Lymph Nodes In Cancer Patients Research Articles

NK Cells in the Lymph Nodes and Their Role in Anti-Tumour Immunity.

The lymph nodes are vital to enable adaptive immune responses to infection. Natural killer (NK) cells are cytotoxic lymphocytes that directly kill cancer cells and modulate the activation of other immune cells during anti-tumour immune response. NK cells in the lymph nodes are involved in the regulation of T-cell and B-cell populations and the clearance of viral infections. In solid tumours, lymph nodes are a frequent site of metastasis and immune cell priming, whilst in haematological malignancies, tumour cells can proliferate in the lymph nodes. Thus, lymph nodes are an important site in anti-tumour immunity and therapy resistance. It is therefore crucial to identify strategies to increase recruitment and overcome suppression of NK cells in the lymph node microenvironment to improve tumour clearance. In this review, we summarise the literature interrogating NK cell phenotype and function in the lymph nodes in the context of infection and cancer and evaluate both current and potential strategies to mobilise and activate NK cells within the lymph nodes of cancer patients.

CD169+ Macrophages in Primary Breast Tumors Associate with Tertiary Lymphoid Structures, Tregs and a Worse Prognosis for Patients with Advanced Breast Cancer

The presence of CD169+ macrophages in the draining lymph nodes of cancer patients is, for unknown reasons, associated with a beneficial prognosis. We here investigated the prognostic impact of tumor-infiltrating CD169+ macrophages in primary tumors (PTs) and their spatial relation to tumor-infiltrating B and T cells. Using two breast cancer patient cohorts, we show that CD169+ macrophages were spatially associated with the presence of B and T cell tertiary lymphoid-like structures (TLLSs) in both PTs and lymph node metastases (LNMs). While co-infiltration of CD169+/TLLS in PTs correlated with a worse prognosis, the opposite was found when present in LNMs. RNA sequencing of breast tumors further confirmed that SIGLEC1 (CD169) expression was associated with mature tertiary lymphoid structure (TLS), and Treg and Breg signatures. We propose that the negative prognostic value related to CD169+ macrophages in PTs is a consequence of an immunosuppressive tumor environment rich in TLSs, Tregs and Bregs.

Abstract 528: MDSC suppress the T cell repertoire and contribute to a pathologic cytokine milieu in cancer patients

Abstract Myeloid derived suppressor cells (MDSC) are elevated in tumors and draining lymph nodes of cancer patients and produce a variety of immune suppressive factors that impair T cell activation and anti-tumor immunity. MDSC are also recruited from the bone marrow in response to T cell activation, including in response to immunotherapies that activate T cells. As MDSC and immune suppressive monocytes are significant producers of IL6, IL1β and TNFα, their elevation and activation in response to T cell activation can promote pathologic levels of these cytokines leading to potentially serious conditions such as cytokine release syndrome. Furthermore, patients deficient in functional antigen-specific T cells have elevated MDSC, consistent with their described suppression of antigen presentation and T cell activation. Therapeutic agents that deplete MDSC may offer both an improved therapeutic index for maintenance of T cell activation while promoting expansion of anti-tumor T cells. AMV564, a bivalent T cell engager that selectively depletes MDSC, is in clinical development in solid tumor patients. The cytokine profiles of patients treated with AMV564 as monotherapy or in combination with pembrolizumab were assessed using multiplex immunoassays, and the peripheral T cell repertoire was assessed by deep sequencing of the TCRβ locus. While CD33 has no apparent functional role on differentiated myeloid cells, on MDSC and immature monocytes, CD33 signaling promotes the production of immune-suppressive factors. Avid binding of clustered CD33 in this active signaling configuration drives the selectivity of AMV564 for these cell types. Analysis of patient samples demonstrates that AMV564 selectively depletes MDSC and promotes T cell activation and increases in effector CD8 and CD4 populations1. AMV564 promotes strong induction of IFNγ and other proinflammatory cytokines and chemokines, but with comparatively limited induction of IL6, IL1β and TNFα, consistent with the role of MDSC in producing these factors. This cytokine profile was maintained in combination with pembrolizumab. Dynamic changes in the peripheral T cell repertoire were apparent for patients treated with AMV564 monotherapy or in combination with pembrolizumab. Observations include significant expansion after one cycle of therapy (p = 0.008) including T cell clones not detectable at baseline, changes in diversity that reflect increases in middle-frequency clones, and oscillation in the peripheral T cell fraction consistent with T cell trafficking to tissues and tumors. Repertoire expansion correlated with increases in effector memory CD8 T cells. These findings in patients treated with AMV564 support the role of MDSC in both limiting the priming and activation of anti-tumor T cells as well as contributing to an immune suppressive and pathologic cytokine response to T cell activation. 1. Smith, V et. al. Cancer Res. 2020;80(16):5699 Citation Format: Sterling Eckard, Aurelien Sarde, Li Mei, Curtis Ruegg, Patrick Chun, Victoria Smith. MDSC suppress the T cell repertoire and contribute to a pathologic cytokine milieu in cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 528.

