Importance of tumor cells in axillary node sinus margins ('clandestine' metastases) discovered by serial sectioning in operable breast carcinoma

A Study of Sentinel Node Biopsy in T1 Breast Cancer Treatment: Experience of 48 Cases

Axillary clearance in breast cancer has been proven to be unnecessary in more than 50% of cases. Sentinel node biopsy (SNB) is a new technique that can be used to avoid unneccesary axillary clearance in breast cancer surgery. Our integrated team, consisting of surgeons, pathologists and nuclear medicine physicians, studied 48 cases of T1 breast cancer with lymphoscintigraphy-guided SNB. Before starting this study, the team performed 20 SNBs as a learning procedure. 500 μCi of 99mTc-nanocoll in 0.2 mL were injected around the lesion, under US or x-ray guidance if necessary. Static images in anterior, lateral and lateral oblique view collected at the end of a 20 min dynamic study were used to mark the SN on the skin. During surgery a gamma probe was used to guide SN resection, and node invasion was assessed with cytokeratin immunohistochemistry. In 14 patients tracer uptake was observed in a single node, in 30 patients in 2–4 nodes, whereas in four patients the nodes were scintigraphically missed. Surgical resection was possible in 42 nodes out of 54. All but two patients with negative immunohistochemistry for cancer cell clusters showed metastasis-free axillary nodes. All patients with positive SNBs (13) showed involved axilla. In four patients the lymphatic drainage was towards the intramammary chain; one node was juxtaclavicular and one node was intramammary in the upper outer quadrant. The overall sensitivity of the method was about 80%, the specificity about 90% with a diagnostic accuracy about 80%. SNB is a promising method for surgical decision-making regarding axillary clearance in breast cancer. Adequate training of an interdisciplinary team is needed in order to successfully perform SNB and assess SN invasion. Its unusual anatomic location can be encountered and technical care is necessary to correctly identify and remove them.

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.

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.

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.

Impact of micrometastases in the sentinel node of patients with invasive breast cancer

PURPOSE

Lymph node metastases are the most significant prognostic indicator for patients with breast cancer. Sentinel node biopsy (SNB) has led to an increase in the detection of micrometastases in the sentinel node (SN). This prospective study was designed to determine the survival impact of micrometastases in SNs of patients with invasive breast cancer. This study is based on the new sixth edition of the American Joint Committee on Cancer (AJCC) staging criteria.

PATIENTS AND METHODS

Between January 1, 1992 and April 30, 1999, 790 patients entered this prospective study at the John Wayne Cancer Institute. The SN was examined first by hematoxylin and eosin (HE), and if the SN was negative with HE, then immunohistochemical staining was performed. The patients were then divided into four groups based on AJCC nodal staging: pN0(i-), no evidence of tumor (n = 486); pN0(i+), tumor deposit < or = 0.2 mm (n = 84); pN1mi, tumor deposit more than 0.2 mm but < or = 2 mm (n = 54), and pN1, tumor deposit more than 2 mm (n = 166). Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The log-rank test was used to determine differences in DFS and OS of patients from different groups.

RESULTS

At a median follow-up of 72.5 months, the size of SN metastases was a significant predictor of DFS and OS.

CONCLUSION

Patients with micrometastatic tumor deposits, pN0(i+) or pN1mi, do not seem to have a worse 8-year DFS or OS compared with SN-negative patients. As expected, there was a significant decrease in 8-year DFS and OS in patients with pN1 disease in the SN.

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.

The application of sentinel lymph node mapping in colon cancer

Lymph node status is the most important prognostic factor for colorectal carcinoma. Complete lymph node dissection has historically been an integral part of the surgical treatment of these diseases. Sentinel lymph node mapping is a newer technology that allows selective removal of the first node draining a tumor. Sentinel node mapping is well accepted for the management of breast carcinoma and cutaneous melanoma, and has resulted in reduced morbidity without adversely affecting survival. Sentinel node mapping is currently being investigated for treatment of colorectal cancers. Recent studies show promise for incorporating the sentinel node mapping technique for treatment of several gastrointestinal malignancies.

Occult tumor cells in lymph nodes as a predictor for tumor relapse in pancreatic adenocarcinoma

BACKGROUND AND AIMS

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

MATERIALS AND METHODS

A total of 154 "tumor-free" lymph nodes from 59 patients with pancreatic cancer who underwent intentionally curative tumor resection were examined by immunohistochemistry for disseminated tumor cells.

RESULTS

Fifty (32.5%) of the "tumor-free" lymph nodes obtained from 36 (61%) patients displayed disseminated tumor cells. Multivariate survival analysis revealed that the presence of disseminated tumor cells in "tumor-free" lymph nodes is an independent prognostic factor for both a significantly reduced relapse-free survival (p = 0.03) and overall survival (p = 0.02).

CONCLUSIONS

The frequent occurrence and prognostic impact of immunohistochemically identifiable disseminated tumor cells in lymph nodes of patients with operable pancreatic cancer supports the need for a refined staging system of excised lymph nodes, which should include immunohistochemical examination.

