Sentinel lymph node biopsy in head and neck cancer

Efficacy of different sentinel lymph node biopsy protocols in oral squamous cell carcinoma: Systematic review and meta-analysis

The sentinel node biopsy (SNB) is highly protocolized in other cancers, however, this is not the case for oral squamous cell carcinoma patients, hence our objective was to evaluate the different protocols published. A specific study protocol was designed and subsequently registered on PROSPERO (Ref. CRD42021279217). Twenty‐three articles were included in the meta‐analysis. The grouped sensitivity of the SNB was 82% (95% CI: 0.74–0.88), and the grouped specificity was 100% (95% CI: 0.99–1.00). The use of other radiotracers other than pre‐operative lopamidol showed higher values of sensitivity of 82.80% (95% CI: 76.90%–87.50%; p < 0.001). The use of the blue dye stain showed higher sensitivity values of 85.60% (95% CI: 71.90%–93.20%), compared to sensitivity values of 77.50% when it was not used (95% CI: 69.10%–84.20%) (p < 0.001). Diagnostic rates are variable and they were significantly better when 99mTc was used in all its variations and accompanied by the blue dye staining.

Sentinel lymph node biopsy in high-risk cutaneous squamous cell carcinoma of the head and neck

INTRODUCTION

Cutaneous squamous cell carcinoma (cSCC) shows malignant behaviour in 3-4% of patients with locoregional metastases and a poor prognosis, metastases that are difficult to predict clinically. Therefore, sentinel lymph node biopsy (SLNB) has been assessed, with contradictory findings thus far. We aimed to clarify the prognostic value of SLNB in high-risk cSCC patients.

PATIENTS AND METHODS

We completed a retrospective clinical study amongst 63 patients, preoperatively classified as N0 with a high-risk primary cSCC of the head and neck who underwent SLNB between 2001 and 2014 at Helsinki University Hospital (Finland). Considered high risk, the inclusion criteria comprised at least two of the following characteristics: tumour diameter ≥10 mm and/or thickness ≥4 mm and a specific tumour location, such as the lips, ear, scalp and central face. Patients were followed-up postoperatively for a median of 4.1 years (0.2-13.8 years).

RESULTS

Only four (6.3%) patients had positive sentinel nodes. One of these patients died of cSCC, while the other three ultimately survived their disease. Five (7.9%) patients showed a negative SLNB, but developed recurrence within one year postoperatively. Recurrence appeared in the neck lymph nodes concurrently with locoregional soft-tissue invasion in all patients. Amongst these patients, three died for cSCC and the remaining two from other causes. Comparing the SLNB-positive and SLNB-negative groups with recurrence, we identified no significant differences in terms of patient or tumour characteristics.

CONCLUSIONS

SLNB appears to carry no prognostic value for identifying recurrent disease amongst high-risk cSCC in the head and neck area.

Ultrasound-guided contrast-enhanced sentinel node biopsy of the head and neck in a porcine model

Objective

To test the feasibility of contrast-enhanced ultrasound (CEUS)–guided sentinel lymph node biopsy (SNB) of the head and neck in a porcine model.

Study Design and Setting

In this prospective, non-randomized study, methylene blue and Sonazoid were injected into the lateral tongue or floor of mouth (FOM) of four swine. Real-time CEUS was used to identify contrast in the lymphatic channels flowing to the sentinel lymph node (SLN). Endoscopic or open SNB was performed. Neck dissection was then performed, and the residual nodal packet was examined for remaining contrast-enhancing or blue dye–stained nodes.

Results

In all eight procedures, the SLN was visualized with ultrasound and blue dye. Seven procedures identified a single SLN, and one identified two SLNs. Subsequent neck dissections revealed no other nodes containing methylene blue or contrast in the nodal specimen or operative bed.

Conclusion/Significance

CEUS-guided SNB of the head and neck in swine is feasible, with success comparable to blue dye–guided SNB. This technique may offer several advantages over traditional techniques, and warrants further study.

Photoacoustic Imaging for Cancer Detection and Staging

Cancer is one of the leading causes of death in the world. Diagnosing a cancer at its early stages of development can decrease the mortality rate significantly and reduce healthcare costs. Over the past two decades, photoacoustic imaging has seen steady growth and has demonstrated notable capabilities to detect cancerous cells and stage cancer. Furthermore, photoacoustic imaging combined with ultrasound imaging and augmented with molecular targeted contrast agents is capable of imaging cancer at the cellular and molecular level, thus opening diverse opportunities to improve diagnosis of tumors, detect circulating tumor cells and identify metastatic lymph nodes. In this paper we introduce the principles of photoacoustic imaging, and review recent developments in photoacoustic imagingas an emerging imaging modality for cancer diagnosis and staging.