The microbiome of HPV-positive tonsil squamous cell carcinoma and neck metastasis

BackgroundOropharyngeal squamous cell carcinoma (OPSCC) has now surpassed cervical cancer as the most common site of HPV-related cancer in the United States. HPV-positive OPSCCs behave differently from HPV-negative tumors and often present with early lymph node involvement. The bacterial microbiome of HPV-associated OPSCC may contribute to carcinogenesis, and certain bacteria may influence the spread of cancer from the primary site to regional lymphatics. ObjectiveTo determine the bacterial microbiome in patients with HPV-associated, early tonsil SCC and compare them to benign tonsil specimens. MethodThe microbiome of primary tumor specimens and lymph nodes was compared to benign tonsillectomy specimens with pan-pathogen microarray (PathoChip). ResultsA total of 114 patients were enrolled in the study. Patients with OPSCC had a microbiome that shifted towards more gram-negative. Numerous signatures of bacterial family and species were associated with the primary tumors and lymph nodes of cancer patients, including the urogenital pathogens Proteus mirabilis and Chlamydia trachomatis, Neisseria gonorrhoeae, Shigella dysenteriae, and Orientia tsutsugamushi. ConclusionOur results suggest that detection of urogenital pathogens is associated with lymph node metastasis for patients with HPV-positive OPSCCs. Additional studies are necessary to determine the effects of the OPSCC microbiome on disease progression and clinical outcomes.

Comprehensive analysis of T-cell receptor sequencing in resectable squamous cell lung cancer patients with neoadjuvant therapy of PD-1 inhibitor and chemotherapy.

e21012 Background: Cancer therapies alter the tumor microenvironment such as the infiltration of T cells. Neoadjuvant therapy to squamous cell lung cancer patients using PD-1 inhibitor expands specific T cell clones. However, the T cell clones and diversity in tumors and lymph nodes according to different neoadjuvant settings remain largely unknown. In this study, we used T-cell receptor (TCR) sequencing technology to investigate the TCR clonotypes and diversities in squamous cell NSCLC patients who received neoadjuvant chemotherapy and PD-1 inhibitor plus chemotherapy. Methods: Tumor tissues, non-metastatic lymph nodes (NMLN)s, and available metastatic lymph nodes (MLNs) were collected from two patient groups. Each group enrolled three patients who received either neoadjuvant chemotherapy or PD-1 inhibitor plus chemotherapy. DNA samples were harvested and processed for multiplex PCR for the third complementary determining region (CDR3) of TCR-β chain followed by the next generation sequencing analysis. Differences of the CDR3 clonotypes and clonal diversities were analyzed by bioinformatics tools including the Mixcr software. Results: For all the six patients, TCR clonotypes in the tumor tissues were found to be fewer than those from the lymph nodes in the same patient, consistent with a hypothesis that most of the tumor infiltrated T cells after therapy derive from the lymph nodes. Some clonotypes among the top 10 highest frequencies were found in different samples from the same patient, further supporting the lymph node origin of the tumor infiltrating T cells after therapies. Interestingly, TCR clonal diversity was higher in the NMLNs compared with the MLNs, but clonotype overlap with tumor tissues was higher in the MLNs than NMLNs; these results could imply that TCR clonotypes in the primary lymph node were more stimulated. Additionally, there were very few clonotypes shared between different patients, indicating the heterogeneity of immune response for different individuals. Due to the limited sample size, we could not find the systemic difference between the two patient groups. Conclusions: TCR sequencing technology can detect the CDR3 clonotypes in tumor tissues and lymph nodes of cancer patients, providing new opportunities for revealing patients' response to chemotherapy and immunotherapy. Further analysis will be performed to investigate TCR clonotype differences caused by immunotherapy.