Accuracy of pathologic examination in detection of complete response after chemoradiation for esophageal cancer

BACKGROUND

Although a substantial proportion of patients undergoing neoadjuvant chemoradiation for invasive esophageal cancer develop a pathologic complete response (pCR), these patients nonetheless have a poor 5-year survival rate. We hypothesized that routine pathologic examination fails to identify some residual cancer.

METHODS

Patients undergoing esophagectomy for cancer at 2 tertiary care centers were identified. Archived tumor blocks were retrieved for patients with pCR, sectioned at 50-mum intervals and reexamined for residual cancer.

RESULTS

Seventy patients underwent neoadjuvant chemoradiation. Tumor blocks were available for 23 of 26 complete responders. A total of 159 blocks were reexamined. One patient was found to have a possible focus of residual invasive adenocarcinoma versus high-grade dysplasia. The remaining 22 patients had no residual disease.

CONCLUSIONS

A more aggressive examination protocol for postchemoradiation esophagectomy specimens may not result in significant upstaging. Inadequate pathologic examination is likely not a major factor in the suboptimal survival in patients with pCR.

Significance of micrometastases on the survival of women with T1 breast cancer

BACKGROUND

The most important factor in predicting survival among women with newly diagnosed breast cancer is the status of the axillary lymph nodes. Although straightforward to define, the impact of micrometastases on survival remains to be completely determined.

METHODS

A review of data from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute was performed using 43,921 cases diagnosed from January 1988 through December 2001. Among women with invasive breast carcinomas <or=2 cm undergoing a resection of the primary malignancy and an axillary lymph node dissection, there were 42,197 cases without lymph node metastases and 1724 cases with micrometastases. Survival differences among these 2 groups were evaluated and are reported here.

RESULTS

Survival at 12 years was modestly affected by the presence of either solitary (5.0%) or multiple lymph nodes (3.6%) with micrometastases when compared with lymph node-negative cases. In subgroup analyses, the decreased survival associated with micrometastases was inconsistent. The most significant survival disadvantage associated with micrometastases was found in cases with Grade 3 carcinomas.

CONCLUSIONS

The modest and variable impact of micrometastases on long-term survival indicates that micrometastases are an important, but not a dominant, prognostic indicator.

Clinical outcome of patients with lymph node-negative breast carcinoma who have sentinel lymph node micrometastases detected by immunohistochemistry

BACKGROUND

The ideal pathologic assessment of sentinel lymph nodes (SLNs) in patients with breast carcinoma remains controversial. The authors evaluated how detailed assessment of SLNs using immunohistochemistry (IHC) and serial sectioning would affect treatment decisions and outcomes in patients with breast carcinoma who had negative SLNs on standard hematoxylin and eosin staining.

METHODS

The SLNs from patients who were treated between June 1998 and June, 1999 and who had negative lymph node status determined by hematoxylin and eosin staining (n = 84 patients) were evaluated further with serial sectioning and cytokeratin IHC. Patients were offered adjuvant therapy based on primary tumor factors.

RESULTS

The median patient age was 57 years, and the median tumor size was 1.2 cm. At a median follow-up of 40.2 months, 81 patients (96%) were alive with no evidence of disease, 1 patient was alive with disease, 1 patient had died of disease, and 1 patient had died of other causes. Fifteen patients (18%) had micrometastases identified on IHC. Of the total 84 patients, information regarding adjuvant therapy was not available for 5 patients. Of the remaining 79 patients, 10 patients (13%) were not offered adjuvant chemotherapy but had positive SLN status determined by IHC. SLN status based on IHC evaluation did not correlate with age (P = 0.077), tumor size (P = 0.717), grade (P = 0.148), estrogen receptor status (P = 1.000), or lymphovascular invasion (P = 0.274). Furthermore, IHC-detected positive SLN status did not correlate with distant metastasis (P = 0.372) or overall or distant metastasis-free survival (P = 0.543 and P = 0.540, respectively).

CONCLUSIONS

Although the finding of SLN micrometastases by IHC may change management in > 12% of patients, preliminary results suggested that such micrometastases do not affect outcomes significantly.

The clinical significance of axillary lymph node micrometastases in breast cancer

OBJECTIVE

To evaluate the clinical significancer of axillary lymph-node micrometastases, in the era of sentinel lymph node (SLN) biopsy.

DATA SOURCES

Searches of MEDLINE (1966-2003) and an extensive manual review of journals were performed using the key search terms breast cancer, axillary lymph-node micrometastases, micrometastatic disease, and SLN biopsy.

STUDY SELECTION

All articles identified from the data sources were evaluated and all information deemed relevant was included for this review.

CONCLUSIONS

Axillary lymph-node micrometastases can be detected by serial sectioning, immunohistochemistry, or reverse transcriptase-polymerase chain reaction (RT-PCR). The presence of axillary SLN micrometastases is generally associated with a worse prognosis and is an indication for axillary lymph node dissection (ALND) and adjuvant therapy. The clinical significance of micrometastases identified by RT-PCR remains unknown and further research with longer follow-up is needed to ascertain the clinical implications of a positive result.

