Pancreatic Neuroendocrine Tumors Patients Research Articles

Prevalence of metastases outside the liver and abdominal lymph nodes on 68Ga-DOTATOC-PET/CT in patients with small intestinal and pancreatic neuroendocrine tumours.

Metastases outside the liver and abdominal/retroperitoneal lymph nodes are nowadays detected frequently in patients with neuroendocrine tumours (NETs), owing to the high sensitivity of positron emission tomography (PET) with Gallium-68-DOTA-somatostatin analogues (68Ga-SSA) and concomitant diagnostic computed tomography (CT). Our aim was to determine the prevalence of extra-abdominal metastases on 68Ga-DOTATOC-PET/CT in a cohort of patients with small intestinal (Si-NET) and pancreatic NET (Pan-NET), as well as that of pancreatic metastasis in patients with Si-NET. Among 2090 patients examined by 68Ga-DOTATOC-PET/CT at two tertiary referral centres, a total of 1177 patients with a history of Si- or Pan-NET, were identified. The most recent 68Ga-DOTATOC-PET/CT report for each patient was reviewed, and the location and number of metastases of interest were recorded. Lesions outside the liver and abdominal nodes were found in 26% of patients (n = 310/1177), of whom 21.5% (255/1177) were diagnosed with Si-NET and 4.5% (55/1177) Pan-NET. Bone metastases were found in 18.4% (215/1177), metastases to Virchow's lymph node in 7.1% (83/1177), and lung/pleura in 4.8% (56/1177). In the subset of 255 Si-NET patients, 5.4% (41/255) manifested lesions in the pancreas, 1.5% in the breast (18/255), 1.3% in the heart (15/255) and 1% in the orbita (12/255). In Si-NET patients, the Ki-67 proliferation index was higher in those with ≥2 metastatic sites of interest, than with 1 metastatic site, (p <0.001). Overall, extra-abdominal or pancreatic metastases were more often found in patients with Si-NET (34%) than in those with Pan-NET (13%) (p <0.001). Bone metastases were 2.6 times more frequent in patients with Si-NET compared to Pan-NET patients (p <0.001). Lesions to the breast and orbita were encountered in almost only Si-NET patients. In conclusion, lesions outside the liver and abdominal nodes were detected in as many as 26% of the patients, with different prevalence and metastatic patterns in patients with Si-NET compared to Pan-NET. The impact of such metastases on overall survival and clinical decision-making needs further evaluation.

Deciphering pancreatic neuroendocrine tumors: Unveiling through circulating small extracellular vesicles

The survival rate over a five-year period for rare pancreatic neuroendocrine tumors (PanNET) is notably lower compared to other neuroendocrine tumors due to late-stage detection, which is a consequence of the absence of suitable diagnostic markers; therefore, there exists a critical need for an early-stage biomarker-specific to PanNETs. This study introduces a novel approach, investigating the impact of small extracellular vesicles (sEV) in PanNET growth and metastasis. As proof of concept, this study shows a correlation between sEV concentration in controls and PanNET. Notably, higher sEV concentrations were observed in PanNETs than in controls (p < 0.0001) with a sensitivity of 100%. Further, apparent differences were observed in the sEV concentrations between controls and grades 1 PanNET (p = 0.005). The expression of sEV markers was confirmed using CD63, TSG101, CD9, Flotillin-1, and GAD65 antibodies. Additionally, the expression of cancer marker BIRC2/cIAP1 (p = 0.002) and autophagy marker Beclin-1 (p = 0.02) were observed in plasma-derived sEVs and PanNET tissue. This study represents the first to indicate the increased secretion of sEV in PanNET patients' blood plasma, proposing potential function of sEV as a new biomarker for early-stage PanNET detection.

SQSTM1/p62 is a prognostic molecular marker and potential therapeutic target for pancreatic neuroendocrine tumours.

