Axillary sentinel lymph node biopsy: An overview

Lymph node metastases: importance of detection and treatment strategies

INTRODUCTION

Lymphatic vessels are the preferential route of most solid tumors to spread their metastases in the body. The onset of metastatic nests in draining lymph nodes (LNs) are a significant indicator of cancer progression and a dismaying sign of worsen staging. Therefore, the individuation and elimination of cancer cells within the lymphatic system (LS) are an important goal. Nevertheless, the targeting of the LS with traditional contrast agents and/or chemotherapeutics is difficult, due to its anatomical structure. For this reason, many studies on new lymphatic delivery systems have been carried out, both to improve lymphatic imaging and to selectively carry chemotherapeutics to LNs, reducing the exposure of healthy tissues to the cytotoxic substances. This is an overview of the present situation in the field of detection and treatment strategies of lymphatic metastases, taking into account the use of nano-drug delivery systems. Nanocarriers, thanks to their small size and other physicochemical characteristics, are suitable vectors for imaging and chemotherapy of the LS.

AREAS COVERED

The role of the LS in tumor progression and importance of treatment and imaging strategies of lymphatic metastases.

EXPERT OPINION

The nanoparticles are a promising approach for treatment and detection of lymphatic metastases. However further studies are necessary in order to evaluate their efficacy in human clinical application.

Comparison of the sentinel node procedure between patients with multifocal and unifocal breast cancer in the EORTC 10981-22023 AMAROS Trial: identification rate and nodal outcome

INTRODUCTION

Multifocal breast cancer is associated with a higher risk of nodal involvement compared to unifocal breast cancer and the drainage pattern from multifocal localisations may be different. For this reason, the value of the sentinel node biopsy (SNB) procedure for this indication is debated. The aim of the current analysis was to evaluate the sentinel node identification rate and nodal involvement in patients with a multifocal tumour in the EORTC 10981-22023 AMAROS trial.

PATIENTS AND METHODS

From the first 4000 registered patients, 342 were identified with a multifocal tumour on histological examination and compared to a randomly selected control group of 684 patients with a unifocal tumour. The outcome of the SNB was assessed.

RESULTS

The sentinel node was identified in 96% of the patients with a multifocal tumour and in 98% of those with unifocal disease. In the multifocal group, 51% had a metastasis in the sentinel node compared to 28% in the unifocal group; and further nodal involvement after a positive sentinel node was found in 40% (38/95) and 39% (39/101) respectively.

CONCLUSION

In this prospective international multicentre study, the 96% detection rate indicates that the SNB procedure can be highly effective in patients with a multifocal tumour. Though the tumour-positive rate of the sentinel node was twice as high in the multifocal group compared to the unifocal group, further nodal involvement after a positive sentinel node was similar in both groups. This suggests that the SNB procedure is safe in patients with multifocal breast cancer.

Two lymph nodes draining the mouse liver are the preferential site of DC migration and T cell activation

BACKGROUND & AIMS

Lymph nodes (LNs) play a critical role in host defence against pathogens. In rodents, lymphatic anatomy and drainage have been characterized for many different organs. Surprisingly, the LNs draining the mouse liver have not been clearly identified. This knowledge is of central importance to allow accurate characterization of immune responses to pathogens infecting the liver. It is also important for exploring immune responses in hepatic tumour models, and mechanisms underlying the relative tolerogenic properties of the liver. In this study, we used both anatomical and immunological approaches to identify the LN(s) draining the mouse liver.

METHODS

Evans Blue and purified dendritic cells were directly injected into the hepatic parenchyma.

RESULTS

Using Evans Blue, we identified three LNs adjacent to the liver that stained with the dye within the first 5 min, which we termed portal, coeliac, and first mesenteric LNs. We also provide evidence that dendritic cells (DCs) injected under the liver capsule preferentially migrate to the coeliac and portal nodes, leading to local activation of antigen-specific naïve CD8 and CD4 T cells, suggesting this is a route of lymphatic drainage from the liver. Consistent with this result, cell-associated antigen injected under the liver capsule was also cross-presented to CD8 T cells in these nodes.