Breast cancer patients with pN0(i+) and pN1(mi) sentinel nodes have high rate of nonsentinel node metastases

BACKGROUND

The recent American Joint Committee on Cancer revision of the staging system for breast cancer classifies sentinel node metastases < 0.2 mm (pN0[i+]) as node negative and those > 0.2 mm but < 2 mm are designated pN1(mi). We examined the association between size of sentinel node metastases and rate of nonsentinel node metastases, specifically in the subgroup of patients with micrometastases.

STUDY DESIGN

We examined the nonsentinel nodes of 124 patients with positive sentinel nodes and correlated the likelihood of nonsentinel node involvement with the size of the metastasis in the sentinel node and primary tumor characteristics.

RESULTS

Nonsentinel node metastases were found in 19% (6 of 31) of patients with sentinel node metastases <or= 0.2 mm, 20% (6 of 30) of patients with metastases 0.2 mm to 2 mm, and 46% (29 of 63) of patients with metastases > 2 mm. Multivariate analysis found that involvement of the majority of sentinel nodes (p = 0.01) and sentinel metastases > 2 mm (p = 0.001) were significantly related to presence of metastases in nonsentinel nodes. Age, tumor size, pathology, multifocality, satellites, and lymphovascular invasion were not significantly related to nonsentinel node metastases in multivariate analysis.

CONCLUSIONS

These findings indicate that frequency of nonsentinel node metastases with sentinel node metastases <or= 0.2 mm is comparable to the frequency when sentinel metastases are > 0.2 to 2 mm. Omitting complete axillary dissection in pN1(mi) and pN0(i+) patients may leave residual disease in up to 20% of these patients.

Missed micrometastatic disease in breast cancer

In the era of sentinel lymph node (SLN) biopsy for breast cancer, ultrastaging by enhanced pathologic techniques (serial sections and/or immunohistochemical [IHC] staining) has become logistically feasible for the first time. Retrospective studies suggest that SLN (and bone marrow) micrometastases detected by these methods are prognostically significant, but controversy still surrounds the significance of micrometastases detected only by IHC, and especially of isolated tumor cells. This heterogeneity among micrometastases may confound the interpretation of current prospective clinical trials that aim to determine their significance. A major challenge for future investigations will be to determine if SLN and bone marrow micrometastases represent similar or distinct biologic phenomena, and whether this distinction will have any implications for treatment.

Intraoperative examination of sentinel lymph nodes by ultrarapid immunohistochemistry

The recently developed method of ultrarapid immunohistochemistry (IHC) was applied to the intraoperative examination of sentinel lymph nodes (SLNs) in breast cancer patients. In a prospective study of 50 patients with invasive breast carcinomas, a total of 60 SLNs were studied. Among them, 33 SLNs from 30 patients were studied intraoperatively using a direct immunoperoxidase method with anticytokeratin antibody clone MNF116. This technique has a turnaround time of less than 20 minutes. Ultrarapid IHC revealed 15 positive SLNs compared to 14 positive SLNs using hematoxylin and eosin (H and E) frozen sections. The one SLN missed in H and E frozen sections presented with cytokeratin-positive isolated tumor cells in the lymph node sinus. After paraffin embedding, H and E-stained serial step sections of the SLN specimens detected another two patients with isolated tumor cells. We also examined the remaining axillary lymph nodes (ALNs) by H and E-stained serial step paraffin sections. From 17 of the 30 patients with positive SLNs, 6 patients also had metastatic involvement of the ALNs of level I or II. Thus ultrarapid IHC was a very sensitive and rapid technique for the intraoperative detection of metastatic involvement of SLNs in breast cancer patients. This technique may be a useful complementary tool for the intraoperative study of SLNs, particularly in tumors that are a diagnostic challenge, such as lobular carcinoma.

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.

Predictive factors for local recurrence in 2006 patients with surgically resected small breast cancer

BACKGROUND

Analyses of predictive factors for local recurrences are important, as an increasing number of patients with early breast cancer opt for a breast-conserving procedure. This study investigates whether factors predictive of local recurrence differ between patients treated with conservative or radical surgery.

PATIENTS AND METHODS

Two thousands and six patients with invasive breast carcinoma (< or =25 mm) were included. Of these patients, 717 were treated conservatively (lumpectomy and breast irradiation) and 1289 were treated with total mastectomy. All patients had axillary dissection and received lymph node irradiation if axillary nodes were positive. Most patients did not receive adjuvant chemotherapy or additive hormonal treatments. The mean duration of follow-up was 20 years. The main end point was the total local recurrence rate. The risk factors of local recurrence were estimated by multivariate analyses and interaction tests were used for intergroup comparisons.

RESULTS

Statistically significant predictive factors for mastectomized patients were histological grade, extensive axillary node involvement (10 nodes or more), and inner quadrant tumors, which were of borderline significance. Young age, however, was not a prognostic indicator for local recurrence. The main statistically significant factor for patients treated with a conservative approach was young age (< or =40 years). These younger patients had a five-fold increased risk of developing a breast recurrence compared with patients older than 60 years.

