Sentinel node staging for breast cancer: intraoperative molecular pathology overcomes conventional histologic sampling errors

Addressing the challenges of applying precision oncology

Precision oncology is described as the matching of the most accurate and effective treatments with the individual cancer patient. Identification of important gene mutations, such as BRCA1/2 that drive carcinogenesis, helped pave the way for precision diagnosis in cancer. Oncoproteins and their signaling pathways have been extensively studied, leading to the development of target-based precision therapies against several types of cancers. Although many challenges exist that could hinder the success of precision oncology, cutting-edge tools for precision diagnosis and precision therapy will assist in overcoming many of these difficulties. Based on the continued rapid progression of genomic analysis, drug development, and clinical trial design, precision oncology will ultimately become the standard of care in cancer therapeutics.

Intraoperative diagnosis of sentinel lymph node metastases in breast cancer treatment with one-step nucleic acid amplification assay (OSNA)

INTRODUCTION

The aim of the study was to evaluate the clinical usefulness of a one-step nucleic acid amplification assay (OSNA) for intraoperative detection of metastases to sentinel lymph nodes (SLNs) in comparison to examination of frozen sections, and to summarize the results of previous studies.

MATERIAL AND METHODS

We enrolled 98 patients aged 58.13 ±10.74 years treated surgically for breast cancer, and 99 biopsies of SLNs were followed by analysis of 105 SLNs. The central 1 mm slice of SLN was used for examination of frozen sections, whereas 2 outer slices of SLNs were analyzed intraoperatively with OSNA. Detection of isolated tumor cells (ITC), micrometastases or macrometastases with OSNA extended surgery to axillary lymph node dissection. Congruency of results was assessed between OSNA and examination of frozen sections.

RESULTS

One-step nucleic acid amplification assay detected metastases in 29/105 SLNs in surgery of 27/99 breasts, including ITC in 3/29 SLNs, micrometastases in 12/29 and macrometastases in 14/29. One-step nucleic acid amplification assay detected significantly more metastases to SLNs than examination of frozen sections (p < 0.0001). All 8 inconsistent results were positive in OSNA and negative in examination of frozen sections; ITC were identified in 2/8 SLNs and micrometastases in 6/8 SLNs. Sensitivity for OSNA was calculated as 100%, specificity as 90.47%, and κ was 79.16%.

CONCLUSIONS

One-step nucleic acid amplification assay analysis allows rapid and quantitative detection of mRNA CK19 with high specificity and a low rate of false positives. One-step nucleic acid amplification assay is a reliable tool for intraoperative diagnosis of whole SLNs during surgery of breast cancer. One-step nucleic acid amplification assay minimizes the need for secondary surgery and avoids delays in the adjuvant treatment.

Evaluation of the Metasin assay for intraoperative assessment of sentinel lymph node metastases in breast cancer

AIMS

Sentinel lymph node (SLN) biopsy is the preferred surgical technique for staging the axilla in clinically node-negative breast cancer. Accurate intraoperative staging allows for the immediate performance of an axillary clearance in node-positive patients. We assessed the Metasin assay for the intraoperative analysis of SLNs in a prospective evaluation of 250 consecutive patients undergoing intraoperative SLN analysis at the Breast Unit, University Hospital, Southampton, UK.

METHODS

Metasin uses a quantitative reverse transcription PCR to detect two markers of metastasis: cytokeratin 19 (CK19) an epithelial marker and mammaglobin (MGB) a breast specific marker. Metasin results were compared with the results from routine paraffin block histopathology.

RESULTS

Metasin was robust, with a failure rate of <1%, and demonstrated excellent accuracy and reproducibility. The average turnaround time for the Metasin assay was 42 min, the largest variable being the number of nodes assayed. A total of 533 SLNs were evaluated with 75 patients testing positive for MGB and/or CK19. Based on the analysis of individual SLNs, the overall concordance between Metasin and histology was 92.3% (sensitivity 88.7%, specificity 92.9%). When adjusted for tissue allocation bias, the concordance was 93.8% (sensitivity 89.8%, specificity 94.6%). In this evaluation, 57/250 patients (23%) proceeded to axillary clearance based on Metasin results and were considered spared a second operative procedure.

CONCLUSIONS

Metasin has proven to be an accurate, reproducible and reliable laboratory test. The analysis time is acceptable for intraoperative use, and in comparison to routine histology demonstrates acceptable concordance, sensitivity and specificity.

