Progression of Metastasis through Lymphatic System

Lymphadenopathies: A Retrospective Study of Epidemiology, Characteristics, Diagnosis and Treatment Outcomes of Patients in a Tertiary Hospital in Mogadishu-Somalia

Introduction

Lymphadenopathies, which can be caused by infections, malignant diseases, autoimmune disorders, and many other diseases, pose a challenge to clinicians in sub-Saharan Africa, as well as all over the world. The purpose of this research was to identify the clinical and diagnostic characteristics of Somalian patients suffering from swollen lymph nodes.

Methods

Under the purview of this study, the diagnoses, patient clinical courses, and treatment outcomes were ascertained retrospectively by analyzing the biochemical, microbiological, radiological, and pathological data of the cases in all age groups who underwent therapy for lymphadenitis at Mogadishu Somali Turkey Recep Tayyip Erdoğan Training and Research Hospital between January 2016 and September 2023.

Results

During the study period, 317 patients were followed up, with 53.3% of the patients as female, 46.7% as male, 28.1% as pediatric, 63.1% as adult, and 8.8% were elderly patients. With 58.7% of diagnoses, tuberculous lymphadenitis was the most common, pursued by malignant causes (21.8%). The most commonly affected lymph node was the cervical region, the symptom detected was lymph node swelling, the radiological method used was ultrasonography, and the biopsy method was fine needle aspiration biopsy. It was determined that benign conditions, including tuberculosis were more common in pediatric group and younger adults (p<0.001), and weight loss was a significant in terms of malignancy and tuberculosis (p<0.001). White blood cell value (p<0.001), erythrocyte sedimentation rate (p<0.001), and C-reactive protein (p:0.001) revealed differences across the diagnostic groups.

Conclusion

Almost two-thirds of patients were diagnosed with tuberculosis lymphadenitis. Our finding revealed tuberculosis as the commonest cause of lymphadenopathy followed by malignant causes. Therefore, before screening for malignant causes, tuberculosis should be the first diagnosis considered in Somalia, particularly in a patient presenting with weight loss and swelling of the lymph nodes.

Artificial intelligence performance in ultrasound-based lymph node diagnosis: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Accurate classification of lymphadenopathy is essential for determining the pathological nature of lymph nodes (LNs), which plays a crucial role in treatment selection. The biopsy method is invasive and carries the risk of sampling failure, while the utilization of non-invasive approaches such as ultrasound can minimize the probability of iatrogenic injury and infection. With the advancement of artificial intelligence (AI) and machine learning, the diagnostic efficiency of LNs is further enhanced. This study evaluates the performance of ultrasound-based AI applications in the classification of benign and malignant LNs.

METHODS

The literature research was conducted using the PubMed, EMBASE, and Cochrane Library databases as of June 2024. The quality of the included studies was evaluated using the QUADAS-2 tool. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated to assess the diagnostic efficacy of ultrasound-based AI in classifying benign and malignant LNs. Subgroup analyses were also conducted to identify potential sources of heterogeneity.

RESULTS

A total of 1,355 studies were identified and reviewed. Among these studies, 19 studies met the inclusion criteria, and 2,354 cases were included in the analysis. The pooled sensitivity, specificity, and DOR of ultrasound-based machine learning in classifying benign and malignant LNs were 0.836 (95% CI [0.805, 0.863]), 0.850 (95% CI [0.805, 0.886]), and 33.331 (95% CI [22.873, 48.57]), respectively, indicating no publication bias (p = 0.12). Subgroup analyses may suggest that the location of lymph nodes, validation methods, and type of primary tumor are the sources of heterogeneity.

CONCLUSION

AI can accurately differentiate benign from malignant LNs. Given the widespread use of ultrasonography in diagnosing malignant LNs in cancer patients, there is significant potential for integrating AI-based decision support systems into clinical practice to enhance the diagnostic accuracy.

Modeling the lymph node stromal cells in oral squamous cell carcinoma: insights into the stromal cues in nodal metastasis

The study explores the development and characterization of lymph node stromal cell cultures (LNSCs) from patients with oral squamous cell carcinoma (OSCC), highlighting the importance of understanding tumor-node cross-talk for effective prognostic and therapeutic interventions. Herein, we describe the development and characterization of primary lymph node stromal cells (LNSCs, N = 14) from nodes of metastatic and non-metastatic OSCC patients. Primary cultures were established by the explant method from positive (N + ; N = 2), and negative nodes (N0m; N = 4) of the metastatic patients (N = 3) as well as negative (N0nm; N = 8) nodes from non-metastatic (N = 4) patients. STR profiling confirmed the purity and novelty, while characterization by immunocytochemistry/flow cytometry revealed heterogeneous cell populations consisting of fibroblastic reticular cells (CD31-Gp38 +) and double negative cells (CD31-Gp38-). Transcriptomic profiling indicated molecular alterations in the cells based on the non-metastatic, the pre-metastatic or metastatic status of the nodes, pro-inflammatory, matrix remodeling, and immune evasion being the primary pathways. Assessment of the protein levels for five selected markers (MX1, ISG15, CPM, ITGB4 and FOS) in the cell lines revealed that CPM levels were significantly reduced in the N + and N0m nodes whereas ISG15 levels reduced in N0m. Significantly, the profiling also provided insights into possible glycosylation of CPM (N0nm) and ISGylation of ISG15 (N0m). Cytokine profiling indicated release of chemokines/anti-proliferative cytokines from the negative nodes, while angiogenic/pro-metastatic cytokines were released from the nodes of metastatic patients. The lymph node stromal cell models established in the study with distinctive transcriptomic/cytokine characteristics will be invaluable in delineating the processes underlying nodal metastasis.

Cancer immunotherapy response persists after lymph node resection

Lymphatic transport facilitates the presentation of cancer antigens in tumor-draining lymph nodes (tdLNs), leading to T cell activation and the generation of systemic antitumor immune surveillance. Surgical removal of LNs to control cancer progression is routine in clinical practice. However, whether removing tdLNs impairs immune checkpoint blockade (ICB) is still controversial. Our analysis demonstrates that melanoma patients remain responsive to PD-1 checkpoint blockade after LN dissection. We were able to recapitulate the persistent response to ICB after complete LN resection in murine melanoma and mammary carcinoma models. Mechanistically, soluble antigen and antigen-carrying migratory dendritic cells are diverted to non-directly tumor draining LNs (non-tdLNs) after tdLN dissection. Consistently, robust ICB responses in patients with head and neck cancer after primary tumor and tdLN resection correlated with the presence of reactive LNs in distant areas. These findings indicate that non-tdLNs sufficiently compensate for the removal of direct tdLNs and sustain the response to ICB.

Visualizing the Tumor Microenvironment: Molecular Imaging Probes Target Extracellular Matrix, Vascular Networks, and Immunosuppressive Cells

The tumor microenvironment (TME) is a critical factor in cancer progression, driving tumor growth, immune evasion, therapeutic resistance, and metastasis. Understanding the dynamic interactions within the TME is essential for advancing cancer management. Molecular imaging provides a non-invasive, real-time, and longitudinal approach to studying the TME, with techniques such as positron emission tomography (PET), magnetic resonance imaging (MRI), and fluorescence imaging offering complementary strengths, including high sensitivity, spatial resolution, and intraoperative precision. Recent advances in imaging probe development have enhanced the ability to target and monitor specific components of the TME, facilitating early cancer diagnosis, therapeutic monitoring, and deeper insights into tumor biology. By integrating these innovations, molecular imaging offers transformative potential for precision oncology, improving diagnostic accuracy and treatment outcomes through a comprehensive assessment of TME dynamics.

Lymph node metastasis in cancer: Clearing the clouds to see the dawn

Lymph node metastasis (LNM) is often regarded as an indicator of poor prognosis in various cancers. Despite over three centuries of exploration since its discovery, the molecular mechanisms underlying LNM remain inconclusive. This review summarizes the molecular mechanisms of LNM, using the "PUMP+" principle for clarification. Pathological examination remains the gold standard for LNM diagnosis, yet there is a need to explore early diagnostic strategies that can effectively improve patient outcomes. With the advent of immunotherapy, discussions on the fate of lymph nodes (LN) have emerged, emphasizing the importance of preserving LN integrity prior to immunotherapy. This, in turn, poses higher demands for diagnostic accuracy and precision treatment of LNM. This review comprehensively discusses the molecular mechanisms, diagnostic methods, and treatment strategies for cancer lymph node metastasis, along with current bottlenecks and future directions in this field.

