Tagging sentinel lymph nodes: a study of 100 patients with breast cancer

Evans Blue Dye: A Revisit of Its Applications in Biomedicine

Evans blue (EB) dye has owned a long history as a biological dye and diagnostic agent since its first staining application by Herbert McLean Evans in 1914. Due to its high water solubility and slow excretion, as well as its tight binding to serum albumin, EB has been widely used in biomedicine, including its use in estimating blood volume and vascular permeability, detecting lymph nodes, and localizing the tumor lesions. Recently, a series of EB derivatives have been labeled with PET isotopes and can be used as theranostics with a broad potential due to their improved half-life in the blood and reduced release. Some of EB derivatives have even been used in translational applications in clinics. In addition, a novel necrosis-avid feature of EB has recently been reported in some preclinical animal studies. Given all these interesting and important advances in EB study, a comprehensive revisiting of EB has been made in its biomedical applications in the review.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

High-speed dynamic 3D photoacoustic imaging of sentinel lymph node in a murine model using an ultrasound array

Noninvasive photoacoustic sentinel lymph node (SLN) mapping with high spatial resolution has the potential to improve the false negative rate and eliminate the use of radioactive tracers in SLN identification. In addition, the demonstrated high spatial resolution may enable physicians to replace SLN biopsy with fine needle aspiration biopsy, and thus reduce the risk of associated morbidity. The primary goal of this study is to demonstrate the feasibility of high-speed 3D photoacoustic imaging of the uptake and clearance dynamics of Evans blue dye in SLNs. The photoacoustic imaging system was developed with a 30 MHz ultrasound array and a kHz repetition rate laser system. It acquires one 3D photoacoustic image of 166 B-scan frames in 1 s, with axial, lateral, and elevational resolutions of 25, 70, and 200 microm, respectively. With optic-fiber based light delivery, the entire system is compact and is convenient to use. Upon injection of Evans blue, a blue dye currently used in clinical SLN biopsy, SLNs in mice and rats were accurately and noninvasively mapped in vivo using our imaging system. In our experiments, the SLNs were found to be located at approximately 0.65 mm below the skin surface in mice and approximately 1.2 mm in rats. In some cases, lymph vessels and lymphatic valves were also imaged. The dye dynamics--accumulation and clearance--in SLNs were quantitatively monitored by sequential 3D imaging with temporal resolution of as high as approximately 6 s. The demonstrated capability suggests that high-speed 3D photoacoustic imaging should facilitate the understanding of the dynamics of various dyes in SLNs and potentially help identify SLNs with high accuracy.

Lymphatic mapping and sentinel lymph node biopsy in early-stage breast carcinoma: a metaanalysis

BACKGROUND

Lymphatic mapping with sentinel lymph node biopsy has the potential for reducing the morbidity associated with breast carcinoma staging. It has become a widely used technology despite limited data from controlled clinical trials.

METHODS

A systematic review of the world's literature of sentinel lymph node (SLN) biopsy in patients with early-stage breast carcinoma was undertaken by using electronic and hand searching techniques. Only studies that incorporated full axillary lymph node dissection (ALND), regardless of SLN results, were included. Individual study results along with weighted summary measures were estimated using the Mantel-Haenszel method. The correlations of outcomes with the study size, the proportion of positive lymph nodes, the technique used, and the study quality were evaluated.

RESULTS

Between 1970 and 2003, 69 trials were reported that met eligibility criteria. Of the 8059 patients who were studied, 7765 patients (96%) had successfully mapped SLNs. The proportion of patients who had successfully mapped SLNs ranged from 41% to 100%, with > 50% of studies reporting a rate < 90%. Lymph node involvement was found in 3132 patients (42%) and ranged from 17% to 74% across studies. The false-negative rate (FNR) ranged from 0% to 29%, averaging 7.3% overall. Eleven trials (15.9%) reported an FNR of 0.0, whereas 26 trials (37.7%) reported an FNR > 10%. Significant inverse correlations were observed between the FNR and both the number of patients studied (r = - 0.42; P < 0.01) and the proportion of patients who had successfully mapped SLNs nodes (r = - 0.32; P = 0.009).

CONCLUSIONS

Lymphatic mapping with SLN biopsy is used widely to reduce the complications associated with ALND in patients with low-risk breast carcinoma. This systematic review revealed a wide variation in test performance.

99mTc-Evans blue dye for mapping contiguous lymph node sequences and discriminating the sentinel lymph node in an ovine model

BACKGROUND

The aim of this study was to investigate the potential of (99m)Tc-Evans blue for discriminating the sentinel lymph node in multitiered lymph node sequences by using an ovine model. (99m)Tc-Evans blue is an agent that has both radioactive and color signals in a single dose. Previous studies in smaller animal models suggested that this agent could have advantages over the dual-injection technique of radiocolloid/blue dye.