Model predictions for the wide-angle x-ray scatter signals of healthy and malignant breast duct biopsies

Wide-angle x-ray scatter (WAXS) could potentially be used to diagnose ductal carcinoma in situ (DCIS) in breast biopsies. The regions of interest were assumed to consist of fibroglandular tissue and epithelial cells and the model assumed that biopsies with DCIS would have a higher concentration of the latter. The scattered number of photons from a 2-mm diameter column of tissue was simulated using a 110-kV beam and selectively added in terms of momentum transfer. For a 1-min exposure, specificities and sensitivities of unity were obtained for biopsies 2- to 20-mm thick. The impact of sample and tumor cell layer thicknesses was studied. For example, a biopsy erroneously estimated to be 8 mm would be correctly diagnosed if its actual thickness was between 7.3 and 8.7 mm. An 8-mm thick malignant biopsy can be correctly diagnosed provided the malignant cell layer thickness is [Formula: see text]. WAXS methods could become a diagnostic tool for DCIS within breast biopsies.

A multicentre validation of Metasin: a molecular assay for the intraoperative assessment of sentinel lymph nodes from breast cancer patients

AIMS

Treatment strategies for breast cancer continue to evolve. No uniformity exists in the UK for the management of node-positive breast cancer patients. Most centres continue to use conventional histopathology of sampled sentinel lymph nodes (SLNs), which requires delayed axillary clearance in up to 25% of patients. Some use touch imprint cytology or frozen section for intraoperative testing, although both have inherent sensitivity issues. An intraoperative molecular diagnostic approach helps to overcome some of these limitations. The aim of this study was to assess the clinical effectiveness of Metasin, a molecular method for the intraoperative evaluation of SLNs.

METHODS AND RESULTS

RNA from 3296 lymph nodes from 1836 patients undergoing SLN assessment was analysed with Metasin. Alternate slices of tissue were examined in parallel by histology. Cases deemed to be discordant were analysed by protein gel electrophoresis. There was concordance between Metasin and histology in 94.1% of cases, with a sensitivity of 92% [95% confidence interval (CI) 88-94%] and a specificity of 97% (95% CI 95-97%). Positive and negative predictive values were 88% and 98%, respectively. Over half of the discordant cases (4.4%) were ascribed to tissue allocation bias (TAB).

CONCLUSIONS

Clinical validation of the Metasin assay suggests that it is sufficiently sensitive and specific to make it fit for purpose in the intraoperative setting.

An intra-operative RT-LAMP method allows rapid and reliable detection of sentinel lymph node metastasis in breast cancer patients

The rapid determination of metastasis in sentinel lymph nodes (SLNs) of breast cancer patients plays a significant role in the selection of a surgery strategy. Although a previous one-step nucleic acid amplification assay that uses reverse-transcription (RT) loop-mediated isothermal amplification (LAMP) has showed specific advantages over traditional pathological examination, its target marker requires optimisation. In addition to epithelial-specific CK19, the internal control gene PBGD and the breast-specific PIP were included in the new method. After the RT-LAMP primers were designed and verified using a cell line, the performance of our method was evaluated by comparing it with the corresponding result of the Food and Drug Administration approved breast lymph node (BLN) assay and routine pathological examination. One hundred and seventy-four valid SLN samples from 101 patients were collected from five hospitals. The threshold of reaction time for CK19, PIP and PBGD was defined as 16, 20 and 20 min, respectively. Compared with the BLN assay, the concordance rate of our method was 95.4% (166/174). Statistical analysis revealed that the two methods are consistent (kappa = 0.890, P < 0.001). When compared with pathological examination, the performance of our method (sensitivity = 81.3%, specificity = 89.7%, kappa = 0.691, P < 0.001) was similar to that of the BLN assay (sensitivity = 87.5%, specificity = 84.9%, kappa = 0.668, P < 0.001). This result demonstrates the potential usefulness of our method in clinical practice. In conclusion, we preliminarily established an intra-operative diagnostic method that assimilates the merits of previous assays. In contrast with the BLN assay and pathological examination, our method can be completed in 30 min and shows high sensitivity, specificity and consistency, which we consider as promising for clinical application.

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.

