Occult axillary lymph node metastases are of no prognostic significance in breast cancer

The incidence and significance of micrometastases in lymph nodes of patients with ductal carcinoma in situ and T1a carcinoma of the breast

AIM

To report the incidence and predictive value of positive axillary nodes in ductal carcinoma in situ (DCIS) and T1a carcinoma of the breast.

METHODS

Cases from The Netherlands Cancer Institute were used to determine the incidence of lymph-node metastases. All consecutive patients with primary breast cancer that were treated between 1989 and 1998 and who had undergone axillary dissection were selected. Patients were identified with pure DCIS (n = 71), DCIS with small invasion (n = 12), invasive ductal/lobular carcinoma (IDC/ILC) < or =5 mm (n = 18) or tubular carcinoma < or =10 mm (n = 17). All archived lymph nodes of these patients were re-evaluated using immunohistochemistry (IHC).

RESULTS

In DCIS the incidence increased from 1.4% with routine staining to 11% with IHC. For DCIS with small invasion it was 0 vs 27%, respectively. In IDC/ILC sized 2-5 mm the incidence rose from 6 to 12% and in tubular carcinoma < or =10 mm from 0 to 12%. All but one of the immunohistochemically detected metastases were isolated tumour cells (n = 9) or small (micro)metastases (n = 4). Maximally two nodes per patient were affected. None of the patients with positive lymph nodes died during follow-up (mean 102 months).

CONCLUSIONS

Survival of our patients appeared not to be influenced by the finding of micrometastases in the lymph nodes by IHC. Immunohistochemistry of the sentinel node seems not contributive to further treatment in these patients.

Impact of lymph node micrometastasis in hilar bile duct carcinoma patients

AIM: To immunohistochemically examine micrometastasis and VEGF-C expression in hilar bile duct carcinoma (HBDC) and to evaluate the clinical significance of the results.

METHODS: A total of 361 regional lymph nodes from 25 patients with node-negative HBDC were immunostained with an antibody against cytokeratins 8 and 18 (CAM 5.2), and immunohistochemical staining of VEGF-C was performed in 34 primary resected tumors.

RESULTS: Lymph node micrometastasis was detected in 6 (24%) of the 25 patients and 10 (2.8%) of the 361 lymph nodes. Patients with micrometastasis showed significantly poorer survival rates than those without (P = 0.025). VEGF-C expression was positive in 17 (50%) of 34 HBDC, and significantly correlated with lymph node metastasis (P = 0.042) and microscopic venous invasion (P = 0.035).

CONCLUSIONS: It is suggested that immunohistochemically detected lymph node micrometastasis has an impact on the outcome of HBDC. VEGF-C expression is highly correlated with lymph node metastasis in HBDC and might therefore be a useful predictor.

Prognostic value of lymphovascular invasion in women with lymph node negative invasive breast carcinoma

This study aimed to test the hypothesis that lymphovascular invasion adds prognostic information to histological grade and tumour size in node-negative invasive carcinoma of the breast. Lymphovascular invasion was assessed in haematoxylin and eosin tumour sections from 2760 patients with node-negative invasive breast carcinoma treated with definitive surgery. Patients were divided into two groups: 990 in the no adjuvant therapy series (diagnosed in 1974-1988) with median follow-up of 13 years; and 1765 in the selective adjuvant therapy series (1988-2000) with median follow-up of 6.8 years. Lymphovascular invasion was identified in 19% of tumours and was associated with larger tumour size, higher histological grade and younger age. Overall, survival was associated on multivariate analysis with lymphovascular invasion, histological grade and tumour size in both patient series, and with histological type in the no adjuvant therapy series. In conclusion, lymphovascular invasion is an independent prognostic factor in node-negative breast cancer and should be considered in decisions about adjuvant treatment in this group of women.

Analysis of micrometastatic disease in sentinel lymph nodes from resectable colon cancer: results of Cancer and Leukemia Group B Trial 80001

PURPOSE

To determine whether sentinel lymph node (LN) sampling (SLNS) could reduce the number of nodes required to characterize micrometastatic disease (MMD) in patients with potentially curable colon cancer.

PATIENTS AND METHODS

Cancer and Leukemia Group B 80001 was a study to determine whether SLNS could identify a subset of LNs that predicted the status of the nodal basin for resectable colon cancer and, therefore, could be extensively evaluated for the presence of micrometastases. Patients enrolled onto this study underwent SLNS after injection of 1% isosulfan blue, and both sentinel nodes (SNs) and non-SNs obtained during primary tumor resection were sectioned at multiple levels and stained using anti-carcinoembryonic antigen and anticytokeratin antibodies.

