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

Does the Presence of Cytokeratin Positive Individual Tumor Cells (N0(I+)) in Sentinel Lymph Nodes Affect Clinical Outcomes in Breast Cancer Patients Treated with Accelerated Partial Breast Irradiation

Purpose

To report a primary objective clinical outcome of ipsilateral breast cancer recurrence following accelerated partial breast irradiation (APBI) with N_0(i+) (single tumor cells or clusters <2mm) in sentinel lymph nodes. The secondary objective was to observe any incidence of ipsilateral breast failure.

Patients and Methods

Between March 2004 and April 2016, a total of 747 patients were enrolled in one of two APBI (Accelerated Partial Breast Irradiation) breast protocols (Phase II NCT01185145 and Phase III NCT01185132). Nineteen patients with N_0(i+) disease were treated between February 2005 and December 2015. Patient eligibility included a primary invasive or DCIS tumor size <3 cm, N0(i+) disease, and margin width of >2 mm. All enrolled patients presented in this report had sentinel lymph node examinations. Clinical outcomes of ipsilateral breast, axillary and combined regional (breast or axillary) recurrences were analyzed.

Results

Median follow-up for all patients was 5 years (1–8 years). No patient experienced either ipsilateral breast or axillary recurrence.

Conclusion

There has been scarce information/reporting of the treatment of patients with cytokeratin positive individual tumor cells N_0(i+) with APBI. The authors have presented data which suggest that the successful outcomes of these patients might warrant further study.

Prognostic significance of occult lymph node metastases in breast cancer: a meta-analysis

Background

Occult metastases in axillary lymph nodes have been reported to be associated with poor prognosis in patients with breast cancer. However, studies on the prognostic value of occult metastases have shown controversial results. This meta-analysis aimed to evaluate the prognostic significance of occult lymph node metastases in breast cancer.

Methods

Studies published until May, 2020, which retrospectively examined negative lymph nodes by stepsectioning and/or immunohistochemistry, were retrieved from MEDLINE, EMBASE, CNKI, and Cochrane Library databases. The pooled Relative Risk (RR) with 95% confidence interval (95% CI) for overall survival (OS) and disease-free survival (DFS) were calculated to examine the associations between occult metastases and prognosis.

Results

Patients with occult metastases in axillary lymph nodes had poorer five-year DFS (RR = 0.930; 95% CI = 0.907–0.954) and OS (RR = 0.972; 95% CI = 0.954–0.990). Furthermore, the DFS (RR = 0.887; 95% CI = 0.810–0.972) and OS (RR = 0.896; 95% CI = 0.856–0.939) of patients with occult metastases were significantly lower after a ten-year follow-up.

Conclusions

Occult metastases in the axillary lymph nodes are associated with poorer DFS andOS of patients with breast cancer. Occult metastases might serve as a predictive factor of survival outcomes in patients with breast cancer.

Adjuvant chemotherapy for breast cancer patients with axillary lymph node micrometastases

BACKGROUND

The axillary lymph node status is one of the most important prognostic factors in patients with early breast cancer. However, the impact of axillary lymph node micrometastases on survival remains unclear. There are no consistent recommendations for adjuvant chemotherapy (CHT). In this context, we aimed to investigate the impact of micrometastases on the clinical outcome of breast cancer patients according to the adjuvant CHT performed.

PATIENTS AND METHODS

We conducted a retrospective population-based registry study of 26,465 patients aged between 24 and 97 years with primary breast cancer diagnosed between 2003 and 2017. Of these patients, 8856 with early breast cancer were eligible for analysis: 8316 (93.9%) were node negative and 540 (6.1%) had lymph node micrometastases.

RESULTS

The median follow-up was 7.2 years, with a confidence interval (CI) of 7.1-7.3 years. Patients with lymph node micrometastases (pN1mi) without adjuvant CHT have reduced 10-year overall survival (OS) and recurrence-free survival (RFS) compared to patients who had axillary lymph node micrometastases and received an adjuvant CHT. However, this effect disappeared after adjustment for age, tumor size and tumor grading. Furthermore, in the group of patients with lymph node micrometastases, the administration of adjuvant CHT did not improve OS or RFS, compared to patients with lymph node micrometastases without adjuvant CHT: hazard ratio for treated patients was 1.51 (95% CI 0.80-2.85, p = 0.208) for OS and 1.12 (95% CI 0.63-1.97, p = 0.705) for RFS.

CONCLUSION

Patients with axillary lymph node micrometastases showed a comparable outcome to node negative patients and their outcome was not significantly improved with CHT. Thus, axillary lymph node micrometastases should not be considered in the treatment decision.

