Purpose
Gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) are increasing in incidence, and accurate staging is important for selecting the appropriate treatment.
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Ga-DOTATATE imaging is a ...promising approach for detecting GEPNETs and could help in selecting optimal therapeutic strategies. The aim of this study was to prospectively determine the clinical utility of
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Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) in detecting unknown primary and metastatic GEPNETs.
Patients and Methods
One hundred thirty-one patients were enrolled in a prospective study of patients undergoing
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Ga-DOTATATE PET/CT,
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In-pentetreotide single-photon emission computed tomography (SPECT)/CT and multiphasic CT scan, and/or magnetic resonance imaging in a blinded fashion with comprehensive biochemical testing. The primary outcome measure was the detection of lesions by each imaging study.
Results
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Ga-DOTATATE PET/CT imaging detected 95.1% of lesions (95% CI, 92.4% to 96.8%) with an average maximum standardized uptake value of 65.4 ± 47 (range, 6.9 to 244), anatomic imaging detected 45.3% of lesions (95% CI, 37.9% to 52.9%), and
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In-pentetreotide SPECT/CT detected 30.9% of lesions (95% CI, 25.0% to 37.5%), with a significant difference between imaging modalities (P < .001). In four of 14 patients (28.6%),
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Ga-DOTATATE PET/CT found a previously unknown primary tumor, and detected primary GEPNET, lymph node, and distant metastases correctly in 72 of 113 lesions (63.7%) when compared with histopathology, with 22.1% and 38.9% detected by using
111
In-pentetreotide SPECT/CT and anatomic imaging, respectively. On the basis of findings with
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Ga-DOTATATE PET/CT, 43 of 131 patients (32.8%) had a change in management recommendation. In patients with carcinoid symptoms but negative biochemical testing,
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Ga-DOTATATE PET/CT detected lesions in 65.2% of patients, 40% of which were detected neither by anatomic imaging nor by
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In-pentetreotide SPECT/CT.
Conclusion
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Ga-DOTATATE PET/CT imaging provides important information for accurate staging of GEPNETs and selection of appropriate treatment interventions even in the absence of biochemical evidence of disease in symptomatic patients.
Multiple accessory pathways (APs) can develop in patients with Ebstein anomaly. Rarely, these APs can participate in antidromic atrioventricular reentrant tachycardia (AVRT) which can be ...life-threatening and requires unique considerations for acute management and ultimate ablation. These considerations are discussed herein.
Abstract
Despite numerous therapeutic advances in cancers, the treatment of glioblastoma multiforme (GBM) remains a challenge. Boosting T-lymphocyte mediated responses against GBM offers a promising ...approach towards solving this problem. Herein, we present a therapeutic vaccination strategy that promotes the phagocytosis of tumor cells, enhances tumor antigen presentation, and induces a tumor-specific adaptive immune response with subsequent tumor eradication. This strategy consists of subcutaneous injection of irradiated whole tumor cells (rWTC) pulsed with phagocytic agonists (Mannan-BAM), TLR ligands (LTA, Poly (I:C), and R-848), and anti-CD40 agonistic antibody (collectively abbreviated as rWTC-MBTA). We evaluated the therapeutic efficacy of rWTC-MBTA strategy in mouse syngeneic GBM tumor models with GL261 and SB28 cells. In GL261 GBM model, complete regression (CR) of intracranial tumors was achieved in 70% (7/10) of rWTC-MBTA treated animals while none survived in the control group. Of note, the therapeutic efficacy of rWTC-MBTA was abolished in CD4-T and/or CD8-T lymphocyte depleted mice. Immunophenotyping analyses of peripheral lymph nodes and brain tumors of rWTC-MBTA treated mice demonstrated increased antigen presenting cells (dendritic cells and MHC II+ monocytes) and increased cytotoxic IFNγ, TNFα, and granzyme B-secreting CD4-T and CD8-T cells. All three CR mice that were rechallenged with GL261 cells intracranially 14 months after their last rWTC-MBTA treatment resisted tumor development, confirming the establishment of long-term immunological memory. In SB28 GBM model, 80% (8/10) rWTC-MBTA treated mice survived past 95 days after tumor cell implantation without any GBM-related symptoms, with median survival being only 35 days in control groups. In summary, our study demonstrated that rWTC-MBTA strategy can induce potent adaptive immune response against GBM in pre-clinical models.
Citation Format: Herui Wang, Rogelio Medina, Juan Ye, Samik Chakraborty, Ondrej Uher, Mitchell Sun, Jan Zenka, Mark R. Gilbert, Karel Pacak, Zhengping Zhuang. Irradiated whole tumor cells pulsed with mannan-BAM, TLR ligands and anti-CD40 antibody serve as a potent tumor cell vaccine against glioblastoma abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 691.
