former it succeeds, but some of the definitions would appear to be based on limited established data.

Pathologic evaluation of inguinal sentinel lymph nodes in vulvar cancer patients: a comparison of immunohistochemical staining versus ultrastaging with hematoxylin and eosin staining

OBJECTIVES

To evaluate the value of immunohistochemical (IHC) staining of inguinal sentinel lymph nodes (SLN) found to be negative for metastatic disease by ultrastaging with hematoxylin and eosin (H&E) staining.

METHODS

An IRB approved study identified 29 patients who had undergone an inguinal sentinel lymph node dissection for squamous cell carcinoma of the vulva. All sentinel lymph nodes found to be negative for metastatic disease based on ultrastaging with H&E staining were reevaluated with pancytokeratin antibody (AE1/AE3) immunohistochemical (IHC) staining to detect micrometastasis.

RESULTS

Twenty-nine patients with squamous cell carcinoma of the vulva underwent an inguinal sentinel node dissection. Nineteen patients had inguinal dissections negative for metastatic disease, 2 patients had bilateral inguinal metastasis, and 8 patients had unilateral inguinal metastasis. A total of 42 groin dissections with SLN biopsies were performed; 12 groins were positive for metastatic disease and 30 were negative based on ultrastaging with eosin and hematoxylin staining. A total of 107 sentinel lymph nodes (2.5 SLN per groin) were obtained, of which 18 SLN contained metastatic disease identified by ultrastaging and staining with H&E. Two SLN contained micrometastasis less than 0.3mm in size and 16 SLN contained metastasis greater than 2mm in size. Eighty-nine SLN found to be negative for metastasis by ultrastaging with H&E staining were also negative for micrometastasis on evaluation with pancytokeratin antibody AE1/AE3 IHC staining.

CONCLUSIONS

The addition of immunohistochemical staining to ultrastaging with H&E staining in the pathologic evaluation of inguinal sentinel lymph nodes does not increase the detection of micrometastasis in patients with primary squamous cell carcinoma of the vulva.

Sentinel lymph node biopsy in head and neck cancer

In the past decade, the technique of sentinel lymph node biopsy (SLNB) has been applied to a vast array of primary neoplasms, ranging from head and neck melanoma to vulvar carcinoma. At present, experience with SLNB is greatest in patients with melanoma and breast cancer. In view of the well known complications associated with cervical node dissection, it has been suspected for some time that cervical SLNB, if successful, might reduce the morbidity associated with the definitive care of patients with head and neck cancers. This report assesses the current status of SLNB in the treatment of head and neck cancers; while formal investigations of the efficacy of this technique are recommended, SLNB has not yet been demonstrated to possess the same level of utility seen in SLNB in melanoma and breast cancer patients. As a consequence, the application of SLNB to head and neck cancers remains an experimental technique--one which has not yet acquired the status of the standard of patient care.

[Sentinel lymph node biopsy in breast cancer patients--results and experience after 500 sentinel lymph node biopsies]

INTRODUCTION

Sentinel lymph node biopsy (SLNB) is a widely used technique for axillary staging in breast cancer patients. The principle to evaluate the axillary status of a breast cancer patient with a less invasive surgery than axillary lymph node dissection (ALND) meets the new minimally invasive concept in breast cancer surgery. Some breast cancer centers proceed to SLNB without ALND in SLN-negative patients.

PATIENTS AND METHODS

Between March 1998 and March 2002, 500 SLNBs were performed. After a learning period with SLNB and ALND in 75 patients with a sensitivity of 96.2% and a false-negative rate of 3.8%, SLNB alone without further ALND was performed in a group of patients. In addition, the feasibility of SLNBin patients with locally advanced breast cancer, in patients after neoadjuvant chemotherapy and in patients with multicentricity was evaluated. The combined method with blue dye and technetium-99m-labeled human albumin for identification of SLNs was applied.

RESULTS

500 SLNBs were performed. The identification rate was 86.2%. After exclusion of patients with neoadjuvant chemotherapy and patients with multicentricity, the identification rate was 94.5%. SLNs were positive in 41.3% of patients and negative in 58.7% of patients.

DISCUSSION

SLNB is an excellent method for axillary stag-ing and an alternative for ALND in a certain group of breast cancer patients.