CONCLUSIONS

Younger patients with early breast cancer treated with breast-conserving surgery should in particular be followed up at regular intervals so that any sign of local failure can be diagnosed early.

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

The significance of occult metastases in axillary lymph nodes in patients with carcinoma of the breast is controversial. Additional sections were cut from the axillary lymph nodes of 477 women with invasive carcinoma of the breast, in whom no metastases were seen on initial assessment of haematoxylin and eosin stained sections of the nodes. One section was stained with haematoxylin and eosin, and one using immunohistochemistry with two anti-epithelial antibodies (CAM5.2 and HMFG2). Occult metastases were found in 60 patients (13%). The median follow-up was 18.9 years with 153 breast cancer related deaths. There was no difference in survival between those with and those without occult metastases. Multivariate analysis, however, showed that survival was related to tumour size and histological grade. This node-negative group was compared with a second group of 202 patients who had one involved axillary node found on initial assessment of the haematoxylin and eosin sections; survival was worse in the patients in whom a nodal metastasis was found at the time of surgery. Survival was not related to the size of nodal metastases in the occult metastases and single node positive groups. Some previous studies have found a worse prognosis associated with occult metastases on univariate analysis, but the evidence that it is an independent prognostic factor on multivariate analysis is weak. We believe that the current evidence does not support the routine use of serial sections or immunohistochemistry for the detection of occult metastases in the management of lymph node negative patients, but that the traditional factors of histological grade and tumour size are useful.

Detection and Significance of Occult Axillary Metastatic Disease in Breast Cancer Patients

After clinical staging, the single most important prognostic factor for patients with newly diagnosed primary breast cancer is the presence or absence of detectable metastases to axillary lymph nodes when examined by conventional light microscopy. More sensitive methods of determination of lymph node status, such as evaluation of serial sections, immunohistochemical staining, and use of molecular biological assays increase the rate of detection of micrometastases. Although the feasibility of enhanced detection of occult axillary metastatic disease is well established, the prognostic significance of such detection is only recently starting to emerge. Furthermore, the enormous recent interest in the application of sentinel lymph node biopsy as an alternative to the evaluation of the entire axilla in patients with breast cancer makes the first-time detailed evaluation for micrometastases practically feasible. In this review the different methods of detecting micrometastatic disease in the axilla and the significance of such findings are discussed.

Lymphatic Mapping and Sentinel Lymph Node Biopsy

The status of the regional nodal basin remains the most important prognostic indicator of survival. The current standard of care for the management of invasive breast cancer is the complete removal of the tumor, with documentation of negative margins by either mastectomy or lumpectomy, followed by complete axillary lymph node dissection. Data suggest that complete lymph node dissection (CLND) provides better local control of the disease and may actually offer a survival advantage. Lymphatic mapping and sentinel lymph node (SLN) biopsy are clearly changing this long-held paradigm and have the potential to change the standard of surgical care of the breast cancer patient. The purpose of this report is to describe the lymphatic mapping experience at the H. Lee Moffitt Cancer Center and Research Institute. From April 1994 to January 1999, 1,147 consecutive breast cancer patients were enrolled in an institutional review board-approved lymphatic mapping protocol. Lymphatic mapping was performed using Tc99m-labeled sulfur colloid and isosulfan blue dye. An SLN was defined as any blue node and/or any hot node with ex vivo radioactivity counts >/=10 times an excised non-SLN or in situ radioactivity counts >/=3 times the background counts. Lymphatic mapping was successful in identifying the SLN in 1,098 of 1,147 (95.7%) cases. In the first 186 patients, all of whom underwent CLND following SLN biopsy, one false-negative biopsy was encountered for a false-negative rate of 0.83%. The method of diagnosis (excisional versus minimally invasive) does not appear to impact on lymphatic mapping. Tumor size, however, is directly related to the probability of axillary lymph node involvement. Advances in technology and the development of minimally invasive surgical techniques have heralded a new era in surgery. Lymphatic mapping and SLN biopsy may actually prove to be a more accurate method of identifying metastases to the axilla by allowing a more focused pathologic examination of the axillary node(s) at highest risk for metastasis. With adequate training, this technique can be readily implemented as a valuable tool in the surgical treatment of breast cancer.

Detection of micrometastases in lymph nodes from patients with breast cancer

BACKGROUND

Sentinel node biopsy affords the opportunity of focused examination of lymph nodes, including the use of the reverse transcriptase-polymerase chain reaction (RT-PCR). The mammaglobin gene is expressed by breast cancers but has not been detected in histologically normal lymph nodes. This study compared mammaglobin RT-PCR with routine histology in the sentinel and non-sentinel nodes of patients with breast cancer.

METHODS

Patients with breast cancer underwent tumour excision, sentinel node biopsy and axillary dissection. All nodes were bisected and half of each node was sent for routine histological examination. The other half underwent RNA extraction and mammaglobin RT-PCR.