Current Approaches to Diagnosis and Treatment of Ductal Carcinoma In Situ and Future Directions

The presentation and treatment of ductal carcinoma in situ (DCIS) has changed substantially over the years. While previously an incidental pathologic finding in more advanced, palpable tumors, the institution of screening mammography has repositioned this disease entity as one largely diagnosed as a non-palpable lesion, often prior to any invasive disease. As DCIS is a precursor to invasive carcinoma, evolution in the approach to treatment has followed in the footsteps of that for invasive disease, including breast conservation therapy, adjuvant radiation, and use of antihormonal therapy. Survival outcomes for DCIS are very high and more recent literature has investigated tailoring therapeutic approaches to avoid overtreatment. Two important areas of ongoing clinical debate concerning overtreatment include use of preoperative MRI and the role of adjuvant radiation. The heterogeneity of the disease makes it difficult to differentiate lesions that would benefit from more aggressive treatment from those in which overtreatment could be avoided. Clinical characteristics, such as histologic appearance, age at diagnosis, and margin status at tumor excision have been established as moderate predictors of disease recurrence, but none has provided strong enough evidence as to guide consensus decisions on adjuvant therapy. Continuing research seeks to define the genetic and molecular characteristics that can predict disease course and serve as the potential targets for novel therapeutic agents. While several markers have shown promise in differentiating tumor aggressiveness, there is still much to be discovered about the precise mechanisms of disease progression and how this can be applied clinically to optimize treatment.

Occult metastases in node-negative breast cancer: A Surveillance, Epidemiology, and End Results-based analysis

INTRODUCTION

The role of immunohistochemistry (IHC) for detecting occult lymph node disease in patients initially found to be node-negative by routine pathology is controversial. In this study, we evaluated trends associated with overall survival in node-negative breast cancer patients staged by IHC.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for all patients with invasive breast adenocarcinoma and negative lymph nodes on routine pathology between 2004 and 2011 who underwent IHC to evaluate for occult nodal disease. Overall survival stratified by N-stage was compared with Kaplan-Meier analysis. Multivariate analysis was performed using a Cox proportional hazards model.

RESULTS

Overall, 93,070 patients were identified, including 4,657 patients with isolated tumor cells (<0.2 mm diameter or <200 cells) and 6,720 patients with micrometastases (0.2-2 mm diameter). Kaplan-Meier curves demonstrated a difference in overall survival across all groups (P < .0001). On multivariate analysis, micrometastases remained an independent predictor for survival compared with IHC-negative patients (hazard ratio 1.40, 95% confidence interval 1.28-1.53), whereas isolated tumor cells were not a significant predictor (hazard ratio 1.05, 95% confidence interval 0.92-1.20).

CONCLUSION

Patients with occult micrometastases in axillary lymph nodes found via IHC demonstrated a significant overall survival difference, but isolated tumor cells have no prognostic significance.

One Step Nucleic Acid Amplification (OSNA) positive micrometastases and additional histopathological NSLN metastases: Results from a single institution over 53 months

INTRODUCTION

The role of sentinel lymph node micrometastases on histopathological analysis is controversial in axillary staging and management in clinically node negative breast cancer. Long-term studies addressing the clinical relevance of occult breast cancer in sentinel lymph nodes based on molecular analysis are lacking. One Step Nucleic Acid Amplification (OSNA), a highly sensitive assay of cytokeratin 19 mRNA, is used intra-operatively for the detection of lymph node macro- and micrometastases in breast cancer.

AIM

The aim of this study is to review the rate of micrometastases and further histopathological NSLN metastases, in our unit following the introduction of OSNA in Guildford.

METHODS

Data was collected prospectively from the period of introduction 01/12/2008 to 31/05/2013. All patients eligible for sentinel lymph node biopsy were offered OSNA and operations were performed by the consultant breast surgeons. Presence or absence of micro-metastases depends on the agreed cut-off point on the amplification curve. On detection of micrometastases (+) and positive but inhibited (i+) metastases, a level 1 axillary clearance (ANC) was performed and for a macrometastasis (++), a level 3 ANC was carried out.

RESULTS

66% of the patients had negative SLN (n = 672) and 34% (n = 336) had positive sentinel lymph nodes who had further axillary surgery. Of these, 45% (n = 152/336) had macrometastases, 40% (n = 136/336) had micrometastases and 15% (48/336) had positive but inhibited results. There was no difference in the patient demographics and tumour characteristics in the various positive SLN groups. In patients with micrometastases, 15% (20/136) had further positive NLSNs and a further 6% (8/136) had >4 overall positive nodes (SLN + NSLN) thus requiring adjuvant supraclavicular/chest wall radiotherapy (p < 0.05). 25% of node positive patients had further NLSN metastases (85/336) and in these patients, the ratio of positive SLN/harvested SLN (+SLN/SLN) is constant at 1:1. This shows the likelihood of further positive NSLNs if all the harvested lymph nodes are positive. This linear trend is present in both micro-and macrometastases, thus correlating with the size and number of NSLN metastases.

CONCLUSION

Our study reflects the tumour burden of NSLNs based on the molecular analysis of the SLN. OSNA has the potential to accurately identify axillary micrometastases. Micro-metastases are important as some of the patients with micrometastases had overall four positive nodes [SLN + NSLN] (criteria for radiotherapy in the absence of other adverse clinicopathological features). Also, our study highlights certain factors that predict the NSLN metastases, pending validation by further prospective long-term data. This will allow accurate calculation of the axillary tumour burden, particularly in patients with micro-metastases.

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.