Novel diagnostic procedure for determining metastasis to sentinel lymph nodes in breast cancer using a semi-dry dot-blot method

We developed an easy, quick and cost-effective detection method for lymph node metastasis called the semi-dry dot-blot (SDB) method, which visualizes the presence of cancer cells with washing of sectioned lymph nodes by anti-pancytokeratin antibody, modifying dot-blot technology. We evaluated the validity and efficacy of the SDB method for the diagnosis of lymph node metastasis in a clinical setting (Trial 1). To evaluate the validity of the SDB method in clinical specimens, 180 dissected lymph nodes from 29 cases, including breast, gastric and colorectal cancer, were examined. Each lymph node was sliced at the maximum diameter and the sensitivity, specificity and accuracy of the SDB method were determined and compared with the final pathology report. Metastasis was detected in 32 lymph nodes (17.8%), and the sensitivity, specificity and accuracy of the SDB method were 100, 98.0 and 98.3%, respectively (Trial 2). To evaluate the efficacy of the SDB method in sentinel lymph node (SLN) biopsy, 174 SLNs from 100 cases of clinically node-negative breast cancer were analyzed. Each SLN was longitudinally sliced at 2-mm intervals and the sensitivity, specificity, accuracy and time required for the SDB method were determined and compared with the intraoperative pathology report. Metastasis was detected in 15 SLNs (8.6%), and the sensitivity, specificity, accuracy and mean required time of the SDB method were 93.3, 96.9, 96.6 and 43.3 min, respectively. The SDB method is a novel and reliable modality for the intraoperative diagnosis of SLN metastasis.

Metasin-an intra-operative RT-qPCR assay to detect metastatic breast cancer in sentinel lymph nodes

Nodal status is one of the most important prognostic factors in breast cancer. Established tests such as touch imprint cytology and frozen sections currently used in the intra-operative setting show variations in sensitivity and specificity. This limitation has led to the development of molecular alternatives, such as GeneSearch, a commercial intra-operative real-time quantitative Polymerase Chain Reaction (RT-qPCR) assay that allows the surgeon to carry out axillary clearance as a one-step process. Since GeneSearch has been discontinued, we have developed the replacement Metasin assay, which targets the breast epithelial cell markers CK19 and mammaglobin mRNA and identifies metastatic disease in sentinel lymph nodes. The optimised assay can be completed within 32 min (6 min for RNA preparation and 26 min instrument run time), making its use feasible in the intraoperative setting. An analysis by Metasin of 154 archived lymph node homogenates previously analysed by both parallel histology and GeneSearch showed concordance for 148 cases. The sensitivity and specificity of Metasin compared with GeneSearch were 95% (CI 83%–99%) and 97% (CI 91%–99%) respectively; compared with histology they were 95% (CI 83%–99%) and 97% (CI 91%–99%), respectively. The sensitivity and specificity of GeneSearch compared with histology were 90% (CI 77%–96%) and 97% (CI 93%–99%) respectively. The positive predictive value of Metasin was 90% and negative predictive value was 98% for both histology and GeneSearch. The positive predictive value of GeneSearch was 92% and the negative predictive value was 97% compared to histology. The discordance rates of Metasin with both GeneSearch and histology were 3.89%. In comparison, the discordance rate of GeneSearch with histology was 4.5%. Metasin’s robustness was independently evaluated on 193 samples previously analysed by GeneSearch from the Jules Bordet Institute, where Metasin yielded comparable results.

GeneSearch™ BLN Assay could replace frozen section and touch imprint cytology for intra-operative assessment of breast sentinel lymph nodes

BACKGROUND

Breast cancer sentinel lymph node (SLN) biopsy has become a common procedure. The GeneSearch™ Breast Lymph Node Assay is a real-time reverse-transcriptase polymerase chain reaction assay for detecting nodal metastases larger than 0.2 mm. The trial is a prospective multi-center clinical trial conducted to validate the assay in China.

METHODS

Four hundred and seventy-nine consecutive prospective patients were enrolled from six centers. SLNs were sectioned along the short axis into multiple blocks. Odd blocks were tested by the assay intra-operatively, and even blocks were assessed by post-operative histology. Six 4- to 6-μm-thick sections were taken every 150 μm per block. In addition, intra-operative histological assessments were performed on the even blocks of 214 patients by frozen section (FS) and all blocks of 156 patients by touch imprint cytology (TIC).