Neolymphogenesis and Immunogistogochemical Study of Lymph Nodes in Breast Cancer

Background. Our previous studies have shown that postnatally formed lymph nodes (PNFLN) can serve as a source of biological signals activating antitumour immune reactions and suppressing the spread of metastatic malignant cells.Aim. To determine the expression of CD3, CD20, CD68 in native, sentinel and postnatally induced lymph nodes of the axillary zone in breast cancer.Materials and methods. The study involved an analysis of digitalized images of the immunohistochemical expression of a fixed panel of antibodies CD3, CD20, CD68. The expression levels were assessed quantitatively by counting the expressed cells in each studied node for four main structural and functional zones.Results and Discussion. The results of a comparative immunohistochemical study of native, sentinel and postnatally induced lymph nodes showed that the content of CD3, CD20, CD68 demonstrates fundamental differences in different lymph node structures.Сonclusions1. In postnatally induced lymph nodes, compared to native and sentinel lymph nodes, the distinct expression of antibodies to the main immunocompetent cells, which realize key immune responses in the lymph node, can indicate an increased functional status of the newly formed lymph nodes. 2. The study demonstrated a high level of antigenic stimulation of T and B lymphocytes in postnatally induced lymph nodes, as well as indicated a possible role of macrophage cells in the stimulation of neolymphogenesis and the formation of new lymph nodes. 3. The study provides the basis for further research into postnatal induced lymph nodes in cancer patients.

Radiomic Features, the Bridge Between CT and FDG PET Images: Estimating the PET Parameters of Lymph Node from CT with Deep Learning Method

Background: Radiomic features might bridge CT to FDG PET parameters (SUVmax, SUVmean and SUVsum). Therefore, the estimation models were trained and validated for the lymph nodes of cancer patients. Methods: The lymph nodes (LNs) of the lung cancer (LC) patients from SMU (n= 1239) were used as the training cohort, and both PET/CT and thin-section CT were collected. Those of the esophagus cancer (EC) from SMU (n=301), and the LC from AMU (n=204) and TCIA (n=47 and 82) were used as the validation cohorts. The radiomic features of LNs on CT serials (short axis diameter >3mm) were extracted. The feature selection and model training strategy were investigated, and the influential factors of proposed deep learning models were explored. Findings: From each LN of the patients, 141 features (1683 variables) were extracted. In the training cohort, the top 20 features on the combined and thin- section CT serials were sorted by the deep learning method, and the identical 2, 2 and 3 features between the serials were trained against SUVmax, SUVmean and SUVsum by the logarithmically transferred model, respectively. In the validations, the logarithms of SUMsum model performed well in the SMU EC cohort (r=0.847, bias= 0.024, P=0.843) with particular coefficients for different scanners. The absolute biases of all the models were slightly affected by LN volume, injected dose, acquisition time, pathology classification and LN metastasis. Interpretation: Several radiomic features could be used to estimate PET parameters of lymph nodes. Trial Registration: ClinicalTrials.gov (NCT03648151). Funding Statement: Collaborative Innovation Center for Molecular Imaging and Precise D&T Center of Shanxi Medical University (Grant No. MP201604). Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: The protocol was approved by the ethics committees at the First Affiliated Hospital of Shanxi Medical University (SMU) and the First Affiliated Hospital of Anhui Medical University (AMU). For a retrospective study, the review boards approved to waive the requirement for informed consent.