METHODS

Doses of (99m)Tc-Evans blue ( approximately 21 MBq) containing Evans blue dye (approximately 4 mg) were administered to the hind limbs or fore limbs of sheep to map the lymphatic drainage patterns, validate its ability to identify the sentinel lymph node, and examine the reproducibility of the technique. The study protocol was repeated with (99m)Tc-antimony trisulfide colloid and Patent Blue V dye. After the operative exposure, lymph nodes were identified with the gamma probe and then excised and analyzed for radioactivity (percentage of injected dose) and blue color.

RESULTS

After the administration of (99m)Tc-Evans blue, all lymph nodes harvested (35 of 35) in either short chains or long basins were hot and blue. The sentinel lymph nodes concentrated more radioactivity than the second-tier nodes to the extent of 2:1 to 215:1. For radiocolloid/Patent Blue V, the ratios were lower, at 2:1 to 3:1.

CONCLUSIONS

(99m)Tc-Evans blue was found to better discriminate the sentinel lymph node than (99m)Tc-antimony trisulfide colloid/Patent Blue V in variable multitier lymph node anatomy, and it is an agent that promises to have positive clinical applications.

A critical review of variables affecting the accuracy and false-negative rate of sentinel node biopsy procedures in early breast cancer

Radionuclide sentinel lymph node localization and biopsy is a staging procedure that is being increasingly used to evaluate patients with invasive breast cancer who have clinically normal axillary nodes. The most important prognostic indicator in patients with invasive breast cancer is the axillary node status, which must also be known for correct staging, and influences the selection of adjuvant therapies. The accuracy of sentinel lymph node localization depends on a number of factors, including the injection method, the operating surgeon's experience and the hospital setting. The efficacy of sentinel lymph node mapping can be determined by two measures: the sentinel lymph node identification rate and the false-negative rate. Of these, the false-negative rate is the most important, based on a review of 92 studies. As sentinel lymph node procedures vary widely, nuclear medicine physicians and radiologists must be acquainted with the advantages and disadvantages of the various techniques. In this review, the factors that influence the success of different techniques are examined, and studies which have investigated false-negative rates and/or sentinel lymph node identification rates are summarized.

Le traitement chirurgical conservateur du cancer du sein

Breast-conserving treatment for breast cancer combines lumpectomy, axillary nodes treatment and radiotherapy of the breast. Conservative surgery and radiotherapy is now the standard treatment for unifocal, non inflammatory tumors, less than 3 cm in diameter. The widespread use of mammographic screening leads to a significant increase in the proportion of non palpable breast carcinomas, and has contributed to increase the proportion of breast conserving treatments. Neoadjuvant treatments (chemotherapy, radiotherapy and hormonotherapy) can also extend the indications of breast conservation to breast carcinomas larger than 3 cm. Furthermore, in the last ten years, new surgical procedures (sentinel node biopsy, oncoplastic surgery, minimal invasive surgery) have been developed, increasing the surgical possibilities. After a learning phase to establish new standards for these procedures, all these techniques are now part of our standard surgical apparel, thus extending the possibilities of breast conserving surgery.

Malignant Pleural and Pericardial Effusion in Invasive Breast Cancer: Impact of the Site of the Primary Tumor

BACKGROUND

Malignant effusion in invasive breast cancer, either pleural or pericardial, is associated with a poor survival rate. We investigated the role of the location of invasive breast cancer in developing malignant pleural or pericardial effusion.

METHODS

Three thousand eight hundred and fifty six women with a history of invasive breast cancer between 1960 and 1994 were analyzed in a retrospective study. Two hundred and six patients (5.34%; group A) developed malignant pleural and/or pericardial fluid as the first visible clinical sign of distant metastasis. A control group of 206 patients (group B) without malignant effusions were matched in terms of clinical and pathological characteristics. The two groups were compared in respect of the location of the primary tumor. Fifty patients in group A (n = 50; 24.2%) had tumors in the inner quadrants, 83 patients (n = 83; 40.3%) in the outer quadrants, and 13 patients (n = 13; 6.3%) in a central location. No data were available for 60 patients (n = 60; 29.1%). In group B, 12 patients (n = 12; 5.9%) had tumors in the inner quadrants, 140 patients (n = 140; 68.0%) in the outer quadrants, 14 patients (n = 14; 6.8%) had centrally located tumors, while no data were available for 40 patients (n = 40; 19.4%). Invasive ductal carcinomas (IDC) located in the inner quadrants were highly significantly associated with increased pleural or pericardial effusion as the first site of distant metastasis (p <or= 0.0001; chi-square tests).