RESULTS

Using standard histopathology, SNs failed to predict the presence of nodal disease in 13 (54%) of 24 node-positive patients. Immunostains were performed for patients whose LNs were negative by standard histopathology. Depending on the immunohistochemical criteria used to assign LN positivity, SN examination resulted in either an unacceptably high false-positive rate (20%) or a low sensitivity for detection of MMD (40%).

CONCLUSION

By examining both SNs and non-SNs, this multi-institutional study showed that SNs did not accurately predict the presence of either conventionally defined nodal metastases or MMD. As a result, SLNS is not a useful technique for the study of MMD in patients with colon cancer.

Does the Method of Biopsy Affect the Incidence of Sentinel Lymph Node Metastases?

More detailed examination of the sentinel lymph node (SLN) in breast cancer has raised concerns about the clinical significance of micrometastases, specifically isolated tumor cells detected only through immunohistochemical (IHC) staining. It has been suggested that these cells do not carry the same biologic implications as true metastatic foci and may represent artifact. A retrospective institutional review board-approved review was conducted on clinically node-negative breast cancer patients who underwent SLN biopsy (SLNB) between 1997 and 2003. Retrospective analysis of tumor characteristics and the method of the initial diagnostic biopsy were correlated with the presence and nature of metastatic disease in the SLN. Of 537 SLNBs, 123 (23%) were hematoxylin-eosin (H&E) positive. SLN positivity strongly correlated with tumor size (p<0.001) and tumor grade (p=0.025), but not with the method of biopsy (needle versus excisional biopsy). Prior to July 2002, we routinely evaluated H&E-negative SLNs with IHC (n=381). Of the 291 H&E-negative patients, 26 had IHC-only detected micrometastases (9%). The likelihood of detecting IHC-only metastases did not correlate with tumor size or grade, but was significantly higher in patients undergoing excisional biopsy than core needle biopsy. While the method of biopsy has no demonstrable effect on the likelihood of finding metastases in the SLN by routine serial sectioning and H&E staining, it may significantly impact the likelihood of finding micrometastases by IHC. IHC should not be used routinely in the evaluation of the SLN and caution should be used when basing treatment decisions (completion axillary lymph node dissection or adjuvant therapy) on IHC-only detected micrometastases.

Significance of lymph node micrometastasis in pN0 hilar bile duct carcinoma

AIMS

To examine micrometastasis in node-negative hilar bile duct carcinoma (HBDC) using an immunohistochemical method and evaluated the clinical significance.

METHODS

Four hundred and twenty three regional lymph nodes from 28 patients with node-negative HBDC who had undergone a resection were immunostained with an antibody against cytokeratins eight and 18 (CAM 5.2).

RESULTS

Lymph node micrometastasis was detected in 11 of the 28 patients and 14 of the 423 lymph nodes. Lymph node micrometastasis was significantly correlated with the pT classification (p=0.03), the histopathological grading (p=0.01) and venous invasion (p=0.05). The 5-year survival rate of the patients with lymph node micrometastasis was 21.8%, as opposed to 66.5% in the patients without micrometastasis. Patients with micrometastasis showed a significantly poorer survival rate than those without micrometastasis (p=0.02).

CONCLUSION

The results suggest that immunohistochemically detected lymph node micrometastasis has an impact on the outcome in HBDC.

Utilizing prognostic and predictive factors in breast cancer

In order to make optimal treatment recommendations for patients with early-stage breast cancer, it is essential to accurately determine the patient's underlying risk of disease recurrence and choose a therapy to which the individual is most likely to respond. Lymph node status, tumor size, histopathologic features including tumor type and grade, and hormone receptor status are well-accepted prognostic factors related to breast cancer. In addition, hormone receptor status is a very strong predictor of response to hormonal therapy. However, our currently accepted prognostic and predictive factors fall short and there is a critical need to more accurately identify those most likely to require or benefit from particular therapies. Attention has therefore focused on the determination of novel prognostic and predictive factors. The most promising new factor is the level of urokinase plasminogen activator and its inhibitor plasminogen activator inhibitor. Other putative factors include proliferative rate, the presence of lymphatic or vascular invasion, human epidermal growth factor receptor 2 (HER-2/neu or erbB-2) positivity, the presence of micrometastases in lymph nodes or bone marrow, and gene expression profile by microarray analysis, and by RNA-based methodology. Data regarding potential new prognostic factors are constantly emerging. These studies are frequently challenging to interpret as they are often retrospective, based on relatively small numbers of patients, include a mix of treated and untreated women, and often do not control for other known prognostic factors. Therefore, new data must be interpreted with caution.