RESULTS

Sentinel node biopsy was successful in 50 (96 per cent) of 52 patients. Mammaglobin expression was detected in nine (8 per cent) of 119 histologically negative sentinel nodes (Clopper-Pearson 95 per cent confidence interval (c.i.) 4 to 14 per cent) and in 13 (5 per cent) of 247 histologically negative non-sentinel nodes (95 per cent c.i. 3 to 9 per cent). Mammaglobin expression was detected in four (13 per cent) of 31 patients with histologically negative sentinel nodes (95 per cent c.i. 4 to 30 per cent) and in six (14 per cent) of 44 patients with histologically negative non-sentinel nodes (95 per cent c.i. 5 to 27 per cent). The false-negative rate for sentinel node biopsy was zero using histology results and 10 per cent using RT-PCR.

CONCLUSION

RT-PCR screening of axillary nodes for mammaglobin expression increased the detection of breast cancer metastases compared with routine histology.

Micro-metastases in axillary lymph nodes: an increasing classification and treatment dilemma in breast cancer due to the introduction of the sentinel lymph node procedure

BACKGROUND

Sentinel lymph node (SN) biopsy will increasingly replace axillary lymph node dissection (ALND) for staging in breast cancer. For daily practice, examination of the SN by serial sectioning (SS) and/or immunohistochemistry (IHC) is being promoted. Use of these techniques may result into stage migration due to the increased detection of micro-metastases. The consequence may be overshooting of patients with adjuvant therapy, as the prognostic relevance of (small) micro-metastases and isolated tumor cells is unclear.

METHODS

The prognostic impact of micro-metastases is determined by reviewing ALND studies with a follow up of at least 5 years, including more than 100 patients, before the SN era. Furthermore, studies in which conventionally haematoxylin-eosin (H&E) negative SNs are investigated for occult metastases by SS and/or IHC are reviewed.

RESULTS

In only one of eight studies, occult metastases were an independent risk factor for reduced survival. The outcome is dependent on the size of the nodal metastasis. IHC and SS as used in the SN procedure indeed induce a shift from pNO to pN1a (according to TNM).

CONCLUSION

By the thorough pathologic examination of the SN, isolated tumor cells and micro-metastases are more frequently detected. We propose to classify small micro-metastases (<0.5 mm) in a separate pN1a(min) category (min for minimal) to prevent stage migration. As the prognostic relevance of isolated tumor cells and (small) micrometastases has not been proven, the value of adjuvant therapy can be questioned for patients with otherwise good prognostic factors.

Occult metastases in sentinel nodes of 200 patients with operable breast cancer

BACKGROUND

Up to 30% of patients with operable breast cancer and negative regional lymph nodes experience disease recurrence within 10 years. Serial sectioning and immunohistochemical staining of these nodes have revealed 9% to 30% occult metastases.

METHODS

Sentinel nodes from 200 patients with T1 and T2 invasive breast carcinoma were step-sectioned at 2- to 3-mm intervals, fixed in 10% formalin, and embedded in paraffin. Sections were taken from the face of the blocks and stained with hematoxylin and eosin (H&E). The blocks were then cut completely, and sections at .25-mm intervals were stained with cytokeratin and examined.

RESULTS

Tumor metastases were found in 34 patients when the sentinel nodes were examined at 2- to 3-mm intervals and in an additional 51 patients when the nodes were sectioned in their entirety at .25-mm intervals and stained with cytokeratin, bringing the total number of patients with metastases to 85. Of the 51 patients whose metastases were detected by 2- to 3-mm sectioning and cytokeratin staining, 27 had isolated tumor cells and 24 had clusters of innumerable malignant cells, all of which were visualized and confirmed by H&E staining of the adjacent sections.

CONCLUSIONS

Histologic examination of sentinel nodes of patients with invasive breast cancer sectioned at 2- to 3-mm intervals and stained with H&E significantly underestimates nodal metastases. Sectioning of the entire sentinel nodes at .25-mm intervals and staining with cytokeratin detects metastases as either isolated cells or as clusters.

Importance of missed axillary micrometastases in breast cancer patients

Axillary lymph node metastases dramatically worsen the prognosis of patients with breast cancer. Despite this prognostic significance, routine histologic examination of axillary lymph nodes examines less than 1% of the submitted material. It is therefore obvious that micrometastatic disease is missed with this rather cursory examination, and the question arises as to the significance of this missed disease. Most lines of evidence suggest that missed axillary micrometastases exist and contribute to patient mortality. Most large studies of breast cancer micrometastases have suggested that undetected axillary micrometastases can be identified with more detailed examinations of the regional lymph nodes and that this group of patients has a poorer prognosis than those with no metastases identified. In addition, small-volume nodal disease, too small to be detected by traditional hematoxylin and eosin staining, has been shown to be capable of producing tumors in animal models. Finally, micrometastases have been shown to be of significance in other diseases. This article reviews the lines of evidence and the ongoing studies that are attempting to clarify the significance of micrometastatic disease in patients with breast cancer.

Breast cancer sentinel node metastases: histopathologic detection and clinical significance

BACKGROUND

Lymphatic mapping with sentinel lymphadenectomy (LM/SL) is an accurate and less morbid means of determining the tumor status of the axilla in breast cancer patients than standard level I and II axillary lymph node dissection (ALND). This review addresses the handling and pathologic examination of the sentinel node (SN), the clinical significance of tumor within the SN, and the risk factors for non-SN tumor involvement.

