The feasibility of intraoperative diagnosis of sentinel lymph node metastases in breast cancer

The diagnostic performance of the one-step nucleic acid amplification assay for the detection of sentinel lymph node metastases in cytokeratin 19-positive breast cancer: a PRISMA-compliant meta-analysis

Background

The status of the sentinel lymph nodes (SLNs) is an important prognostic factor for many different types of cancer. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid intraoperative molecular diagnostic tool for LN metastasis detection. We aimed to evaluate and summarize the value of the OSNA assay for the diagnosis of SLN metastasis in cytokeratin 19 (CK19)-positive breast cancer.

Methods

To evaluate the diagnostic value, the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were pooled. The threshold effect, followed by subgroup analysis, was performed to explore the source of heterogeneity. A sensitivity analysis was performed to assess the stability of this meta-analysis model. Fagan plots and likelihood ratio scattergrams were used to explore the potential clinical significance.

Results

A total of 29 eligible studies, which consisted of 5,331 patients with 10,343 SLNs, were included in this meta-analysis. The pooled sensitivity, specificity, PLR, NLR, and DOR were 0.86 (95% CI: 0.85-0.88), 0.94 (95% CI, 0.94-0.95), 18.00 (95% CI, 13.54-23.92), 0.13 (95% CI, 0.10-0.17), and 138.99 (95% CI, 86.66-222.92), respectively. The AUC was 0.97 (95% CI, 0.95-0.98). Sensitivity analysis showed that four studies had an impact on the pooled results and mainly contributed to the heterogeneity. Fagan's nomogram revealed that the prior probability was 50%, the post-probability positive was 95%, and the post-probability negative was 11%.

Discussion

Our results suggested that OSNA can predict the occurrence of SLN metastasis in CK19-positive breast cancer. However, more well-designed and multicenter diagnostic tests are needed to validate our results.

Update on Sentinel Lymph Node Methods and Pathology in Breast Cancer

Breast cancer stands out as the most commonly diagnosed cancer among women globally. Precise lymph node staging holds critical significance for both predicting outcomes in early-stage disease and formulating effective treatment strategies to control regional disease progression in breast cancer patients. No imaging technique possesses sufficient accuracy to identify lymph node metastases in the early stages (I or II) of primary breast cancer. However, the sentinel node procedure emerges as a valuable approach for identifying metastatic axillary nodes. The sentinel lymph node is the hypothetical first lymph node or group of nodes draining a cancer. In case of established cancerous dissemination, it is postulated that the sentinel lymph nodes are the target organs primarily reached by metastasizing cancer cells from the tumor. The utilization of the sentinel node technique has brought about changes in the assessment of lymph nodes. It involves evaluating the sentinel node during surgery, enabling prompt lymph node dissection when the sentinel node procedure is positive. Additionally, histological ultra-stratification is employed to uncover occult metastases. This review aims to provide an update of this valuable technique, with focus on the practical aspects of the procedure and the different histological protocols of sentinel node evaluation in breast cancer.

Update on sentinel node pathology in breast cancer

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting. Patients treated with neoadjuvant therapy, who represent a population with more extensive disease and aggressive tumor biology, were not included in Z0011 and similar trials, and thus, the evidence cannot be extrapolated to them. Recent trials have supported the safety and accuracy of sentinel lymph node biopsy (SLNB) in these patients when clinically node negative at the time of surgery. ALND remains the standard of care for any amount of residual disease in the SLNs and intraoperative evaluation of SLNs is still of value for real time surgical decision making. Given the potential prognostic significance of residual small metastases in treated lymph nodes, as well as the decreased false negative rate with the use of cytokeratin immunohistochemistry (IHC), it may be reasonable to maintain a low threshold for the use of cytokeratin IHC in post-neoadjuvant cases. Further recommendations for patients treated with neoadjuvant therapy await outcomes data from ongoing clinical trials. This review will provide an evidence-based discussion of best practices in SLN evaluation.

Imprint cytology versus frozen section analysis for intraoperative assessment of sentinel lymph node in breast cancer

Introduction

Sentinel lymph node (SLN) biopsy is the gold standard for surgical staging of the axilla in breast cancer (BC). Frozen section (FS) remains the most popular means of intraoperative SLN diagnosis. Imprint cytology (IC) has also been suggested as a less expensive and equally accurate alternative to FS. The aim of our study was to perform a direct comparison between IC and FS on the same SLNs of BC cases operated in a single center by the same surgical team.

Materials and methods

Into this prospective study we enrolled 60 consecutive patients with histologically proven T1–T3 BC and clinically negative axilla. Sentinel nodes were detected using a standard protocol. The SLN(s) was always assessed by IC as well as FS analysis and immunohistochemistry. Nevertheless, all intraoperative decisions were based on FS analysis.

Results

During the study period 60 patients with invasive BC were registered, with 80 SLNs harvested. Mean number of SLN(s) identified for each patient was 1.33. The sensitivity and specificity were 90% and 100%, respectively, for IC, and 80% and 100% for FS. Relevant positive/negative predictive values were 100%/98% for IC and 100%/96.15%, respectively, for FS. Overall accuracy was 98% for IC and 97% for FS. Therefore, statistically significant difference between the two methods in the detection of positive nodes was not elucidated (p=1.000).

Conclusions

IC appeared to be marginally more sensitive than FS in detecting SLN metastatic activity. Overall accuracy was 98.75%. With regard to the primary lesion characteristics, we conclude that initial lesion size and lymphovascular invasion play a pivotal role in metastatic involvement of the SLN with the dimensions of metastasis bearing no correlation with tumor size. Therefore, IC appears to be a sensitive and accurate method for the intraoperative assessment of SLN in BC patients, but further studies are required to confirm this interesting data.

Sentinel node detection in early breast cancer with intraoperative portable gamma camera: UK experience

PURPOSE

Access to nuclear medicine department for sentinel node imaging remains an issue in number of hospitals in the UK and many parts of the world. Sentinella^® is a portable imaging camera used intra-operatively to produce real time visual localisation of sentinel lymph nodes.