Rapid molecular detection of metastatic head and neck squamous cell carcinoma as an intraoperative adjunct to sentinel lymph node biopsy

OBJECTIVES/HYPOTHESIS

Clinical staging of early head and neck squamous cell carcinoma (SCCHN) is often inaccurate, leading to elective neck dissection to detect the 30% of patients with micrometastatic disease. Sentinel node biopsy accurately stages the regional lymphatics, but intraoperative pathology is only moderately sensitive, and final pathology takes several days to complete. To facilitate immediate neck dissection where necessary, we have identified several promising marker genes of SCCHN metastasis and developed a rapid, accurate, and automated quantitative real-time polymerase chain reaction (PCR) (qRT-PCR) assay for intraoperative use.

STUDY DESIGN

Prospective tissue collection, retrospective pathologic correlation with qRT-PCR.

METHODS

From a 40-gene marker screen, we quantified expression of 11 potential tumor genes using a test set of primary tumors (n = 32) and metastatic (n = 19) and benign (n = 10) lymph nodes. Eight patients' paired primary tumor and metastatic nodes were included. A validation set of 442 grossly tumor-negative nodes was evaluated for expression of the most promising markers, comparing metastasis detection by qRT-PCR with pathologic analysis (hematoxylin and eosin and immunohistochemistry). A novel multiplexed, automated, single-tube qRT-PCR assay was used to analyze more than 100 lymph nodes using a two-marker, 35-minute assay to determine its negative predictive value.

RESULTS

Based on expression of 11 tumor-associated genes from the marker screen, the two most promising markers of SCCHN metastasis in the test set, pemphigus vulgaris antigen (PVA) and tumor-associated calcium signal transducer 1 (TACSTD1), also known as epithelial cell adhesion molecule (EpCAM), were selected. Development of a multiplexed qRT-PCR assay for the detection of metastasis compared favorably with pathologic analysis in the additional 442-node set. A rapid, multiplexed assay using PVA and TACSTD1 demonstrated excellent reproducibility, linearity, and accuracy (≈96% negative predictive value) for identifying positive (n = 40) and negative (n = 62) nodes in a validation subset.

CONCLUSIONS

Detection of metastatic SCCHN using multiplexed qRT-PCR can be rapid, accurate, and automated and may enable sentinel node biopsy to be used for intraoperative decision-making. PCR amplification of tumor marker genes is an effective method of intraoperative molecular staging of SCCHN and could more appropriately guide application of neck dissection in pN+ SCCHN patients, sparing 60% to 70% of pN0 patients from unnecessary neck dissection. This technique may also be used for identifying residual neck disease posttreatment, using outpatient fine-needle aspiration biopsy specimens.

Large payloads of gold nanoparticles into the polyamine network core of stimuli-responsive PEGylated nanogels for selective and noninvasive cancer photothermal therapy

A biocompatible photothermal nanomedicine based on a PEGylated nanogel containing gold nanoparticles (GNPs) in a cross-linked network core of stimuli-responsive poly[2-(N,N-diethylamino)ethyl methacrylate] (PEAMA) gel for cancer photothermal therapy (PTT) was prepared through the reduction of Au(iii) ions without any reducing agents. The influence of the reduction conditions, such as pH, temperature, and N/Au ratio (molar ratio of the amino groups in the PEGylated nanogel to the Au(iii) ions), on the formation of the GNPs in the stimuli-responsive PEAMA gel core (reducing environment) was also studied. Note that the PEGylated nanogel containing GNPs prepared at pH 6, 60 degrees C and N/Au = 1 (PEGylated GNG (1)) was found to have the highest GNP-loading capacity with a diameter of about 8 nm, as observed by TEM; viz., about 27 GNPs formed in a single PEAMA gel core. PEGylated GNG (1) showed a remarkable photothermal efficacy (DeltaT = 7.7 degrees C) under irradiation with Ar ion (Ar(+)) laser (514.5 nm) at a fluence of 39 W cm(-2) for 6 min (14 kJ cm(-2)). Note that PEGylated GNG (1) showed non-cytotoxicity in the absence of irradiation with Ar(+) laser (480 microg mL(-1): > 90% cell viability), whereas pronounced cytotoxicity (IC(50) = 110 microg mL(-1)) was observed for PEGylated GNG (1) under irradiation with Ar(+) laser at a fluence of 26 W cm(-2) for 5 min (7.8 kJ cm(-2)), because of the heat-generation from the GNPs in the cells, which resulted in selective and noninvasive cancer PTT. Thus, PEGylated GNG (1), which has a high GNP-loading capacity, would be a promising nanomedicine for cancer PTT.