CONCLUSION

IDC in the inner quadrants were associated with a 4-fold higher rate of malignant pleural or pericardial effusions. Further studies will have to determine whether tumor location is a criterion for more aggressive adjuvant therapy.

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

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

Will we need lymph node dissection at all in the future?

Traditionally in the treatment of primary breast cancer, axillary lymph node dissection (ALND) plays an important role. However, a substantial and increasing percentage of patients appear to have no nodal involvement and have been subjected to ALND unnecessarily. The first reason to perform an ALND is axillary nodal staging. After reviewing the literature, it can be concluded that in clinically node-negative patients an adequately conducted lymphatic mapping by sentinel node procedure is equal to ALND for this purpose. The second reason to perform an ALND is to establish the extent of nodal involvement, which might have an impact on adjuvant treatment recommendations. However, there is no evidence available that patients with extensive nodal involvement (= 4 positive nodes) benefit more from adjuvant systemic treatment (either standard or high dose) in terms of reduction of odds of recurrence and mortality compared to patients with limited nodal involvement and optimally administered so-called standard adjuvant treatment. The third reason to perform an ALND is to ensure axillary tumor control. Reviewing the different treatment options, it can be concluded that in clinically node-negative patients axillary control after axillary radiotherapy appears to be similar to axillary control after ALND. In clinically overt axillary involvement, ALND (with or without adjuvant radiotherapy) may result in an improved regional control. In the near future, ALND will not be the standard of care but will be reserved for those patients with proven axillary lymph node involvement. In microscopic disease, radiotherapy may be an alternative with equal control and less morbidity.

Sentinel lymph node mapping and biopsy for breast cancer at a rural-based university medical center: initial experience with intraparenchymal and intradermal injection routes

BACKGROUND

Recent data suggests that intradermal (ID) injection for sentinel lymph node (SLN) mapping and biopsy in breast cancer is as effective and reproducible as intraparenchymal (IP) injection. The aim of this study was to review our initial experience with IP and ID injection for SLN mapping and biopsy at our rural-based university medical center.

METHODS

From January 4, 1999 to January 5, 2001, 113 of 165 patients with breast cancer underwent attempted SLN mapping and biopsy by either IP (n=63) or ID (n=50) injection. Selection of the IP versus ID injection route was non-randomized and based on surgeon preference. Success of SLN localization was examined.

RESULTS

SLN localization was successful in 82% of IP and 100% of ID for radioisotope (p=0.001), 69% of IP and 92% of ID for blue dye (p=0.002), and 90% of IP and 100% of ID (p=0.024) for radioisotope and blue dye. Identical comparisons made after excluding the first 10 cases, 20 cases, and 30 cases from each injection group showed that the percentage of cases in each group in which the SLN localized changed minimally; however, some of the resultant p values eventually lost statistical significance.

CONCLUSIONS

SLN localization was more successful by ID injection than by IP injection, thus favoring utilization of the ID injection route. The eventual loss of statistical power in some of the comparisons with increasing numbers of initial cases excluded may reflect differential learning curves of the two injection techniques; however, this may simply be a reflection of decreasing sample size used in each subsequent analysis. A prospective randomized trial comparing the IP and ID injection route may be warranted.

Sentinel node biopsy: an in depth appraisal

Sentinel node biopsy (SNB) in primary breast cancer has been taken-up widely to avoid the morbidity attributable to axillary node clearance (ANC). Currently many issues surrounding SNB are undecided. This review summarises why some form of axillary surgery is required and presents data on all aspects of SNB including methodology, clinical results and problems that may delay the introduction of SNB as best practice for all patients with primary breast cancer. There is no long or medium term data relating to the consequences of replacing ANC with SNB, but the mechanisms and probable magnitude of both beneficial and detrimental effects are estimated. A low level of false negative results are inherent to the technique but it is demonstrated that SNB is likely to have an only marginal (0.6%) effect on survival that would be undetectable by clinical trials. Patient sub-groups particularly likely to benefit from SNB are identified.