METHODS

Sentinella^® was tested in a controlled laboratory environment at our centre and we report our experience on the first use of this technology from UK. Moreover, preoperative scintigrams of the axilla were obtained in 144 patients undergoing sentinel node biopsy using conventional gamma camera. Sentinella^® scans were done intra-operatively to correlate with the pre-operative scintigram and to determine presence of any residual hot node after the axilla was deemed to be clear based on the silence of the hand held gamma probe.

RESULTS

Sentinella^® detected significantly more nodes compared with CGC (p < 0.0001). Sentinella^® picked up extra nodes in 5/144 cases after the axilla was found silent using hand held gamma probe. In 2/144 cases, extra nodes detected by Sentinella^® confirmed presence of tumour cells that led to a complete axillary clearance.

CONCLUSIONS

Sentinella^® is a reliable technique for intra-operative localisation of radioactive nodes. It provides increased nodal visualisation rates compared to static scintigram imaging and proves to be an important tool for harvesting all hot sentinel nodes. This portable gamma camera can definitely replace the use of conventional lymphoscintigrams saving time and money both for patients and the health system.

Cost and Budget Impact Analysis of an Accurate Intraoperative Sentinel Lymph Node Diagnosis for Breast Cancer Metastasis

BACKGROUND

Conventional intraoperative sentinel lymph node biopsy (SLNB) in breast cancer (BC) has limitations in establishing a definitive diagnosis of metastasis intraoperatively, leading to an unnecessary second operation. The one-step nucleic amplification assay (OSNA) provides accurate intraoperative diagnosis and avoids further testing. Only five articles have researched the cost and cost effectiveness of this diagnostic tool, although many hospitals have adopted it, and economic evaluation is needed for budget holders.

OBJECTIVE

We aimed to measure the budget impact in Japanese BC patients after the introduction of OSNA, and assess the certainty of the results.

METHODS

Budget impact analysis of OSNA on Japanese healthcare expenditure from 2015 to 2020. Local governments, society-managed health insurers, and Japan health insurance associations were the budget holders. In order to assess the cost gap between the gold standard (GS) and OSNA in intraoperative SLNB, a two-scenario comparative model that was structured using the clinical pathway of a BC patient group who received SLNB was applied. Clinical practice guidelines for BC were cited for cost estimation.

RESULTS

The total estimated cost of all BC patients diagnosed by GS was US$1,023,313,850. The budget impact of OSNA in total health expenditure was -US$24,413,153 (-US$346 per patient). Two-way sensitivity analysis between survival rate (SR) of the GS and OSNA was performed by illustrating a cost-saving threshold: y ≅ 1.14x - 0.16 in positive patients, and y ≅ 0.96x + 0.029 in negative patients (x = SR-GS, y = SR-OSNA). Base inputs of the variables in these formulas demonstrated a cost saving.

CONCLUSION

OSNA reduces healthcare costs, as confirmed by sensitivity analysis.

Triple assessment of sentinel lymph node metastasis in early breast cancer using preoperative CTLG, intraoperative fluorescence navigation and OSNA

BACKGROUND

Sentinel lymph node biopsy (SLNB) became a standard surgical procedure for patients with early breast cancer; however, the optimal method of sentinel lymph node (SLN) identification remains controversial. The current study presents the protocol of our institution for preoperative and intraoperative SLN detection.

METHODS

Fifty female patients with early breast cancer and clinically node-negative axilla were enrolled in this study. All patients underwent preoperative CT lymphography (CTLG), intraoperative SLNB using fluorescence navigation, intraoperative one-step nucleic acid amplification (OSNA) and postoperative hematoxylin and eosin histopathological analysis. Prediction of metastasis by CTLG and detection of metastasis by OSNA were compared to results of histopathology as standard reference.

RESULTS

SLN were identified by preoperative CTLG and intraoperative SLNB with fluorescence navigation in all patients, the identification rate was 100 %. SLN metastases were detected as positive by OSNA in 9 patients (18 %), 4 were (++), 4 were (+) and 1 was (+I). SLN metastases were detected as positive by histopathology in 10 patients (20 %). The concordance rate between OSNA and permanent sections was 90 %. The negative predictive value of CTLG was 80 %.

CONCLUSION

Use of CTLG and fluorescence navigation made performing SLNB with high accuracy possible in institutions that cannot use the radioisotope method. OSNA provided accurate intraoperative method, allowing for completion of axillary node dissection during surgery and avoidance of second surgical procedure in patients with positive SLNs, thereby reducing patient distress and, finally, saving hospital costs.

Detailed evaluation of one step nucleic acid (OSNA) molecular assay for intra-operative diagnosis of sentinel lymph node metastasis and prediction of non-sentinel nodal involvement: experience from a London teaching hospital

One step nucleic acid (OSNA) is a molecular diagnostic assay for intra-operative detection of sentinel node metastases. This study compared OSNA with standard histopathology in 283 nodes from 170 patients to evaluate sensitivity, specificity and concordance of the two methods. Additional analysis was done to investigate how cytokeratin 19 mRNA copy number affects prediction of non-sentinel node positivity. OSNA sensitivity was 93.2% and specificity 95.8%. Concordance between OSNA and histology was 95.6%. In the patients who had axillary clearance, the OSNA mRNA copy number on the sentinel node had 100% negative predictive value for histologically proven metastasis. mRNA copy numbers <1400 were not associated with histologically proven metastasis in subsequent nodes at axillary clearance. OSNA is a reliable method for the intra-operative evaluation of axillary lymph node metastasis even when half of the lymph node is used. Identification of mRNA copy number threshold predicting the positivity of non-sentinel axillary nodes seems to be feasible and would be clinically important.

A differential intra-operative molecular biological test for the detection of sentinel lymph node metastases in breast carcinoma. An extended experience from the first U.K. centre routinely offering the service in clinical practice

INTRODUCTION

One-Step Nucleic acid Amplification (OSNA) is a molecular biological assay of cytokeratin-19 (a breast epithelial marker) mRNA. It can be employed intra-operatively for detection of lymph node metastases in breast carcinoma. Patients with positive sentinel nodes may proceed to axillary lymph node dissection (ALND) level I or higher dependent upon the OSNA quantitative result, during the same surgical procedure, avoiding a second operation and eliminating the technical difficulties possibly associated with delayed ALND.