There have been few studies on the role of autophagy in pancreatic neuroendocrine tumours (PNETs). SQSTM1/p62 (also called Sequestosome 1) is a potential autophagy regulator, and its biological roles and clinical significance in PNETs remain poorly understood. The purpose of this study was to evaluate the clinical significance of SQSTM1/p62 in human PNET specimens and to evaluate its potential value as a therapeutic target by studying its biological function in PNET cell lines. SQSTM1/p62 protein expression was assessed in 106 PNET patient specimens by immunohistochemistry, and the relationship between SQSTM1/p62 protein expression and the clinicopathological features of PNETs in patients was analysed. The proliferation, invasion and apoptosis of SQSTM1/p62-knockdown QGP-1 and INS-1 cells were assessed by the MTT assay, a Transwell assay and flow cytometry. Cell autophagy was assessed by western blotting and mCherry-GFP-LC3B. The protein expression of SQSTM1/p62 in PNET patient specimens was significantly correlated with tumour recurrence (p = 0.005) and worse prognosis (log rank p = 0.020). Downregulation of the SQSTM1/p62 gene inhibited tumour cell proliferation and migration and induced PNET cell death. Downregulation of SQSTM1/p62 activated autophagy in PNET cell lines but blocked autophagic flow. Knockdown of the SQSTM1/p62 gene inhibited mTOR phosphorylation. The SQSTM1/P62 protein could be an independent prognostic marker for PNET patients. Downregulating SQSTM1/P62 can inhibit PNET progression, inhibit mTOR phosphorylation and block autophagic flow.

C1QA and COMP: plasma-based biomarkers for early diagnosis of pancreatic neuroendocrine tumors

Pancreatic Neuroendocrine tumors (PanNET) are challenging to diagnose and often detected at advanced stages due to a lack of specific and sensitive biomarkers. This study utilized proteomics as a valuable approach for cancer biomarker discovery; therefore, mass spectrometry-based proteomic profiling was conducted on plasma samples from 12 subjects (3 controls; 5 Grade I, 4 Grade II PanNET patients) to identify potential proteins capable of effectively distinguishing PanNET from healthy controls. Data are available via ProteomeXchange with the identifier PXD045045. 13.2% of proteins were uniquely identified in PanNET, while 60% were commonly expressed in PanNET and controls. 17 proteins exhibiting significant differential expression between PanNET and controls were identified with downstream analysis. Further, 5 proteins (C1QA, COMP, HSP90B1, ITGA2B, and FN1) were selected by pathway analysis and were validated using Western blot analysis. Significant downregulation of C1QA (p = 0.001: within groups, 0.03: control vs. grade I, 0.0013: grade I vs. grade II) and COMP (p = 0.011: within groups, 0.019: control vs grade I) were observed in PanNET Grade I & II than in controls. Subsequently, ELISA on 38 samples revealed significant downregulation of C1QA and COMP with increasing disease severity. This study shows the potential of C1QA and COMP in the early detection of PanNET, highlighting their role in the search for early-stage (Grade-I and Grade-II) diagnostic markers and therapeutic targets for PanNET.

HPB P28 Continuous glucose monitoring improves the diagnosis of insulinoma and surveillance after endoscopic ablation therapy