Causes of false-negative sentinel node biopsy in patients with breast cancer

Background

Sentinel lymph node (SLN) biopsy has replaced axillary lymph node dissection as the routine staging procedure in clinically node-negative breast cancer. False-negative SLN biopsy results in misclassification and may cause undertreatment of the disease. The aim of this study was to investigate whether serial sectioning of SLNs reveals metastases more frequently in patients with false-negative SLNs than in patients with true-negative SLNs.

Methods

This was a case–control study. Tissue blocks from patients with false-negative SLNs, defined as tumour-positive lymph nodes excised at completion axillary dissection or a subsequent axillary tumour recurrence, were reassessed by serial sectioning and immunohistochemical staining. For each false-negative node, two true-negative SLN biopsies were analysed. Tumour and node characteristics in patients with false-negative SLNs were compared with those in patients with a positive SLN by univariable and multivariable regression analysis.

Results

Undiagnosed SLN metastases were discovered in nine (18 per cent) of 50 patients in the false-negative group and in 12 (11.2 per cent) of 107 patients in the true-negative group (P = 0.245). The metastases were represented by isolated tumour cells in 14 of these 21 patients. The risk of a false-negative SLN was higher in patients with hormone receptor-negative (odds ratio (OR) 2.50, 95 per cent confidence interval 1.17 to 5.33) or multifocal tumours (OR 3.39, 1.71 to 6.71), or if only one SLN was identified (OR 3.57, 1.98 to 6.45).

Conclusion

SLN serial sectioning contributes to a higher rate of detection of SLN metastasis. The rate of upstaging of the tumour is similar in false- and true-negative groups of patients.

Assessment of the Memorial Sloan-Kettering Cancer Center nomogram to predict sentinel lymph node metastases in a Dutch breast cancer population

AIM

Sentinel lymph node (SLN) biopsy is an accepted alternative to axillary lymph node dissection to assess the axillary tumour status in breast cancer patients. Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram to predict the likelihood of SLN metastases in breast cancer patients. Nomogram performance was tested on a Dutch population.

METHODS

Data of 770 breast cancer patients who underwent successful SLN biopsy were collected. SLN metastases were present in 222 patients. A receiver operating characteristic (ROC) curve was drawn and the area under the curve was calculated to assess the discriminative ability of the MSKCC nomogram. A calibration plot was drawn to compare actual versus nomogram-predicted probabilities.

RESULTS

The area under the ROC curve for the predictive nomogram was 0.67 (95% confidence interval 0.63-0.72) as compared to 0.75 in the original population. The nomogram was well-calibrated in the Dutch population.

CONCLUSIONS

In a Dutch population, the MSKCC nomogram estimated risk of sentinel node metastases in breast cancer patients well (i.e. calibration) with reasonable discrimination (area under ROC curve). Nomogram performance on core needle biopsy data has to be evaluated prospectively.

Occult axillary lymph node metastases do not have prognostic significance in early stage breast cancer

BACKGROUND

Axillary lymph node status is one of the most powerful prognostic indicators in patients with breast cancer and has implications for adjuvant treatment. It has been demonstrated that enhanced histologic evaluation of axillary lymph nodes, including serial sectioning of paraffin tissue blocks and immunohistochemical (IHC) staining, increases the rate of detection of occult metastases. The clinical significance of occult lymph node metastases has been the subject of debate.

METHODS

In the current study, the authors identified 267 patients who underwent axillary lymph node dissection (ALND) between 1987 and 1995 and were lymph node negative according to a routine pathologic evaluation, which included the complete submission of all lymph nodes and an examination of 1 hematoxylin and eosin (H&E)-stained section per paraffin block. Patients did not receive systemic chemotherapy or hormone therapy. All of the dissected lymph nodes from these patients were re-evaluated by intensified pathologic methods (serial sectioning with H&E levels plus IHC). Occult metastases were categorized by detection method and size. The clinical significance of the occult metastases was determined.

RESULTS

Thirty-nine patients (15%) who had lymph node-negative results on routine evaluation of their ALND specimens had occult metastases identified. Eight of these patients (20%) had macrometastases >2.0 mm, 15 (40%) had micrometastases (range, >0.2 mm to ≤2 mm), and 16 (40%) had isolated tumor cells (≤0.2 mm). The presence of occult metastases and the size of metastases did not affect recurrence-free or overall survival.

CONCLUSIONS

The presence of occult metastasis did not have clinical significance in this cohort of patients with early stage breast cancer.

Prognostic impact of isolated tumor cells in breast cancer axillary nodes: single tumor cell(s) versus tumor cell cluster(s) and microanatomic location

In breast cancer, it has been shown that pN0(i+) and pN1mi have a comparable negative impact on disease-free survival, compared with pN0. However, pN0(i+) is considered to be a heterogeneous group. We determined the effect of metastatic size and microanatomic location within the pN0(i+) group on breast cancer recurrence. We included all Dutch breast cancer patients diagnosed in 1998-2005 with favorable primary tumor characteristics and a final nodal status of pN0(i+). For this analysis, only patients without adjuvant systemic therapy were eligible (n = 513). Presence of single tumor cells versus cell clusters, metastatic size and microanatomic location were recorded. Primary endpoint was disease-free survival. Analyses were adjusted for age at diagnosis, tumor size, tumor grade, axillary treatment and hormone receptor status. The 5-year disease-free survival of patients with single tumor cell(s) (n = 93) was 78.6% and with tumor cell cluster(s) (n = 404) 77.1%. The hazard ratio for disease events was 1.05 (95% CI 0.63-1.76) for cell cluster(s) compared with single cell(s). In a Cox regression model, doubling of metastatic tumor size corresponded to a hazard ratio of 1.21 (95% CI 1.02-1.43). The adjusted hazard ratio was 0.90 (95% CI 0.54-1.50) for parenchymal (n = 112) versus sinusoidal location (n = 395). Single tumor cells bear similar prognostic information as small tumor cell clusters, even though results do suggest that within the pN0(i+) group, increasing size of nodal involvement is associated with reduced survival. Microanatomic location does not seem to have prognostic relevance.