CONCLUSIONS

These results suggest for the first time that the coeliac and portal nodes are the main LNs draining the liver, and that DCs exiting the liver can elicit primary T cell activation within these lymph nodes; first mesenteric nodes play a secondary role. We propose this nomenclature to be used as common designations for the observed structures.

Sentinel lymph node biopsy in primary breast cancer: trust the radiolabeled colloid method and avoid unnecessary procedures

BACKGROUND

With regard to the sentinel lymph node (SLN) procedure in breast cancer, the study analyzed the impact of discrepancies between the number of clinically and histologically identified SLN, the impact of removing additional non-hot/non-blue but clinically conspicuous lymph nodes (LN), and whether the application of blue dye for mapping is necessary.

METHODS

We analyzed 391 SLN procedures in which 928 SLN were removed. In all cases, radiolabeled colloid and blue dye were used for SLN mapping.

RESULTS

In 60 cases (15.3%), additional LN that were not identified by the surgeon were found by histological examination. In 22 cases (5.3%), tissue which clinically resembled an SLN but was histologically connective tissue, was removed. In 76 cases (19.4%), 133 non-hot/non-blue but clinically conspicuous LN were removed. These additionally removed LN, however, did not alter the axillary staging. In 50.8% of the cases (n = 471), the SLN were marked only by radiolabeled colloid. In 27 cases (2.9%), the surgeon identified the LN through blue coloration alone; however, in all of the latter cases, these SLN were not deciding for axillary staging.

CONCLUSION

The mapping agents may accumulate in axillary tissue and mimic the existence of an SLN. The radiolabeled colloid method alone gives excellent mapping results. The additional application of blue dye is avoidable. Exact surgical preparation enables removal of the SLN only and avoids removal of LN-containing adjacent tissue. The removal of further clinically identifiable enlarged non-hot LN should only be done if there is strong suspicion of metastatic involvement.

Non-invasive, Contrast-enhanced Spectral Imaging of Breast Cancer Signatures in Preclinical Animal Models In vivo

We report here a non-invasive multispectral imaging platform for monitoring spectral reflectance and fluorescence images from primary breast carcinoma and metastatic lymph nodes in preclinical rat model in vivo. The system is built around a monochromator light source and an acousto-optic tunable filter (AOTF) for spectral selection. Quantitative analysis of the measured reflectance profiles in the presence of a widely-used lymphazurin dye clearly demonstrates the capability of the proposed imaging platform to detect tumor-associated spectral signatures in the primary tumors as well as metastatic lymphatics. Tumor-associated changes in vascular oxygenation and interstitial fluid pressure are reasoned to be the physiological sources of the measured reflectance profiles. We also discuss the translational potential of our imaging platform in intra-operative clinical setting.

Fluorescence imaging and whole-body biodistribution of near-infrared-emitting quantum dots after subcutaneous injection for regional lymph node mapping in mice

PURPOSE

This study compares fluorescence imaging to mass spectroscopy (inductively coupled plasma-mass spectroscopy, ICP-MS) for detection of quantum dots (QDs) in sentinel lymph node (LN) mapping of breast cancer.

PROCEDURES

We study the accumulation of near-infrared-emitting QDs into regional LNs and their whole-body biodistribution in mice after subcutaneous injection, using in vivo fluorescence imaging and ex vivo elemental analysis by ICP-MS.

RESULTS

We show that the QD accumulation in regional LNs is detectable by fluorescence imaging as early as 5 min post-delivery. Their concentration reaches a maximum at 4 h then decreases over a 10-day observation period. These data are confirmed by ICP-MS. The QD uptake in other organs, assessed by ICP-MS, increases steadily over time; however, its overall level remains rather low.

CONCLUSIONS

Fluorescence imaging can be used as a non-invasive alternative to ICP-MS to follow the QD accumulation kinetics into regional LNs.

Sentinel lymph node biopsy in breast cancer: a comprehensive literature review

Sentinel lymph node biopsy has emerged as the new standard of care for nodal staging in early-stage breast disease. In the this review, the procedure of SLNB in breast cancer will be examined in greater detail with the aim of understanding techniques that may improve results and of identifying future research questions in this field.