Hypermetabolic activity by FDG-PET after immunogenic chemotherapy and multi-peptide immunotherapy in ovarian cancer.

e17079 Background: There are several reports of increased of SUV in the lymph nodes of cancer patients after immune manipulation such as the administration of vaccines and checkpoint inhibitors. However the clinical importance of these phenomena is poorly understood. The administration of two immunogenic drugs and eight peptides in HGSOC induced atypical bright zones in multiple lymph nodes and, in areas with microscopic disease where potentially we can have cancer stem cells (CSC’s). Methods: We enrolled N = 10 HGSOC after the local IRB ethic committee approval. All the patients had 3 recurrences with mPFS = 8 months of the third relapse. The last FDG-PET scan was used as basal image for the study. Blood was collected for cellular and humoral immunology analysis such as Granzyme B ELISPOT and ELISA. Tissue was used for IHC analysis for the evaluation of CD8, FOXP3, Th1, and proteins related with CSC’s. The patients received 50 mg of oxaliplatin and 30 mg of doxorubicin total dose every week four times simultaneously with multi peptide immunotherapy. A second FDG-PET scan was performed after the termination of the treatment. Results: After the treatment 100% of the patients showed intense atypical bright uptake areas in lymph nodes and in the peritoneum. There was a correlation between the brightness intensity (SUV), and the Granzyme B production (p = 0.001). We found multiple bright small lesions in the peritoneum that were not visible before treatment. We demonstrated the presence of proteins related with CSC’s in the original tumor tissue and an antibody immune response against EGFR (P = 0.005), Ape-1 (p = 0.003) and Bcl-2 (p = 0.05). Conclusions: Immunotherapy may produce hypermetabolic activity that could lead to overtreatment when evaluated by FDG-PET in HGSOC. Vaccination may activate lymph nodes and anti-cancer immune interventions may also activate CD8 and Th1 cells able to accumulate in CSC’s clusters and increased notably the SUV, which may lead to false relapse interpretation by the radiologists and oncologists.

Vaccine-draining lymph nodes of cancer patients for generating anti-cancer antibodies

BackgroundOur research is focused on using the vaccine draining lymph node to better understand the immune response to cancer vaccines and as a possible source of anti-cancer reagents. We evaluated vaccine draining lymph nodes archived from a clinical study in melanoma patients and determined the reaction of B cells to the vaccine peptides.MethodsMononuclear cells (MNCs) were recovered from cryopreserved lymph nodes that were directly receiving drainage from multi-peptide melanoma vaccine. The patients were enrolled on a vaccine study (NCT00089219, FDA, BB-IND No. 10825). B cell responses in the vaccine-draining lymph nodes were studied under both stimulated and un-stimulated conditions. Cryopreserved cells were stimulated with CD40L, stained with multiple human cell-surface markers (CD19, CD27, IgM) to identify different categories of B cell sub populations with flow cytometry. Hybridomas were generated from the lymph node cells after CD40L-stimulation. Cells were fused to murine plasmacytoma P3X63.Ag8.653 using Helix electrofusion chamber. ELISA was used to evaluate hybridoma derived antibody binding to vaccine peptides.ResultsViable MNCs were satisfactorily recovered from lymph nodes cryopreserved from six vaccine study patients 8–14 years previously. B cell ELISPOT demonstrated responses for each patient to multiple vaccine peptides. CD40L stimulation of lymph node cells increased the proportion of CD19+ CD27+ cells from 12 to 65% of the sample and increased the proportion of class-switched cells. Screening of IgG secreting clones demonstrated binding to melanoma vaccine peptides.ConclusionsB cells were successfully recovered and expanded from human cryopreserved vaccine-draining lymph nodes. Individual B cells were identified that secreted antibodies that bound to cancer vaccine peptides. The ability to reliably generate in vitro the same antibodies observed in the blood of vaccinated patients will facilitate research to understand mechanisms of human antibody activity and possibly lead to therapeutic antibodies.

Lymphatic imaging to assess rheumatoid flare: mechanistic insights and biomarker potential.