Sentinel lymph node micrometastasis in human breast cancer: an update

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Breast cancer survival in relation to the metastatic tumor burden in axillary lymph nodes

PURPOSE

The aim of this study was to determine the prognostic significance of lymph node micrometastases in patients with breast cancer.

PATIENTS AND METHODS

Between September 2000 and January 2004, 3,369 patients with breast cancer were included in a prospective cohort. According to their lymph node status, they were classified in the following four groups: 2,383 were node negative, 107 had isolated tumor cells, 123 had micrometastases, and 756 had macrometastases. Median follow-up time was 52 months. Kaplan-Meier estimates and the multivariate Cox proportional hazard regression model were used to analyze survival.

RESULTS

Five-year cause-specific and event-free survival rates were lower for patients with micrometastases (pN1mi) than for node-negative (pN0) patients (94.1% v 96.9% and 79.6% v 87.1%, respectively; P = .020 and P = .032, respectively). There was no significant survival difference between node-negative patients and those with isolated tumor cells. The overall survival of pN1mi and pN0 patients did not differ.

CONCLUSION

This study demonstrates a worse prognosis for patients with micrometastases than for node-negative patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Micrometastases or isolated tumor cells and the outcome of breast cancer

BACKGROUND

The association of isolated tumor cells and micrometastases in regional lymph nodes with the clinical outcome of breast cancer is unclear.

METHODS

We identified all patients in The Netherlands who underwent a sentinel-node biopsy for breast cancer before 2006 and had breast cancer with favorable primary-tumor characteristics and isolated tumor cells or micrometastases in the regional lymph nodes. Patients with node-negative disease were randomly selected from the years 2000 and 2001. The primary end point was disease-free survival.

RESULTS

We identified 856 patients with node-negative disease who had not received systemic adjuvant therapy (the node-negative, no-adjuvant-therapy cohort), 856 patients with isolated tumor cells or micrometastases who had not received systemic adjuvant therapy (the node-positive, no-adjuvant-therapy cohort), and 995 patients with isolated tumor cells or micrometastases who had received such treatment (the node-positive, adjuvant-therapy cohort). The median follow-up was 5.1 years. The adjusted hazard ratio for disease events among patients with isolated tumor cells who did not receive systemic therapy, as compared with women with node-negative disease, was 1.50 (95% confidence interval [CI], 1.15 to 1.94); among patients with micrometastases, the adjusted hazard ratio was 1.56 (95% CI, 1.15 to 2.13). Among patients with isolated tumor cells or micrometastases, the adjusted hazard ratio was 0.57 (95% CI, 0.45 to 0.73) in the node-positive, adjuvant-therapy cohort, as compared with the node-positive, no-adjuvant-therapy cohort.

CONCLUSIONS

Isolated tumor cells or micrometastases in regional lymph nodes were associated with a reduced 5-year rate of disease-free survival among women with favorable early-stage breast cancer who did not receive adjuvant therapy. In patients with isolated tumor cells or micrometastases who received adjuvant therapy, disease-free survival was improved.

Prognostic significance of occult axillary lymph node metastases after chemotherapy-induced pathologic complete response of cytologically proven axillary lymph node metastases from breast cancer

BACKGROUND

Primary systemic chemotherapy has been a standard of care for the management of locally advanced breast cancer (LABC) patients and has increasingly been used for patients with large operable breast cancer. Pathologic complete response (pCR) of axillary lymph node metastases predicted an excellent probability of long-term disease-free and overall survival. Although the clinical significance of occult lymph node metastases in patients with breast cancer was extensively studied, their prognostic value in patients with LABC after primary chemotherapy was not known. This study evaluated the detection rate and clinical significance of occult lymph node metastases in lymph nodes that contained metastatic carcinoma at the time of initial diagnosis and converted to negative based on routine pathologic examination after primary systemic chemotherapy.

METHODS

Fifty-one patients with LABC and cytologically involved axillary lymph nodes that converted to negative after preoperative chemotherapy were identified from 2 prospective clinical trials. All lymph node sections were reviewed, 1 deeper level hematoxylin and eosin-stained section of each lymph node was obtained and immunohistochemical staining for cytokeratin (CK) was performed. A total of 762 lymph nodes were evaluated for occult metastases. Kaplan-Meier survival curves were used for calculating disease-free and overall survival times.