Targeting gold nanocages to cancer cells for photothermal destruction and drug delivery

IMPORTANCE OF THE FIELD

Plasmonic nanoparticles provide a new route to treat cancer owing to their ability to convert light into heat effectively for photothermal destruction. Combined with the targeting mechanisms possible with nanoscale materials, this technique has the potential to enable highly targeted therapies to minimize undesirable side effects.

AREAS COVERED IN THIS REVIEW

This review discusses the use of gold nanocages, a new class of plasmonic nanoparticles, for photothermal applications. Gold nanocages are hollow, porous structures with compact sizes and precisely controlled plasmonic properties and surface chemistry. Also, a recent study of gold nanocages as drug-release carriers by externally controlling the opening and closing of the pores with a smart polymer whose conformation changes at a specific temperature is discussed. Release of the contents can be initiated remotely through near-infrared irradiation. Together, these topics cover the years from 2002 to 2009.

WHAT THE READER WILL GAIN

The reader will be exposed to different aspects of gold nanocages, including synthesis, surface modification, in vitro studies, initial in vivo data and perspectives on future studies.

TAKE HOME MESSAGE

Gold nanocages are a promising platform for cancer therapy in terms of both photothermal destruction and drug delivery.

Molecular markers of micrometastasis in oral cavity carcinomas

Objective: To examine the expression of candidate markers for micrometastasis.

Study Design: Cross-sectional analysis of subjects with oral cavity carcinomas who underwent sentinel lymph node biopsy (SLNB) and subsequent immunohistochemical (IHC) analysis.

Subjects and Methods: Two groups were identified based on SLNB status: negative SLNB (19/30) and positive SLNB (11/30). Specimens underwent IHC using conjugated monoclonal antibodies for membrane type-1 matrix metalloproteinase (MT1-MMP), CD44, focal adhesion kinase-1, and E-cadherin. Staining results were evaluated to determine if a particular marker was associated with SLNB status or other histopathologic prognosticators.

Results: For MT1-MMP, 21 percent (3/14) of evaluable specimens stained positively in the SLNB(−) group and 67 percent (4/6) stained positively in the SLNB(+) group ( P = 0.12). No statistically significant association was seen between any marker's staining pattern and SLNB status alone. When MT1-MMP staining was evaluated in tumors with SLNB(+) or perineural invasion (PNI) present on histopathology, six of nine specimens (67%) stained positively for MT1-MMP, vs one of 11 (9%) in specimens lacking either negative prognosticator ( P = 0.016, RR = 7.33).

Conclusion: Preliminary results suggest that MT1-MMP positivity in primary tumor specimens may identify aggressive tumor types, evidenced by the presence of micrometastasis or PNI.

Sentinel node biopsy and head and neck tumors—Where do we stand today?

BACKGROUND

Sentinel lymph node sampling may be studied profitably in series of patients with 1 tumor type, such as breast carcinoma, in 1 anatomic locale. The present work analyzes the efficacy of sentinel node sampling in a pathologically diverse group of lesions from an anatomically diverse region such as the head and neck; however, there are risks conflating the findings in different tumors with radically different behaviors, in the process producing muddled data. This report reviews the head and neck experience with sentinel sampling and concludes that certain tumor types that have a known propensity for aggressive behavior are the best candidates for trials employing sentinel node sampling; candidates include many cutaneous melanomas of the head and neck, oropharyngeal squamous carcinomas, and selected thyroid carcinomas. Despite the growing popularity of sentinel node sampling in a variety of regions of the body, however, at this juncture this technique remains an investigational procedure, pending demonstration of a tangible improvement in patient outcome through its use. It is recommended that studies of the efficacy of this technique strive, whenever possible, to segregate results of different tumor types in different head and neck locales from one another so as to produce more focused findings for discrete types of malignancies, and not group together tumor types that may in reality exhibit different biological behaviors.