Metabolic insights into tumor lymph node metastasis in melanoma

Although accounting for only a small amount of skin cancers, melanoma contributes prominently to skin cancer-related deaths, which are mostly caused by metastatic diseases, and lymphatic metastasis constitutes the main route. In this review, we concentrate on the metabolic mechanisms of tumor lymph node (LN) metastasis in melanoma. Two hypotheses of melanoma LN metastasis are introduced, which are the premetastatic niche (PMN) and parallel progression model. Dysregulation of oxidative stress, lactic acid concentration, fatty acid synthesis, amino acid metabolism, autophagy, and ferroptosis construct the metabolic mechanisms in LN metastasis of melanoma. Moreover, melanoma cells also promote LN metastasis by interacting with non-tumor cells through metabolic reprogramming in TIME. This review will deepen our understanding of the mechanism of lymph node metastasis in melanoma.

Tips and tricks for a proper radiological assessment of abdominal and pelvic lymph nodes

The assessment of lymph node dimensions is a commonly used criterion in analyzing lymphatic involvement related to inflammatory or neoplastic diseases. However, it is important to understand that the interpretation of lymph nodes goes beyond simply considering their size. A pathologic lymph node can present with enlarged dimensions, a heterogeneous appearance, increased cortex thickness, irregular contours, or a lobulated shape. In this context, it is essential to consider not only the dimensions but also the morphology, attenuation, and enhancement of lymph nodes on imaging exams. This article aims to demonstrate how characteristics of lymph nodes, beyond their size, can provide crucial insights that assist in diagnostic reasoning, focusing on computed tomography. By emphasizing different enhancement patterns, attenuation, and the potential contents related to these patterns, the study seeks to show how these features can indicate possible differential diagnoses and guide more accurate clinical assessments.

Magnetic Resonance Imaging-Guided Cryoablation of Prostate Cancer Lymph Node Metastasis

PURPOSE

To evaluate the safety and effectiveness of magnetic resonance (MR) imaging-guided cryoablation of prostate cancer metastatic lymph nodes (LNs).

MATERIALS AND METHODS

Fifty-two patients with prostate cancer who underwent MR imaging-guided LN ablation from September 2013 to June 2022 were retrospectively reviewed. Of these, 6 patients were excluded because adequate ablation margins (3-5 mm) could not be achieved secondary to adjacent structures. The remaining 46 patients (mean age, 70 years [SD ± 7]) underwent 55 MR imaging-guided cryoablation procedures of metastatic LNs (25 in the pelvic sidewall, 20 within the pelvic region, and 10 in the abdomen) with procedural intent of complete ablation. Locoregional tumor control (ie, technical success in the target LN) was evaluated on initial follow-up positron emission tomography (PET) scans at a mean of 4 months (SD ± 2). Preablation and postablation prostate-specific antigen (PSA) levels were recorded. Imaging follow-up continued until a median of 27.5 months (range: 3-108 months).

RESULTS

Ninety-five percent (52/55) of treated LNs demonstrated no considerable activity on PET scans at initial follow-up at 4 months (SD ± 2). PSA decreased to an undetectable level of <0.1 ng/mL after cryoablation in 14 of 46 (30.4%) patients with corresponding lack of activity in 13 of 46 (28.2%) patients on continued PET imaging follow-up. Only 6 of 55 (10.9%) patients had transient adverse events, which all resolved with no long-term sequelae.

CONCLUSIONS

MR imaging-guided percutaneous cryoablation of metastatic LNs is a safe and technically effective technique for treating metastatic prostate cancer in LNs.

Deciphering breast cancer dynamics: insights from single-cell and spatial profiling in the multi-omics era

As one of the most common tumors in women, the pathogenesis and tumor heterogeneity of breast cancer have long been the focal point of research, with the emergence of tumor metastasis and drug resistance posing persistent clinical challenges. The emergence of single-cell sequencing (SCS) technology has introduced novel approaches for gaining comprehensive insights into the biological behavior of malignant tumors. SCS is a high-throughput technology that has rapidly developed in the past decade, providing high-throughput molecular insights at the individual cell level. Furthermore, the advent of multitemporal point sampling and spatial omics also greatly enhances our understanding of cellular dynamics at both temporal and spatial levels. The paper provides a comprehensive overview of the historical development of SCS, and highlights the most recent advancements in utilizing SCS and spatial omics for breast cancer research. The findings from these studies will serve as valuable references for future advancements in basic research, clinical diagnosis, and treatment of breast cancer.

Diffusion-Weighted Magnetic Resonance Imaging for the Diagnosis of Lymph Node Metastasis in Patients with Biliary Tract Cancer

Objective: The diagnostic efficacy of the apparent diffusion coefficient (ADC) in diffusion-weighted magnetic resonance imaging (DW-MRI) for lymph node metastasis in biliary tract cancer was investigated in the present study. Methods: In total, 112 surgically resected lymph nodes from 35 biliary tract cancer patients were examined in this study. The mean and minimum ADC values of the lymph nodes as well as the long-axis and short-axis diameters of the lymph nodes were assessed by computed tomography (CT). The relationship between these parameters and the presence of histological lymph node metastasis was evaluated. Results: Histological lymph node metastasis was detected in 31 (27.7%) out of 112 lymph nodes. Metastatic lymph nodes had a significantly larger short-axis diameter compared with non-metastatic lymph nodes (p = 0.002), but the long-axis diameter was not significantly different between metastatic and non-metastatic lymph nodes. The mean and minimum ADC values for metastatic lymph nodes were significantly reduced compared with those for non-metastatic lymph nodes (p < 0.001 for both). However, the minimum ADC value showed the highest accuracy for the diagnosis of histological lymph node metastasis, with an area under the curve of 0.877, sensitivity of 87.1%, specificity of 82.7%, and accuracy of 83.9%. Conclusions: The minimum ADC value in DW-MRI is highly effective for the diagnosis of lymph node metastasis in biliary tract cancer. Accurate preoperative diagnosis of lymph node metastasis in biliary tract cancer should enable the establishment of more appropriate treatment strategies.

Paired organoids from primary gastric cancer and lymphatic metastasis are useful for personalized medicine

BACKGROUND

Organoids are approved by the US FDA as an alternative to animal experiments to guide drug development and for sensitivity screening. Stable organoids models of gastric cancer are desirable for personalized medicine and drug screening.

METHODS

Tumor tissues from a primary cancer of the stomach and metastatic cancer of the lymph node were collected for 3D culture. By long-term culture for over 50 generations in vitro, we obtained stably growing organoid lines. We analyzed short tandem repeats (STRs) and karyotypes of cancer cells, and tumorigenesis of the organoids in nude mice, as well as multi-omics profiles of the organoids. A CCK8 method was used to determine the drugs sensitivity to fluorouracil (5-Fu), platinum and paclitaxel.

RESULTS

Paired organoid lines from primary cancer (SPDO1P) and metastatic lymph node (SPDO1LM) were established with unique STRs and karyotypes. The organoid lines resulted in tumorigenesis in vivo and had clear genetic profiles. Compared to SPDO1P from primary cancer, upregulated genes of SPDO1LM from the metastatic lymph node were enriched in pathways of epithelial-mesenchymal transition and angiogenesis with stronger abilities of cell migration, invasion, and pro-angiogenesis. Based on drug sensitivity analysis, the SOX regimen (5-Fu plus oxaliplatin) was used for chemotherapy with an optimal clinical outcome.

CONCLUSIONS

The organoid lines recapitulate the drug sensitivity of the parental tissues. The paired organoid lines present a step-change toward living biobanks for further translational usage.