RESULTS

A total of 1046 SLNs were excised. Overall performance of the assay compared to post-operative histology was accuracy of 91.4 %, sensitivity of 87.5 %, and specificity of 92.9 %. There were no significant differences in assay performance of each center. After a learning curve of about 10 cases, the assay could be performed in a median time of about 35 min. The sensitivity of the assay was similar to the FS (84.9 %, P = 0.885) and was significantly higher than the TIC (70.0 %, P = 0.007) while the specificity of all were comparable.

CONCLUSION

The GeneSearch™ Breast Lymph Node Assay is an accurate and rapid intra-operative assay for breast SLNs and it can replace FS and TIC for application.

Reliability of whole sentinel lymph node analysis by one-step nucleic acid amplification for intraoperative diagnosis of breast cancer metastases

OBJECTIVE

To assess the reliability of using the One-Step Nucleic Acid Amplification (OSNA) assay as a single test on whole sentinel lymph nodes (SLN) as a method of intraoperative diagnosis and staging of SLNs in breast cancer.

BACKGROUND

Combining histological and molecular assessment of metastasis on the same SLN may not fully reproduce the actual load of cancer cells present in the SLN and create problems in decisions regarding axillary dissection.

METHODS

Selection criteria for the whole SLN OSNA test required that the primary tumor expressed CK19 in more than 80% of tumor cells. Imprint cytology analysis of SLNs was performed together with the OSNA.

RESULTS

Of the 279 patients enrolled for SLN evaluation, 123 gave consent to the OSNA protocol and 156 to the standard histology. Thirteen patients were excluded from OSNA evaluation because of low CK19 gene expression in the primary tumor; only 2.3% were truly negative. The kappa of concordance between the imprint cytology and OSNA results was 0.52. The rate of macrometastases determined by OSNA was 11% versus 20% determined by histology, whereas the rate of OSNA-micrometastases (18%) was significantly higher than that determined by histology (8%). The rate of SLN-negative cases was similar between the 2 protocols. Macrometastases correlated with the presence of vascular invasion in both protocols. The rate of axillary lymph node metastases was consistent with SLN tumor load.

CONCLUSIONS

Intraoperative OSNA assay performed on the whole SLN gave objective and reproducible results that were useful for directing decisions regarding axillary dissection and for accurately defining the SLN stage.

Routine clinical use of the one-step nucleic acid amplification assay for detection of sentinel lymph node metastases in breast cancer patients: results of a multicenter study in Japan

BACKGROUND

The objective of this study was to confirm, by means of a multicenter study conducted in Japan, the reliability and usefulness of the one-step nucleic acid amplification (OSNA) assay in routine clinical use for sentinel lymph node biopsy (SLNB) of breast cancer patients.

METHODS

Patients with Tis-T2N0M0 breast cancer who underwent SLNB before systemic chemotherapy comprised the study cohort. A whole sentinel lymph node (SLN) was examined intraoperatively with the OSNA assay except for a 1-mm-thick, central slice of the lymph node, which underwent pathologic examination after the operation. For patients who underwent axillary dissection, non-SLNs were examined with routine pathologic examination.

RESULTS

In total, 417 SLNBs from 413 patients were analyzed. SLN metastases were detected with greater sensitivity by the OSNA assay than by pathologic examination (22.5% vs 15.8%; P < .001), as expected from the difference in size of the specimens examined. Patients who had SLN metastases assessed with the OSNA assay proved to harbor non-SLN metastases with an overall risk ratio of 33.7%. The risk of non-SLN metastasis was significantly lower for patients who had positive SLNs assessed as OSNA+ than for those who had SLNs assessed as OSNA++ (17.6% vs 44%; P = .012).

CONCLUSIONS

The OSNA assay can be used for routine clinical SLNB, and its assessment for volume of metastasis may be a powerful predictive factor for non-SLN metastasis. Further studies with more patients are needed to confirm the usefulness of this assay for selection in the clinical setting of patients who do not need axillary dissection.

Diagnosis of the sentinel lymph node in breast cancer: a reproducible molecular method: a multicentric Spanish study

AIMS

Standardization of the sentinel node (SN) as a diagnostic tool has not yet been achieved, because the protocol for histopathological study is highly variable between centres. We compared the results of a new method with conventional histological tests and evaluated its feasibility for intra-operative evaluation, and propose it as a method to standardize the sentinel node evaluation procedure.