RESULTS

Occult axillary lymph node metastases were identified in 8 of 51 (16%) patients. In 6 patients, occult metastases were found in only 1 lymph node. In 7 patients, only isolated CK-positive cells were identified. In all cases, occult carcinoma cells were embedded within areas of fibrosis, foreign body giant cell reaction, and extensive histiocytosis. Patients with occult lymph node metastases tended to have a higher frequency of residual primary breast tumors than those without occult metastases (4 of 8 vs 7 of 43, respectively). There was no statistically significant difference in disease-free or overall survival times between patients with and without occult metastases after a median follow-up 63 months.

CONCLUSIONS

Persistent occult axillary lymph node metastases were not uncommon in patients with axillary lymph node-positive LABC who experienced a pCR in involved lymph nodes after preoperative chemotherapy. However, such occult metastases did not adversely affect the good prognosis associated with axillary lymph node pCR. Therefore, routine lymph node CK evaluation was not recommended after primary chemotherapy.

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.

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

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

Prognostic value of extracapsular invasion and fibrotic focus in single lymph node metastasis of gastric cancer

BACKGROUND

Histological findings of metastatic lymph nodes are important prognosticators in patients with gastric cancer. The aim of this study was to clarify the clinical significance of various pathological characteristics of the early phase of lymph node metastasis in patients with gastric cancer, by selecting patients with tumors that had single lymph node metastases, no serosal invasion, and no metastases to the peritoneum, liver, or distant organs.

METHODS

Seventy-eight patients were eligible and were entered in this study. These patients were subdivided according to the following histological characteristics of the one metastatic lymph node: size of the metastasis (i.e., amount of tumor cells [AT]), proliferating pattern (PP), intranodal location (IL), and the presence or absence of extracapsular invasion (ECI) and/or fibrotic focus (FF). Associations between clinicopathological factors, survival, and the nodal findings were examined.

RESULTS

There were no correlations between AT or PP and any clinicopathological factors. IL was significantly correlated with venous invasion and the pathological characteristics of the primary tumor. ECI and FF were observed significantly more frequently in pT2 than in pT1 cancer. Overall survival (OS) differed significantly according to depth of invasion, venous invasion, and the presence or absence of ECI or FF, although OS was not affected by AT, PP, or IL. The 10-year overall survival rates of patients with and without ECI were 50% and 80%, respectively, while these rates for patients with and without FF were 50% and 79%, respectively. Multivariate analysis revealed that ECI and FF were significant prognosticators of survival.

CONCLUSION

These results strongly suggested that the presence of ECI or FF could affect the survival of patients with gastric cancer.

The Nottingham prognostic index for invasive carcinoma of the breast

A useful prognostic factor in breast cancer has key roles, including identification of a group of patients whose prognosis is so good they do not require further treatment, such as adjuvant systemic therapy, after local surgery, and secondly a group with a poor prognosis for whom additional treatment would be appropriate. To be of clinical use, prognostic factors must show a wide separation in the outcome of the groups identified and select adequate numbers in each group. No single prognostic factor in invasive carcinoma of the breast satisfies all these criteria. However, the Nottingham prognostic index (NPI), which combines nodal status, tumour size and histological grade, does satisfy these criteria. The NPI has been validated by further studies in Nottingham and by studies in several other countries. Predictive factors, such as oestrogen receptor and HER-2 status, predict whether a tumour is likely to respond to a treatment, and are complimentary to prognostic factors. The NPI can be used in combination with predictive factors to select patients for systemic adjuvant treatments. There is the potential to improve the NPI by inclusion of other factors, such as vascular invasion, but any such alterations would require further validation.

The clinical significance of sentinel lymph node micrometastasis in breast cancer

INTRODUCTION

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

METHODS

Literature review facilitated by Medline and PubMed databases.

RESULTS

Published studies have reported divergent results regarding the significance and implications of ALN MM in general and sentinel lymph node (SLN) MM in particular. Some studies demonstrate no associations, whilst others have found these to be indicators of poor prognosis, associated with non-SLN involvement, in addition to local and distant failure. Absolute consensus regarding the optimal analytical technique for SLNs has yet to be reached, particularly concerning immunohistochemical (IHC) techniques targeting cytokeratins and the utility of contemporary molecular analysis.

CONCLUSION

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

Sentinel node 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.

Significance of sentinel lymph node micrometastases in human breast cancer

BACKGROUND

The significance of micrometastatic disease in the sentinel lymph nodes (SLN) of patients with invasive breast cancer has been questioned. The objective of our study was to review the impact of micrometastatic carcinoma detected by SLN biopsy.

STUDY DESIGN

Between January 1997 and May 2004, 2,408 patients with invasive breast cancer and an SLN with micrometastatic (N0[i+], N1mi) or no metastatic (N0[i-]) disease were identified through our breast database. Slide review was performed and reclassified by the 6(th) edition of the American Joint Committee on Cancer Staging Manual. Of these, 27 were excluded from analysis because of evidence of macrometastatic disease on slide review or enrollment in the American College of Surgeons Oncology Group Z10 study.