A Tumor-Activatable Liposomal Nanoprobe for Selective Visualization of Metastatic Lymph Nodes

The precise identification of sentinel lymph nodes (SLNs) during surgery and assessment of their benign status is crucial for accurate tumor staging and optimal treatment strategizing. Currently, a deficiency exists in non-invasive in vivo diagnostic techniques that can accurately pinpoint SLNs during surgery while simultaneously evaluating their benign status. Here, a tumor-activatable liposomal nanoprobe (nTAL) is developed, remotely loaded with clinically approved photosensitizer, methyl aminolevulinate (MAL), to noninvasively visualize the tumor metastasis lymph nodes (LNs) with precision. Benefited from the highly efficient LNs draining of nanosized liposome and tumor cell-specific transformation of the non-fluorescent MAL to fluorescent protoporphyrin IX (PPIX), nTAL succeeded in targeting the SLNs and differentiated the metastatic from the benign ones with a positive correlation between PPIX generation and tumor cell infiltration in LNs. Moreover, the nTAL technology is capable of probing the early metastatic stage with a primary tumor size of 50 mm3. This study provides a new strategy for intraoperative visualization of real-time sentinel node dissection.

Cancer metastasis through the lymphatic versus blood vessels

Whether cancer cells metastasize from the primary site to the distant sites via the lymphatic vessels or the blood vessels directly into the circulation is still under intense study. In this review article, we follow the journey of cancer cells metastasizing to the sentinel lymph nodes and beyond to the distant sites. We emphasize cancer heterogeneity and microenvironment as major determinants of cancer metastasis. Multiple molecules have been found to be associated with the complicated process of metastasis. Based on the large sentinel lymph node data, it is reasonable to conclude that cancer cells may metastasize through the blood vessels in some cases but in most cases, they use the sentinel lymph nodes as the major gateway to enter the circulation to distant sites.

Prognostic effect of TCF1+ CD8+ T cell and TOX+ CD8+ T cell infiltration in lung adenocarcinoma

Recent studies have highlighted the pivotal roles of T cell transcription factors TCF-1 and TOX in modulating the immune response in cancer, with TCF-1 maintaining CD8+ T cell stemness and TOX promoting T cell exhaustion. The prognostic significance of these factors in lung adenocarcinoma (LUAD) remains a critical area of investigation. The retrospective study included 191 patients with LUAD who underwent surgery, of whom 83% were in stages II and III. These patients were divided into exploratory (n = 135) and validation (n = 56) groups based on the time of diagnosis. Multiplex fluorescence immunohistochemistry was used to examine the infiltration levels of CD8+ T cells, TCF1+ CD8+ T cells, and TOX+ CD8+ T cells. The percentage of CD8+ T cells in tumor was markedly lower than that in stroma (p < 0.05). In tumor-draining lymph nodes (TDLNs) invaded by tumor, the proportion of stem-like TCF1+ CD8+ T cells was significantly decreased (p < 0.01). Importantly, higher infiltration levels of CD8+ T cells and TCF1+ CD8+ T cells were associated with improved disease-free survival (DFS) (p = 0.009 and p = 0.006, respectively) and overall survival (OS) (p = 0.018 and p = 0.010, respectively). This study underscores the potential of TCF1+ CD8+ T cells as prognostic biomarkers in LUAD, providing insights into the tumor immune microenvironment and guiding future therapeutic strategies.

Single-cell and spatial transcriptomics reveal metastasis mechanism and microenvironment remodeling of lymph node in osteosarcoma

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant bone tumor and is highly prone to metastasis. OS can metastasize to the lymph node (LN) through the lymphatics, and the metastasis of tumor cells reestablishes the immune landscape of the LN, which is conducive to the growth of tumor cells. However, the mechanism of LN metastasis of osteosarcoma and remodeling of the metastatic lymph node (MLN) microenvironment is not clear.

METHODS

Single-cell RNA sequencing of 18 samples from paracancerous, primary tumor, and lymph nodes was performed. Then, new signaling axes closely related to metastasis were identified using bioinformatics, in vitro experiments, and immunohistochemistry. The mechanism of remodeling of the LN microenvironment in tumor cells was investigated by integrating single-cell and spatial transcriptomics.

RESULTS

From 18 single-cell sequencing samples, we obtained 117,964 cells. The pseudotime analysis revealed that osteoblast(OB) cells may follow a differentiation path from paracancerous tissue (PC) → primary tumor (PT) → MLN or from PC → PT, during the process of LN metastasis. Next, in combination of bioinformatics, in vitro and in vivo experiments, and immunohistochemistry, we determined that ETS2/IBSP, a new signal axis, might promote LN metastasis. Finally, single-cell and spatial dissection uncovered that OS cells could reshape the microenvironment of LN by interacting with various cell components, such as myeloid, cancer-associated fibroblasts (CAFs), and NK/T cells.

CONCLUSIONS

Collectively, our research revealed a new molecular mechanism of LN metastasis and clarified how OS cells influenced the LN microenvironment, which might provide new insight for blocking LN metastasis.

Unraveling a hidden player in lymphovascular invasion in bladder cancer

Tumor invasion into the lymphatic vasculature represents a critical step during malignant progression of epithelial cancers. In this issue of Cancer Cell, Zheng et al. unravel how cancer-associated fibroblasts interact with lymphatic endothelial cells and the extracellular matrix to promote lymphatic tumor invasion and suggest that these processes could be treatment targets.

Acute stress transiently activates macrophages and chemokines in cervical lymph nodes

Acute restraint stress (RS) is routinely used to study the effects of psychological and/or physiological stress. We evaluated the impact of RS on cervical lymph nodes in rats at molecular and cellular levels. Male Sprague-Dawley rats were subjected to stress by immobilization for 30, 60, and 120 min (RS30, RS60, and RS120, respectively) and compared with rats of a no-stress control (C) group. The expression of genes encoding chemokines CXCL1/CXCL2 (Cxcl1 and Cxcl2) and their receptor CXCR2 (Cxcr2) was analyzed using reverse transcription-quantitative PCR (RT-qPCR) and microarray analyses. Immunohistochemistry and in situ hybridization were performed to determine the expression of these proteins and the macrophage biomarker CD68. Microarray analysis revealed that the expression of 514 and 496 genes was upregulated and downregulated, respectively, in the RS30 group. Compared with the C group, the RS30 group exhibited a 23.0-, 13.0-, and 1.6-fold increase in Cxcl1, Cxcl2, and Cxcr2 expression. Gene Ontology analysis revealed the involvement of these three upregulated genes in the cytokine network, inflammation, and leukocyte chemotaxis and migration. RT-qPCR analysis indicated that the mRNA levels of Cxcl1 and Cxcl2 were significantly increased in the RS30 group but were reverted to normal levels in the RS60 and RS120 groups. Cxcr2 mRNA level was significantly increased in the RS30 and RS120 groups compared with that in the C group. RS-induced CXCL1-immunopositive cells corresponded to B/plasma cells, whereas CXCL2-immunopositive cells corresponded to endothelial cells of the high endothelial venules. Stress-induced CXCR2-immunopositive cells corresponded to macrophages. Psychological and/or physiological stress induces an acute stress response and formation of an immunoreactive microenvironment in cervical lymph nodes, with the CXCL1/CXCL2-CXCR2 axis being pivotal in the acute stress response.

The role of micrometastasis in high-risk skin cancers

The propensity to metastasize is the most important prognostic indicator for solid cancers. New insights into the mechanisms of early carcinogenesis have revealed micrometastases are generated far earlier than previously thought. Evidence supports a synergistic relationship between vascular and lymphatic seeding which can occur before there is clinical evidence of a primary tumour. Early vascular seeding prepares distal sites for colonisation while regional lymphatics are co-opted to promote facilitative cancer cell mutations. In response, the host mounts a global inflammatory and immunomodulatory response towards these cells supporting the concept that cancer is a systemic disease. Cancer staging systems should be refined to better reflect cancer cell loads in various tissue compartments while clinical perspectives should be broadened to encompass this view when approaching high-risk cancers. Measured adjunctive therapies implemented earlier for low-volume, in-transit cancer offers the prospect of preventing advanced disease and the need for heroic therapeutic interventions. This review seeks to re-appraise how we view the metastatic process for solid cancers. It will explore in-transit metastasis in the context of high-risk skin cancer and how it dictates disease progression. It will also discuss how these implications will influence our current staging systems and its consequences on management.