METHODS AND RESULTS

Trial 1 included 181 cases; in parallel, 2-mm-thick sections of the SN were processed alternately for histological analysis and for the one-step nucleic acid amplification (OSNA) procedure. A final concordance of 99.45% was observed in the first trial of our study. For trial 2, the timing of every procedural step was recorded in an electronic database in order to discern the time spent for each step, the total SN evaluation time and to identify areas of improvement. In the second trial, after a learning period and feedback on data recorded, we spent a mean of 31 min for the entire SN evaluation procedure.

CONCLUSION

Our multi-centric trial using the OSNA assay for sentinel node evaluation in breast cancer demonstrates that this is a highly sensitive, specific and reproducible technique that allows for standardization of the SN diagnostic procedure, a necessary, and until now unresolved, issue.

The sensitivity and specificity of sentinel lymph node biopsy for breast cancer at Baylor University Medical Center at Dallas: a retrospective review of 488 cases

Sentinel lymph node (SLN) biopsy has become the standard of care for breast carcinoma management, as it precludes the negative morbid effects-including decreased shoulder range of motion, lymphedema, and paresthesias-of unnecessary axillary lymph node dissection. However, the method of pathologic evaluation of the lymph node has been scrutinized to obtain the greatest sensitivity, specificity, and negative predictive value, ultimately for the benefit of the patient. This retrospective study analyzed 488 biopsies completed by two surgeons and read by multiple pathologists affiliated with Pathologists Biomedical Laboratories. When metastatic disease was not grossly obvious, analysis of the SLN began with touch imprint cytology and, if necessary, a frozen section analysis. On the subsequent day, three levels of the SLN were analyzed with hematoxylin and eosin stain and immunohistochemistry with cytokeratin AE1-3 and the appropriate control. Touch imprint cytology and/or frozen section analysis (where applicable) correctly identified 78 of 89 macrometastases, with a sensitivity of 88%, specificity of 100%, and negative predictive value of 97%. Sensitivity was 72% for micrometastases and 60% for isolated tumor cells, each with 100% specificity. In conclusion, the sensitivity and specificity of SLN biopsy at our institution compares with the higher end of percentages reported in the literature.

Raman spectroscopy--a potential new method for the intra-operative assessment of axillary lymph nodes

Sentinel Lymph Node Biopsy has become the standard surgical procedure for the sampling of axillary lymph nodes in breast cancer. Intra-operative node assessment of these nodes would allow definitive axillary surgery to take place immediately with associated benefits for patient management. Our experimental study aims to demonstrate that a Raman spectroscopy probe system could overcome many of the disadvantages of current intra-operative methods. 59 axillary lymph nodes, 43 negative and 16 positive from 58 patients undergoing breast surgery at our district general hospital were mapped using Raman micro-spectroscopy. These maps were then used to model the effect of using a Raman spectroscopic probe by selecting 5 and 10 probe points across the mapped images and evaluating the impact on disease detection. Results demonstrated sensitivities of up to 81% and specificities of up to 97% when differentiating between positive and negative lymph nodes, dependent on the number of probe points included. The results would have concurred with histopathology assessment in 89% and 91% of cases in the 5 and 10 point models respectively. Using Raman spectroscopy in this way could allow lymph node assessment within a time-frame suitable for intra-operative use.

[Intraoperative molecular assessment of sentinel nodes in the breast cancer using the Gene Search BLN Assay technique: our experience about 126 patients]

INTRODUCTION

Intraoperative molecular assay Gene Search BLN Assay (BLN) detects sentinel lymph node (SLN) metastasis in breast cancer. Our objective was to compare BLN to the definitive conventional histologic methods and to experiment the management of BLN in routine.

MATERIAL AND METHODS

Each SLN was cut into alternate slabs. Half slabs were analysed with the intraoperative BLN molecular method, and the other slabs with the definitive histologic method.

RESULTS

Two hundred and thirty four SLN have been analysed (124 patients). Thirty-five SLN had metastasis for 29 patients (23.4%). BLN correctly identified 28 patients. Two cases of discordance between BLN and standard method were found, probably explained by a sample bias. The sensibility of BLN is 96.4%, the sensitivity is 99%, the predictive positive value is 96.4%, the predictive negative value is 99% and the concordance is 98.4%. The surgery time increases and there is a need to adapt the theatre organization accordingly.