Predictors of invasive breast cancer in patients with an initial diagnosis of ductal carcinoma in situ: a guide to selective use of sentinel lymph node biopsy in management of ductal carcinoma in situ

BACKGROUND

The role of sentinel lymph node biopsy (SLNB) in patients with an initial diagnosis of ductal carcinoma in situ (DCIS) has not been well defined. The purpose of our study was to determine when the risk of finding invasive disease on final pathology in patients with an initial diagnosis of DCIS was sufficiently high to justify use of SLNB.

STUDY DESIGN

The records of 398 consecutive patients from our prospective database with an initial diagnosis of DCIS, treated between July 1999 and December 2002, were analyzed. Associations between clinical and pathologic factors and patient selection for SLNB and outcomes were analyzed for significance using univariate and multivariate analyses.

RESULTS

Of the 398 patients, 80 (20%) were found to have invasive disease on final pathology. Multivariate analysis revealed 4 independent predictors of invasive cancer on final pathology: 55 years of age or younger (odds ratio [OR], 2.19; p = 0.024), diagnosis by core-needle biopsy (OR, 3.76; p = 0.006), mammographic DCIS size of at least 4 cm (OR, 2.92; p = 0.001), and high-grade DCIS (OR, 3.06; p = 0.002). A total of 141 patients (35%) underwent SLNB as a component of their initial operation. Multivariate analysis revealed that the presence of comedonecrosis (OR, 2.69; p = 0.007) and larger mammographic DCIS size (OR, 1.18; p = 0.0002) were independent predictors of patients' undergoing SLNB. Of these 141 patients, 103 (73%) were diagnosed by core-needle biopsy, 42 (30%) had invasive disease on final pathology, and 14 (10%) had a positive sentinel lymph node: 12 (86%) by hematoxylin and eosin staining and 2 by immunohistochemistry. The only independent predictor of a positive SLN was the presence of a palpable tumor (OR, 4.28, p = 0.042). Of these 14 patients with a positive sentinel node, only 11 (79%) had invasive cancer on final pathology.

CONCLUSIONS

SLNB should not be performed routinely for all patients with an initial diagnosis of DCIS. Risks and benefits of SLNB should be discussed with patients who are younger, are diagnosed by core-needle biopsy, or have large or high-grade DCIS.

Prognostic value of nodal micrometastases in patients with cancer of the gastro-oesophageal junction

AIMS

Aim of this study was to examine the presence and the prognostic impact of immunohistochemically identified nodal micrometastases in patients with gastro-oesophageal junction (GEJ) carcinomas.

METHODS

Between January 1988 and December 2000, 148 patients underwent a radical (R0) resection with a two-field lymphadenectomy for a GEJ carcinoma. Specimens of 60 patients in whom conventional haematoxylin and eosin (H & E) examination did not demonstrate lymph-node metastases (pN0) were available for immunohistochemical (IHC) analysis using antibodies AE1/AE3 directed against cytokeratins. Paraffin embedded material of all retrieved lymph nodes in these patients were serially sectioned and analysed by one pathologist after H & E examination for the presence of micrometastases by IHC.

RESULTS

In 60 resection specimens initially staged as pN0 a total of 524 lymph nodes were available for IHC analyses. Micrometastases were detected in 126 out of 524 lymph nodes (24%), corresponding with 18 of the 60 patients (30%) who were upstaged by this technique. Compared with the pN0 group, the disease free survival (DFS) was significantly lower in patients with nodal involvement at IHC (p<0.001). Survival of patients with IHC identified micrometastatic disease was comparable to those with H & E positive lymph nodes.

CONCLUSIONS

Micrometastases in regional nodes were detected by cytokeratin-specific IHC in 30% of radical resected GEJ tumours without overt nodal involvement. Their presence conveys a worse prognosis with a significant reduced DFS, suggesting that the finding of micrometastases should be included in the staging system.

Immunohistochemically detected lymph node metastases from breast carcinoma

BACKGROUND

The authors applied the sixth edition of the American Joint Committee on Cancer (AJCC) classification system to their previously published group of patients with breast carcinoma who had immunohistochemically detected lymph node metastases.