Determining Accurate Dye Combinations for Sentinel Lymph Node Detection: A Systematic Review

Background

Lymphatic dyes are commonly used to map the drainage path from tumor to lymphatics, which are biopsied to determine if spread has occurred. A blue dye in combination with technetium-99 is considered the gold standard for mapping, although many other dyes and dye combinations are used. Not all of these substances have the same detection efficacy.

Methods

A systematic review of PubMed, SCOPUS, Web of Science, and Medline was performed. The predefined search terms were (indocyanine green OR isosulfan blue OR lymphazurin OR patent blue OR methylene blue OR fluorescein OR technetium-99) AND combination AND dye AND (sentinel lymph node biopsy OR lymphedema OR lymphatics OR lymph OR microsurgery OR cancer OR tumor OR melanoma OR carcinoma OR sarcoma).

Results

The initial search returned 4267 articles. From these studies, 37 were selected as candidates that met inclusion criteria. After a full-text review, 34 studies were selected for inclusion. Eighty-nine methods of sentinel lymph node (SLN) detection were trialed using 22 unique dyes, dye combinations, or other tracers. In total, 12,157 SLNs of 12,801 SLNs were identified. Dye accuracy ranged from 100% to 69.8% detection. Five dye combinations had 100% accuracy. Dye combinations were more accurate than single dyes.

Conclusions

Combining lymphatic dyes improves SLN detection results. Replacing technetium-99 with ICG may allow for increased access to SLN procedures with comparable results. The ideal SLN tracer is a low-cost molecule with a high affinity for lymphatic vessels due to size and chemical composition, visualization without specialized equipment, and no adverse effects.

Lymphoma and Other Lymph Node Pathologies Among Adult Patients with Lymphadenopathy in Abakaliki, Nigeria

INTRODUCTION

Lymphadenopathy is usually due to benign or malignant conditions. It can also be local or systemic in distribution and can involve peripheral or deep-seated lymph nodes. This study aimed to determine the prevalence of lymphoma and the distribution pattern of lymph node pathologies among adult patients who presented with lymphadenopathy and its relationship with age and sex.

METHODS

A retrospective study was conducted, and a record of all cases of lymphadenopathy with histological diagnosis over 5-year period (January 2017 to December 2021) was extracted from Departments of Anatomical Pathology of Alex Ekwueme Federal University Teaching Hospital, Abakaliki. The data generated were analyzed using Statistical Package for Social Sciences (SPSS) software, version 26.

RESULTS

One hundred and ninety results were extracted with an age range of 18 to 94 years and a mean age of 41 ± 16 years. They were made up of 75 (39.5%) males and 115 (60.5%) females, with a male-to-female ratio of 1:1.5. The prevalence of lymphoma was 50.0% (95/190). Thirty-five (18.4%) were Hodgkin's lymphoma (HL), while 60 (31.6%) were non-Hodgkin's lymphoma (NHL). Other pathologies manifested by cases of lymphadenopathy include metastatic tumor deposits (38 (20%)), reactive lymphoid hyperplasia (29 (15.3%)), and tuberculous lymphadenitis (18 (9.5%)). Others include sinus histiocytosis (4 (2.1%)), dermatopathic lymphadenitis (5 (2.6%)), and Castleman's disease (1 (0.5%)).

CONCLUSION

About half of all patients who presented with lymphadenopathy were lymphoma with a high prevalence of 50%, and the majority were NHL. Other major causes of lymphadenopathy were metastatic tumor deposits, reactive lymphoid hyperplasia, and tuberculous lymphadenitis. Any case of lymphadenopathy should be properly investigated early for effective management.

Prognostic Value of Baseline 18F-FDG PET/CT to Predict Brain Metastasis Development in Melanoma Patients

To investigate the value of 18F-FDG-PET/CT in predicting the occurrence of brain metastases in melanoma patients, in this retrospective study 201 consecutive patients with pathology-proven melanoma, between 2008 and 2021, were reviewed. Those who underwent 18F-FDG-PET/CT for initial staging were considered eligible. Baseline assessment included histopathology, 18F-FDG-PET/CT, and brain MRI. Also, all patients had serial follow-ups for diagnosing brain metastasis development. Baseline 18F-FDG-PET/CT parameters were analysed using competing risk regression models to analyze their correlation with the occurrence of brain metastases. Overall, 159 patients entered the study. The median follow-up was six years. Among clinical variables, the initial M-stage and TNM-stage were significantly correlated with brain metastasis. Regarding 18F-FDG-PET/CT parameters, regional metastatic lymph node uptake values, as well as prominent SULmax (pSULmax) and prominent SUVmean (pSUVmean), were significantly correlated with the outcome. Cumulative incidences were 10% (6.3-16%), 31% (24.4-38.9%), and 35.2% (28.5-43.5%) after 1, 5, and 10 years. There were significant correlations between pSULmax (p-value < 0.001) and pSULpeak (p-value < 0.001) and the occurrence of brain metastases. The higher these values, the sooner the patient developed brain metastases. Thus, baseline 18F-FDG-PET/CT may have the potential to predict brain metastasis in melanoma patients. Those with high total metabolic activity should undergo follow-up/complementary evaluations, such as brain MRI.

The Evolving Landscape of B Cells in Cancer Metastasis

Metastasis is the leading cause of cancer mortality. Functional and clinical studies have documented diverse B-cell and antibody responses in cancer metastasis. The presence of B cells in tumor microenvironments and metastatic sites has been associated with diverse effects that can promote or inhibit metastasis. Specifically, B cells can contribute to the spread of cancer cells by enhancing tumor cell motility, invasion, angiogenesis, lymphangiogenesis, and extracellular matrix remodeling. Moreover, they can promote metastatic colonization by triggering pathogenic immunoglobulin responses and recruiting immune suppressive cells. Contrastingly, B cells can also exhibit antimetastatic effects. For example, they aid in enhanced antigen presentation, which helps activate immune responses against cancer cells. In addition, B cells play a crucial role in preventing the dissemination of metastatic cells from the primary tumor and secrete antibodies that can aid in tumor recognition. Here, we review the complex roles of B cells in metastasis, delineating the heterogeneity of B-cell activity and subtypes by metastatic site, antibody class, antigen (if known), and molecular phenotype. These important attributes of B cells emphasize the need for a deeper understanding and characterization of B-cell phenotypes to define their effects in metastasis.

Identifying Lymph Node Metastasis-Related Factors in Breast Cancer Using Differential Modular and Mutational Structural Analysis

Complex diseases are generally caused by disorders of biological networks and/or mutations in multiple genes. Comparisons of network topologies between different disease states can highlight key factors in their dynamic processes. Here, we propose a differential modular analysis approach that integrates protein-protein interactions with gene expression profiles for modular analysis, and introduces inter-modular edges and date hubs to identify the "core network module" that quantifies the significant phenotypic variation. Then, based on this core network module, key factors, including functional protein-protein interactions, pathways, and driver mutations, are predicted by the topological-functional connection score and structural modeling. We applied this approach to analyze the lymph node metastasis (LNM) process in breast cancer. The functional enrichment analysis showed that both inter-modular edges and date hubs play important roles in cancer metastasis and invasion, and in metastasis hallmarks. The structural mutation analysis suggested that the LNM of breast cancer may be the outcome of the dysfunction of rearranged during transfection (RET) proto-oncogene-related interactions and the non-canonical calcium signaling pathway via an allosteric mutation of RET. We believe that the proposed method can provide new insights into disease progression such as cancer metastasis.