METHODS

The seminal works that have addressed pathologic examination of ALND specimens and SN specimens are summarized, and the important studies attempting to identify predictors of non-SN metastases in patients with a tumor-involved SN are reviewed.

RESULTS

Standard single-section hematoxylin-eosin (H&E) examination is inadequate for reliable detection of axillary or SN metastases. Large studies appropriately powered to detect a survival difference for patients with micrometastatic disease are reviewed. The current data on the clinical significance of micrometastatic nodal disease is inconclusive. While several strong predictors of non-SN tumor involvement have been identified, none is reliable enough to allow omission of ALND in patients with a tumor-involved SN.

CONCLUSIONS

Routine examination of the SN specimen should include serial sections with H&E stain. Ongoing prospective clinical trials should help to define the clinical significance of SN micrometastases. Furthermore, these trials could help identify predictors of non-SN metastasis that would allow a subset of patients with a tumor-involved SN to avoid the morbidity of ALND.

Clinical significance of occult metastatic cells in bone marrow of breast cancer patients

The early and clinically occult spread of viable tumor cells to the organism is increasingly considered a hallmark in cancer progression, as emerging data suggest that these cells are precursors of subsequent distant relapse. Using monoclonal antibodies to epithelial cytokeratins or tumor-associated cell membrane glycoproteins, individual carcinoma cells can be detected on cytologic bone marrow preparations at frequencies of 10(-5) to 10(-6). Prospective clinical studies have shown that the presence of these immunostained cells in bone marrow, as a frequent site of overt metastases, is prognostically relevant with regard to relapse-free and overall survival. This screening approach may be, therefore, used to improve tumor staging and guide the stratification of patients for adjuvant therapy in clinical trials. Another promising application is monitoring the response of micrometastatic cells to adjuvant therapies, which, at present, can only be assessed retrospectively after an extended period of clinical follow-up. The present review summarizes the current data on the clinical significance of occult metastatic breast cancer cells in bone marrow.

Micrometastasis to axillary lymph nodes and bone marrow in breast cancer patients

The axillary lymph nodes of 100 lymph node-negative breast cancer patients with known bone marrow status have been re-examined to explore the presence of micrometastasis in lymph nodes and the covariance of micrometastasis to bone marrow and lymph nodes. Nodes were serially sectioned at three intervals of 100 microm, followed by immunohistological (two sections) and haematoxylin-eosin staining (one section). Tumours were mainly T1 and T2, and the patients had on average 13 (4-22) lymph nodes removed. In two patients, micrometastasis was detected in one node. Another 25 patients possessed single positive immunostained cells mimicking tumour cells. These cells have been shown to be false positive cells by Perl and melanin staining. One patient had metastasis to several nodes missed by the original examination. Immunocytochemical detection of micrometastasis in bone marrow revealed 11 marrow-positive patients. This study has identified a low frequency of micrometastasis to lymph nodes, and no covariance with micrometastasis in the bone marrow was seen. Bone marrow micrometastasis may be an independent prognostic variable, separate from axillary node status.

Prognostic and predictive factors in primary breast cancer and their role in patient management: The Nottingham Breast Team

Breast cancer is the most common carcinoma amongst women in the Western world, yet there are now encouraging signs that improvements in mortality may be a realistic target. Increasing breast awareness amongst women due to better health education can lead to earlier clinical detection. In addition, population screening with mammography can achieve a significant improvement in survival. With significant changes in the range and type of therapeutic options available for patients with breast cancer, there is now a trend towards patients exercising their right in management and therapeutic decisions. All these developments highlight the increasing importance of prognostic and predictive factors in the management of patients with breast cancer. In this review we will discuss current prognostic and predictive factors with particular emphasis on those of relevance in routine histopathology, especially with respect to their clinical applications.

Comparative analysis of micrometastasis to the bone marrow and lymph nodes of node-negative breast cancer patients receiving no adjuvant therapy

PURPOSE

In node-negative patients, of whom up to 30% will recur within 5 years after diagnosis, markers are still needed that identify patients at high enough risk to warrant further adjuvant treatment. In the present study we analyzed whether a correlation exists between microscopic tumor cell spread to bone marrow and to lymph nodes and attempted to determine which route is clinically more important.

PATIENTS AND METHODS

According to a prospective design, bone marrow aspirates and axillary lymph nodes of level I (n = 1,590) from 150 node-negative patients with stage I or II breast cancer were analyzed immunocytochemically with monoclonal anticytokeratin (CK) antibodies. We investigated associations with prognostic factors and the effect of micrometastasis on patients' prognosis.

RESULTS

CK-positive cells in bone marrow aspirates were present in 44 (29%) of 150 breast cancer patients, whereas only 13 patients (9%) had such positive findings in lymph nodes; simultaneous microdissemination to bone marrow and lymph nodes was seen in merely two patients. No correlation of bone marrow micrometastases with other risk factors was assessed. Reduced 4-year distant disease-free and overall survival were each associated with a positive bone marrow finding (P =.032 and P =.014, respectively) but not with lymph node micrometastasis. Multivariate analysis revealed an independent prognostic effect of bone marrow micrometastasis on survival, with a hazards ratio of 6.1 (95% confidence interval, 1.2 to 31.3) for cancer-related death (P =.031) in our series.