AIMS

Our Breast Unit was the first in the UK to implement this novel technique in routine practice. This study reviews our first 44-month data following introduction of OSNA "live" on whole sentinel nodes following an extensive validation study (Snook et al.).(9) METHODS: Data was collected prospectively from the period of introduction 01/12/2008 to 30/08/2012. All patients eligible for sentinel node biopsy were offered OSNA and operations were performed by five consultant breast surgeons. On detection of macro-metastasis a level II/III and for a micro-metastasis a level I ALND was performed.

RESULTS

A total of 859 patients (1709 sentinel lymph nodes) were analysed. All except one were females. The majority underwent wide local excision (73.4%, n = 631) or mastectomy 25% (n = 215) and 1.6% (13) underwent SLN biopsy alone. IDC was seen in 79% (n = 680) of the patients and 53.5% (n = 460) had grade II tumours. One-third (30.8%, n = 265) had positive sentinel nodes and had further axillary surgery at the time of SLN biopsy. Of these, 47% (n = 125/265) had macro-metastases, 38% (n = 101/265) had micro-metastases and 14.7% (n = 39/265) had "positive but inhibited" results. Positive non-sentinel lymph nodes (NSLN) were seen in 35% (44/125) of those with macro-metastases; 17.8% (18/101) of the patients with micro-metastases and 10.2% (4/39) of the "positive but inhibited" group.

CONCLUSION

In our series over a third of our patients had positive lymph nodes detected with OSNA allowing them to proceed directly to axillary surgery at the same operation. This technique eliminates the need for a second operation in sentinel lymph node positive patients and avoids the anxiety waiting for histological results.

Achieving breast cancer surgery in a single setting with intraoperative frozen section analysis of the sentinel lymph node

BACKGROUND

Current guidelines recommend full axillary lymph node dissection (ALND) whenever the SLN is positive for metastases. In our institute, we aim to complete surgery in a single setting and base the decision for ALND on the intraoperative FS analysis of the SLN. In this study, we evaluate the efficacy this practice in terms of the accuracy of FS analysis, patient recall rate, and additional time required for FS analysis.

MATERIALS AND METHODS

Retrospective review was performed of 586 patients who underwent SLN biopsy at our institution from January 1, 2006 to December 31, 2010. Intraoperative FS analysis was routinely performed in all cases with a preoperative diagnosis of invasive breast cancer and in selected cases of ductal carcinoma in situ according to surgeon preference.

RESULTS

The SLN was positive for metastases in 123 (22.7%) patients; this was identified on FS analysis in 107 patients. FS analysis had a sensitivity of 87.0% and specificity of 100% and resulted in a patient recall rate of 3%. Micrometastasis accounted for most of the false negative FS results. These deposits were mostly detected only on deeper sectioning of the permanent sections of the SLN. An invasive lobular histology and lymphovascular invasion were found to be independent predictors of a false negative FS on multivariate analysis (P < .01). Intraoperative FS did not significantly prolong operating times.

CONCLUSION

Intraoperative FS analysis is an accurate and efficient means of rapid SLN assessment and allows ALND to be completed in a single setting.

Reliability of frozen section in breast sentinel lymph node examination

OBJECTIVES

Sentinel lymph node (SLN) examination in breast carcinoma is crucial to spare patients unnecessary lymph node (LN) dissection. The specificity and accuracy of SLN examination by frozen section has been variable in many studies. This study aims to describe our experience in frozen section (FS) analysis of SLN.

METHODS

We have retrospectively analyzed data from 449 axillary SLN subjected to FS examination from 440 patients with breast cancer. All patients had free axillary LN clinically.

RESULTS

Out of 449 cases, no false positive cases were found on FS (specificity of 100 %). Twenty-six cases were false negative (6 interpretation-related reasons and 20 technical-related reasons). The overall sensitivity was 84 % with a total accuracy rate of 93 % and interpretation sensitivity of 96 %. Three cases were deferred. Twenty-two of the false negative cases were micrometastases, whereas 4 were macrometastases. The interpretation-related false negative cases were not related to the subtype of carcinoma (ductal vs. lobular). However, they were all of low nuclear grade.

CONCLUSION

These findings are similar to most published data. FS is a reliable method for evaluating SLN. The most common cause of false negative diagnosis is sampling error. More attention should be paid to low-grade tumors. Moreover, in FS analysis, we recommend to totally submit SLNs that are less than 5 mm in diameter, bisecting them if possible, and to serially section SLNs that are at least 5 mm at 2-mm intervals.

The presence of sinusoidal CD163(+) macrophages in lymph nodes is associated with favorable nodal status in patients with breast cancer

As macrophages are some of the first cells to encounter metastatic tumor cells in sentinel lymph nodes (SLN) and natural killer (NK) cells are critical to the cytotoxicity of abnormal cells, we sought to determine if these cell populations were altered in the presence of nodal metastasis. We used immunohistochemistry to assess the SLN of 47 patients with breast cancer (36 with nodal metastasis and 11 without nodal metastasis) and 10 control lymph nodes. We assessed metastatic areas and nonmetastatic areas separately for CD163, a marker of macrophages, and ANK-1, a marker for precursors of activated NK cells. Positively stained cells were manually counted in multiple high-power fields and averaged. Groups were compared with the Kruskal-Wallis test. Spearman rank order test was used for correlations. There was a lower frequency of CD163(+) macrophages in the SLN of patients with breast cancer (median, 11.0 %; range, 4.1-20.4 %) than controls (median, 16.5 %; range, 8.9-19.6 %; p = 0.002). There were no differences in the expression of ANK between patients with cancer (median, 1.4 %; range, 0.23-6.3 %) and controls (median, 1.5 %; range, 0.60-5.4 %; p = 0.5). In patients with nodal metastasis, the accumulation of CD163(+) cells in the sinuses correlated negatively with CD8(+) tumor-infiltrating lymphocytes (r (2) = 0.23; p = 0.001). These results suggest that the reduction of CD163(+) macrophages in the sinuses of the SLN is associated with nodal metastasis and may have a role in regional immunity.