RESULTS

Of 2,381 patients, 2,108 were N0(i-), 151 were N0(i+), and 122 were N1mi. Overall and disease-free survivals of patients with an N1mi SLN were substantially worse than those in patients with an N0(i-) SLN (p < 0.001 and p=0.006, respectively). Additional positive non-SLNs were identified in 15.5% (15 of 97) of N1mi patients and 9.3% (10 of 107) of N0(i+) patients undergoing completion axillary lymph node dissection. Overall survival of the N0(i+) SLN patients not undergoing axillary dissection was substantially less than those undergoing axillary dissection (p=0.02).

CONCLUSIONS

Detection of micrometastatic carcinoma (N1mi) in the SLNs of invasive breast cancer patients is a major indicator of poorer survival compared with N0(i-) patients. Although survival of patients with an N0(i+) SLN does not statistically differ from that of N0(i-) patients, 9.3% of these patients had additional axillary nodal disease on axillary dissection, and N0(i+) patients had a decreased survival when axillary dissection was omitted.

The Prognostic Significance of Micrometastases in Breast Cancer: A SEER Population-Based Analysis

INTRODUCTION

The prognostic significance of lymph node micrometastases in breast cancer is controversial. We hypothesized that the survival of patients with solely micrometastatic disease (N1mi) would be intermediate to patients with 1-3 tumor-positive lymph nodes (N1) and those with no positive lymph nodes (N0).

METHODS

We queried the surveillance, epidemiology and end results (SEER) database for all patients between 1992 and 2003 with invasive ductal or lobular breast cancer without distant metastases and < or = 3 axillary nodes with macroscopic disease. Patients were stratified by nodal involvement and compared using the Kaplan-Meier method. Cox proportional hazards regression was utilized to compare survival after adjusting for patient and tumor characteristics.

RESULTS

Between 1992 and 2003, N1mi diagnoses increased from 2.3% to 7% among the 209,720 study patients (p < 0.001). In a T-stage stratified univariate analysis, N1mi patients had a worse prognosis in T2 lesions. On multivariate analysis, N1mi remained a significant prognostic indicator across all patients (p < 0.0001) with a hazard ratio of 1.35 compared to N0 disease and 0.82 compared to N1 disease. Other negative prognostic factors included male gender, estrogen-receptor negativity, progesterone-receptor negativity, lobular histology, higher grade, older age, higher T-stage, and diagnosis in an earlier time period.

CONCLUSION

Nodal micrometastasis of breast cancer carries a prognosis intermediate to N0 and N1 disease, even after adjusting for tumor- and patient-related factors. Prospective study is warranted and the results of pending trials are highly anticipated. Until then adjuvant therapy trials should consider using N1mi as a stratification factor when determining nodal status.

Doctor, what are my chances of having a positive sentinel node? A validated nomogram for risk estimation

PURPOSE

Lymph node metastasis is a multifactorial event. Several variables have been described as predictors of lymph node metastasis in breast cancer. However, it is difficult to apply these data-usually expressed as odds ratios-to calculate the probability of sentinel lymph node (SLN) metastasis for a specific patient. We developed a user-friendly prediction model (nomogram) based on a large data set to assist in predicting the presence of SLN metastasis.

PATIENTS AND METHODS

Clinical and pathologic features of 3,786 sequential SLN biopsy procedures were assessed with multivariable logistic regression to predict the presence of SLN metastasis in breast cancer. The model was subsequently applied to 1,545 sequential SLN biopsies. A nomogram was created from the logistic regression model. A computerized version of the nomogram was developed and is available on the Memorial Sloan-Kettering Cancer Center (New York, NY) Web site.

RESULTS

Age, tumor size, tumor type, lymphovascular invasion, tumor location, multifocality, and estrogen and progesterone receptors were associated with SLN metastasis in multivariate analysis. The nomogram was accurate and discriminating, with an area under the receiver operating characteristic curve of 0.754 when applied to the validation group.

CONCLUSION

Newly diagnosed breast cancer patients are increasingly interested in information about their disease. This nomogram is a useful tool that helps physicians and patients to accurately predict the likelihood of SLN metastasis.

Adjuvant chemotherapy for early-stage breast cancer

Systemic chemotherapy is an integral component of the adjuvant treatment strategy for women who have early-stage breast cancer and accounts for significant improvements in breast cancer-specific mortality. Decisions regarding adjuvant therapy are increasingly complex with the advent of new therapeutic strategies, a growing body of literature on the molecular biology and natural history of breast cancer, and advances in therapeutic techniques and early detection. Ultimately, the risk-benefit calculus will continue to evolve in response to these advances and one hopes that clinicians will soon be able to tailor treatment recommendations to the biology of an individual cancer and the needs of the affected individual.

The impact of nodal isolated tumor cells on survival of breast cancer patients

BACKGROUND

Isolated tumor cells (ITCs), often detectable only with immunohistochemical techniques, have an unknown significance in the prognosis of breast cancer. The American Joint Committee on Cancer guidelines classify such patients as N0 (immunohistochemistry +), staging them with node-negative patients. We sought to further elucidate the impact of ITCs on survival.

METHODS

We conducted a retrospective review of all women at our institution with breast cancer from 1996 to 2005. Of 514 patients, 16 had isolated tumor cells detected only with immunohistochemical staining. Survival then was compared with historical survival rates for women with node-free disease.

