Total loss of VHL gene function impairs neuroendocrine cancer cell fitness due to excessive HIF2α activity.

Loss-of-function germline von Hippel-Lindau (VHL) tumor suppressor mutations cause VHL disease, which predisposes individuals to kidney cancer, hemangioblastomas, and paragangliomas. The risk that a given VHL disease family will manifest some or all these tumor types is profoundly influenced by the VHL allele it carries. For example, almost all VHL disease families that develop paraganglioma have missense VHL mutations. VHL families with null VHL alleles develop kidney cancer and hemangioblastomas without a high risk of paraganglioma. The latter is surprising because the VHL gene product, pVHL, suppresses the HIF2 transcription factor and gain-of-function HIF2 mutations are also linked to paraganglioma. Paragangliomas arise from the sympathetic or parasympathetic nervous system. Given the lack of human paraganglioma cell lines, we studied the effects of inactivating VHL in neuroblastoma cell lines, which also arise from the sympathetic nervous system. We found that total loss of pVHL function profoundly impairs the fitness of neuroblastoma cell lines in a HIF2-dependent manner both ex vivo and in vivo. This fitness defect can be rescued by pVHL variants linked to paraganglioma, but not by pVHL variants associated with a low risk of paraganglioma. These findings suggest that HIF2 activity above a critical threshold prevents the development of paraganglioma.

FTO-mediated DSP m6A demethylation promotes an aggressive subtype of growth hormone-secreting pituitary neuroendocrine tumors.

BACKGROUND: Growth hormone-secreting pituitary neuroendocrine tumors can be pathologically classified into densely granulated (DGGH) and sparsely granulated types (SGGH). SGGH is more aggressive and associated with a poorer prognosis. While epigenetic regulation is vital in tumorigenesis and progression, the role of N6-methyladenosine (m6A) in aggressive behavior has yet to be elucidated. METHODS: We performed m6A-sequencing on tumor samples from 8 DGGH and 8 SGGH patients, complemented by a suite of assays including ELISA, immuno-histochemistry, -blotting and -fluorescence, qPCR, MeRIP, RIP, and RNA stability experiments, aiming to delineate the influence of m6A on tumor behavior. We further assessed the therapeutic potential of targeted drugs using cell cultures, organoid models, and animal studies. RESULTS: We discovered a significant reduction of m6A levels in SGGH compared to DGGH, with an elevated expression of fat mass and obesity-associated protein (FTO), an m6A demethylase, in SGGH subtype. Series of in vivo and in vitro experiments demonstrated that FTO inhibition in tumor cells robustly diminishes hypoxia resistance, attenuates growth hormone secretion, and augments responsiveness to octreotide. Mechanically, FTO-mediated m6A demethylation destabilizes desmoplakin (DSP) mRNA, mediated by the m6A reader FMR1, leading to prohibited desmosome integrity and enhanced tumor hypoxia tolerance. Targeting the FTO-DSP-SSTR2 axis curtailed growth hormone secretion, therefor sensitizing tumors to octreotide therapy. CONCLUSION: Our study reveals the critical role of FTO in the aggressive growth hormone-secreting pituitary neuroendocrine tumors subtype and suggests FTO may represent a new therapeutic target for refractory/persistent SGGH.

Non-functional alpha-cell hyperplasia with glucagon-producing NET: a case report.

Introduction: Alpha-cell hyperplasia (ACH) is a rare pancreatic endocrine condition. Three types of ACH have been described: functional or nonglucagonoma hyperglucagonemic glucagonoma syndrome, reactive or secondary to defective glucagon signaling, and non-functional. Few cases of ACH with concomitant pancreatic neuroendocrine tumors (pNETs) have been reported and its etiology remains poorly understood. A case report of non-functional ACH with glucagon-producing NET is herein presented. Case report: A 72-year-old male was referred to our institution for a 2 cm single pNET incidentally found during imaging for acute cholecystitis. The patient's past medical history included type 2 diabetes (T2D) diagnosed 12 years earlier, for which he was prescribed metformin, dapagliflozin, and semaglutide. The pNET was clinically and biochemically non-functioning, apart from mildly elevated glucagon 217 pg/ml (<209), and 68Ga-SSTR PET/CT positive uptake was only found at the pancreatic tail (SUVmax 11.45). The patient underwent a caudal pancreatectomy and the post-operative 68Ga-SSTR PET/CT was negative. A multifocal well-differentiated NET G1, pT1N0M0R0 (mf) strongly staining for glucagon on a background neuroendocrine alpha-cell hyperplasia with some degree of acinar fibrosis was identified on pathology analysis. Discussion and conclusion: This case reports the incidental finding of a clinically non-functioning pNET in a patient with T2D and elevated glucagon levels, unexpectedly diagnosed as glucagon-producing NET and ACH. A high level of suspicion was required to conduct the glucagon immunostaining, which is not part of the pathology routine for a clinically non-functioning pNET, and was key for the diagnosis that otherwise would have been missed. This case highlights the need to consider the diagnosis of glucagon-producing pNET on an ACH background even in the absence of glucagonoma syndrome.