Comparison of vital dye-guided lymphatic mapping and dye plus gamma probe-guided sentinel node biopsy in breast cancer

The optimal technique for sentinel lymph node biopsy (SLNB) is still debated. SLNB with peritumoral injection of Patent blue dye was performed in 129 clinically T1-T2 and N0 breast cancers in 127 patients (group A); it was later replaced by combined dye and radiocolloid-guided SLNB preceded by lymphoscintigraphy in 72 breast cancer patients (group B). This study compares these two methods. All patients underwent completion axillary dissection. Means of 1.4 and 1.3 SLNs were identified in groups A and B, respectively. The mean number of non-SLNs for the whole series was 14.9 (range 5-42). The first 53 cases of lymphatic mapping (dye only) comprised the institutional learning period during which the identification rate of at least 1 SLN in 30 consecutive attempts reached 90%. The identification rate for the subsequent 76 group A patients was 92%. The accuracy rate of SLNBs for overall axillary nodal status prediction and the false-negative rate for group A patients (after excluding the learning-phase cases) were 93% and 10%, respectively. All 72 group B cases had at least one SLN identified, and only one false-negative case occurred in this group (accuracy and false-negative rates of 99% and 3%, respectively). Both the dye-only and the combined SLNB methods are suitable for SLN identification, but the latter works better and results in higher accuracy, a higher negative predictive value, and a lower false-negative rate. It is therefore the method of choice.

Internal mammary lymph nodes and sentinel node biopsy in breast cancer

The long-term follow-up of patients treated with extended radical mastectomy has proved that the internal mammary node (IMN) status is an important prognosticator of breast cancer. Patients with isolated IMN involvement seem to have the same outcome as those with limited axillary disease, and these patients may therefore be overstaged in the TNM system. Sentinel node biopsy (SNB) of IMNs may be an ideal staging procedure, but lymphatic mapping studies demonstrate that data from extended radical mastectomy series cannot be extrapolated to patients suitable for SNB, where the IMN involvement is <5% overall, and around 1% for IMN metastases without axillary disease. Current evidence does not allow internal mammary SNB to be recommended as a standard procedure, but as patients with IMN involvement may benefit from adjuvant systemic treatment, internal mammary SNB should be further studied in this context.

Sentinel node biopsy for breast cancer may have little to offer four-node-samplers

The aims of the study were to determine how often four node axillary sampling (4NAS) encompasses the sentinel node (SN) and to compare the relative sensitivity of 4NAS with sentinel node biopsy (SNB) for axillary node staging. 200 patients with breast cancer were preoperatively injected with 27 MBq 99m-Tc-labelled colloid adjacent to the tumour. At operation, standard 4NAS was performed. Each node was counted ex vivo using a probe. A search was then made to find a node with higher counts in vivo directed by the probe. If found, it was excised. Each node was submitted separately to pathology. A SN was identified in 191 patients (96%). The SN was contained in the 4NAS in 153 patients (80%) and identified separately in 38 patients (20%). Of 60 node-positive patients, 49 were positive by 4NAS and SNB, the SN was not identified in 2 and in 8 the SN was falsely negative compared with 4NAS. For 1 patient, the SN was positive and the 4NAS negative. SNB performed using radiolabelled colloid has no advantage over 4NAS when nodes are assessed by standard histological technique.

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

STUDY AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comprehensive review of sentinel lymphadenectomy in breast cancer

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

Controversies in sentinel lymph node biopsy for breast cancer

Sentinel lymph node biopsy, validated in melanoma staging, is currently under investigation for breast cancer staging. Reports suggest that the sentinel lymph node has a high predictive value in determining the presence of axillary metastases. Identification of a sentinel lymph node that is free of metastatic tumor cells may eliminate the necessity of performing a standard axillary lymph node dissection with its attendant morbidity. Numerous techniques are utilized to identify the sentinel node with approximately the same success rate. This paper will address some of the controversial areas of sentinel lymph node biopsy and offer an option for physicians who want to develop a sentinel lymph node program in their hospital.

Management of the axilla in primary breast cancer

Treatment of the axilla with either radiotherapy or surgery remains an integral part of the management of patients with invasive breast cancer. In general, the standard treatment of the axilla involves a partial ALND (surgical clearance of axillary nodes from levels I and II). There is as yet no evidence that axillary treatment improves survival, but the issue remains controversial. Axillary lymph node dissection is an effective staging procedure and is essential for local control of disease in the axilla, although, with increased emphasis on mammographic screening and early detection, the incidence of node-positive breast cancers is decreasing. Today, only about 30% to 40% of all invasive breast cancers are node-positive. Thus, in most cases, the potential morbidity of ALND could be avoided if the status of the axillary nodes were ascertained with a less invasive procedure. The SLNB may eventually prove to be a preferred alternative to routine ALND. It must first be demonstrated, however, that SLNB (without completion ALND) does not adversely affect outcome. Randomized controlled trials must address these concerns, and surgeons must await completion of these studies before accepting SLNB as the standard of care.