CONCLUSION

The Gene Search BLN Assay gives a great interest for the patient, the surgeon and the pathologist because it increases the quality of the intraoperative analysis by comparison with the intraoperative conventional histology.

Positron emission tomography (PET) for assessment of axillary lymph node status in early breast cancer: A systematic review and meta-analysis

PURPOSE

Sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) are used to assess axillary nodal status in breast cancer, but are invasive procedures associated with morbidity, including lymphoedema. This systematic review evaluates the diagnostic accuracy of positron emission tomography (PET), with or without computed tomography (CT), for assessment of axillary nodes in early breast cancer.

METHODS

Eleven databases including MEDLINE, EMBASE and the Cochrane Library, plus research registers and conference proceedings, were searched in April 2009. Study quality was assessed using the QUality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. Sensitivity and specificity were meta-analysed using a bivariate random effects approach.

RESULTS

Across 26 studies evaluating PET or PET/CT (n = 2591 patients), mean sensitivity was 63% (95% CI: 52-74%; range 20-100%) and mean specificity 94% (95% CI: 91-96%; range 75-100%). Across 7 studies of PET/CT (n = 862), mean sensitivity was 56% (95% CI: 44-67%) and mean specificity 96% (90-99%). Across 19 studies of PET-only (n = 1729), mean sensitivity was 66% (50-79%) and mean specificity 93% (89-96%). Mean sensitivity was 11% (5-22%) for micrometastases (≤2 mm; five studies; n = 63), and 57% (47-66%) for macrometastases (>2 mm; four studies; n = 111).

CONCLUSIONS

PET had lower sensitivity and specificity than SLNB. Therefore, replacing SLNB with PET would avoid the adverse effects of SLNB, but lead to more false negative patients at risk of recurrence and more false positive patients undergoing unnecessary ALND. The present evidence does not support the routine use of PET or PET-CT for the assessment of the clinically negative axilla.

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.

Utility of the GeneSearch breast lymph node assay for the rapid evaluation of sentinel lymph nodes in breast cancer

BACKGROUND

The potential for reducing the need for second surgery for axillary lymph node dissection (ALND) has made the intraoperative evaluation of sentinel lymph nodes (SLNs) attractive. The goal of the current study was to evaluate the clinical application of the breast lymph node (BLN) assay, a real-time reverse transcriptase-polymerase chain reaction assay for SLN metastases, by comparing this test with routine pathologic examination.

METHODS

A total of 117 patients with breast cancer underwent breast surgery with SLN biopsy. Each SLN was cut in half along the plane of the longest dimension. Half of each lymph node was examined by the 2 markers of the BLN assay, mammaglobin and cytokeratin 19, and the other half was examined by hematoxylin and eosin staining (H&E) and immunohistochemical staining (IHC) for pancytokeratins.

RESULTS

A total of 204 SLNs were obtained from 117 patients. H&E staining identified metastases in 31 SLNs (15.2%), and IHC staining detected metastases in 6 SLNs; 40 SLNs from 32 patients were found to be positive for metastasis using the BLN assay. The assay results were correlated with the pathologic diagnoses by H&E and IHC staining (P<.001). The sensitivity of the BLN assay compared with pathologic findings classified according to the TNM classification was 95.7% for macrometastases, 60.0% for micrometastases, and 55.6% for isolated tumor cells.

CONCLUSIONS

The 2-marker BLN assay performs in a manner that is comparable to, and analyzes more tissue than, routine pathologic examination. Therefore, clinical intraoperative use of the BLN assay for SLNs may result in a reduction in the need for second surgery for ALND.

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.

Efficacy of intraoperative GeneSearch Breast Lymph Node (BLN) Assay for breast cancer metastasis detection in sentinel lymph node in Chinese patients