Positron emission tomography in diagnosis and management of invasive breast cancer: current status and future perspectives

[18F]fluorodeoxyglucose positron emission tomography (FDG-PET) is a metabolic imaging modality that has increasing applications in oncology, neurology, and cardiology. Among the oncology applications, breast cancer is one of the most extensively studied diseases. FDG-PET has been performed for diagnosis, staging, and restaging of invasive breast cancer and for monitoring responsiveness to therapies. At the present time, the results of FDG-PET in detection of primary breast cancer and axillary staging are mixed and inconclusive. However, results demonstrating the superiority of FDG-PET over anatomic imaging modalities in detection of distant metastasis, recurrence, and monitoring therapies are relatively well documented. These applications have been accepted by medical professionals and the public, as evidenced by a recent decision by the Centers for Medicare and Medicaid Services (formerly Health Care Financing Agency) to provide coverage for the procedure. Future trends in this exciting area include development of novel breast cancer-specific PET radiopharmaceuticals and use of dedicated breast PET technologies for scans of breast/axillary lesions. PET/computed tomography technology, which combines anatomic and molecular/biochemical information, is also rapidly proliferating and should help to further improve the management of patients with breast cancer. The role of FDG-PET in breast cancer is increasing and evolving, and this metabolic imaging modality, in conjunction with newer tracers and other anatomic imaging methods, should improve diagnosis and management of patients with breast cancer

Histologic localization of sentinel lymph node metastases in breast cancer

Data from a recent study support the hypothesis that axillary lymph node metastases frequently localize near the inflow junction of the afferent lymphatic vessel. Our goal was to evaluate the microscopic location of axillary sentinel lymph node metastases in a prospective study of breast cancer patients. A total of 305 axillary sentinel lymph nodes from 213 breast cancer patients undergoing surgery at our institution were evaluated. Preoperative lymphoscintigraphy using technetium-labeled sulfur colloid and intraoperative isosulfan blue dye injection were used for identifying the sentinel lymph node. Intraoperatively, the surgeon placed a suture either at the point of entry of isosulfan blue dye or at the area with the highest radioactive counts, and this area was inked at the grossing bench before processing. Metastases were identified in 55 of the 305 lymph nodes examined. Thirty-four nodes contained metastases in both the inked half and the opposite half. Metastatic tumor was identified in the inked half alone in 18 lymph nodes. Only three nodes contained metastatic tumor in the opposite half with no tumor in the inked half (p <0.001). Similar results were found when nodes tagged at the point of blue dye entry and nodes tagged at the area with the highest radioactive counts were analyzed separately. Our findings suggest that metastatic tumor has a higher probability of being present in the region of the inflow junction of the afferent lymphatic vessel. This information may be useful in determining the optimal method for evaluating axillary sentinel lymph node specimens from breast cancer patients.

Therapeutic relevance of breast cancer micrometastases in sentinel lymph nodes

BACKGROUND AND METHODS

This review examines the various methods of detecting occult breast cancer metastasis in the sentinel lymph node (SLN). The prognostic relevance of such micrometastases and isolated tumour cells, and their impact on stage migration and decision making with respect to axillary dissection and adjuvant systemic therapy, are discussed.

RESULTS

Examination of SLNs by serial section with haematoxylin and eosin and/or immuno histochemical staining significantly increases the detection rate of micrometastases, even in patients with very small (T1) tumours. However, the prognostic relevance of isolated tumour cells and small micrometastases is uncertain. Moreover, deciding which patients might benefit from axillary dissection is complicated by the fact that adjuvant radiotherapy and systemic chemotherapy alone may eradicate most micrometastases.

CONCLUSION

Ongoing randomized trials comparing the results of SLN biopsy alone with those of axillary dissection should answer the question of whether isolated tumour cells and small micrometastases are clinically relevant. This should also indicate which patients with SLN micrometastasis are likely to benefit from axillary dissection. In this sense, SLN biopsy must be considered still to be at an investigative stage; outwith clinical trials complete axillary dissection should be performed on all patients with SLN micrometastasis.

Pathological examination of sentinel lymph node in breast cancer: potential problems and possible solutions

Sentinel lymph node (SLN) biopsy has emerged during the last few years as a viable option for staging the axilla in the treatment of breast carcinoma. This procedure can potentially identify patients who would be helped by full axillary lymph node dissection (the SLN-positive cases), and those who would not (the SLN-negative cases). Review of the literature confirms the promise of SLN; however, the possible problems in the pathological handling of SLN, including the microscopic misinterpretation of benign structures and "spurious" immunohistochemical staining, need wider recognition.

New technique to assess the axilla for breast cancer metastases using cell separation technology

INTRODUCTION

Accurate staging of the axilla for metastatic disease is critical in deciding on the optimal management of patients with breast cancer. Lymph node status is the most powerful prognostic factor. Current standard surgical management of breast cancer involves axillary dissection for staging. Pathological staging by routine histology, however, is known to understage the disease extent because only one or two sections are taken from each node, a sampling of less than 1% of most nodes. Sentinel node biopsy is currently under trial to determine if thorough pathological staging of the most likely involved node is more accurate than standard pathological assessment of all nodes. The present pilot study was undertaken to investigate an alternative method of assessing all axillary nodes for cancer cells.