METHODS

The original lymph node-negative slides from 218 patients, including 129 patients with infiltrating duct carcinoma (IDC) and 89 patients with infiltrating lobular carcinoma (ILC), were reviewed and then destained to perform immunohistochemistry. Each tumor cell deposit was measured. Single tumor cells could not counted or measured (because the distance separating the most distant cells could be > 2.0 mm), but they were separated into Class 1 (sparse) and Class 2 (numerous). According to the AJCC classification, isolated tumor cells (ITCs) should be classified as pN0(i+) when they measure < or = 0.2 mm and pN1mi when they measure < or = 2.0 mm but > 0.2 mm.

RESULTS

ITCs were found in 13 IDCs (10%) and in 37 ILCs (41%) and corresponded in IDCs to a single deposit of a few tumor cells that measured < or = 0.2 mm (associated with a single tumor cell in 3 tumors) and were classified as pN0(i+). In ILCs, ITCs corresponded to single tumor cells with an irregular distribution throughout the entire lymph node section (24 ITCs and 13 ITCs in Class 1 and Class 2, respectively) and were difficult to classify.

CONCLUSIONS

The results suggest that there are 2 categories of pN0(i+): measurable tumor cell deposits < or = 0.2 mm, which were found exclusively in IDCs; and nonmeasurable ITCs, which were found in ILCs and rarely in IDCs. The new classification is difficult to apply to ITCs that are detected by immunohistochemistry in ILCs.

A concept for the clinical implementation of sentinel lymph node biopsy in patients with breast carcinoma with special regard to quality assurance

The development of standardized and reproducible clinical pathways is an important precondition for quality assurance in medicine, especially if a new method has not yet been ultimately validated. Sentinel lymph node biopsy (SLNB) is a widely accepted new surgical procedure in the treatment of early breast carcinoma. However, numerous steps of the method and details of the technique are not standardized and, thus, hamper quality assurance for SLNB. The German Society of Senology appointed an interdisciplinary consensus committee to work out guidelines for the standardized performance and quality-assured implementation of SLNB on a nationwide, homogeneous standard. The committee consisted of surgeons, gynecologists, radiooncologists, nuclear physicians, oncologists, and pathologists. Relevant questions related to patient selection, lymphatic mapping, surgery, histopathologic work-up, further local and systemic treatment decisions, patient information, training, and follow-up were evaluated with respect to clinical evidence, objectivity, and reproducibility. Clinical pathways were developed on the basis of this analysis. Requirements to the performing institutions and surgeons were defined.

Pathological Evaluation of Sentinel Lymph Nodes for Breast Cancer

Recently, sentinel lymph node (SLN) biopsy has been employed to avoid unnecessary lymph node dissection, because SLN negativity for carcinoma metastases may imply an extremely low possibility of non-SLN involvement. Pathological evaluation is essential, but standardized procedures have not yet been determined. Intraoperative consultation, either by frozen section (multiple slices are desirable) or touch imprint cytology, are usually very useful. Their accuracy, however, is variable and depends on the procedures used, but specificity is characteristically 100%, and the missed metastatic focus is always quite minute. After fixation, multiple sections, immunohistochemistry, and their combination will be able to detect small metastatic foci more frequently. The clinical significance of small or submicro- or occult metastases have not yet been clarified, and further investigations are needed. If the SLN is positive for carcinoma metastases, both the procedure for detection and the size of the metastatic focus should be clarified on the pathological reports.

Sentinel node micrometastasis in breast cancer

Extra information is not always valuable

Management of local recurrence of breast cancer

This article reviews the management of isolated recurrences after primary treatment of breast cancer. These recurrences may occur within the breast after breast-conserving surgery, on the chest wall after mastectomy, or in the axilla. While often a marker of concurrent or future metastatic disease, local management with curative intent is advocated if the recurrence is isolated at presentation. Systemic therapy at this time (readjuvant) may well have benefit and should be more thoroughly investigated. Changes in breast cancer management, including sentinel lymph node biopsy, neoadjuvant chemotherapy, hormonal therapy and partial breast irradiation, may change the implications and management of isolated local breast, chest wall and axillary recurrences.

Occult Micrometastases in Axillary Lymph Nodes Predict Subsequent Distant Metastases in Stage I Breast Cancer: A Case-Control Study with 15-Year Follow-Up

BACKGROUND

The prognostic significance of occult axillary metastases was evaluated in patients with stage I breast cancer.