Proliferation of draining lymphatic vessels coupled with dynamic changes in lymph node volume and flow are characteristic features in rheumatoid arthritis (RA). Furthermore, impaired lymph egress from inflamed synovium is associated with joint flare in murine models of inflammatory-erosive arthritis. Unfortunately, advances towards a greater understanding of lymphatic changes in RA pathogenesis have been slow due to the absence of outcome measures to quantify lymphatic function in vivo. While lymphoscintigraphy is the current standard to assess lymphedema and sentinel lymph nodes in cancer patients, its sensitivity and specificity are inadequate to study lymphatics in RA. The emergence of high-resolution MRI, power Doppler ultrasound, and near-infrared imaging that permits real-time quantification of lymphatic function in animal models has been a major advance, and these techniques have produced a new paradigm of altered lymphatic function that underlies both acute arthritic flare and chronic inflammation. In acute flare, lymphatic drainage increases several fold, whereas no lymphatic contractions are detected in lymph vessels draining chronic arthritic joints. Moreover, these outcomes are now being adapted to study lymphatics in RA towards the development of novel biomarkers of arthritic flare and the discovery of new therapeutic targets. In particular, interventions that directly increase lymphatic egress from diseased joints by opening collateral lymphatic vessels, and that restore lymphatic vessel contractions, provide novel therapeutic approaches with potential for minimal toxicity and immunosuppression. To summarize the origins of this field, recent advances, and future directions, we herein review: current knowledge of lymphatics in RA based on classic literature; new in-vivo imaging modalities that have elucidated how lymphatics modulate acute versus chronic joint inflammation in murine models; and how these preclinical outcome measures are being translated to study lymphatic function in RA inflammation and how effective RA therapies alter lymphatic flow and lymph nodes draining flaring joints. Trial registration: ClinicalTrials.gov NCT02680067. Registered 7 December 2015; ClinicalTrials.gov NCT01098201. Registered 30 March 2010; and ClinicalTrials.gov NCT01083563. Registered 8 March 2010.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-016-1092-0) contains supplementary material, which is available to authorized users.

Growing indications for CEUS: The kidney, testis, lymph nodes, thyroid, prostate, and small bowel

Contrast enhanced ultrasonography (CEUS) is increasingly used for non-hepatic applications as well, so that nearly all organs have been investigated. Among them, there is a growing clinical use for a variety of pathologies of the kidney, testis, and small bowel. The possibility to differentiate benign from malignant nodes in cancer patients has been investigated. A new application is in the detection of sentinel nodes after intradermal microbubble injection. The need to distinguish thyroid nodules eligible for fine needle aspiration cytology has led to the use of CEUS in thyroid examinations as well. The potential of CEUS for prostate cancer detection has been extensively investigated, with encouraging initial results. Early promise, however, has not been fulfilled. New perspective regards evaluation of the extent of prostate tissue devascularization following ablative treatments.

Abstract 3638: Vaccine-draining lymph nodes of cancer patients for generating anticancer antibodies

Abstract Human vaccine studies regularly demonstrate vaccine-induced antibodies in the blood. Characterization of these antibodies shows that they exhibit an extensive range of bioactive mechanisms. Unfortunately, there is not yet a reliable method by which to produce these important antibodies. Human antibodies may not require any molecular modification for therapeutic application and have a much faster pipeline to clinical studies than animal-derived antibodies. Lymph nodes are the primary destination of tumor or vaccine antigens. In the node, B cells undergo clonal expansion and somatic hypermutation, leading to the affinity-matured populations of effector B cells secreting antibodies that bind to the tumor or vaccine. The cancer vaccine-draining node is the ideal source of B cells that produce anticancer antibodies. Despite multiple human cancer vaccine studies, very little research has been done to recover the B cells responsible for vaccine-induced anticancer antibodies. In the present study, we used mononuclear cells from surgically removed vaccine-draining lymph nodes of melanoma patients vaccinated with 6 melanoma peptides derived from cancer-testis antigens and from melanocytic differentiation proteins for generating anti-vaccine peptide antibodies. The lymph node draining the vaccination site was localized by lymphatic mapping with a radiotracer. The development and maturity of B cells were assessed by determining phenotypic characters of lymph node cells using multicolor flow cytometry. The results showed that these vaccine-draining nodes contain high numbers of class-switched (CD19+CD27+IgD-IgM-) B cells and plasmablasts (CD19+CD38+IgM-). B-cell ELISpot assay was used to quantify the proportion of B cells in vaccine-draining lymph nodes that secrete anti-melanoma peptide antibodies. Positive ELISpot responses were observed in patients who also showed serum antibody-reactivity towards the vaccine peptides. The identification of lymph node cell samples exhibiting strong B-cell responses allows efficient generation and screening of hybridomas that secrete antibodies against cancer vaccine antigens. This study establishes a step-wise protocol for generating anti-cancer antibodies from vaccine-draining lymph nodes. We anticipate that the ability to reliably generate in vitro the same antibodies observed in the blood of vaccinated patients will further stimulate research to understand mechanisms of human antibody activity. Citation Format: Girja S. Shukla, Stephanie C. Pero, Yu-jing Sun, Chelsea L. Carman, Walter C. Olson, Craig L. Slingluff, David N. Krag. Vaccine-draining lymph nodes of cancer patients for generating anticancer antibodies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3638. doi:10.1158/1538-7445.AM2014-3638