METHODS

After routine material was taken from lymph nodes for standard pathological assessment, discarded parts of nodes were used for the study technique. These node parts were mechanically disaggregated, and the cell suspension centrifuged on a density gradient to separate any tumour cells (into the pellet) from lymphocytes (at the top of the gradient). The pellet was then assessed by haematoxylin and eosin and immunohistochemistry.

RESULTS

The results of the present study proved highly significant. The technique detected metastatic cells in three nodes which were negative on routine pathology, in one case changing the status of the patient from node-negative to node-positive.

DISCUSSION

It is concluded that the technique examined in the present paper has the potential to reduce sampling error, may offer far more accurate axillary staging than routine histopathology, and should be further evaluated in a controlled trial.

Recommendations for sentinel lymph node processing in breast cancer

The status of the sentinel lymph node (SLN) has been shown to accurately reflect the presence or absence of metastases in the axilla in patients with breast cancer. This study was designed to determine the optimal protocol for SLN processing. A total of 173 SLNs from 96 breast cancer patients who had successful SLN localization and underwent completion axillary node dissection were identified. All SLNs were negative for metastases by initial routine histologic evaluation. The nodes were submitted in a total of 300 blocks. Each block was serially sectioned to produce 10 levels. Pan-cytokeratin stain was performed on levels 3 and 8. All other levels were stained with hematoxylin and eosin. Metastases were identified in 22 SLNs from 19 patients by examining all 10 levels. The first two hematoxylin and eosin- or the first cytokeratin-stained levels were positive for metastases in 21 (95.5%) of the 22 positive SLNs. Two additional hematoxylin and eosin-stained and one cytokeratin-stained levels of each SLN correctly identified the status of the node in 94 (97.9%) of 96 patients. Therefore, we recommend that after an initial hematoxylin and eosin-stained section, two additional hematoxylin and eosin-stained sections and one cytokeratin-stained section should be evaluated.

What the clinician needs from the pathologist: evidence-based reporting in breast cancer

Histopathology has a vital role in determining breast cancer management and pathologists must be part of the clinical team. Carcinoma size, grade, and especially lymph node status remain the best available prognostic factors. Metastatic carcinoma in axillary nodes is more important than any other prognostic factor presently available. ER status is an important predictor of response to endocrine manipulation, but its independent prognostic significance, and that of micrometastatic disease, circulating carcinoma cells and other molecular factors, even well-studied ones such as HER2 status, are less clear. Pathology is the first clinical speciality to subject its practice to rigorous scientific analysis, and it has stood up well. However, workers without appropriate experience in Pathology or scientific design have created difficulties by undertaking poorly planned studies with ill-defined end-points, lacking appropriate quality control. New analytical techniques and therapeutic targets make it essential that we learn from past mistakes and integrate pathologists into the research teams pursing clinical trials and the assessment of new bio-markers. Without this, input resource will be wasted on false leads that could have been curtailed. Morphology alone will not be enough to select patients likely to benefit in trials of new therapies, but selection 'tests' must be appropriate. The confusion of tests for selection of patients to receive Herceptin shows what happens when this process fails. Much of the microarray data being put into data-bases has no quality control, and meta-analysis of this data will produce even more conflict than the clinical trials. This can be avoided, as the ability to standardise is available.

Histologic detection and clinical implications of micrometastases in axillary sentinel lymph nodes for patients with breast carcinoma

BACKGROUND

Sentinel lymph node (SLN) biopsy is used increasingly in patients with clinically lymph node negative, early-stage breast carcinoma, because it can spare axillary dissection when the sentinel lymph nodes are negative. The question arises, however, whether complete axillary lymph node dissection (ALND) also is necessary in patients with only micrometastases (< or = 2 mm in greatest dimension) in axillary SLNs. The authors carried out the current study to ascertain the risk of non-SLN axillary metastases in such patients and to assess the detection rate of SLN micrometastases in relation to the sectioning interval and the number of sections examined.

METHODS

The authors examined 109 patients with micrometastatic SLNs from a series of 634 patients with carcinoma of the breast who underwent SLN biopsy and complete ALND as part of the surgical treatment for their disease. The SLNs were sectioned completely at 50-microm intervals, and the sections were examined intraoperatively.

RESULTS

The overall frequency of metastases in axillary non-SLNs was 21.8%. The frequency was correlated significantly with the size of the SLN micrometastatic focus (P = 0.02): 36.4% of patients with foci > 1 mm had metastases in axillary lymph nodes--a percentage approaching 44.7% of patients with macrometastatic SLNs--whereas only 15.6% of patients with micrometastases < or = 1 mm had other involved axillary lymph nodes.

CONCLUSIONS

Outside of clinical trials, patients with T1 and small T2 breast carcinoma and micrometastatic SLNs should undergo complete ALND for adequate staging. However, patients with SLN micrometastases up to 1 mm in greatest dimension have a significantly lower risk of additional axillary metastases, raising the question of whether ALND may be avoided in this subgroup of patients.