CONCLUSION

Immunocytochemical detection of micrometastatic cells in bone marrow but not in lymph nodes is an independent prognostic risk factor in node-negative breast cancer that may have implications for surgery and stratification into adjuvant therapy trials.

The role of selective sentinel lymph node dissection in breast cancer

Axillary nodal status continues to be the most statistically significant predictor of survival for patients with breast cancer. Although still providing regional control of axillary disease, axillary dissection is more important as a staging and prognostic tool. Trials are currently underway to investigate the possibility of replacing the current standard treatment of breast cancer, axillary lymph node dissection, with the less invasive lymphatic mapping and sentinel lymph node biopsy. This issue and the technical aspects of sentinel lymph node mapping for breast cancer are discussed in detail in this article.

Pathologic analysis of the sentinel lymph node

The development of the sentinel lymph node concept has had a revolutionary effect on the way radical cancer surgery is viewed. The selective excision of the sentinel node alone has been proposed as an alternative to complete regional lymphadenectomy. This article addresses the sentinel lymph node hypothesis and the role of pathologic analysis, radiation safety, intraoperative and postoperative assessment, pathologic analysis in prognosis, and polymerase chain reaction-based studies.

[Lymph node mapping and axillary sentinel lymph node biopsy in 243 invasive breast cancers with no palpable nodes. The south Lyon hospital center experience]

STUDY AIM

To evaluate the effect of intraoperative lymph node mapping and sentinel lymph node dissection (SLND) on the axillary staging of patients with N0 breast carcinoma. Two techniques were used: blue dye alone (Evans Blue and Patent Blue) and combined technique (blue dye and isotope).

METHODS

The incidence of axillary node metastasis in axillary lymph node dissection (ALND) and SLND was compared prospectively. Multiple sections of each SLN were examined by HPS staining and immunohistochemical techniques. Two sections of each non sentinel node in ALND specimens were examined by routine HPS staining.

RESULTS

243 patients underwent ALND after SLN biopsy. The SLN detection rate was 225/243 cases (92.59%): 89.94% with blue dye alone and 100% with the combined technique. The false-negative rate was less than 2%.

CONCLUSION

SN biopsy is an accurate staging technique for N0 breast cancer. SLN biopsy with multiple sections and immunohistochemical staining of the SLN can identify significantly more patients with lymph node metastases than ALND with routine HPS staining.

Evaluation of axillary sentinel lymph node biopsy by immunohistochemistry and multilevel sectioning in patients with breast carcinoma

BACKGROUND

Axillary lymph node dissection for evaluation of the presence or absence of metastatic disease is the single most important prognostic factor for patients with newly diagnosed primary breast cancer. Recently, sentinel lymph node (SLN) biopsy is being investigated as an alternative to the evaluation of the entire axilla. We evaluated whether the application of multilevel sectioning and immunohistochemistry in SLNs will increase the accuracy of detection of metastatic deposits.

METHODS

Between October 1998 and July 1999, 38 patients with breast carcinoma (25 ductal, 5 lobular, 4 tubular, and 4 mixed ductal and lobular) underwent successful SLN biopsy followed by complete axillary node dissection. Sentinel lymph nodes were localized with a combination of isosulfan blue dye and radionuclide colloid injection. Frozen sections and permanent sections of SLNs were examined. All negative SLNs were examined for micrometastases by 3 additional hematoxylin-eosin (H&E)-stained sections and immunohistochemistry with the cytokeratins AE1/AE3.

RESULTS

Sentinel lymph nodes were successfully identified surgically in 38 (93%) of 41 patients. There was a 97% correlation between the results of the frozen sections and the permanent H&E-stained sections. Twelve (32%) of 38 patients showed evidence of metastatic disease in their SLN by routine H&E staining. In 7 (58%) of 12 patients with positive nodes, the sentinel node was the only positive node. The 26 patients with negative SLN examination by H&E were further analyzed for micrometastases; 5 (19%) were found to have metastatic deposits by immunohistochemistry. Of these patients, 2 were also converted to node positive by detection of micrometastatic disease by examination of the additional H&E levels.

CONCLUSIONS

Sentinel lymph nodes can be accurately identified in the axilla of breast cancer patients. Evaluation of SLNs provides reliable information representative of the status of the axilla in these patients. Immunohistochemistry and, to a lesser degree, detailed multilevel sectioning are able to further improve our ability to detect micrometastatic disease in SLNs of breast cancer patients.