Abstract Background Insulinomas are the most common functioning pancreatic neuroendocrine tumours (PNET) and are classically diagnosed according to Whipple’s triad. The gold-standard diagnostic test (72 hour fasting glucose/C-peptide) is difficult for patients, and risks mis-diagnosing patients who only experience post-prandial symptoms. Moreover, the advent of endoscopic ablative techniques means that confirming successful treatment can be challenging when compared with surgical resection. This study aimed to investigate the value of continuous glucose monitoring (CGM) to: a) confirm the diagnosis of insulinoma; b) guide symptom management whilst awaiting definitive treatment; and c) as a surveillance tool in patients electing for non-surgical interventions. Methods A 61-year-old healthy male presented with post-prandial sweating, vacant episodes and reduced exercise tolerance which resolved upon consuming glucose. Computed Tomography demonstrated a 2cm exophytic hypervascular lesion in the pancreatic body, consistent with a NET, and correlated with an Octreotide avid lesion upon SPECT/CT. Overnight fasting glucose/c-peptide was not confirmatory. The target glucose range was defined as 4.0-9.9 mmol/L and critical hypoglycaemia as ≤2.9mmol/L. Data from CGM were analysed (Time in range and critical hypoglycaemia [Chi2]; glycaemic control and glycaemic variability [T-test]) during diagnosis, in the first week post-ablation, and the recovery phase beyond 3 weeks. Results Data from 22,008 glucose levels were analysed over a 90 day period. Time in range during diagnosis was 67.25%, 82.8% (p&amp;lt;0.0001) post-ablation, and 98.9% (P&amp;lt;0.0001) during recovery. Critical hypoglycaemia occurred in 5.2% of measurements during diagnosis, 1.9% (p&amp;lt;0.0001) post-ablation, and 0.1% (p&amp;lt;0.0001) during recovery. Glucose levels (mean [SD] mmol/L) were 4.4 (0.47) during diagnosis, 4.9 (0.29) (p=0.0001) post-ablation, and 5.7 (0.42) (p&amp;lt;0.0001) during recovery. Glycaemic variability (mean [SD] %CV) was 19.4 (5.09) during diagnosis, 20.17 (5.60) post-ablation (p=0.630), and 11.3 (5.53) (p&amp;lt;0.0001) during recovery. Temporal changes identifying post-prandial hypoglycaemia during diagnosis, and resolution during recovery, are illustrated (Figure 1). Conclusions CGM has utility to accurately diagnose insulinoma when standard tests are negative, and to improve quality of life by alerting patients to life-threatening critical hypoglycaemia. As parenchymal preserving non-operative therapies increase in popularity, especially for patients with small PNETs, sensitive, reliable, and acceptable surveillance techniques are required in order to confirm treatment success and monitor for recurrence. Proactive engagement with commissioning and regulatory bodies is necessary in order to harness the potential from emerging technologies, so that PNET patients can benefit in a similar manner as those with type 1 Diabetes Mellitus.

Pancreatic neuroendocrine tumor progression and resistance to everolimus: the crucial role of NF-kB and STAT3 interplay.

The finding of mTOR overactivation in patients affected by pancreatic neuroendocrine tumors (Pa-NETs) led to their treatment with the mTOR inhibitor everolimus. Unfortunately, the efficacy of everolimus is restricted by the occurrence of resistance. The mechanisms leading to Pa-NETs' progression and resistance are not well understood. Notably, chronic inflammation is implicated in NET development. NF-kB is involved in inflammation and drug resistance mechanisms through the activation of several mediators, including STAT3. In this respect, NF-κB and STAT3 interaction is implicated in the crosstalk between inflammatory and tumor cells. We investigated the expression of NF-kB in different Pa-NETs by RT-qPCR and immunohistochemistry. Then, we studied the role of NF-κB and STAT3 interplay in QGP-1 cells. Subsequently, we assessed the impact of NF-κB and STAT3 inhibitors in QGP-1 cell proliferation and spheroids growth. Finally, we evaluated the implication of the NF-kB pathway in everolimus-resistant Pa-NET cells. We found that the increased NF-kB expression correlates with a higher grade in Pa-NETs. The activation of the STAT3 pathway induced by TNFα is mediated by NF-kB p65. NF-kB p65 and STAT3 inhibitors decrease QGP-1 viability, spheroids growth, and Pa-NETs cell proliferation. These effects are maintained in everolimus-resistant QGP-1R cells. Interestingly, we found that NF-kB, STAT3, IL-8, and SOCS3 are overexpressed in QGP-1R compared to QGP-1. Since the NF-kB pathway is implicated in Pa-NETs' progression and resistance to everolimus, these data could explain the potential use of NF-kB as a novel therapeutic target in Pa-NET patients.