Metastasis to sentinel lymph nodes in breast cancer is associated with maturation arrest of dendritic cells and poor co-localization of dendritic cells and CD8+ T cells

The regional immune systems of patients with breast cancer are immunosuppressed. Dendritic cells are professional antigen-presenting cells and present cancer-associated antigens to the adaptive immune system in sentinel lymph nodes. Dendritic cells may promote, or inhibit, an adaptive immune response to specific antigens. Our aim was to assess whether dendritic cells were associated with nodal metastasis in patients with breast cancer. Sentinel lymph nodes of 47 patients with breast cancer with varying degrees of nodal disease and ten controls were evaluated using immunohistochemistry for the accumulation of dendritic cells in general (CD1a(+)), mature dendritic cells (CD208(+)), and plasmacytoid dendritic cells (CD123(+)). Cytotoxic T cell and regulatory T cell accumulation were also evaluated. Sentinel lymph nodes with macrometastases demonstrated fewer mature dendritic cells than sentinel lymph nodes without metastasis (p = 0.028), but not controls. There were fewer mature dendritic cells to cytotoxic T cells in sentinel lymph nodes with metastasis than those without (p = 0.033). Also, there were more regulatory T cells to mature dendritic cells in sentinel lymph nodes with metastasis than those without (p = 0.02). In conclusion, our study suggests that sentinel lymph nodes with metastasis have arrest of maturation of dendritic cells, fewer mature dendritic cell interactions with cytotoxic T cells, and more regulatory T cells than sentinel lymph nodes without metastasis in patients with breast cancer. These findings extend our understanding of regional immunosuppression and suggest that most regional immunosuppressive changes are associated with nodal metastasis in breast cancer.

Intraoperative assessment of sentinel lymph nodes in breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) reduces the morbidity of axillary clearance and is the standard of care for patients with clinically node-negative breast cancer. The ability to analyse the sentinel node during surgery enables a decision to be made whether to proceed to full axillary clearance during primary surgery, thus avoiding a second procedure in node-positive patients.

METHODS

Current evidence for intraoperative sentinel node analysis following SLNB in breast cancer was reviewed and evaluated, based on articles obtained from a MEDLINE search using the terms 'sentinel node', 'intra-operative' and 'breast cancer'.

RESULTS AND CONCLUSION

Current methods for evaluating the sentinel node during surgery include cytological and histological techniques. Newer quantitative molecular assays have been the subject of much recent clinical research. Pathological techniques of intraoperative SLNB analysis such as touch imprint cytology and frozen section have a high specificity, but a lower and more variably reported sensitivity. Molecular techniques are potentially able to sample a greater proportion of the sentinel node, and could have higher sensitivity.

Multicentre evaluation of intraoperative molecular analysis of sentinel lymph nodes in breast carcinoma

Background

Ideally, intraoperative sentinel lymph node (SLN) analysis in breast cancer should be automated, have high concordance with extensive histopathology, and be applicable in any hospital setting. A prospective multicentre evaluation of the one-step nucleic acid amplification (OSNA) automated molecular diagnostic system of SLN analysis was undertaken.

Methods

Intraoperative examination of SLNs from 204 patients with breast cancer was performed by OSNA at four sites in the UK. Half of each SLN was assessed by OSNA (for cytokeratin 19 mRNA) and the remaining half was paraffin embedded for intensive histological examination at ten levels. Discordant cases were reanalysed by further molecular biological techniques and by additional histological examination of all remaining nodal material to ascertain whether the discordance was due to an uneven distribution of metastases, known as tissue allocation bias (TAB).

Results

After exclusion of samples affected by TAB, the overall concordance rate for OSNA versus histopathology was 96·0 per cent, with a sensitivity of 91·7 per cent and a specificity of 96·9 per cent. The median time to process a single SLN was 32 (range 22–97) min, and that for two nodes 42 (30–73) min.

Conclusion

OSNA enables accurate automated intraoperative diagnosis and can be used successfully in different UK hospitals. When the SLN is shown to be positive, the patient can undergo immediate axillary clearance under the same anaesthetic rather than having a delayed second procedure.

Modified Alcian blue enhances the intraoperative diagnosis of sentinel lymph node metastasis in invasive lobular carcinoma: a prospective study

CONTEXT

The sensitivity of an intraoperative diagnosis of sentinel lymph node metastasis of invasive lobular carcinoma using conventional staining is low.

OBJECTIVE

To develop a fast, modified, Alcian blue stain to decrease the intraoperative false-negative results in testing for metastatic invasive lobular carcinoma.

DESIGN

Modified Alcian blue was optimized. Patients who had invasive lobular carcinoma on needle biopsy were candidates for this study. Touch preparations from every sentinel lymph node were prospectively prepared in the same manner, one stained with modified Alcian blue and one with conventional staining. These slides were independently interpreted.

RESULTS

A total of 121 sentinel lymph nodes from 31 patients with invasive lobular carcinoma were studied. There were 11 patients (35.5%) who had at least one positive lymph node test result. There were a total of 18 positive lymph node results (14.9%). Although 10 sentinel lymph nodes with abnormalities were detected in 7 patients with conventional staining, modified Alcian blue detected 15 sentinel lymph node abnormalities in 10 patients. Modified Alcian blue increased the sensitivity compared with conventional staining from 63.6% to 90.9% (calculated based on the number of patients) and from 55.6% to 83.3% (calculated based on number of sentinel lymph nodes). The staining process takes approximately 11 minutes.

CONCLUSIONS

Modified Alcian blue stain is a relatively rapid, cheap, highly sensitive, and specific method of detecting metastatic invasive lobular carcinoma. This method can be used in conjunction with conventional staining methods used intraoperatively.

Intraoperative assessment of sentinel node using imprint cytology

BACKGROUND

Sentinel lymph node (SLN) biopsy has replaced axillary sampling as the axillary staging procedure of choice in patients with breast cancer. Accurate intraoperative evaluation of the SLN would allow axillary lymph node clearance to be performed during the initial operation when the SLN is positive for metastatic disease. The aim of the present study was to assess the accuracy of intraoperative imprint cytology (IC) of the SLN in two different institutions in the United Kingdom.