'Missed' micrometastases--the extent of the problem

The value of detecting micrometastases in patients with breast cancer has been debated for many years. The aim of this study was to determine whether and why such tumour deposits are missed at the time of reporting. The series comprised 272 patients treated surgically for breast carcinoma. For node-negative cases, the haematoxylin and eosin stained slides were re-examined. Those still remaining negative were stained with epithelial membrane antigen marker (EMA). Hilar sections were used in 76% of cases. Micrometastases were found in 35 cases reported as node-negative: 15 being identified on re-examination and 20 after staining with EMA, a gain of 44%, including 20 of embolic type. All were found in hilar sections of the nodes. The patients in whom micrometastases were found on further examination had significantly smaller tumour deposits than those reported as node-positive. In cases with infiltrating ductal carcinoma these presented as embolic growth, while those with infiltrating lobular carcinoma, for example, tended to colonize the nodal parenchyma, giving nodal growth. Differentiation between these growth patterns enables pathologists to distinguish between the dangerous embolic type and the less important nodal growth. In conclusion, many of these micrometastases can be detected if the slides reported as node-negative on first reading are re-examined. In those remaining negative, immunohistochemical staining is recommended.

Sentinel Lymph Node Biopsy in Breast Cancer

One of the most important prognostic indicators in patients with breast cancer is axillary lymph node status. Sentinel lymph node (SLN) biopsy has emerged as a potential alternative to routine axillary dissection in clinically node-negative early breast cancer. This procedure requires a specialized but multidisciplinary approach utilizing the surgeon, nuclear radiologist and pathologist. SLN biopsy allows adequate assessment of the axillary nodal status in patients with early breast cancer, with minimal—if any—morbidity. Blue dye and lymphoscintigraphy are complementary techniques, and the success rate is maximized when the two methods are used together. Focused histopathologic examination on one or two lymph nodes most likely to contain metastases [SLN(s)], using serial sectioning and immunohistochemical techniques, allows an improved staging to be performed. Detection of metastases on SLN(s) is not only a prognostic indicator, but it also dictates whether the patient should receive further surgery and adjuvant chemotherapy. Until data regarding the long-term results of the SLN biopsy are available, this method should be considered investigational and be performed by surgeons experienced in this technique to achieve a failure rate of less than 2 per cent.

Comprehensive review of sentinel lymphadenectomy in breast cancer

Sentinel lymph node dissection (SLND) is a minimally invasive technique to stage axillary lymph nodes in breast cancer. The complications associated with SLND are minimal, especially when compared to routine axillary lymph node dissection (ALND), and it can be performed with an overall identification rate of greater than 90% and a false-negative rate less than 5%. Despite this, SLND is not ready to replace routine axillary dissection, since we have no long-term results for these patients. What the clinical recurrence rates will be in women who undergo SLND only and how that will translate into survival rates has yet to be discovered. SLND is also a difficult technique to perform, as documented in the early SLND studies. It is imperative that each individual surgeon perform a series of cases in which SLND is combined with immediate ALND, so that identification rates and false-negative rates can be determined. Once a track record of successfully performed SLND has been established, SLND can be solely used for node-negative women. It is strongly recommended that all surgeons join one of the National Cancer Institute (NCI)-sponsored clinical trials for SLND in early breast cancer, so that many of these questions concerning SLND can finally be answered.

Lymphatic mapping and sentinel lymph node biopsy in patients with breast cancer

The standard of care for the evaluation of axillary nodal involvement remains complete lymph node dissection. Lymphatic mapping and sentinel lymph node (SLN) biopsy are changing this long-held paradigm; indeed, several leading institutions already reserve complete axillary dissection for patients with metastasis to the SLN. In addition to reviewing the literature, this chapter describes our lymphatic mapping experience at the H Lee Moffitt Cancer Center and Research Institute with 1147 breast cancer patients. Our results, in addition to a meta-analysis of data from 12 institutions comprising an additional 1842 patients undergoing complete axillary dissection, demonstrate that SLN biopsy is an accurate method of axillary staging. Although the results from small series may exaggerate the probability of false negative results, the risk of nodal disease based on tumor size and other risk factors should be evaluated when considering the results of SLN sampling.

Tumour micrometastases: the influence of angiogenesis

INTRODUCTION

Many cancer patients have undetected micrometastatic disease at first presentation which ultimately progresses. Angiogenesis-the development of an independent blood supply-is a key event in the growth of metastases. Improved understanding of the influence of angiogenesis on micrometastatic growth may lead to new therapeutic intervention.

METHODS

This study examines current concepts of the significance of micrometastases and the role of angiogenesis in their development and destruction. A comprehensive review of the literature on micrometastasis and angiogenesis was performed using the Medline database between 1966 and 1999.

CONCLUSIONS

Advances in technology have improved our ability to diagnose metastatic disease, but micrometastases in loco-regional lymph nodes and at distant sites can only be detected by sophisticated histological techniques. While the significance of micrometastases remains controversial, there is increasing evidence that micrometastatic status provides useful prognostic information and should be part of standard staging techniques. Anti-angiogenic therapy has the potential to favourably influence management of certain cancers by manipulating a number of key events in the metastatic process.

Micrometastases: have they an impact on prognosis?

Current routine histopathologic methods may fail in detecting lymph node micrometastases, while the introduction of newer, sensitive techniques, such as immunohistochemistry and molecular analysis, can improve their detection. The literature reveals that the presence of micrometastases has clinical and prognostic implications.