Differentiation of osteolytic metastases and Schmorl's nodes in cancer patients using dual-energy CT: Advantage of spectral CT imaging

PurposeTo assess the reliability of dual-energy CT (DECT) spectral imaging for the differentiation of bone metastases (BMs) from Schmorl's nodes (SNs) in the vertebrae of cancer patients. Materials and methodsIn this retrospective study, 102 cancer patients who underwent DECT (GE spectral CT Discovery CT750 HD scanner) had 110 low density vertebral lesions. Each lesion was characterized as a BM or SN, based on the typical MRI or SPECT/PET-CT findings as well as size and number change in the 6 months follow-up. The means of 140kVp polychromatic CT values, 40–140keV monochromatic CT values, slopes (k) of the spectral curves, bone(water) and water(bone) densities of BMs and SNs were measured and compared with independent-samples t-test. The difference values of the two lesions and their respective normal bone tissue were calculated (normal density−lesion density) and compared using independent-samples t-test. ROC curves were used to compare the diagnostic efficacies of these measures in the identification of SNs and BMs. Results110 lesions consisting of 69 BMs and 41 SNs were identified. The spectral curve patterns and slopes for BMs and SNs were different (p<0.05). The water(bone) density of BMs (1009.02±59.25mg/cm3) was higher than that of SNs (892.00±83.65mg/cm3) (p<0.01) while the bone(water) density (43.57±50.87mg/cm3) was lower than that of SNs (174.60±94.61mg/cm3) (p<0.01). The 40keV CT value, k, bone(water) density and water(bone) density had a higher diagnostic efficacy for differentiating the two lesions than polychromatic CT value (p<0.05). ConclusionsDual-energy CT imaging is accurate enough for identification of osteolytic metastases and Schmorl's nodes.

Supraclavicular Lymph Nodes Detected by 18F-FDG PET/CT in Cancer Patients: Assessment With 18F-FDG PET/CT and Sonography

The purposes of this study were to assess the diagnostic accuracy of 18F-FDG PET (FDG PET) for the detection of metastatic supraclavicular lymph nodes (LNs) and to propose an optimal diagnostic strategy with additional sonography, contrast-enhanced CT (CECT), or both. One hundred supraclavicular LNs initially detected using FDG PET were examined using sonography. Regardless of the imaging findings, all 100 supraclavicular LNs underwent sonography-guided fine-needle aspiration biopsy. The maximum standardized uptake values (SUVsmax) of the supraclavicular LNs were measured, and a receiver operating characteristic (ROC) analysis was performed to determine the cutoff SUVmax. Then we evaluated the diagnostic performance of FDG PET and figured out the optimal combination of FDG PET and sonography or CECT to improve the diagnostic accuracy of the imaging studies and minimize procedures. In total, 86 of 100 PET-detected supraclavicular LNs were malignant. With application of the cutoff value obtained by ROC analysis (SUVmax=3.0), the diagnostic accuracy of FDG PET was 75.0% with a sensitivity of 74.4% and specificity of 78.6%. For supraclavicular LNs with an SUVmax of more than 3.0, FDG PET showed a positive predictive value of 95.5%; for supraclavicular LNs with an SUVmax of 3.0 or less, sonography excluded all false-negative FDG PET cases and showed a high negative predictive value of 100%. When sonography was selectively applied to cases with an SUVmax of 3.0 or less, the overall diagnostic accuracy increased to 92%. Our study revealed a high incidence rate of metastasis in PET-detected supraclavicular LNs in cancer patients. We believe that our proposed diagnostic workflow could decrease unnecessary diagnostic procedures in the evaluation of PET-positive supraclavicular LNs in cancer patients with reliability.