Computational drug discovery pipelines identify NAMPT as a therapeutic target in neuroendocrine prostate cancer.

Neuroendocrine prostate cancer (NEPC) is an aggressive advanced subtype of prostate cancer that exhibits poor prognosis and broad resistance to therapies. Currently, few treatment options are available, highlighting a need for new therapeutics to help curb the high mortality rates of this disease. We designed a comprehensive drug discovery pipeline that quickly generates drug candidates ready to be tested. Our method estimated patient response to various therapeutics in three independent prostate cancer patient cohorts and selected robust candidate drugs showing high predicted potency in NEPC tumors. Using this pipeline, we nominated NAMPT as a molecular target to effectively treat NEPC tumors. Our in vitro experiments validated the efficacy of NAMPT inhibitors in NEPC cells. Compared with adenocarcinoma LNCaP cells, NAMPT inhibitors induced significantly higher growth inhibition in the NEPC cell line model NCI-H660. Moreover, to further assist clinical development, we implemented a causal feature selection method to detect biomarkers indicative of sensitivity to NAMPT inhibitors. Gene expression modifications of selected biomarkers resulted in changes in sensitivity to NAMPT inhibitors consistent with expectations in NEPC cells. Validation of these markers in an independent prostate cancer patient dataset supported their use to inform clinical efficacy. Our findings pave the way for new treatments to combat pervasive drug resistance and reduce mortality. Furthermore, this research highlights the use of drug sensitivity-related biomarkers to understand mechanisms and potentially indicate clinical efficacy.

Well-Differentiated Neuroendocrine of Left Kidney.

Null.

Incidence, survival, and prognostic nomogram of patients with small intestinal neuroendocrine tumors: A SEER population-based study.

Small intestinal neuroendocrine tumors (SI-NETs) are a group of rare and significantly heterogeneous tumors with limited research currently available. This study aimed to investigate the incidence, survival, and prognostic factors of SI-NETs. We selected data from the surveillance, epidemiology, and end results (SEER) database between 2000 and 2019 and evaluated the incidence trend of SI-NETs during this period. We utilized the Kaplan-Meier method to examine the association between clinical variables and survival rates. Based on the multivariable Cox regression analysis results, we developed a nomogram to predict the 1-, 2-, and 3-year cancer-specific survival (CSS) of SI-NETs patients. We evaluated the consistency, accuracy, and clinical utility of the nomogram by drawing calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA) curves. The incidence of SI-NETs showed an upward trend in recent years. Age, grade, T stage, M stage, and primary tumor surgery were independent risk factors for CSS in SI-NETs patients. The nomogram model based on these risk factors showed high accuracy and clinical benefit. SI-NETs are rare tumors with an increasing incidence rate. The nomogram model is expected to be an effective tool for personalized prognosis prediction in SI-NETs patients, which may benefit clinical decision-making.

AB092. Imaging the histopathology subtypes of the growth hormone-secreting pituitary neuroendocrine tumor.