RESULTS

The 16 women with N0 (i+) disease had stage I or II disease. There was no documented recurrence among these women, with an average follow-up period of 2.5 years.

CONCLUSIONS

Our data suggest that ITCs detected in lymph nodes do not adversely impact survival or disease-free survival compared with women with node-negative disease. Larger studies will be required to confirm these findings.

Management of the axilla in women with breast cancer

The approach towards axillary surgery should be selective and flexible, with its management tailored to patient choice and tumour characteristics, and concordant with local practice guidelines and available resources. Sentinel-lymph-node biopsy has been embraced as a standard of care in many centres around the world and has revolutionised management of the axilla during the past decade. Nonetheless, data for long-term outcomes remain scarce, and there are persistent variations in practice and inconsistencies in methodology. An international perspective has been sought on important issues relating to management of the axilla, which includes not only the indications and techniques for sentinel-lymph-node biopsy, but also lymph-node sampling, axillary-lymph-node dissection, and observation alone. In this Review, we initially present an overview, which focuses on biological models of lymphatic networks within the breast and patterns of tumour dissemination. A set of key questions are posed with preliminary comments from the authors, followed by a series of collective viewpoints from experts within several different countries.

Relationship between histologic features of primary breast carcinomas and axillary lymph node micrometastases: Detection and prognostic significance

The incidence and prognostic significance of micrometastases (Mic-Met) in axillary lymph nodes (LNs) is still controversial. We compared Mic-Met detection of invasive mammary carcinomas (IMCs) in axillary LNs using second review of hematoxylin and eosin (H&E)-stained slides and immunohistochemistry (IHC) relating them with features of the primary tumor, and determining their influence on overall survival (OS) and disease-free survival (DFS). We studied 188 cases of IMCs with no axillary metastases in the initial reports. The original H&E slides of LN were re-viewed and new sections were submitted for IHC using pancytokeratin (AE1/AE3). All primary breast tumors were re-viewed and classified according to Page et al (1998) and College of American Pathologists criteria (2000). Tumors were graded using the Nottingham grading system. Kaplan-Meier curves were used to evaluate OS and DFS of 147 patients. Mic-Met detection was correlated to histologic features of primary tumor (size, type, grade, lymphatic/blood vessel invasion). Mic-Met were detected in 26/188 cases (by IHC: 23/188, 12.2%; by H&E: 12/188, 6.4%). The re-view of H&E slides showed good specificity (98.2%), but low sensitivity (39.1%), when compared with IHC. There was no relationship between features of primary tumor and Mic-Met detection, including patients with lobular carcinomas or IMCs with lobular features. There was no statistical difference in OS and DFS of patients with and without Mic-Met, but patients with Mic-Met presented lower survival curves. In conclusion, there was no relationship between histologic features of primary tumor and presence of Mic-Met, nor between Mic-Met detection and patients survival.

Sentinel lymph node biopsy as the new standard of care in the surgical treatment for breast cancer

During the recent years, based on the results of validation studies, the sentinel lymph node biopsy has replaced routine axillary dissection as the new standard of care in early breast cancer. The technique represents a minimally invasive, highly accurate method for axillary staging, which could spare approximately 65-70% of patients unnecessary axillary dissection and its related morbidity. Several technical and clinical controversies have been raised during the development of this new technique; the authors review the most important issues, some questions have already been answered and others are still under debate. As far as the technical aspects are concerned, mapping techniques, appropriate surgical training, options for pathological examination of sentinel lymph nodes and the issue of nonaxillary sentinel lymph nodes are discussed. An update on clinical controversies demonstrates that factors such as large tumor size, palpable axillary nodes, multifocality and multicentricity, previous breast and axillary surgery, and pregnancy are no longer regarded as absolute contraindications for sentinel lymph node biopsy. Feasibility, accuracy and timing of sentinel lymph node biopsy in patients undergoing neoadjuvant chemotherapy remain unsolved issues, as well as the indication of the technique for some subgroups of in situ lesions. Finally, one of the most attractive open forums for debate will be discussed: whether or not completion of axillary dissection in the case of positive SLN is always required.

Pathological Evaluation of Sentinel Lymph Nodes

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

Frequency and prognostic significance of occult tumor cells in lymph nodes in patients with adenocarcinoma of the papilla of Vater

BACKGROUND

Occurrence of tumor relapse is frequent in patients with carcinoma of the papilla of Vater despite the absence of residual tumor detectable at primary surgery. Therefore it has to be assumed that current tumor staging procedures fail to identify minimal amounts of tumor cells disseminated to secondary organs, which might be precursors of subsequent metastatic relapse. The aim of the study was to assess the frequency and prognostic impact of minimal tumor cell spread in lymph nodes classified as 'tumor-free' in routine histopathologic evaluation.

MATERIALS AND METHODS

A total of 41 'tumor-free' lymph nodes from 23 patients with adenocarcinoma of the papilla of Vater who underwent curative tumor resection (R0) were examined by immunohistochemistry with the monoclonal anti-EpCAM antibody Ber-EP4 for minimal disseminated tumor cells.