Radiomics analysis from magnetic resonance imaging in predicting the grade of nonfunctioning pancreatic neuroendocrine tumors: a multicenter study

ObjectivesTo explore the potential of radiomics features to predict the histologic grade of nonfunctioning pancreatic neuroendocrine tumor (NF-PNET) patients using non-contrast sequence based on MRI.MethodsTwo hundred twenty-eight patients with NF-PNETs undergoing MRI at 5 centers were retrospectively analyzed. Data from center 1 (n = 115) constituted the training cohort, and data from centers 2–5 (n = 113) constituted the testing cohort. Radiomics features were extracted from T2-weighted images and the apparent diffusion coefficient. The least absolute shrinkage and selection operator was applied to select the most important features and to develop radiomics signatures. The area under receiver operating characteristic curve (AUC) was performed to assess models.ResultsTumor boundary, enhancement homogeneity, and vascular invasion were used to construct the radiological model to stratify NF-PNET patients into grade 1 and 2/3 groups, which yielded AUC of 0.884 and 0.684 in the training and testing groups. A radiomics model including 4 features was constructed, with an AUC of 0.941 and 0.871 in the training and testing cohorts. The fusion model combining the radiomics signature and radiological characteristics showed good performance in the training set (AUC = 0.956) and in the testing set (AUC = 0.864), respectively.ConclusionThe developed model that integrates radiomics features with radiological characteristics could be used as a non-invasive, dependable, and accurate tool for the preoperative prediction of grade in NF-PNETs.Clinical relevance statementOur study revealed that the fusion model based on a non-contrast MR sequence can be used to predict the histologic grade before operation. The radiomics model may be a new and effective biological marker in NF-PNETs.Key PointsThe diagnostic performance of the radiomics model and fusion model was better than that of the model based on clinical information and radiological features in predicting grade 1 and 2/3 of nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs).Good performance of the model in the four external testing cohorts indicated that the radiomics model and fusion model for predicting the grades of NF-PNETs were robust and reliable, indicating the two models could be used in the clinical setting and facilitate the surgeons’ decision on risk stratification.The radiomics features were selected from non-contrast T2-weighted images (T2WI) and diffusion-weighted imaging (DWI) sequence, which means that the administration of contrast agent was not needed in grading the NF-PNETs.

European Neuroendocrine Tumor Society 2023 guidance paper for functioning pancreatic neuroendocrine tumour syndromes.

This ENETS guidance paper aims to provide practical advice to clinicians for the diagnosis, treatment and follow-up of functioning syndromes in pancreatic neuroendocrine tumours (NET). A NET-associated functioning syndrome is defined by the presence of a clinical syndrome combined with biochemical evidence of inappropriately elevated hormonal levels. Different hormonal syndromes can be encountered in pancreatic NET patients, including insulinoma, gastrinoma as well as the rare glucagonoma, VIPoma, ACTHoma, PTHrPoma, carcinoid syndrome, calcitoninoma, GHRHoma and somatostatinoma. The recommendations provided in this paper focus on the biochemical, genetic and imaging work-up as well as therapeutic management of the individual hormonal syndromes in well-differentiated, grade 1-3, functioning NET with the primary tumour originating in the pancreas, and for specific subtypes also in the duodenum.

Targeted deep sequencing reveals the genetic heterogeneity in well-differentiated pancreatic neuroendocrine tumors with liver metastasis.