BACKGROUND: Sparsely granulated (SG) growth hormone-secreting pituitary neuroendocrine tumors (GH-PitNETs) often present with a more aggressive clinical course compared to densely granulated (DG) tumors. These subtypes exhibit distinct biological and imaging characteristics. Thus, this study aims to differentiate between the histopathological subtypes of GH-PitNETs using pre-operative magnetic resonance imaging (MRI). METHODS: A retrospective analysis was conducted on 83 acromegalic patients treated at our institution between 2000 and 2010. Tumor volumes were segmented from preoperative MRIs, including T1-weighted, T2-weighted, T1 with contrast, and T2 fluid attenuated inversion recovery (FLAIR) sequences. Reference regions of interest (ROIs) were delineated using gray and white matter from the same sequences. Two pathologists reviewed pathology specimens for anti-cytokeratin (CAM 5.2) and Pit-1 expression. Clinical and radiological biomarkers were compared between SG and DG patients. RESULTS: A total of 83 patients with complete histopathology and 51 patients with complete MRIs were included in the analysis. SG PitNETs exhibited higher rates of supra-sellar invasion (61.5%, P<0.001), larger tumor sizes, lower pre-operative GH levels, and increased post-operative residual tumor (65.4%, P<0.001) compared to DG PitNETs. Additionally, SG PitNETs showed greater hyperintensity on T2-weighted images and enhanced contrast, whereas DG PitNETs exhibited less contrast enhancement. Utilization of these imaging biomarkers demonstrated an 94.1% accuracy in T2 FLAIR and overall of 78.7% predicting the histopathological subtypes of GH-PitNETs. CONCLUSIONS: Distinct histopathological subtypes of GH-PitNETs represent crucial prognostic factors. Utilizing multimodal pre-operative MRIs, clinicians can accurately identify sparsely granulated GH-PitNETs, facilitating improved treatment planning strategies.

Angiogenic biomarkers of response to treatment with peptide receptor radionuclide therapy in neuroendocrine tumours.

BACKGROUND: Neuroendocrine tumours (NETs) are a heterogeneous group of tumours, which is characterized by rich vascularization. The role of angiogenesis in NETs has been widely researched. Peptide receptor radionuclide therapy (PRRT) is an effective treatment method for patients with disease progression in NETs. Due to the heterogeneousness of NETs, the response to treatment varies. Currently, the finding of efficient markers helpful in assessing the response to treatment in NETs is crucial. The aim of this study was to assess chromogranin A (CgA) and angiogenic factors in gastro-entero-pancreatic (GEP) and broncho-pulmonary (BP) NET patients treated with PRRT. MATERIAL AND METHODS: The study group included 40 patients with GEP NETs and BP NETs who completed four cycles of PRRT. Serum levels of CgA and angiogenic factors such as vascular endothelial growth factor (VEGF), its receptors (VEGF-R1, VEGF-R2, VEGF-R3), were assessed before and after four cycles of PRRT. All tests were determined using ELISA. RESULTS: The concentration of CgA, VEGF-R1 and VEGF-R2 decreased significantly, whereas VEGF-R3 increased significantly after PRRT. PRRT did not affect VEGF, it was similar before and after the radioisotope treatment. Based on AUROC, only for VEGF-R1 AUC was a consequence of 0.7 which can be considered as a good response to PRRT treatment. CONCLUSIONS: VEGF-R1 may be a potential biomarker useful in assessing the effectiveness of PRRT in NET patients.

Navigating the diagnostic gray zone: a challenging case of pancreatic high-grade neuroendocrine neoplasm.

BACKGROUND: Grade 3 neuroendocrine tumor (G3 PanNET) and poorly differentiated neuroendocrine carcinoma (PanNEC) of the pancreas are considered distinct entities from a biological and prognostic perspective but may have overlapping features complicating a definitive diagnosis. CASE PRESENTATION: A 52-year-old female presented with a pancreatic body mass and liver lesions. Initial biopsies showed variable lower- and higher-grade morphologies and modestly elevated Ki67 proliferation index up to 30%, leading to a diagnosis of G3 PanNET. The patient underwent everolimus treatment followed by surgical resection, revealing a complex tumor with features of both G3 PanNET and PanNEC, including admixed well- and poorly differentiated morphologies, modestly elevated hotspot Ki67 of 28%, retained ATRX/DAXX expression, and loss of RB expression. The final diagnosis rendered was "high-grade neuroendocrine neoplasm" with discussion of both entities in the differential. Post-operatively, the patient remains alive with stable metastases. CONCLUSIONS: This case highlights the diagnostic complexities of distinguishing G3 PanNET and PanNEC even with the support of ancillary immunohistochemical and molecular studies. In addition, such cases raise the possibility that G3 PanNET and PanNEC may lie on a spectrum of disease with potential biological overlap.

Advances in Management of Nonfunctional Pancreas Neuroendocrine Tumors.

This article presents updates in the surgical management of non-functional sporadic pancreas neuroendocrine tumors NET, including considerations for assessment of biologic behavior to support decision-making, indications for surgery, and surgical approaches tailored to the unique nature of neuroendocrine tumors.