RESULTS

Twelve (29.3%) of the 41 'tumor-free' lymph nodes obtained from 9 (39.1%) of the 23 patients displayed EpCAM-positive cells. Kaplan-Meier survival analysis revealed that patients with EpCAM-positive cells in lymph showed a clearly reduced relapse-free and overall survival compared with patients without such cells. However, these differences were not statistically significant (p = 0.13 for relapse-free survival, p = 0.11 for overall survival).

DISCUSSION

Immunohistochemical assessment may refine the staging of resected lymph nodes in patients with carcinoma of the papilla of Vater. However, the presence of minimal disseminated tumor cells in lymph nodes had no significant impact on the prognosis in these patients.

Is axillary clearance the standard of care for breast cancer patients with sentinel node involvement?

Sentinel node biopsy (SNB) has become accepted for staging the axilla in early breast cancer with avoidance of axillary lymph node dissection (ALND) in patients with negative SNB. For those with positive SNB, the standard surgical management is ALND; however, this approach is increasingly being challenged. The central problem is that it is not possible to preoperatively predict whether the SNB will be positive, and it is even more difficult to determine the likelihood of nonsentinel node positivity. Various histopathological features indicate increased risk of nonsentinel node metastasis, including size of SNB metastasis, presence of lymphovascular invasion, multifocality, number of involved sentinel nodes and, conversely, the number of negative sentinel nodes. These features have been combined to produce predictive nomograms but, understandably, these still lack precision. Presently, the decision to avoid ALND will depend upon both the clinician and the patient's impression of risk, but if either requires assurance that no residual axillary disease remains, a completion clearance will be required.

Pathologic Examination of the Sentinel Lymph Node: What Is the Best Method?

Sentinel lymph node biopsy (SLNB) has become an acceptable alternative to complete axillary dissection to determine whether breast cancer has spread to axillary lymph nodes. Yet the best method for pathologic examination of the sentinel lymph node (SLN) remains controversial. For years there has been speculation that micrometastases in axillary lymph nodes were clinically insignificant and thus lymph nodes did not require sectioning at close intervals. Yet essentially all studies, including a recent large prospective study, have found a significantly poorer prognosis associated even with metastases less than 2 mm in size-the most common definition of micrometastasis-suggesting that such small metastases cannot be safely overlooked. The use of immunohistochemistry (IHC) to detect keratin proteins will reveal metastatic breast carcinoma in about 18% of axillary lymph nodes that appear negative on routine stains. The preponderance of evidence to date suggests a significantly poorer prognosis in patients with such occult metastases, although data from large prospective studies are lacking. Molecular techniques such as polymerase chain reaction (PCR) offer even more sensitive methods for detecting occult metastasis in SLNs, although false positives are a particular problem in techniques that do not permit morphologic correlation, and for now they remain a research tool. Intraoperative examination of the SLN permits a completion axillary dissection to be performed during the same procedure if metastatic tumor is found; however, intraoperative techniques such as cytologic examination and frozen section lack sensitivity, and can result in loss of up to 50% of the SLN tissue. A proposal for optimal pathologic examination of the SLN is offered based on the above data.

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

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

Biological Significance of Occult Micrometastases in Histologically Negative Axillary Lymph Nodes in Breast Cancer Patients Using the Recent American Joint Committee on Cancer Breast Cancer Staging System

The biological significance of occult metastases in axillary lymph nodes of breast cancer patients is controversial. The purpose of the study was to determine the prognostic significance of occult micrometastases using the current American Joint Committee on Cancer (AJCC) staging system in a cohort of women with node-negative breast cancer, of whom 5% received adjuvant systemic therapy and who all had long-term follow-up. We studied a cohort of 214 consecutive histologically node-negative breast cancer patients with a median follow-up of 8 years. Blocks of the axillary lymph nodes were assessed for occult micrometastases by examination of an additional hematoxylin-eosin-stained slide and by immunohistochemical staining using an antibody to low molecular weight keratin. Occult metastases were classified according to the sixth edition of the AJCC cancer staging manual. We examined the prognostic effects of occult micrometastases and other clinicopathologic features on recurrence outside the breast with disease-free interval (DFI) and survival from breast cancer with disease-specific survival (DSS). Cytokeratin-positive tumor cells were identified in the lymph nodes in 29 of 214 cases (14%). Two cases had isolated tumor cells and no cluster larger than 0.2 mm [pN0(i+)], whereas 27 of 214 (13%) had micrometastases (larger than 0.2 mm and <or=2.0 mm] (pN1mi). None of the cases had macrometastases. With median 8 years follow-up, occult micrometastases were not significantly associated with any of the clinicopathologic features. In addition, occult micrometastases were not significantly associated with DFI or DSS and thus were not included in the multivariate analysis. On multivariate analysis, lymphovascular invasion was significantly associated with DFI (p < 0.001) and DSS (p = 0.02), whereas percentage S-phase was significantly associated with DSS (p = 0.02). This study, in which 95% of patients did not receive adjuvant systemic therapy, suggests that breast cancer patients with occult micrometastases in axillary lymph nodes have a similar prognosis to those with no micrometastases. This information is important with regard to the practice of sentinel node biopsy and subsequent axillary node dissection and to the decision to administer adjuvant therapy based on detection of micrometastases in lymph nodes.