Recent Advance in Lymph Dynamic Analysis in Lymphatics and Lymph Nodes

Lymphatics are a unidirectional transport system that carries fluid from the interstitial space and back into the blood stream. Initial lymphatics take up not only fluid but also high-molecular-weight substances, such as plasma proteins and hyaluronan; immune cells, such as lymphocytes, macrophages, and dendritic cells; and colloidal particles, such as carbon particles, bacteria, and tattoo dye. Interstitially injected colloidal particles are known to accumulate in the regional lymph nodes. This phenomenon is applied to find sentinel lymph nodes in cancer patients. Lymph flow rate and composition are influenced by interstitial fluid, lymphatic pump activity, and intra-lymphatic pressure. Lymph composition is changed during its flow downstream. In this review, the main focus is on the mechanisms of lymph formation at the initial lymphatics and lymph transport through the collecting lymphatics and lymph nodes. (*English Translation of J Jpn Coll Angiol, 2008, 48: 113-123.).

Endobronchial ultrasound-guided transbronchial needle aspiration biopsy is useful evaluating mediastinal lymphadenopathy in a cancer center

Background:Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy is used to stage mediastinal lymph nodes in cancer patients to optimize treatment strategies. In this retrospective study, the authors determined the utility of EBUS-TBNA biopsy in the evaluation of mediastinal lymphadenopathy at a high-volume cancer center.Materials and Methods:The pathology database was searched for all patients who had undergone EBUS-TBNA biopsy of mediastinal lymph nodes over a one-year period. Cytologic diagnoses were correlated with clinical histories, subsequent resection, and clinical follow-up data.Results:Of 928 lymph node samples, 226 (24%) were diagnosed as malignant, 4 (0.4%) were suspicious for malignancy, 9 (1%) were atypical, 640 (69%) were benign, and 47 (5%) were insufficient for evaluation. In 89 (9.6%) cases, the patients had surgical resection. There was one false positive, in which the primary tumor contained infiltrating lymphocytes, had been sampled. There were five false-negative cases, which resulted from sampling errors, including two with micrometastases. The sensitivity, specificity, and positive and negative predictive value rates for EBUS-TBNA biopsy in the evaluation of mediastinal lymph nodes were 68.7% and 98.6% and 91.6% and 93.5%, respectively on a per lymph node basis. The overall clinical sensitivity, specificity, and positive and negative predictive value rates after one year clinical/radiological and histologic follow-up were 97%, 99.3%, 96.7% and 99.4%, respectively.Conclusions:EBUS-TBNA biopsy is a sensitive and specific method for evaluating mediastinal lymphadenopathy in patients with lung and other primary tumors.

Three-Dimensional High-Frequency Characterization of Cancerous Lymph Nodes

High-frequency ultrasound (HFU) offers a means of investigating biologic tissue at the microscopic level. High-frequency, three-dimensional (3-D) quantitative-ultrasound (QUS) methods were developed to characterize freshly-dissected lymph nodes of cancer patients. Three-dimensional ultrasound data were acquired from lymph nodes using a 25.6-MHz center-frequency transducer. Each node was inked prior to tissue fixation to recover orientation after sectioning for 3-D histologic evaluation. Backscattered echo signals were processed using 3-D cylindrical regions-of-interest to yield four QUS estimates associated with tissue microstructure ( i.e., effective scatterer size, acoustic concentration, intercept and slope). QUS estimates were computed following established methods using two scattering models. In this study, 46 lymph nodes acquired from 27 patients diagnosed with colon cancer were processed. Results revealed that fully-metastatic nodes could be perfectly differentiated from cancer-free nodes using slope or scatterer-size estimates. Specifically, results indicated that metastatic nodes had an average effective scatterer size ( i.e., 37.1 ± 1.7 μm) significantly larger ( p < 0.05) than that in cancer-free nodes ( i.e., 26 ± 3.3 μm). Therefore, the 3-D QUS methods could provide a useful means of identifying small metastatic foci in dissected lymph nodes that might not be detectable using current standard pathology procedures. (E-mail: mamou@rrinyc.org)