Advances in photoacoustic imaging aided by nano contrast agents: special focus on role of lymphatic system imaging for cancer theranostics

Photoacoustic imaging (PAI) is a successful clinical imaging platform for management of cancer and other health conditions that has seen significant progress in the past decade. However, clinical translation of PAI based methods are still under scrutiny as the imaging quality and clinical information derived from PA images are not on par with other imaging methods. Hence, to improve PAI, exogenous contrast agents, in the form of nanomaterials, are being used to achieve better image with less side effects, lower accumulation, and improved target specificity. Nanomedicine has become inevitable in cancer management, as it contributes at every stage from diagnosis to therapy, surgery, and even in the postoperative care and surveillance for recurrence. Nanocontrast agents for PAI have been developed and are being explored for early and improved cancer diagnosis. The systemic stability and target specificity of the nanomaterials to render its theranostic property depends on various influencing factors such as the administration route and physico-chemical responsiveness. The recent focus in PAI is on targeting the lymphatic system and nodes for cancer diagnosis, as they play a vital role in cancer progression and metastasis. This review aims to discuss the clinical advancements of PAI using nanoparticles as exogenous contrast agents for cancer theranostics with emphasis on PAI of lymphatic system for diagnosis, cancer progression, metastasis, PAI guided tumor resection, and finally PAI guided drug delivery.

Characterization of hypermetabolic lymph nodes after SARS-CoV-2 vaccination using PET-CT derived node-RADS, in patients with melanoma

This study aimed to evaluate the diagnostic accuracy of Node Reporting and Data System (Node-RADS) in discriminating between normal, reactive, and metastatic axillary LNs in patients with melanoma who underwent SARS-CoV-2 vaccination. Patients with proven melanoma who underwent a 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (2-[18F]-FDG PET/CT) between February and April 2021 were included in this retrospective study. Primary melanoma site, vaccination status, injection site, and 2-[18F]-FDG PET/CT were used to classify axillary LNs into normal, inflammatory, and metastatic (combined classification). An adapted Node-RADS classification (A-Node-RADS) was generated based on LN anatomical characteristics on low-dose CT images and compared to the combined classification. 108 patients were included in the study (54 vaccinated). HALNs were detected in 42 patients (32.8%), of whom 97.6% were vaccinated. 172 LNs were classified as normal, 30 as inflammatory, and 14 as metastatic using the combined classification. 152, 22, 29, 12, and 1 LNs were classified A-Node-RADS 1, 2, 3, 4, and 5, respectively. Hence, 174, 29, and 13 LNs were deemed benign, equivocal, and metastatic. The concordance between the classifications was very good (Cohen's k: 0.91, CI 0.86-0.95; p-value < 0.0001). A-Node-RADS can assist the classification of axillary LNs in melanoma patients who underwent 2-[18F]-FDG PET/CT and SARS-CoV-2 vaccination.

Protein@Cyanine-Based NIR-II Lymphography Enables the Supersensitive Visualization of Lymphedema and Tumor Lymphatic Metastasis

Visualization of the lymphatic system is clinically indispensable for the diagnosis and/or treatment of lymphatic diseases. Although indocyanine green (ICG) lymphography becomes an alternate imaging modality compared to traditional lymphoscintigraphy, it is still far from ideal due to the insufficient detection depth and low spatiotemporal resolution. Herein, protein@cyanine probes are rationally developed to solve the limitations of the current near-infrared-I (NIR-I) lymphography. The protein@cyanine probes are synthesized following a chlorine-containing dye-labeling strategy based on structure-selectivity (facile covalent binding between the dye and protein with a 1:1 molar ratio). As expected, the probes display exceptional NIR-II imaging ability with much-improved imaging contrast/resolution and controllable pharmacokinetics, superior to the clinical ICG. The protein@cyanine probes locate lymph nodes and delineate lymphatic vessels with super-high sensitivity and signal-to-background ratio, enabling real-time diagnosing lymphatic diseases such as lymphedema and tumor lymphatic metastasis. In particular, the NIR-II lymphography provides an opportunity to discover the disparate morbidity rate of primary lymphedema in different types of mice. Given the fact of lacking clinically transferable NIR-II probes, this work not only provides a promising strategy for enriching of the current library of NIR-II probes, but also promotes the clinical translation of NIR-II lymphography technology.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

Immunomodulatory properties of the lymphatic endothelium in the tumor microenvironment

The tumor microenvironment (TME) is an intricate complex and dynamic structure composed of various cell types, including tumor, stromal and immune cells. Within this complex network, lymphatic endothelial cells (LECs) play a crucial role in regulating immune responses and influencing tumor progression and metastatic dissemination to lymph node and distant organs. Interestingly, LECs possess unique immunomodulatory properties that can either promote or inhibit anti-tumor immune responses. In fact, tumor-associated lymphangiogenesis can facilitate tumor cell dissemination and metastasis supporting immunoevasion, but also, different molecular mechanisms involved in LEC-mediated anti-tumor immunity have been already described. In this context, the crosstalk between cancer cells, LECs and immune cells and how this communication can shape the immune landscape in the TME is gaining increased interest in recent years. In this review, we present a comprehensive and updated report about the immunomodulatory properties of the lymphatic endothelium within the TME, with special focus on primary tumors and tumor-draining lymph nodes. Furthermore, we outline emerging research investigating the potential therapeutic strategies targeting the lymphatic endothelium to enhance anti-tumor immune responses. Understanding the intricate mechanisms involved in LEC-mediated immune modulation in the TME opens up new possibilities for the development of innovative approaches to fight cancer.

Cancer cell plasticity and MHC-II-mediated immune tolerance promote breast cancer metastasis to lymph nodes

Tumor-draining lymph nodes (TDLNs) are important for tumor antigen-specific T cell generation and effective anticancer immune responses. However, TDLNs are often the primary site of metastasis, causing immune suppression and worse outcomes. Through cross-species single-cell RNA-Seq analysis, we identified features defining cancer cell heterogeneity, plasticity, and immune evasion during breast cancer progression and lymph node metastasis (LNM). A subset of cancer cells in the lymph nodes exhibited elevated MHC class II (MHC-II) gene expression in both mice and humans. MHC-II+ cancer cells lacked costimulatory molecule expression, leading to regulatory T cell (Treg) expansion and fewer CD4+ effector T cells in TDLNs. Genetic knockout of MHC-II reduced LNM and Treg expansion, while overexpression of the MHC-II transactivator, Ciita, worsened LNM and caused excessive Treg expansion. These findings demonstrate that cancer cell MHC-II expression promotes metastasis and immune evasion in TDLNs.

Preclinical models to understand the biology and to discover new targets in brain metastases

PURPOSE OF REVIEW

Incidence of brain metastases increases overtime therefore it is important to rapidly progress in the discovery of new strategies of treatment for these patients. In consequence, more and more preclinical models of brain metastases (BM) are established to study new treatments for melanoma, lung, and breast cancer BM. Here, we reviewed the most recent findings of new drugs assessed in BM mouse preclinical models.

RECENT FINDINGS

BM are a common metastatic site of several types of solid cancers and can be difficult to treat due to the unique environment of the brain and the blood-brain barrier. Currently, several preclinical models of BM have been demonstrated that new molecular targeted therapies, small metabolic inhibitors, immunotherapies or a combination of these drugs with radiotherapy lead to a reduction of BM growth and an improvement of mouse survival.

SUMMARY

The use of preclinical models of BM is crucial to discover new treatment strategies for patients with BM. In the last years, some new drugs have been highlighted in preclinical models and are now tested in clinical trials including patients with brain metastases.

Lymph node metastasis and tumor-educated immune tolerance: Potential therapeutic targets against distant metastasis

Lymph node metastasis has been shown to positively associated with the prognosis of many cancers. However, in clinical treatment, lymphadenectomy is not always successful, suggesting that immune cells in the tumor and sentinel lymph nodes still play a pivotal role in tumor immunosuppression. Recent studies had shown that tumors can tolerate immune cells through multiple strategies, including tumor-induced macrophage reprogramming, T cells inactivation, production of B cells pathogenic antibodies and activation of regulatory T cells to promote tumor colonization, growth, and metastasis in lymph nodes. We reviewed the bidirectional effect of immune cells on anti-tumor or promotion of cancer cell metastasis during lymph node metastasis, and the mechanisms by which malignant cancer cells modify immune cells to create a more favorable environment for the growth and survival of cancer cells. Research and treatment strategies focusing on the immune system in lymph nodes and potential immune targets in lymph node metastasis were also be discussed.