METHODS

All breast cancer patients who underwent a SLN biopsy using a standard protocol in two hospital breast units were included. The SLN was sent fresh to the pathology laboratory, where it was immediately processed and examined by a cytopathologist using IC. The intraoperative IC results were compared with the final histopathological results. No therapeutic decisions were made based on the results of IC in this study.

RESULTS

A total of 166 patients were included, with 47 positive and 119 negative cases on final histology. Of the 47 patients who were positive on final histology, there were 29 positive and 18 negative cases on IC (sensitivity = 61.7%). All 119 patients who were negative on final histology were negative on IC (specificity, 100%). The negative and positive predictive value of the final histology was 86.9% and 100%, respectively. The accuracy of IC was 89.2%.

CONCLUSIONS

The results from these two breast units are comparable with findings reported in the published literature, confirming that IC can be used to assess SLN biopsy intraoperatively. No unnecessary axillary node clearance would have been carried out based on the results of IC.

Simultaneous Foxp3 and IDO expression is associated with sentinel lymph node metastases in breast cancer

Background

There is evidence that the immune systems of patients with breast cancer are dysfunctional. Regulatory T cells (Tregs), and IDO, an immunosuppressive enzyme, are associated with more advanced disease in some cancers and may promote immunologic tolerance to tumors. Our aim was to assess whether expression of Foxp3, a marker of Tregs, and IDO were linked with nodal metastasis in breast cancer patients. Inhibitors of IDO are available and could potentially demonstrate utility in breast cancer if IDO drives progression of disease.

Methods

Sentinel lymph nodes (SLN) of 47 breast cancer patients with varying degrees of nodal disease and 10 controls were evaluated for expression of Foxp3 and IDO using immunohistochemistry. Positively stained cells were quantified and their distribution within the SLN noted.

Results

The proportion of Foxp3⁺ cells was higher in SLN of cancer patients than controls (19% v. 10%, p < 0.001). Specifically, there were more Foxp3⁺ cells in SLN with metastasis than tumor-free SLN (20% v. 14%, p = 0.02). The proportion IDO⁺ cell in SLN of cancer patients was not statistically different than controls (4.0% v. 1.6%, p = 0.08). In order to demonstrate the combined immunosuppressive effect of Foxp3 and IDO, we categorized each SLN as positive or negative for Foxp3 and IDO. The Foxp3⁺/IDO⁺ group almost exclusively consisted of cancer patients with node positive disease.

Conclusion

In conclusion, our study shows that Foxp3⁺ cells are associated with more advanced disease in breast cancer, a finding that is proving to be true in many other cancers. As IDO has been found to promote differentiation of Tregs, IDO may become a suitable target to abrogate the development of T-cell tolerance and to promote an effective immune response to breast cancer. Our results about the combined expression of IDO and Foxp3 in metastastic SLN support this assumption.

A prospective study comparing touch imprint cytology, frozen section analysis, and rapid cytokeratin immunostain for intraoperative evaluation of axillary sentinel lymph nodes in breast cancer

BACKGROUND

The intraoperative evaluation of axillary sentinel lymph nodes (SLNs) allows the surgeon to complete axillary dissection in 1 setting at the time of the primary breast surgery. However, to the authors' knowledge, there is no consensus regarding the optimal method for intraoperative evaluation of SLNs in breast cancer. The authors of this report prospectively compared touch imprint (TI) cytology with frozen section (FS) analysis and rapid cytokeratin immunostaining (RCI) of SLNs for the intraoperative evaluation of disease and compared the results with final pathologic examination (FP).

METHODS

Patients with invasive breast carcinoma who were diagnosed with lymph node-negative disease (based on preoperative clinical and sonographic evaluation with or without fine-needle aspiration of the indeterminate lymph nodes) and who subsequently were scheduled for lymphatic mapping were eligible to participate in this prospective protocol. TI and FS analysis were performed on all SLNs, and the lymph nodes were stained by the hematoxylin and eosin (H&E) method. RCI was performed using the enhanced polymer 1-step cytokeratin method. The results of TI, FS, RCI, TI plus FS, and FS plus RCI were compared with the results from FP, including 1 H&E stain and cytokeratin immunostain of the third level.

RESULTS

One hundred patients with invasive mammary carcinoma were accrued to the study. Eighty-five tumors were the ductal type, 8 tumors were lobular, 5 tumors were mixed ductal and lobular, 1 was an adenoid cystic tumor, and 1 tumor was metaplastic carcinoma. Seventy-two tumors were staged clinically as T1N0M0, 25 tumors were staged as T2N0M0, and 3 tumors were staged as T3N0M0. Metastatic carcinoma was detected in the SLNs by 1 or more methods, including TI, FS, RCI, and FP, in 20 tumors, which included 12 macrometastases and 8 micrometastases. TI detected 8 of 12 macrometastases (67%), FS detected 12 of 12 macrometastases (100%), RCI detected 12 of 12 macrometastases (100%), and FP detected 12 of 12 macrometastases (100%). TI detected 1 of 8 micrometastases (13%), FS detected 3 of 8 micrometastases (38%), RCI detected 4 of 8 micrometastases (50%), and FP detected 6 of 8 micrometastases (75%). The sensitivities of TI, FS, RCI, TI plus FS, and FS plus RCI (with FP as the gold standard) were 50%, 72%, 78%, and 83%, respectively, and the sensitivities of the same intraoperative methods were 45%, 75%, 80%, and 85%, respectively, with detection of metastatic disease by any method as the gold standard. The specificities of the different methods (with FP as the gold standard) were 100% for TI and 97.5% for FS, RCI, TI plus FS, and FS plus RCI. The specificity of each method was 100% when the detection of metastatic disease by any method was regarded as the gold standard. Although the difference in sensitivity between FS and TI was not statistically significant (P = .08), the difference between RCI and TI bordered on significance (P = .046); however, FS analysis plus RCI was significantly superior to TI (P = .03) and produced results comparable to those of FP.