Abstract
Despite the advances made in cancer treatment over the past decades, one statistic has remained unchanged: metastatic cancer accounts for 90 percent of annual cancer deaths in the United ...States. Our group previously demonstrated that an autologous whole tumor cell vaccine (rWTC-MBTA: irradiated autologous whole tumor cells pulsed with Mannan-BAM, TLR ligands, and anti-CD40 antibody) had a potent anti-tumor immune response and prolonged survival in a mouse colon carcinoma model. To investigate whether rWTC-MBTA would work in “cold” tumor models, we evaluated the vaccine’s effect on preventing and treating tumor metastasis in 4T1 breast tumors. Our data showed that vaccinated mice could significantly prevent lung metastasis in both intravenous injection and mammary pad subcutaneous implantation animal models. Further, we used another metastasis model that more closely mimics clinical practice by resecting the primary tumor after metastasis development. The data showed that vaccinated mice could prevent tumor recurrence, increase T-cell infiltration in the metastatic tumor, and prolong the survival curve. The mechanistic investigation by immunophenotyping revealed that rWTC-MBTA vaccination induced both effector memory (CD44+CD62L−) and center memory (CD44+CD62L+) T cells as well as increased overall CD4+ and CD8+ T-cell count while depletion experiments demonstrated that CD8+ T cells were required for vaccine efficacy. Isolated splenocytes co-cultured with 4T1 cells showed rWTC-MBTA significantly increased T-cell mediated cytotoxicity through TNF-a and IFN-γ in CD107a+CD4+ T cells and Granzyme B and IFN-γ in CD107a+CD8+ T cells. In all experiments, vaccination exerted negligible systemic toxicity. Collectively, our study demonstrates that the rWTC-MBTA vaccine is a safe and promising therapeutic option to prevent and treat tumor metastasis by triggering an antitumor immune response.
Citation Format: Juan Ye, Herui Wang, Mitchell Sun, Ondrej Uher, Mark R. Gilbert, Karel Pacak, Zhengping Zhuang, Rogelio Medina, Samik Chakraborty, Jan Zenka. Unique autologous cancer vaccine comprised of irradiated whole tumor cells and MBTA (rWTC-MBTA) triggers antitumor immune response to prevent metastasis. abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6800.
Hypoxia-inducible factors (HIFs) regulate oxygen sensing and expression of genes involved in angiogenesis and erythropoiesis. Polycythemia has been observed in patients with hepatocellular carcinoma ...(HCC), but the underlying molecular basis remains unknown. Liver tissues from 302 HCC patients, including 104 with polycythemia, were sequenced for
mutations. A germline
mutation was detected in one HCC patient with concurrent polycythemia. Three additional family members carried this mutation, but none exhibited polycythemia or were diagnosed with HCC. The gain-of-function mutation resulted in a HIF-2α protein that was transcribed normally but resistant to degradation. HIF-2α target genes
,
,
, and
were significantly upregulated in the tumor bed but not in the surrounding liver tissue. Polycythemia resolved upon total resection of the tumor tissue. This newly described
mutation may promote HCC oncogenesis.
The vagus nerve (cranial nerve X) is the main nerve of the parasympathetic division of the autonomic nervous system. Vagal paragangliomas (VPGLs) are a prime example of an endocrine tumor associated ...with the vagus nerve. This rare, neural crest tumor constitutes the second most common site of hereditary head and neck paragangliomas (HNPGLs), most often in relation to mutations in the succinate dehydrogenase complex subunit D (SDHD) gene. The treatment paradigm for VPGL has progressively shifted from surgery to abstention or therapeutic radiation with curative-like outcomes. Parathyroid tissue and parathyroid adenoma can also be found in close association with the vagus nerve in intra or paravagal situations. Vagal parathyroid adenoma can be identified with preoperative imaging or suspected intraoperatively by experienced surgeons. Vagal parathyroid adenomas located in the neck or superior mediastinum can be removed via initial cervicotomy, while those located in the aortopulmonary window require a thoracic approach. This review particularly emphasizes the embryology, molecular genetics, and modern imaging of these tumors.
Pheochromocytomas (PCCs) and paragangliomas (PGLs) are neuroendocrine tumors that are mostly benign. Metastatic disease does occur in about 10% of cases of PCC and up to 25% of PGL, and for these ...patients no effective therapies are available. Patients with mutations in the succinate dehydrogenase subunit B (SDHB) gene tend to have metastatic disease. We hypothesized that a down-regulation in the active succinate dehydrogenase B subunit should result in notable changes in cellular metabolic profile and could present a vulnerability point for successful pharmacological targeting.
Metabolomic analysis was performed on human hPheo1 cells and shRNA SDHB knockdown hPheo1 (hPheo1 SDHB KD) cells. Additional analysis of 115 human fresh frozen samples was conducted. In vitro studies using N1,N11-diethylnorspermine (DENSPM) and N1,N12- diethylspermine (DESPM) treatments were carried out. DENSPM efficacy was assessed in human cell line derived mouse xenografts.
Components of the polyamine pathway were elevated in hPheo1 SDHB KD cells compared to wild-type cells. A similar observation was noted in SDHx PCC/PGLs tissues compared to their non-mutated counterparts. Specifically, spermidine, and spermine were significantly elevated in SDHx-mutated PCC/PGLs, with a similar trend in hPheo1 SDHB KD cells. Polyamine pathway inhibitors DENSPM and DESPM effectively inhibited growth of hPheo1 cells in vitro as well in mouse xenografts.
This study demonstrates overactive polyamine pathway in PCC/PGL with SDHB mutations. Treatment with polyamine pathway inhibitors significantly inhibited hPheo1 cell growth and led to growth suppression in xenograft mice treated with DENSPM. These studies strongly implicate the polyamine pathway in PCC/PGL pathophysiology and provide new foundation for exploring the role for polyamine analogue inhibitors in treating metastatic PCC/PGL.
Cell line metabolomics on hPheo1 cells and PCC/PGL tumor tissue indicate that the polyamine pathway is activated. Polyamine inhibitors in vitro and in vivo demonstrate that polyamine inhibitors are promising for malignant PCC/PGL treatment. However, further research is warranted.
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