Research progress of nanovaccine in anti-tumor immunotherapy

Tumor vaccines aim to activate dormant or unresponsive tumor-specific T lymphocytes by using tumor-specific or tumor-associated antigens, thus enhancing the body's natural defense against cancer. However, the effectiveness of tumor vaccines is limited by the presence of tumor heterogeneity, low immunogenicity, and immune evasion mechanisms. Fortunately, multifunctional nanoparticles offer a unique chance to address these issues. With the advantages of their small size, high stability, efficient drug delivery, and controlled surface chemistry, nanomaterials can precisely target tumor sites, improve the delivery of tumor antigens and immune adjuvants, reshape the immunosuppressive tumor microenvironment, and enhance the body's anti-tumor immune response, resulting in improved efficacy and reduced side effects. Nanovaccine, a type of vaccine that uses nanotechnology to deliver antigens and adjuvants to immune cells, has emerged as a promising strategy for cancer immunotherapy due to its ability to stimulate immune responses and induce tumor-specific immunity. In this review, we discussed the compositions and types of nanovaccine, and the mechanisms behind their anti-tumor effects based on the latest research. We hope that this will provide a more scientific basis for designing tumor vaccines and enhancing the effectiveness of tumor immunotherapy.

Three-dimensional histological electrophoresis enables fast automatic distinguishment of cancer margins and lymph node metastases

Tissue diagnosis is important during surgical excision of solid tumors for margin evaluation. Conventional histopathologic methods rely heavily on image-based visual diagnosis by specialized pathologists, which can be time-consuming and subjective. We report a three-dimensional (3D) histological electrophoresis system for rapid labeling and separation of the proteins within tissue sections, providing a more precise assessment of tumor-positive margin in surgically resected tissues. The 3D histological electrophoresis system uses a tumor-seeking dye labeling strategy to visualize the distribution of tumor-specific proteins within sections and a tumor finder that automatically predicts the tumor contour. We successfully demonstrated the system's capability to predict the tumor contours from five murine xenograft models and distinguish the tumor-invaded region of sentinel lymph nodes. Specifically, we used the system to accurately assess tumor-positive margins from 14 patients with cancer. Our 3D histological electrophoresis system serves as an intraoperative tissue assessment technology for more accurate and automatic pathologic diagnosis.

Targeting β-catenin using XAV939 nanoparticle promotes immunogenic cell death and suppresses conjunctival melanoma progression

Many tumors dysregulate Wnt/β-catenin pathway to promote stem-cell-like phenotype, tumorigenesis, immunosuppression, and resistance to targeted cancer immunotherapies. Therefore, targeting this pathway is a promising therapeutic approach to suppress tumor progression and elicit robust anti-tumor immunity. In this study, using a nanoparticle formulation for XAV939 (XAV-Np), a tankyrase inhibitor that promotes β-catenin degradation, we investigated the effect of β-catenin inhibition on melanoma cell viability, migration, and tumor progression using a mouse model of conjunctival melanoma. XAV-Nps were uniform and displayed near-spherical morphology with size stability for upto 5 days. We show that XAV-Np treatment of mouse melanoma cells significantly suppresses cell viability, tumor cell migration, and tumor spheroid formation compared to control nanoparticle (Con-Np) or free XAV939-treated groups. Further, we demonstrate that XAV-Np promotes immunogenic cell death (ICD) of tumor cells with a significant extracellular release or expression of ICD molecules, including high mobility group box 1 protein (HMGB1), calreticulin (CRT), and adenosine triphosphate (ATP). Finally, we show that local intra-tumoral delivery of XAV-Nps during conjunctival melanoma progression significantly suppresses tumor size and conjunctival melanoma progression compared to Con-Nps-treated animals. Collectively, our data suggest that selective inhibition of β-catenin in tumor cells using nanoparticle-based targeted delivery represents a novel approach to suppress tumor progression through increased tumor cell ICD.

ANXA6/TRPV2 axis promotes lymphatic metastasis in head and neck squamous cell carcinoma by inducing autophagy

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is highly aggressive with a significant tropism of lymph nodes, which restricts treatment options and negatively impacts patient outcomes. Although progress has been made in understanding the molecular mechanisms underlying lymphatic metastasis (LM), these mechanisms remain elusive. ANXA6 is a scaffold protein that participates in tumor pathogenesis and autophagy regulation; however, how ANXA6 affects autophagy and LM in HNSCC cells remains unknown.

METHODS

RNA sequencing was performed on HNSCC clinical specimens with or without metastasis as well as on The Cancer Genome Atlas dataset to investigate ANXA6 expression and survival. Both in vitro and in vivo studies were performed to investigate the role of ANXA6 in the regulation of LM in HNSCC. The molecular mechanism by which ANXA6 interacts with TRPV2 was examined at the molecular level.

RESULTS

ANXA6 expression was significantly upregulated in HNSCC patients with LM and higher expression was associated with poor prognosis. ANXA6 overexpression promoted the proliferation and mobility of FaDu and SCC15 cells in vitro; however, ANXA6 knockdown retarded LM in HNSCC in vivo. ANXA6 induced autophagy by inhibiting the AKT/mTOR signaling pathway in HNSCC, thereby regulating the metastatic capability of the disease. Furthermore, ANXA6 expression positively correlated with TRPV2 expression both in vitro and in vivo. Lastly, TRPV2 inhibition reversed ANXA6-induced autophagy and LM.

CONCLUSIONS

These results indicate that the ANXA6/TRPV2 axis facilitates LM in HNSCC by stimulating autophagy. This study provides a theoretical basis for investigating the ANXA6/TRPV2 axis as a potential target for the treatment of HNSCC, as well as a biomarker for predicting LM.

Genes whose expressions in the primary lung squamous cell carcinoma are able to accurately predict the progression of metastasis through lymphatic system, inferred from a bioinformatics analyses

Lymph node metastasis is the most important prognostic factor in patients with lung squamous cell carcinoma. The current findings show that lymph node metastatic tumor cells can arise by programming metastasis in primary tumor cells. Thereby, the genetic alterations responsible for the metastasis could be detected in the primary tumors. This bioinformatic study aimed to determine novel potential prognostic biomarkers shared between primary lung squamous cell tumors (without lymph node metastasis) and lymphatic metastasis, using the Cancer Genome Atlas database. Differentially expressed genes were screened by limma statistical package in R environment. Gene ontology and biological pathways analyses were performed using Enrichr for up-regulated and down-regulated genes. Also, we selected lymph node metastasis related genes among DEGs using correlation analysis between DEGs and suitable references genes for metastasis. Receiver operating characteristic curves was applied using pROC and R package ggplot2 to evaluate diagnostic value of differentially expressed genes. In addition, survival and drug resistance analyses were performed for differentially expressed genes. The miRNA-mRNA interaction networks were predicted by miRwalk and TargetScan databases and expression levels analysis of the miRNAs which were mainly targeting mRNAs was performed using UALCAN database. Protein-protein interaction network analysis and hub genes identification were performed using FunRich and Cytoscape plugin cytoHubba. In this study, a total of 397 genes were differentially expressed not only with a significant difference between N + vs. normal and N0 vs. normal but also with significant difference between N + vs. N0. Identified GO terms and biological pathways were consistent with DEGs role in the lung squamous cell carcinoma and lymph node metastasis. A significant correlation between 56 genes out of 397 differentially expressed genes with reference genes prompted them being considered for identifying lymph node metastasis of lung squamous cell carcinoma. In addition, SLC46A2, ZNF367, AC107214.1 and NCBP1 genes were identified as survival-related genes of patients with lung squamous cell carcinoma. Moreover, NEDD9, MRPL21, SNRPF, and SCLT1 genes were identified to be involved in lung squamous cell carcinoma drug sensitivity/resistance. We have identified several numbers of miRNAs and their related target genes which could emerge as potential diagnostic biomarkers. Finally, CDK1, PLK1, PCNA, ZWINT and NDC80 identified as hub genes for underlying molecular mechanisms of lung squamous cell carcinoma and lymphatic metastasis. Our study highlights new target genes according to their relation to lymph node metastasis, whose expressions in the primary lung squamous cell carcinoma are able to accurately assess the presence of lymphatic metastasis.