Although intraoperative assessment of the sentinel lymph node (SLN) is useful, it has not gained popularity in China as it involves a heavy workload for pathologists. We conducted a prospective clinical feasibility study of the GeneSearch Breast Lymph Node (BLN) Assay performed in 158 SLNs from 97 patients by comparison with postoperative permanent section histopathology, to validate its potential usefulness in China. Every SLN was cut into alternating 1.5 to 3.0 mm slabs. The BLN assay processed 50% of the fresh alternating slabs to detect the presence of cytokeratin 19 and mammaglobin mRNA. Assay results were compared with those for permanent section histopathology and intraoperative imprint cytology. Slides for imprint cytology were prepared from the BLN assay node tissue before it was processed. Full axillary lymph node (ALN) dissections were performed on some patients after a SLN biopsy. The BLN assay was successfully performed on 158 SLNs from 97 patients. Overall performance of the BLN assay compared with permanent section histopathology was sensitivity 83.9% (26/31), specificity 95.5% (63/66), positive predictive value 89.7% (26/29), negative predictive value 92.6% (63/68), and overall agreement 91.8% (89/97). The BLN assay detected about 25% more metastases than imprint cytology. Moreover, the BLN assay correctly identified most of the additional non-sentinel ALNs metastases (P = 0.005). Our results from a large series of Chinese patients with breast cancer indicate that the BLN assay may be a viable alternative for the standard intraoperative procedures used for metastases detection, especially in early stage breast cancer patients. Name of the trial register: GeneSearch Breast Lymph Node (BLN) Assay China Registration Study.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00869674.

Recommendations for research priorities in breast cancer by the coalition of cancer cooperative groups scientific leadership council: imaging and local therapy

Imaging and local therapy are important modalities for detection and management of localized breast cancer. Improvements in screening and local therapy have contributed to reduced breast cancer-associated morbidity and mortality. The Coalition of Cancer Cooperative Groups (CCCG) convened the Scientific Leadership Council (SLC) in breast cancer, an expert panel, to identify priorities for future research and current trials with greatest practice-changing potential. Panelists formed a consensus on research priorities for breast imaging and locoregional therapy, and also identified six trials judged to be of high priority. Current high priority trials included trials determining: (1) the role of accelerated partial breast versus whole-breast radiation (B39), (2) the feasibility, safety, and local and systemic control of small localized breast cancers treated with tumor ablation (Z1072), (3) the role of removal of the primary cancer in selected patients with metastatic disease (E2108), and (4) the clinical and biological effects of pre-operative anti-HER2-directed and ER-directed therapies in localized or locally advanced breast cancer (B41, Z1031, Z1041). Ongoing and future trials will further refine optimal locoregional management, and additional research is required to develop improved screening methods and identify high risk populations most likely to benefit from targeted screening.

[Intraoperative determination of axillary node metastasis by RT-PCR]

The intraoperative determination of axillary node micrometastasis according to the Rapid GeneSearch Breast Lymph Node (BLN) is based on RT-PCR (mRNA of mammaglobine and CK19) detects metastases > 0.2 mm.

PATIENTS AND METHODS

Eighty-three pts between November 2007 and June 2008 were included (33 from Centre Jean-Perrin and 50 from Centre Oscar-Lambret). Lymph nodes were cut in 2 mm slices, and 1 out of 2 was examined with BLN; the others were examined by imprints then histological exam with immunohistochemistry.

RESULTS

Forteen pts had micro- or macrometastasis. Seven were positive with intraoperative imprints including six macrometastasis and one micrometastasis; seven were positive with BLN and seven at histological exam with two cases of discordance. Sensitivity was 92%, specificity 98%. Positive predictive value 92%, and negative predictive value 98%. The median time for intraoperative determination was 40 minutes for 2 SLN.

DISCUSSION

Half each lymph node is study by each method. This explains the discordances observed. Limit of BLN is the absence of CTI detection; however there is no consensus about the necessity of axillary clearance in such a case.

CONCLUSION

In this series BLN reduces axillary clearance and improves comfort patients.

[Gene expression based multigene prognostic and predictive tests in breast cancer]

Patient tailored therapy will serve the fundamentals of future cancer treatment. For this it will be imperative to characterize the tumor and to acquire precise predictive and prognostic information. We can achieve this by using not only monogenic (like ER, PR, HER-2, Ki-67) but also multigene assays, which can provide answers to several diagnostic questions simultaneously. We present a summary of currently available RT-PCR and microarray based multigene tests including MammaPrint, Oncotype DX, BLN Assay, Theros Breast Cancer Index SM, MapQuant DX, ARUP Breast Bioclassifier, Celera Metastatic Score, eXagen BCtm, Invasive Gene Signature, Wound Response Indicator and Mammostrat. Two of these (Oncotype DX and MammaPrint) are already incorporated in several diagnostic protocols. However, multiple unsolved issues deteriorate the value of these tests: generally the validation is poor, the gene sets do not confirm each other, the associated costs are high and the necessary bioinformatics is highly complex.