Contrast-Enhanced MR Imaging of Lymph Nodes in Cancer Patients

The accurate identification and characterization of lymph nodes by modern imaging modalities has important therapeutic and prognostic significance for patients with newly diagnosed cancers. The presence of nodal metastases limits the therapeutic options, and it generally indicates a worse prognosis for the patients with nodal metastases. Yet anatomic imaging (CT and MR imaging) is of limited value for depicting small metastatic deposits in normal-sized nodes, and nodal size is a poor criterion when there is no extracapsular extension or focal nodal necrosis to rely on for diagnosing nodal metastases. Thus, there is a need for functional methods that can be reliably used to identify small metastases. Contrast-enhanced MR imaging of lymph nodes is a non-invasive method for the analysis of the lymphatic system after the interstitial or intravenous administration of contrast media. Moreover, some lymphotrophic contrast media have been developed and used for detecting lymph node metastases, and this detection is independent of the nodal size. This article will review the basic principles, the imaging protocols, the interpretation and the accuracies of contrast-enhanced MR imaging of lymph nodes in patients with malignancies, and we also focus on the recent issues cited in the literature. In addition, we discuss the results of several pre-clinical studies and animal studies that were conducted in our institution.

High-Frequency Quantitative Ultrasound Imaging of Cancerous Lymph Nodes

High-frequency ultrasound (HFU) offers a means of investigating biological tissue at the microscopic level. High-frequency, quantitative-ultrasound (QUS) methods were developed to characterize freshly-dissected lymph nodes of cancer patients. Three-dimensional (3D) ultrasound data were acquired from lymph nodes using a 25.6-MHz center-frequency transducer. Each node was inked prior to 3D histological fixation to recover orientation after sectioning. Backscattered echo signals were processed to yield two QUS estimates associated with tissue microstructure: scatterer size and acoustic concentration. The QUS estimates were computed following established methods using a Gaussian scattering model. Four lymph nodes from a patient with stage-3 colon cancer were evaluated as an illustrative case. QUS images were generated for this patient by expressing QUS estimates as color-encoded pixels and overlaying them on conventional gray-scale B-mode images. The single metastatic node had an average scatterer size that was significantly larger than the average scatterer size of the other nodes, and the statistics of both QUS estimates in the metastatic node showed greater variance than the statistics of the other nodes. Results indicate that the methods may provide a useful means of identifying small metastatic foci in dissected lymph nodes that might not be detectable using current standard pathology procedures.

Regeneration of Autotransplanted Avascular Lymph Nodes in the Rat Is Improved by Platelet-Rich Plasma

The aim of this study was to verify that subcutaneous lymph node transplantation inducing lymphatic regeneration is possible in healthy adult rats, in analogy to results obtained in other species. This rat model was used to determine the effects of lymph node fragmentation as well as sheep erythrocytes and platelet-rich plasma injection on the regeneration of the transplanted lymph nodes. The results show for the first time that the rat is an adequate model to study the regeneration of transplanted lymph nodes. Lymph node fragmentation seems to affect transplant regeneration negatively. An immune challenge by injection of sheep erythrocytes in the drainage area of the transplanted lymph nodes does not improve fragment regeneration. However, injection of syngeneic platelet-rich plasma containing several growth factors resulted in an improvement in regeneration. Lymph node fragment regeneration, although still experimental, could be relevant for lymphedema prevention. Acquired lymphedema has a high prevalence in developed countries as a consequence of the removal and/or radiotherapy of tumor-draining lymph nodes in cancer patients. This disease causes lifelong disability due to chronic swelling and increased risk of infections. It currently lacks an effective treatment.