Pancreatic neuroendocrine tumor is a rare and heterogeneous entity, and approximately half of the patients harbored liver metastasis when initially diagnosed, whose prognosis is dismal. High-throughput sequencing has largely uncovered the genomic features of pancreatic neuroendocrine tumor, but the genetic alterations in the metastatic cases remain relatively unclear, which we aimed to study. Pathologically confirmed well-differentiated pancreatic neuroendocrine tumor samples resected in our hospital from 2000 to 2019 were collected. We performed deep sequencing on the exome of 341 tumor-related genes, and compared the differences of genetic alterations between the metastatic and the non-metastatic cases, as well as between the primary and the paired liver metastatic tumors. Sequencing data of 79 samples from 29 pancreatic neuroendocrine tumor patients were included into analysis. A total of 2,471 somatic variants were identified, 75.5% of which were considered as low-abundance. NOTCH1 was the most frequently mutated gene, altered in 26 (53.1%) pancreatic neuroendocrine tumor samples from 18 (62.1%) patients. Compared with the non-metastatic pancreatic neuroendocrine tumors, the metastatic cases were discovered with more single nucleotide variants and copy number variations, indicating the increased genomic instability. In addition, among the paired metastatic cases, the primary and the metastatic lesions shared limited mutated genes. Through the targeted deep sequencing, we identified the intratumor, intraindividual, and interindividual heterogeneity in the pancreatic neuroendocrine tumor patients, particularly in the metastatic cases, bringing potential challenges for the current biopsy strategies in guiding clinical treatments.

Differences in outcomes of patients with advanced neuroendocrine tumors treated with chemotherapy versus targeted agents.

e16303 Background: Pancreas NETs are uncommon and very rare cancer accounting for around 7% of the pancreatic cancer sub patient population, 4,200 patients in the US diagnoses yearly of all cancers in the pancreas. There are very few treatment options available for Metastatic Pancreatic Neuroendocrine Tumor patients. The survival rate depends on a variety of factors, including whether the tumor can be removed using surgery and if the cancer has spread to other parts of the body. The 5-year survival rate non-metastatic pancreas NETs is 93% while metastatic pancreas NETs is 24%. Therefore, this study compares the 5-year overall survival rate of metastatic pancreatic NETs ineligible for surgery who have received chemotherapy alone versus who have received targeted therapy. Methods: Patient cohorts were generated in an electronic medical records (EMR) TriNetX Research Network of 89M patient lives. Patients were identified as either receiving a targeted therapy or patients who were targeted therapy naïve receiving chemotherapy. Both cohorts had a diagnosis of pancreatic NETs (ICD-10 C25.4), at least one documentation of a related metastasis, and no history of any pancreatic surgery. The 5 year overall survival (OS) from first exposure to either targeted therapy or chemotherapy was analyzed using measures of association and survival analysis conducted via Kaplan-Meier estimator. Cohort comparisons were with propensity score matching (PSM) to control for demographic, comorbidity, medication, and diagnostic procedure confounders. Results: After matching, each cohort accounted for 389 patients (43% female, mean age at index 62 +/- 13 SD). There was a significant 5-year mortality risk difference (11.054%, p = 0.0020) between the chemotherapy only cohort (215 patients, 55.27%) vs. the targeted therapy cohort (172 patients, 44.216%) after adjusting for potential confounding factors. Additionally, the 5-year OS rate was 24.951% in the chemotherapy only cohort and 37.222% in the targeted therapy cohort. The difference in survival between the groups was statistically significant (log-rank p = 0.0001). Conclusions: In these cohorts of patients with metastatic pancreas NETs without surgical treatment, we found that targeted therapy was associated with a significant improvement in 5-year overall survival compared to standard chemotherapy alone. Our results suggest that targeted therapy should be considered as a first line treatment option for this severe patient population.

Characterization of anoikis-based molecular heterogeneity in pancreatic cancer and pancreatic neuroendocrine tumor and its association with tumor immune microenvironment and metabolic remodeling.