Management of the axilla in patients with breast cancer

This article reviews the changes in management of the axilla in patients with breast cancer in the last decade. It discusses the recent advances, existing controversies and provides evidence-based guidelines for use in clinical practice.Sentinel lymph node (SLN) biopsy has replaced the more morbid axillary lymph node dissection (ALND) and four node sampling for axillary nodal staging. Blue dye guided four node sampling is an acceptable alternative when radioisotope facilities are not available. ALND is reserved for patients with proven axillary lymph node involvement.Preoperative axillary ultrasound and fine-needle aspiration cytology or core biopsy of suspicious lymph nodes reliably identifies around 30% of node positive patients. Intraoperative assessment of the SLN using frozen section or real time molecular assays enables surgeons to perform one stage ALND in node positive patients. For those patients in whom intra-operative SLN assessment is negative, but whose final pathology reveals SLN metastasis, standard treatment has been to perform a completion ALND. Predictive models can be used to identify a lowrisk group of SLN-positive patients in whom routine ALND may not be necessary. In the future, completion ALND for microscopic disease will not be the standard of care but axillary radiotherapy may be an alternative with equal control and less morbidity.

Molecular assessment of sentinel lymph node in breast cancer management

Sentinel lymph node biopsy (SLNB) is becoming accepted as standard of care for axillary staging in breast cancer. World Health Organization (WHO) re-classification of axillary metastases into macrometastases, micrometastases and individual tumour cells has highlighted the issues of sampling and further histological examination of the initially negative SLNB. Molecular detection of metastatic breast cancer cells in lymph nodes is now available as a commercial kit for intraoperative use and can resolve the sampling issue. Semiquantitative assessment of axillary lymph node tumour burden can now be made using two separate technologies (histology and reverse transcriptase-polymerase chain reaction). The clinical implications of low metastatic axillary lymph node tumour burden are not clear, and future trials need to include molecular data. The consequences of the availability of molecular assessment are reviewed.

Molecular markers of breast axillary lymph node metastasis

In breast cancer, axillary lymph node status is one of the most important prognostic variables and a crucial component to the staging system. Several clinico-histopathological parameters are considered to be strong predictors of metastasis; however, they fail to accurately classify breast tumors according to their clinical behavior and to predict which patients will have disease recurrence. Methods based on genome-wide microarray analyses have been used to identify molecular markers with respect to the development of axillary lymph node metastasis. Most of these markers can be detected in the primary tumors, which can potentially lead to the ability to identify patients at the time of diagnosis who are at high risk for lymph node metastasis, allowing for early intervention and more suitable adjuvant treatments.

Sentinel node biopsy for the individualization of surgical strategy for cure of early-stage colon cancer

INTRODUCTION

The requirement for nodal analysis currently confounds the oncological propriety of focused purely endoscopic resection for early-stage colon cancer and complicates the evolution of innovative alternatives such as natural orifice transluminal endoscopic surgery (NOTES) and its hybrids. Adjunctive sentinel node biopsy (SNB) deserves consideration as a means of addressing this shortfall.

METHODS

Data from two prospectively maintained databases established for multicentric studies of SNB in colon cancer that employed similar methodologies were pooled to establish technique potency selectively in T1/T2 disease (both overall and under optimized conditions) and to project potential clinical impact.

RESULTS

Of 891 patients with T1-4, M0 intraperitoneal colon cancer, 225 had T1/T2 disease. Sentinel nodes were either not found or were falsely negative in 18 patients with T1/T2 cancers (8%) as compared with 17% (112/646) in those with T3/T4 disease (P = 0.001). Negative predictive value (NPV) in the former exceeded 95%, while sensitivity [including immunohistochemistry (IHC)] was 81%. In the 193 patients with T1/T2 disease recruited from those centers contributing >22 patients, sensitivity was 89% and NPV 97%. Thus, in this cohort, SNB could have correctly prompted localized resection (obviating en bloc mesenteric dissection) in 75% (144) of patients, including 59 with T1 lesions potentially amenable to intraluminal resection alone as their definitive treatment. Forty-four patients (23.4%) would still have conventional resection, leaving three patients (1.6% overall) understaged (11% false-negative rate).

CONCLUSION

These findings support the further investigation of SNB as oncological augment for localized resective techniques. Specific prospective study should pursue this goal.