CONCLUSIONS

The sensitivities of FS, RCI, TI plus FS, and FS plus RCI were better than the sensitivity of TI cytology of axillary SLNs. However, only the combination of FS and RCI was statistically superior to TI and generated results comparable to those of FP in SLNs. RCI can be completed within the time constraints for intraoperative use and, in conjunction with FS, can be useful for generating results closer to those generated by FP. FS analysis plus RCI have a role in the intraoperative evaluation of SLNs.

Comparison of intraoperative frozen section analysis for sentinel lymph node biopsy during breast cancer surgery for invasive lobular carcinoma and invasive ductal carcinoma

BACKGROUND

Sentinel lymph node (SLN) biopsy is the standard of care for the surgical assessment of the axilla during breast cancer surgery. However, the diagnostic accuracy of intraoperative frozen section analysis for confirming metastatic involvement of SLNs in cases of invasive lobular carcinoma (ILC) versus that of invasive ductal carcinoma (IDC) has generated controversy secondary to a frequently low-grade cytologic appearance and an often discohesive pattern displayed by metastatic lymph nodes in ILC. In the current report, we present a comparison of intraoperative frozen section analysis for confirming the presence of metastatic disease within SLNs during breast cancer surgery for ILC and IDC.

METHODS

We evaluated the results of 131 consecutive cases of ILC from 1997 to 2008 and 133 cases of IDC (selected by a random sequence generator program) from amongst 1163 consecutive cases of IDC from the same time period. All cases had at least one SLN that had both intraoperative frozen section analysis and confirmatory permanent section analysis performed.

RESULTS

No statistically significant difference was found in the sensitivity (67% vs. 75%, P = 0.385), specificity (100% vs. 100%), accuracy (86% vs. 92%, P = 0.172), false negative rate (33% vs. 25%, P = 0.385), negative predictive value (81% vs. 89%, P = 0.158), and positive predictive value (100% vs. 100%) for frozen section analysis for confirming the presence of metastatic disease within SLNs during breast cancer surgery for ILC and IDC.

CONCLUSION

Since there was no statistically significant difference in sensitivity, specificity, accuracy, false negative rate, negative predictive value, and positive predictive value between frozen section analysis of SLNs for patients with ILC and IDC, the clinical accuracy of confirming metastatic involvement of SLNs on frozen section analysis for ILC should not be considered inferior to the clinical accuracy for IDC. Therefore, frozen section analysis of all SLNs during breast cancer surgery in patients with ILC should remain the standard of care in order to reduce the risk of the need of a later, separate axillary lymph node dissection.

Intraoperative cytologic evaluation of sentinel lymph nodes in patients with breast carcinoma by scrape preparation

Intraoperative evaluation of sentinel lymph nodes (SLNs) in patients with breast carcinoma allows surgeons to complete axillary lymph node dissection in one procedure if any SLN shows metastasis. The accuracy of intraoperative pathological diagnosis is critical for decision-making. The purpose of this study was to evaluate our rapid intraoperative cytologic diagnosis of SLN through comparing with the final surgical pathologic diagnosis of the corresponding lymph nodes. A total of 454 SLNs from 159 consecutive female patients with a preoperative diagnosis of breast carcinoma over 3-year period were included in this study. After gross examination of each bisected lymph node, a scrape preparation was prepared for each submitted lymph node and was stained by the rapid Papanicolaou method. The intraoperative cytologic diagnosis was compared with the final surgical pathologic diagnoses. The overall sensitivity of intraoperative cytology was 52.5% with specificity of 100%. There were 17 false-negative cases. Of them, six nodes had isolated tumor cells, seven nodes had micrometastasis (0.2-2 mm), and four nodes had macrometastasis (>2 mm). There were no interpretive errors identified. The size of metastasis and tumor grade appeared to be significant factors in detecting metastasis by cytology. In addition, subsequent non-SLN involvement was 9% in patients with micrometastasis versus 50% in patients with macrometastasis (P < 0.05). Our study shows that the intraoperative cytologic evaluation of SLNs in breast carcinoma is a reasonably accurate method. The majority of false-negative cases were due to micrometastasis and isolated tumor cells.

One-step nucleic acid amplification for intraoperative detection of lymph node metastasis in breast cancer patients

PURPOSE

Detection of sentinel lymph node (SLN) metastasis in breast cancer patients has conventionally been determined by intraoperative histopathologic examination of frozen sections followed by definitive postoperative examination of permanent sections. The purpose of this study is to develop a more efficient method for intraoperative detection of lymph node metastasis.

EXPERIMENTAL DESIGN

Cutoff values to distinguish macrometastasis, micrometastasis, and nonmetastasis were determined by measuring cytokeratin 19 (CK19) mRNA in histopathologically positive and negative lymph nodes using one-step nucleic acid amplification (OSNA). In an intraoperative clinical study involving six facilities, 325 lymph nodes (101 patients), including 81 SLNs, were divided into four blocks. Alternate blocks were used for the OSNA assay with CK19 mRNA, and the remaining blocks were used for H&E and CK19 immunohistochemistry-based three-level histopathologic examination. The results from the two methods were then compared.

RESULTS

We established CK19 mRNA cutoff values of 2.5 x 10(2) and 5 x 10(3) copies/muL. In the clinical study, an overall concordance rate between the OSNA assay and the three-level histopathology was 98.2%. Similar results were obtained with 81 SLNs. The OSNA assay discriminated macrometastasis from micrometastasis. No false positive was observed in the OSNA assay of 144 histopathologically negative lymph nodes from pN0 patients, indicating an extremely low false positive for the OSNA assay.

CONCLUSION

The OSNA assay of half of a lymph node provided results similar to those of three-level histopathology. Clinical results indicate that the OSNA assay provides a useful intraoperative detection method of lymph node metastasis in breast cancer patients.

Patients' view on intraoperative diagnosis of sentinel nodes in breast cancer: Is it an automatic choice?

Intraoperative detection of sentinel node metastases in breast cancer enables immediate axillary lymph node dissection. This approach, however, introduces uncertainty for patients as to the extent of surgery. Waking to find a surgical drain implies more extensive surgery and worse prognosis disease. False negative diagnoses may cause disappointment.

AIM

To evaluate patients' views and preferences on intraoperative diagnosis of sentinel nodes in breast cancer.