METHODS

Ninety-six patients with pT1 breast carcinoma who underwent axillary lymph node dissection had negative nodes in routine microscopic examination. Forty-eight patients developed distant metastases within 15 years after surgery (M group) and are compared to 48 age-matched patients who were disease-free for 15 years (NM group). We reexamined 1539 lymph nodes from these patients, using three levels and cytokeratin immunostain.

RESULTS

Occult metastases were detected in 21 patients: 16 of 48 (34%) in the M group and 5 of 48 (11%) in the NM group (P =.007). All metastases measured 2.0 mm or less and were classified as micrometastases (>0.2 mm to 2.0 mm) in 11 cases and as individual tumor cells (individual cells or clusters measuring < or =0.2 mm) in 10 cases. Micrometastases were 10 times more frequent in the M group than in the NM group (10/48 vs. 1/48; P =.004). Although there was no difference in tumor size, histologic type, estrogen receptor status, or type of treatment between the two patient groups, tumors in the M group were of a higher grade, had higher mitotic index and showed lymphovascular invasion. In multiple logistic regression, only high mitotic index and presence of micrometastases showed an independent significant correlation with the subsequent occurrence of distant metastases.

CONCLUSIONS

The presence of micrometastases (>0.2 to 2.0 mm) in axillary nodes is significantly associated with the development of distant metastases in patients with T1 breast cancer.

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.

Current controversies in sentinel lymph node biopsy for breast cancer

Despite the widespread use of sentinel lymph node biopsy (SLNBx) in the surgical management of breast cancer patients, several areas remain controversial. The following controversies are reviewed: Learning curves and validation studies. There clearly is a learning curve, and a completion ALND should be done until adequate proficiency is exhibited, both in terms of identification and false-negative rates. Location of injection. Intradermal injection offers superior identification rates compared with peritumoral injection, with comparable false-negative rates. Subareolar injection is as accurate as peritumoral injection. The value of scintigraphy. Routine scintigraphy does not enhance identification or false-negative rates. Mapping agents. Blue dye and radioactive tracer combined to provide a higher identification rate than either used alone.SLNBx in DCIS. In patients with a high risk of microinvasion, such as large tumors, a mass or high-grade DCIS-SLNBx is justified.SLNBx following neoadjuvant chemotherapy. Although there is evidence that SLNBx after neoadjuvant chemotherapy may be accurate, these data should be applied cautiously. Implications of non axillary SLN, especially internal mammary nodes. Data do not support routine resection of internal mammary sentinel lymph nodes outside a clinical trial. Implications of micrometastases in the sentinel lymph node seen only on immunohistochemistry. Since the significance of such metastases is unclear, decisions regarding treatment of these patients should be individualized. The value of completion axillary lymph node dissection. Is being addressed in clinical trials. Until those studies mature, completion ALND should be performed for patients with SLN metastases, but may be abandoned for patients with a negative SLN.

Towards reasonable workload in diagnosis of sentinel lymph nodes: comparison of two frozen section methods

AIMS

To compare two methods of histological assessment with intraoperative diagnosis of sentinel node metastases in breast cancer.

METHODS AND RESULTS

A total of 204 consecutive breast cancer cases with lymphatic mapping, sentinel node biopsy and intraoperative diagnosis were included. The sentinel nodes in the first 102 cases (method A) were bisected and serially sectioned. In the other 102 cases (method B) the nodes were sliced thinly with a razor blade. All 1-1.5 mm thick slices were mounted on prechilled mounting medium on frozen section buttons. Cytological imprints were also made of the attached tissue slices. Postoperative diagnosis of sentinel lymph node metatases was taken as gold standard. Sentinel node metastases were found in 28 (27%) cases in group A and in 42 (40%) cases in group B (P = 0.05). The median size of the sentinel node metastases was 4.3 mm in group A and 3.3 mm in group B (P < 0.05).

CONCLUSION

Method B finds more and smaller metastases and takes less time and effort in the laboratory. When using method A, many small metastases are not detected at all.

The relevance of occult axillary micrometastasis in ductal carcinoma in situ: a clinicopathologic study with long-term follow-up

BACKGROUND

Ductal carcinoma in situ (DCIS) represents 20% of newly diagnosed breast carcinoma cases. Historically, the incidence of axillary metastasis in DCIS has been small (1-2%) and its significance has been debated. It is widely known that serial sections of lymph nodes coupled with keratin immunohistochemistry (IHC) increases identification of micrometastasis. The advent of sentinel lymph node evaluation underscores the need to reevaluate the significance of occult micrometastases in DCIS.