Non-invasive molecular imaging for precision diagnosis of metastatic lymph nodes: opportunities from preclinical to clinical applications

Lymph node metastasis is an indicator of the invasiveness and aggressiveness of cancer. It is a vital prognostic factor in clinical staging of the disease and therapeutic decision-making. Patients with positive metastatic lymph nodes are likely to develop recurrent disease, distant metastasis, and succumb to death in the coming few years. Lymph node dissection and histological analysis are needed to detect whether regional lymph nodes have been infiltrated by cancer cells and determine the likely outcome of treatment and the patient's chances of survival. However, these procedures are invasive, and tissue biopsies are prone to sampling error. In recent years, advanced molecular imaging with novel imaging probes has provided new technologies that are contributing to comprehensive management of cancer, including non-invasive investigation of lymphatic drainage from tumors, identifying metastatic lymph nodes, and guiding surgeons to operate efficiently in patients with complex lesions. In this review, first, we outline the current status of different molecular imaging modalities applied for lymph node metastasis management. Second, we summarize the multi-functional imaging probes applied with the different imaging modalities as well as applications of cancer lymph node metastasis from preclinical studies to clinical translations. Third, we describe the limitations that must be considered in the field of molecular imaging for improved detection of lymph node metastasis. Finally, we propose future directions for molecular imaging technology that will allow more personalized treatment plans for patients with lymph node metastasis.

Plug-and-Play Lymph Node-on-Chip: Secondary Tumor Modeling by the Combination of Cell Spheroid, Collagen Sponge and T-Cells

Towards the improvement of the efficient study of drugs and contrast agents, the 3D microfluidic platforms are currently being actively developed for testing these substances and particles in vitro. Here, we have elaborated a microfluidic lymph node-on-chip (LNOC) as a tissue engineered model of a secondary tumor in lymph node (LN) formed due to the metastasis process. The developed chip has a collagen sponge with a 3D spheroid of 4T1 cells located inside, simulating secondary tumor in the lymphoid tissue. This collagen sponge has a morphology and porosity comparable to that of a native human LN. To demonstrate the suitability of the obtained chip for pharmacological applications, we used it to evaluate the effect of contrast agent/drug carrier size, on the penetration and accumulation of particles in 3D spheroids modeling secondary tumor. For this, the 0.3, 0.5 and 4 μm bovine serum albumin (BSA)/tannic acid (TA) capsules were mixed with lymphocytes and pumped through the developed chip. The capsule penetration was examined by scanning with fluorescence microscopy followed by quantitative image analysis. The results show that capsules with a size of 0.3 μm passed more easily to the tumor spheroid and penetrated inside. We hope that the device will represent a reliable alternative to in vivo early secondary tumor models and decrease the amount of in vivo experiments in the frame of preclinical study.

Tagging the pre-metastatic node in oral cancer: A cross-sectional study

INTRODUCTION

Lymph node involvement is the first indication of spread of oral squamous cell carcinoma (OSCC) and it is also a most significant prognostic factor. Lymph nodes show various tumor-induced histological changes preceding actual metastasis, viz. increased vascularity, follicular hyperplasia and desmoplasia which leads to pre-metastatic niche formation. This pre-metastatic niche primarily provides a favorable microenvironment to for the survival and subsequent growth of cancer cells within the lymph node.

AIM

A retrospective study to evaluate carcinoma-induced changes in lymph nodes harvested from radical neck dissection in OSCC patients.

OBJECTIVES

1) To evaluate cancer-induced histological changes in positive and negative lymph nodes in OSCC patients. 2) To look for common histopathological changes in both pre-metastatic and metastatic lymph nodes.

MATERIALS AND METHODS

Forty lymph nodes harvested from seven OSCC patients were sectioned and stained (Hematoxylin-Eosin) for documentation of histologically evident morphological and functional alterations. The Chi-square test was applied between the non-metastatic and metastatic lymph nodes findings and a statistically significant difference was seen.

RESULTS

Sections from 28 negative nodes showed changes associated with pre-metastatic niche conditioning whereas, 12 sections exhibit frank metastases.

CONCLUSION

The modified immunological responses and remodeling of the vasculature are the most common histologic tumor-induced pre-metastatic changes. This study reviewed and categorized these histological changes that point to pre-metastatic niche conditioning of lymph nodes.

Fluid-sensitive migration mechanisms predict association between metastasis and high interstitial fluid pressure in pancreatic cancer

A remarkable feature in pancreatic cancer is the propensity to metastasize early, even for small, early stage cancers. We use a computer-based pancreatic model to simulate tumor progression behavior where fluid-sensitive migration mechanisms are accounted for as a plausible driver for metastasis. The model has been trained to comply with in vitro results to determine input parameters that characterize the migration mechanisms. To mimic previously studied preclinical xenografts we run the computer model informed with an ensemble of stochastic-generated realizations of unknown parameters related to tumor microenvironment only constrained such that pathological realistic values for interstitial fluid pressure (IFP) are obtained. The in silico model suggests the occurrence of a steady production of small clusters of cancer cells that detach from the primary tumor and form isolated islands and thereby creates a natural prerequisite for a strong invasion into the lymph nodes and venous system. The model predicts that this behavior is associated with high interstitial fluid pressure (IFP), consistent with published experimental findings. The continuum-based model is the first to explain published results for preclinical models which have reported associations between high IFP and high metastatic propensity and thereby serves to shed light on possible mechanisms behind the clinical aggressiveness of pancreatic cancer.

Lymph Nodes as Anti-Tumor Immunotherapeutic Tools: Intranodal-Tumor-Specific Antigen-Pulsed Dendritic Cell Vaccine Immunotherapy

Simple Summary

In the field of cancer therapy, lymph nodes are important not only as targets for metastases resection but also as prudent target organs for cancer immunotherapy. Lymph nodes comprise a complete structure for the accumulation of a large number of T cells and their distribution throughout the body after antigen presentation and activation of dendritic cells. This review highlights current topics on the importance of lymph node structure in antitumor immunotherapy and intranodal-antigen-presenting mature dendritic cell vaccine therapy. We also discuss the rationale behind intranodal injection methods and their applications in neoantigen vaccine therapy, a new cancer immunotherapy.

Abstract

Hundreds of lymph nodes (LNs) are scattered throughout the body. Although each LN is small, it represents a complete immune organ that contains almost all types of immunocompetent and stromal cells functioning as scaffolds. In this review, we highlight the importance of LNs in cancer immunotherapy. First, we review recent reports on structural and functional properties of LNs as sites for antitumor immunity and discuss their therapeutic utility in tumor immunotherapy. Second, we discuss the rationale and background of ultrasound (US)-guided intranodal injection methods. In addition, we review intranodal administration therapy of tumor-specific-antigen-pulsed matured dendritic cells (DCs), including neoantigen-pulsed vaccines.

Biology of Cancer and PET Imaging: Pictorial Review

Development and spread of cancer is a multi-step and complex process which involves number of alterations, interactions and molecular networks. PET imaging is closely related with biology of cancer as it detects the cancer based on biological and pathological changes in tumor cells and tumor microenvironment. In this review article, biology of development and spread of cancer and role of PET imaging in Oncology was summarized and supported with various PET images demonstrating cancer spread patterns.

Lymphatic Endothelial Markers and Tumor Lymphangiogenesis Assessment in Human Breast Cancer

Metastasis via lymphatic vessels or blood vessels is the leading cause of death for breast cancer, and lymphangiogenesis and angiogenesis are critical prerequisites for the tumor invasion–metastasis cascade. The research progress for tumor lymphangiogenesis has tended to lag behind that for angiogenesis due to the lack of specific markers. With the discovery of lymphatic endothelial cell (LEC) markers, growing evidence demonstrates that the LEC plays an active role in lymphatic formation and remodeling, tumor cell growth, invasion and intravasation, tumor–microenvironment remodeling, and antitumor immunity. However, some studies have drawn controversial conclusions due to the variation in the LEC markers and lymphangiogenesis assessments used. In this study, we review recent findings on tumor lymphangiogenesis, the most commonly used LEC markers, and parameters for lymphangiogenesis assessments, such as the lymphatic vessel density and lymphatic vessel invasion in human breast cancer. An in-depth understanding of tumor lymphangiogenesis and LEC markers can help to illustrate the mechanisms and distinct roles of lymphangiogenesis in breast cancer progression, which will help in exploring novel potential predictive biomarkers and therapeutic targets for breast cancer.