Identification of Wandering Masses and Tumor Heterogeneity on 68Ga-DOTATATE and 18F-FDG PET/CT in Metastatic Grade II Neuroendocrine Tumor with Increased Somatostatin Receptor Expression After Combined Chemotherapy and PRRT.

Neuroendocrine tumors (NETs) may manifest as large masses in the abdominopelvic region that exhibit mobility and shifting, potentially leading to diagnostic uncertainty both before and after treatment. A meticulous analysis of PET/CT scans is advantageous in accurately identifying the precise location of large abdominopelvic masses. Tumor heterogeneity may be present in NETs with large abdominopelvic masses and may be easily identified on dual-tracer (68Ga-DOTATATE and 18F-FDG) PET/CT scans. In this scenario, the combined use of chemotherapy and peptide receptor radionuclide therapy is a more effective treatment option than monotherapy. Here, we present a case of a NET with wandering, large, heterogeneous masses in the abdominopelvic regions that were identified using dual-tracer PET/CT. After the administration of temozolomide chemotherapy in a combined chemotherapy-peptide receptor radionuclide therapy approach, we observed an upregulation in the expression of somatostatin receptor in the abdominopelvic masses.

Prognostic Nomograms for Patients With NF-Pan-NET After Pancreatectomy: A Retrospective Analysis Based on SEER Database.

AIMS: Surgical resection is the primary treatment option for patients diagnosed with nonfunctional pancreatic neuroendocrine tumors (NF-Pan-NETs). However, the postoperative prognostic evaluation for NF-Pan-NET patients remains obscure. This study aimed to construct an efficient model to predict the prognosis of NF-Pan-NET patients who have received surgical resection. METHODS: NF-Pan-NET patients after pancreatectomy were retrieved from the SEER database for the period of 2010 to 2019. A total of 2844 patients with NF-Pan-NET from SEER database were included in our study. After careful screening, six clinicopathological variables including age, grade, AJCC T stage, AJCC N stage, AJCC M stage, and chemotherapy were selected to develop nomograms to predict overall survival (OS) and cancer-specific survival (CSS) respectively of the patients. RESULTS: The novel models demonstrated high accuracy and discrimination in prognosticating resected NF-Pan-NET through various validation methods. Furthermore, the risk subgroups classified by the newly developed risk stratification systems based on the nomograms exhibited significant differences in both OS and CSS, surpassing the efficacy of the AJCC 8th TNM staging system. Novel nomograms and corresponding risk classification systems were developed to predict OS and CSS in patients with NF-Pan-NET after pancreatectomy. CONCLUSION: The models demonstrated superior performance compared to traditional staging systems, providing clinicians with more accurate and personalized guidance for postoperative surveillance and treatment.

Genomic Landscape of Pancreatic Neuroendocrine Tumors and Implications for Clinical Practice.

Pancreatic neuroendocrine tumors (pNETs) are the second most prevalent neoplasms of the pancreas with variable prognosis and clinical course. Our knowledge of the genetic alterations in patients with pNETs has expanded in the past decade with the availability of whole-genome sequencing and germline testing. This review will focus on potential clinical applications of the genetic testing in patients with pNETs. For somatic testing, we discuss the commonly prevalent somatic mutations and their impact on prognosis and treatment of patients with pNET. We also highlight the relevant genomic biomarkers that predict response to specific treatments. Previously, germline testing was only recommended for high-risk patients with syndromic features (MEN1, VHL, TSC, and NF1), we review the evolving paradigm of germline testing in pNETs as recent studies have now shown that sporadic-appearing pNETs can also harbor germline variants.

Theranostics in Neuroendocrine Tumors: Updates and Emerging Technologies.

Advancements in somatostatin receptor (SSTR) targeted imaging and treatment of well-differentiated neuroendocrine tumors (NETs) have revolutionized the management of these tumors. This comprehensive review delves into the current practice, discussing the use of the various FDA-approved SSTR-agonist PET tracers and the predictive imaging biomarkers, and elaborating on Lu177-DOTATATE peptide receptor radionuclide therapy (PRRT) including the evolving areas of post-therapy imaging practices, PRRT retreatment, and the potential role of dosimetry in optimizing patient treatments. The future directions sections highlight ongoing research on investigational PET imaging radiotracers, future prospects in alpha particle therapy, and combination therapy strategies.

Neuroendocrine neoplasms of the thymus.