METHODS

Questionnaire based survey of 100 patients who had previously undergone sentinel node biopsy with intraoperative diagnosis using touch imprint cytology (TIC). Patients were encouraged to add free text comments.

RESULTS

Sixty-four patients responded to the questionnaire. Patients rated the information provided and their understanding of the procedure highly. Fifty-nine percent of respondents overestimated the sensitivity of TIC. Ninety-five percent of patients would choose to undergo intraoperative diagnosis in future if required. Five percent of patients would choose not to undergo intraoperative diagnosis, citing the resultant uncertainty, disappointment on waking and needing time to come in terms with the diagnosis of metastases as reasons.

CONCLUSION

Given the choice, most patients would choose intraoperative diagnosis, though a minority would explicitly not, due to the adverse psychological effect thereof. Despite a good understanding of the procedure, the majority of patients overestimate the sensitivity of intraoperative diagnosis of sentinel nodes, which may heighten disappointment when a false negative diagnosis occurs. Intraoperative diagnosis should not be the automatic choice and patients should be actively involved in this decision making process.

Evaluation of Intraoperative Scrape Cytology for Sentinel Lymph Node Biopsy in Patients with Breast Cancer

The techniques for intraoperative evaluation of sentinel lymph nodes (SLNs) vary. The most common methods include frozen section, imprint cytology/touch preparation cytology, and scrape cytology (SC). The purpose of this study was to evaluate whether there is concordance between the intraoperative SC and the final pathology of SLNs in patients with breast cancer. From October 2001 to June 2005, sentinel lymph node biopsies were attempted in 181 patients with breast cancer using a combination of blue dye and radioisotope. A lymph node was considered an SLN when it was stained with blue dye, had a blue lymphatic afferent, had increased radioactivity, or was abnormal by palpation. SLNs were successfully identified in 180 patients, for an identification rate of 99.4%. Forty-five patients had positive SLNs. In 16 (35%) of those patients, the SLNs were negative intraoperatively by SC. All of the false negatives occurred in SLNs with micrometastases. Thus, SC is an excellent method for identifying macrometastases intraoperatively, but less successful for micrometastases.

Positive and negative aspects of sentinel lymph node biopsy in breast cancer

The sentinel lymph node (SLN) is the first lymph node to receive lymphatic drainage from a tumor. SLN biopsy has become a mainstay of breast cancer management and is used when the axilla is clinically clear of disease. Staging of the axilla in breast cancer is used to predict prognosis and in planning adjuvant treatment. SLN biopsy is not used where there has been previous axillary or breast radiotherapy or surgery, locally advanced or inflammatory disease and stage IV disease. Controversies remain in several specific clinical situations, including management of the axilla following detection of a positive SLN. There are no sufficiently robust predictive tumor features to prevent completion axillary dissection in these cases. However, there is evidence that immediate axillary surgery for operable, clinically node-negative breast cancer provides no survival benefit and may be unnecessary for many women. SLN biopsy may have a role after neoadjuvant chemotherapy, sparing some women from axillary node dissection. Further work is required to ascertain SLN biopsy sensitivity prior to its routine use in the clinic for multicentric and multifocal disease.

Intraoperative imprint cytology of sentinel lymph nodes in breast cancer: initial experience and lessons learnt in establishing a new practice

AIMS

The initial 18 months experience of performing intraoperative imprint cytology for patients with breast cancer undergoing sentinel lymph node biopsy is described for a single institution. The learning process is compared with published results from institutions with many years of experience in order to assess progress in reaching those ideal results, and the methodology used by these institutions is reviewed.

METHODS

A retrospective review was undertaken of the intraoperative imprint cytology results from 103 patients with breast cancer (yielding a total of 170 lymph nodes) who underwent imprint cytology of their sentinel lymph node. The intraoperative imprint cytology results were compared with the final histopathological results. Details regarding the primary tumour characteristics and metastatic deposit size were recorded.

RESULTS

The sensitivity for imprint cytology was 31.1%, with a specificity of 100% and overall accuracy of 77.8%. The sensitivity for detecting macrometastases (>2 mm diameter) was 61.9% and the sensitivity for micrometastases (<2 mm diameter) and including isolated tumour cells was 4.2%.

CONCLUSIONS

The differences in sensitivity in comparison with many studies in the literature are multifactorial, and include technical aspects, such as the methodology used in the final histopathological and intraoperative evaluation of the sentinel lymph nodes, interpretative difficulties, and much lower case numbers. Furthermore, these numbers represent early experience and methods to improve sensitivity and overall accuracy are detailed in this paper.

Frozen section is superior to imprint cytology for the intra-operative assessment of sentinel lymph node metastasis in stage I breast cancer patients

Background

A standard intra-operative procedure for assessing sentinel lymph node metastasis in breast cancer patients has not yet been established.

Patients and methods

One hundred and thirty-eight patients with stage I breast cancer who underwent sentinel node biopsy using both imprint cytology and frozen section were analyzed.

Results

Seventeen of the 138 patients had sentinel node involvement. Results of imprint cytology included nine false negative cases (sensitivity, 47.1%). In contrast, only two cases of false negatives were found on frozen section (sensitivity, 88.2%). There were two false positive cases identified by imprint cytology (specificity, 98.3%). On the other hand, frozen section had 100% specificity.

Conclusion

These findings suggest that frozen section is superior to imprint cytology for the intra-operative determination of sentinel lymph node metastasis in stage I breast cancer patients.

Intraoperative touch imprint cytology for the diagnosis of sentinel lymph node metastases in breast cancer

Background

Intraoperative detection of sentinel lymph node (SLN) metastases enables the surgeon to take an immediate decision to proceed to completion axillary lymph node dissection (ALND). The aim of this study was to determine the accuracy of touch imprint cytology (TIC) for the diagnosis of SLN metastases in sentinel nodes from women with breast cancer.

Methods

Touch imprints from 235 sentinel nodes in 133 women with breast cancer were diagnosed by cytopathology and compared with definitive histopathology results. After a feasibility study, a real-time study was performed with the surgeon proceeding to ALND based on the TIC diagnosis. The clinical opinion of the operating surgeon as to whether the SLN appeared to contain metastases was recorded, as was the time taken for the result to be available.