Modeling Tumor: Lymphatic Interactions in Lymphatic Metastasis of Triple Negative Breast Cancer

Simple Summary

Lymphatic metastasis is a critical prognostic factor of breast cancer aggressiveness and patient survival. Since existing therapeutic approaches have shown limited efficacy, new strategies to identify effective therapeutic targets for reducing breast cancer lymphatic metastasis are needed. We have used novel culture chambers, designed and fabricated by our group, to develop 3D models in which we can study spat ial interactions between breast cancer cells and lymphatic cells as they occur in real-time. This approach provides information on the complex cell–cell interactions involved in lymphatic metastasis of breast cancers. Factors in the secretome of the lymphatic cells promote invasive outgrowths from 3D cultures of breast cancer cells, suggesting that targeting interactions between breast cancer cells and lymphatic cells could be a potential therapeutic approach for the prevention of lymphatic metastasis.

Abstract

Breast cancer frequently metastasizes to lymphatics and the presence of breast cancer cells in regional lymph nodes is an important prognostic factor. Delineating the mechanisms by which breast cancer cells disseminate and spatiotemporal aspects of interactions between breast cancer cells and lymphatics is needed to design new therapies to prevent lymphatic metastases. As triple-negative breast cancer (TNBC) has a high incidence of lymphatic metastasis, we used a three-dimensional (3D) coculture model of human TNBC cells and human microvascular lymphatic endothelial cells (LECs) to analyze TNBC:LEC interactions. Non-invasive analyses such as live-cell imaging in real-time and collection of conditioned media for secretomic analysis were facilitated by our novel microfluidic chambers. The volumes of 3D structures formed in TNBC:LEC cocultures are greater than that of 3D structures formed by either LEC or TNBC monocultures. Over 4 days of culture there is an increase in multicellular invasive outgrowths from TNBC spheroids and an association of TNBC spheroids with LEC networks. The increase in invasive phenotype also occurred when TNBC spheroids were cultured in LEC-conditioned media and in wells linked to ones containing LEC networks. Our results suggest that modeling spatiotemporal interactions between TNBC and LECs may reveal paracrine signaling that could be targeted to reduce lymphatic metastasis.

The Lymphatic System in Breast Cancer: Anatomical and Molecular Approaches

Breast cancer is one of the most important causes of premature mortality among women and it is one of the most frequently diagnosed tumours worldwide. For this reason, routine screening for prevention and early diagnosis is important for the quality of life of patients. Breast cancer cells can enter blood and lymphatic capillaries, then metastasizing to the regional lymph nodes in the axilla and to both visceral and non-visceral sites. Rather than at the primary site, they seem to enter the systemic circulation mainly through the sentinel lymph node and the biopsy of this indicator can influence the axillary dissection during the surgical approach to the pathology. Furthermore, secondary lymphoedema is another important issue for women following breast cancer surgical treatment or radiotherapy. Considering these fundamental aspects, the present article aims to describe new methodological approaches to assess the anatomy of the lymphatic network in the axillary region, as well as the molecular and physiological control of lymphatic vessel function, in order to understand how the lymphatic system contributes to breast cancer disease. Due to their clinical implications, the understanding of the molecular mechanisms governing lymph node metastasis in breast cancer are also examined. Beyond the investigation of breast lymphatic networks and lymphatic molecular mechanisms, the discovery of new effective anti-lymphangiogenic drugs for future clinical settings appears essential to support any future development in the treatment of breast cancer.

The prognostic influence of lymphatic endothelium-specific hyaluronan receptor 1 in cancer: A systematic review

Lymphangiogenesis is a key process in cancer development and metastasis. Lymphatic vessel endothelial hyaluronan receptor 1 (LYVE‐1) is a widely used marker for lymphatic endothelial cells (LEC), which also mediates immune and cancer cell migration. Recently, LYVE‐1–positive tumor cells were shown to acquire LEC‐like phenotype and exploit this receptor for lymphatic dissemination. Furthermore, selective targeting of LYVE‐1 impaired the growth of cancer‐related vasculature and reduced metastasis in vivo, signifying its role in therapeutic and prognostic applications. Although numerous studies have investigated the role of LYVE‐1 in cancer, a unifying detailed review of its prognostic utility is lacking to date. Thus, we compiled and critically appraised evidence from clinical studies comprising a total of 2352 patients diagnosed with different types of cancer and using a variety of experimental approaches. Collectively, most studies revealed a significant association between LYVE‐1 overexpression and dismal outcome of at least one survival estimate. Furthermore, the importance of vasculature location, intra‐ or peritumoral, and the influence of various lymphangiogenesis‐related parameters, such as lymphatic vessel density and invasion, were discussed. However, the specificity of LYVE‐1 staining is challenged by its expression in non‐LEC cells, implying the need for double labelling to better estimate its prognostic significance. In conclusion, this is to our knowledge the first comprehensive systematic review on the prognostic value of LYVE‐1 in cancer. More well‐designed studies across different populations and the development of standardized protocols would be paramount for the consistency of LYVE‐1 findings and for its potential transferability to clinical practice in future.

Green Metallic Nanoparticles for Cancer Therapy: Evaluation Models and Cancer Applications

Metal-based nanoparticles are widely used to deliver bioactive molecules and drugs to improve cancer therapy. Several research works have highlighted the synthesis of gold and silver nanoparticles by green chemistry, using biological entities to minimize the use of solvents and control their physicochemical and biological properties. Recent advances in evaluating the anticancer effect of green biogenic Au and Ag nanoparticles are mainly focused on the use of conventional 2D cell culture and in vivo murine models that allow determination of the half-maximal inhibitory concentration, a critical parameter to move forward clinical trials. However, the interaction between nanoparticles and the tumor microenvironment is not yet fully understood. Therefore, it is necessary to develop more human-like evaluation models or to improve the existing ones for a better understanding of the molecular bases of cancer. This review provides recent advances in biosynthesized Au and Ag nanoparticles for seven of the most common and relevant cancers and their biological assessment. In addition, it provides a general idea of the in silico, in vitro, ex vivo, and in vivo models used for the anticancer evaluation of green biogenic metal-based nanoparticles.

Fatty Acid Receptor CD36 Functions as a Surrogate Parameter for Lymph Node Metastasis in Oral Squamous Cell Carcinoma

Simple Summary

The frequent occurrence of occult cervical lymph node metastasis is still a therapeutic challenge in oral squamous cell carcinoma (OSCC) and represents a limiting factor in terms of survival. The common staging of malignancy is not precise enough to predict the development of lymph node metastases and additional prognostic factors are needed. In this study we show that CD36, a protein related to fatty acid metabolism, is expressed in OSCC and correlates with the occurrence of lymph node metastasis. CD36 may be useful as a specific parameter for lymph node metastasis and as a progression parameter for survival. Therefore, CD36 could be useful for risk stratification regarding lymph node metastasis in OSCC and, beyond that, CD36 could also be a possible therapeutic target in future.

Abstract

Purpose: To investigate the expression pattern of CD36 in a patient population with oral squamous cell carcinoma (OSCC) and to correlate CD36 expression with clinical and histopathological parameters. The hypothesis was that CD36 expression correlates with the occurrence of lymph node metastasis. Methods: To address the study objectives, a retrospective cohort study was conducted. Study variables included demographic, histopathological and survival data. CD36 expression patterns were assessed by immunohistochemistry on tissue microarrays (TMA). Logistic regression analysis, survival analysis and Cox proportional hazards model were performed. Results: High CD36 expression correlated significantly with a higher T-status, grading and occurrence of lymph node metastasis. The logistic regression with binary N status as a dependent variable showed that high CD36 expression increased the chance for lymph node metastasis 45-fold (OR = 44.7, 95% CI: 10.0–316). Patients with high CD36 expression had lower probabilities of progression-free survival. CD36 had a small and non-significant independent influence on progression-free survival. Conclusions: CD36 is expressed in OSCC and correlates with tumor grading, T-status, and especially the occurrence of lymph node metastasis. CD36 may be useful for risk stratification regarding lymph node metastasis in OSCC.