METHODS

Patients with DCIS and negative axillary lymph nodes from 1974 to 1992 were selected from the Saint Barnabas Medical Center Tumor Registry. All diagnoses were confirmed, and paraffin blocks were retrieved after acceptance into the study. Seven serial sections were obtained from each block and evaluated with two cytokeratin IHC stains. Clinical follow-up ranged from 10 to 28 years.

RESULTS

One hundred two patients were included in the study. Micrometastases were identified in 13 patients (13%), mostly on 1 level and composed of microscopic clusters in the subcapsular sinus. Seven of these lymph node-positive patients (58%) had high-grade comedo DCIS, 4 (33%) had intermediate grades of various types of DCIS, and one had a low-grade micropapillary DCIS. The overall disease recurrence rate was 12%, but micrometasis was not detected in any of the patients who developed disease recurrence.

CONCLUSIONS

Serial IHC evaluation of lymph nodes dramatically increased the identification of occult micrometastasis. However, IHC detected micrometastasis has no apparent clinical significance in DCIS, based on the current long-term clinicopathologic study. Therefore, the authors questioned the significance of occult micrometastasis, identified by IHC, in DCIS of any type and extent. Further evaluation and follow-up of lymph node micrometastases in patients with invasive tumors of various sizes are needed. The current findings would not support altering the stage of patients with DCIS and micrometastasis detected by IHC only.

Predictive Factors for the Status of Non-sentinel Nodes in Breast Cancer Patients with Tumor Positive Sentinel Nodes

In patients with tumor positive sentinel nodes, axillary lymph node dissection is routinely performed while a majority of these patients have no tumor involvement in the non-sentinel nodes. The authors tried to identify a subgroup of patients with a tumor positive sentinel node without non-sentinel node tumor involvement. In 135 consecutive patients with tumor positive sentinel nodes and axillary lymph node dissection performed, the incidence of non-sentinel node involvement according to tumor and sentinel node related factors was examined. The size of the sentinel node metastasis, size of primary tumor and number of tumor positive sentinel nodes were the three factors significantly predicting the status of the non-sentinel nodes. The size of the sentinel node metastasis was the strongest predictive factor (P < 0.0001). In a subgroup of 41 patients with a stage T1 tumor and micrometastatic involvement in the sentinel node only 2 patients (5%) had non-sentinel node involvement. In patients with small primary tumors and micrometastatic involvement of the sentinel nodes, the chance of non-sentinel node involvement is small but cannot be discarded. Because the clinical relevance of micrometastases in lymph nodes is still unclear it is not advisable to omit axillary lymph node dissection even in these patients.

Interpretive disparity among pathologists in breast sentinel lymph node evaluation

BACKGROUND

Immunohistochemical staining on breast sentinel lymph nodes (SLN) is controversial.

METHODS

Twenty-five SLN cases were reviewed by 10 pathologists (three academic, seven private) including 5 negative by both hematoxylin and eosin (H&E) and immunohistochemistry, 11 micrometastases (<2 mm) negative by H&E but positive by immunohistochemistry, and 8 micrometastases and 1 macrometastasis (>2 mm) positive for both H&E and immunohistochemistry. Answers included "positive," "negative," and "indeterminate" for each slide.

RESULTS

The mean number of incorrect responses was 6.6 for immunohistochemistry and 5 for H&E. Twelve percent of cases were correct by all 10 pathologists; 80% of positive IHC cases had at least one pathologist score it incorrectly. As tumor cells decrease in number, incorrect responses increase. When tumor cells numbered less than 10, more than 30% of pathologists answered incorrectly.

CONCLUSIONS

As tumor cells decrease in number pathologists' ability to recognize them decreases. We propose adding "indeterminate" to "positive" and "negative" when tumor cells number less than 10.

Pathological work-up of sentinel lymph nodes in breast cancer. Review of current data to be considered for the formulation of guidelines

Controversies and inconsistencies regarding the pathological work-up of sentinel lymph nodes (SNs) led the European Working Group for Breast Screening Pathology (EWGBSP) to review published data and current evidence that can promote the formulation of European guidelines for the pathological work-up of SNs. After an evaluation of the accuracy of SN biopsy as a staging procedure, the yields of different sectioning methods and the immunohistochemical detection of metastatic cells are reviewed. Currently published data do not allow the significance of micrometastases or isolated tumour cells to be established, but it is suggested that approximately 18% of the cases may be associated with further nodal (non-SN) metastases, i.e. approximately 2% of all patients initially staged by SN biopsy. The methods for the intraoperative and molecular assessment of SNs are also surveyed.