Results

TIC detected metastases with a sensitivity of 81·1 per cent and a specificity of 100 per cent. False-negative TIC diagnoses were associated with micrometastases and lobular carcinoma. The majority of false-negative diagnoses were due to sampling rather than interpretation errors. Clinical assessment of sentinel nodes had a sensitivity of 64·3 per cent and a specificity of 87·6 per cent.

Conclusion

TIC is feasible and enables the rapid diagnosis of SLN metastases with an acceptable accuracy for clinical use in ductal carcinoma of the breast.

Meta-analysis of sentinel node imprint cytology in breast cancer

BACKGROUND

Intraoperative diagnosis of breast cancer metastases in axillary sentinel nodes is desirable to avoid a second operation for lymphadenectomy. Imprint or touch-preparation cytology is a popular technique that has high specificity and a wide range of sensitivity.

METHODS

A systematic search of electronic databases was performed. Included articles were assessed for methodological and reporting quality. Random-effects model pooled estimates of sensitivity and specificity were calculated. Single-variable and multivariable meta-regression analyses were performed for predictors of sensitivity.

RESULTS

Thirty-one studies were included; all were of good methodological quality but reporting quality varied. Pooled sensitivity of imprint cytology was 63 (95 per cent confidence interval (c.i.) 57 to 69) per cent and specificity was 99 (95 per cent c.i. 98 to 99) per cent. Pooled sensitivity for macrometastases was 81 per cent and that for micrometastases 22 per cent. Mean or median primary tumour size (P = 0.004), the prevalence of metastases (P = 0.103) and the proportion of micrometastases (P = 0.022) were significant risk factors in single-variable meta-regression analysis. Only the proportion of micrometastases remained significant in multivariable analysis. Frozen sectioning had better sensitivity than imprint cytology in three of four direct comparisons.

CONCLUSION

Imprint cytology is simple and rapid, and has good sensitivity for macrometastases. The significance of poor sensitivity for micrometastases will be determined by trials investigating their natural history.

Rapid immunohistochemistry enhances the intraoperative diagnosis of sentinel lymph node metastases in invasive lobular breast carcinoma

BACKGROUND

The sensitivity of the intraoperative diagnosis of sentinel lymph node (SLN) micrometastases and the metastases of invasive lobular carcinoma (ILC) is low. The goal of the current study was to assess whether the use of intraoperative, rapid immunohistochistochemistry (IHC) enhances the intraoperative detection of micrometastases and metastases of ILC.

METHODS

The sensitivity of the intraoperative diagnosis of SLN metastasis was evaluated in 438 patients when using rapid IHC with a cytokeratin biomarker. The results were compared with those obtained for 557 patients without rapid IHC but with conventional staining.

RESULTS

For patients with ILC, the sensitivity of the intraoperative diagnosis was 87% (45 of 52) in the IHC group and 66% (39 of 59) in the non-IHC group (P = 0.02). The sensitivity of the intraoperative diagnosis was similar for patients with other types of invasive cancer regardless of the use of rapid IHC. However, rapid IHC enhanced marginally the intraoperative diagnosis of the smallest micrometastases, isolated tumor cells (P = 0.06).

CONCLUSIONS

Rapid IHC with cytokeratin labeling enhanced the intraoperative diagnosis of SLN metastases in patients with ILC. It may also improve the intraoperative diagnosis of micrometastases.

The prevalence of non-sentinel node metastases in breast cancer patients with sentinel node micrometastases

AIMS

The aim of the study was to estimate the prevalence of and risk factors for non-sentinel node (NSN) involvement in breast cancer patients with sentinel node (SN) micrometastases.

METHODS

Eighty-four patients with SN micrometastases were included. Both the SN and NSN were examined using serial sectioning and immunohistohemistry. Various indices were evaluated as possible risk factors for NSN involvement.

RESULTS

NSN involvement was found in 22/84 patients. The median size of the NSN metastases was 1.25 mm (0.01-12 mm). The NSN metastases were larger than 2 mm in 8 patients and smaller than 0.2 mm in 6 patients. NSN involvement was observed in 14/35 patients with metastatic findings in all removed SN. Three of the 23 patients with 2 or 3 tumour negative SN had NSN metastases. None of the 12 patients with 4 or more uninvolved SN had NSN metastases. NSN involvement could not excluded by other patient, tumour or sentinel node related factors.

CONCLUSIONS

Every fourth patient will have residual disease in the axilla, 10% even large metastases, if axillary clearance is omitted in patients with SN micrometastases. The risk of NSN involvement seems negligible in patients with a single SN micrometastasis and four or more healthy SN harvested.

Sentinel lymph node biopsy in male breast cancer patients

The concept of sentinel node biopsy has been validated for female breast cancer patients whereas, ALND remains the standard of care for male breast cancer patients with similar tumours. We evaluated the results of SLN biopsy in male breast cancer patients with clinically negative axillae. This study included all male breast cancer patients who underwent SLN biopsy between February 1998 and October 2003. All patients had negative axillae on clinical examination. All patients underwent pre-operative lymphoscintigraphy. SLN biopsy was performed using a combination of Patent blue V and 99mTc-radiolabelled colloidal albumin injected peritumourally. Nine patients, 26-79 years of age, were included in the study. Pre-operative lymphoscinitgraphy identified SLNs in all patients. Intraoperatively, SLNs were successfully localised in all patients. The mean number of SLNs encountered was 2.4. Five patients had a positive SLN, four a negative SLN. Five patients (one with a negative SLN, four with a positive SLN) had been elected pre-operatively to undergo ALND regardless of findings on SLN biopsy. ALND confirmed the SLN to be negative in one patient (false-negative rate: 0%) and three of the four patients with positive SLN(s) had additional positive nodes in the axilla. SLN biopsy accurately predicted axillary lymph node status in these five patients. These findings compare favourably with findings reported in the literature regarding SLN biopsy in female breast cancer patients. SLN biopsy accurately staged the axilla in male breast cancer patients and should be considered for axillary staging in male breast cancer patients with clinically negative axillae.