Neuroendocrine neoplasms of the thymus (tNENs), including typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma, are rare tumors with scarce clinical and pathological data available in the literature. They share many common features with neuroendocrine neoplasms in other organs, such as those in the lungs, while demonstrating some distinct clinical and pathological features. This review aims to give an updated overview of each category of tNENs, focusing primarily on the pathologic diagnosis and differential diagnosis of these tumors.

Giant laryngeal neuroendocrine neoplasm causing airway obstruction: A case report and literature review.

RATIONALE: Laryngeal neuroendocrine neoplasm (NEN) is a rare and heterogeneous disease that originates from neuroendocrine cells. It mainly occurs in middle-aged and elderly men. Due to the lack of specific clinical and imaging manifestations, diagnosis and treatment of the disease pose a challenge. Therefore, a consensus on the diagnosis and treatment of the disease is necessary. By discussing this case, we will be able to gain further insight into laryngeal NEN and will be able to provide some recommendations for the future management of this rare disease. PATIENT CONCERNS: A 67-year-old man was admitted to our department with a history of sore throat and dyspnea. After admission, the patient experienced acute airway obstruction and experienced an emergency bedside tracheotomy. DIAGNOSES: Flexible fiberoptic laryngoscopy and enhanced CT showed a cauliflower-like mass in the left supraglottic region and obstructed most of the laryngeal cavity. We biopsied the mass, and the pathology showed a poorly differentiated adenocarcinoma. INTERVENTIONS: A horizontal hemilaryngectomy and left neck dissection were performed. At 4 weeks after the operation, the patient underwent chemotherapy and radical radiotherapy. OUTCOMES: After a 1-year postoperative follow-up, the patient recovered well and showed no signs of recurrence. LESSONS: Laryngeal neuroendocrine neoplasm is very rare, early diagnosis remains difficult. Radical surgery combined with postoperative chemoradiotherapy is currently the most appropriate treatment.

An autopsy case of an adult woman with Rapid-Onset Obesity with Hypoventilation, Hypothalamic, Autonomic Dysregulation, and Neuroendocrine Tumors (ROHHAD(NET)) syndrome developing nonalcoholic steatohepatitis and hepatocellular carcinoma: A case report.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is an important etiology of hepatocellular carcinoma (HCC), and there is no established therapy for this syndrome. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, autonomic dysregulation, and neural crest tumor (ROHHAD(NET)) is an extremely rare syndrome considered to be life-threatening, with death occurring around 10 years of age. We present the oldest known autopsy case of this syndrome that developed HCC. This case provided important information on not only improving the course of this syndrome, but also understanding the natural history and therapeutic modalities of NASH and HCC. METHODS: The patient was diagnosed with ROHHAD(NET) syndrome in childhood, and liver cirrhosis due to NASH was diagnosed at age 17. HCC was detected at age 20, and embolization and irradiation were performed. At age 21, she died from accidental acute pancreatitis and subsequent liver failure and pulmonary hemorrhage. RESULTS: Rapid onset of obesity, hypoventilation, and hypothalamic disturbance appeared in childhood and was diagnosed as this syndrome. At age 17, liver cirrhosis due to NASH was diagnosed by liver biopsy, and at age 20, HCC was diagnosed by imaging. Transarterial chemoembolization and irradiation were performed, and the HCC was well controlled for a year. CONCLUSION: At age 21, she died from accidental acute pancreatitis, subsequent liver failure and pulmonary hemorrhage. Autopsy revealed that the HCC was mostly necrotized. This case was valuable not only for other ROHHAD(NET) syndrome cases, but also in improving our understanding of the natural history of NASH and HCC.

[New oncological indications for liver transplantation]. / Nouvelles indications oncologiques à la transplantation hépatique.

Transplantation oncology represents a specificity of liver transplantation. Hepatocellular carcinoma is now an accepted indication with very good long-term results. Cholangiocarcinoma, hepatic -metastases from colorectal cancer and neuroendocrine tumors are emerging indications with outcome superior to those that can be achieved with systemic treatments in very selected patients.

La transplantation pour des indications oncologiques représente une particularité exclusive de la transplantation hépatique. Le carcinome hépatocellulaire est désormais une indication confirmée par de très bons résultats à long terme. Le cholangiocarcinome, les métastases hépatiques du cancer colorectal et neuro­endocrine représentent des indications émergentes avec des ­résultats supérieurs à ceux obtenus avec les traitements systémiques, sous réserve d'une rigoureuse sélection des patients.