Accumulating evidence suggests that anoikis plays a crucial role in the onset and progression of pancreatic cancer (PC) and pancreatic neuroendocrine tumors (PNETs); nevertheless, the prognostic value and molecular characteristics of anoikis in cancers are yet to be determined. We gathered and collated the multi-omics data of several human malignancies using the TCGA pan-cancer cohorts. We thoroughly investigated the genomics and transcriptomics features of anoikis in pan-cancer. We then categorized a total of 930 patients with PC and 226 patients with PNETs into distinct clusters based on the anoikis scores computed through single-sample gene set enrichment analysis. We then delved deeper into the variations in drug sensitivity and immunological microenvironment between the various clusters. We constructed and validated a prognostic model founded on anoikis-related genes (ARGs). Finally, we conducted PCR experiments to explore and verify the expression levels of the model genes. Initially, we identified 40 differentially expressed anoikis-related genes (DE-ARGs) between pancreatic cancer (PC) and adjacent normal tissues based on the TCGA, GSE28735, and GSE62452 datasets. We systematically explored the pan-cancer landscape of DE-ARGs. Most DE-ARGs also displayed differential expression trends in various tumors, which were strongly linked to favorable or unfavorable prognoses of patients with cancer, especially PC. Cluster analysis successfully identified three anoikis-associated subtypes for PC patients and two anoikis-associated subtypes for PNETs patients. The C1 subtype of PC patients showed a higher anoikis score, poorer prognosis, elevated expression of oncogenes, and lower level of immune cell infiltration, whereas the C2 subtype of PC patients had the exact opposite characteristics. We developed and validated a novel and accurate prognostic model for PC patients based on the expression traits of 13 DE-ARGs. In both training and test cohorts, the low-risk subpopulations had significantly longer overall survival than the high-risk subpopulations. Dysregulation of the tumor immune microenvironment could be responsible for the differences in clinical outcomes between low- and high-risk groups. These findings provide fresh insights into the significance of anoikis in PC and PNETs. The identification of subtypes and construction of models have accelerated the progress of precision oncology.

Determination and characterization of molecular heterogeneity and precision medicine strategies of patients with pancreatic cancer and pancreatic neuroendocrine tumor based on oxidative stress and mitochondrial dysfunction-related genes.

Mitochondria are significant both for cellular energy production and reactive oxygen/nitrogen species formation. However, the significant functions of mitochondrial genes related to oxidative stress (MTGs-OS) in pancreatic cancer (PC) and pancreatic neuroendocrine tumor (PNET) are yet to be investigated integrally. Therefore, in pan-cancer, particularly PC and PNET, a thorough assessment of the MTGs-OS is required. Expression patterns, prognostic significance, mutation data, methylation rates, and pathway-regulation interactions were studied to comprehensively elucidate the involvement of MTGs-OS in pan-cancer. Next, we separated the 930 PC and 226 PNET patients into 3 clusters according to MTGs-OS expression and MTGs-OS scores. LASSO regression analysis was utilized to construct a novel prognostic model for PC. qRT-PCR(Quantitative real-time PCR) experiments were performed to verify the expression levels of model genes. The subtype associated with the poorest prognosis and lowerest MTGs-OS scores was Cluster 3, which could demonstrate the vital function of MTGs-OS for the pathophysiological processes of PC. The three clusters displayed distinct variations in the expression of conventional cancer-associated genes and the infiltration of immune cells. Similar molecular heterogeneity was observed in patients with PNET. PNET patients with S1 and S2 subtypes also showed distinct MTGs-OS scores. Given the important function of MTGs-OS in PC, a novel and robust MTGs-related prognostic signature (MTGs-RPS) was established and identified for predicting clinical outcomes for PC accurately. Patients with PC were separated into the training, internal validation, and external validation datasets at random; the expression profile of MTGs-OS was used to classify patients into high-risk (poor prognosis) or low-risk (good prognosis) categories. The variations in the tumor immune microenvironment may account for the better prognoses observed in high-risk individuals relative to low-risk ones. Overall, our study for the first time identified and validated eleven MTGs-OS remarkably linked to the progression of PC and PNET, and elaborated the biological function and prognostic value of MTGs-OS. Most importantly, we established a novel protocol for the prognostic evaluation and individualized treatment for patients with PC.

Comment on: Are Parenchyma-Sparing Resections Really Appropriate for Small (

Comment on: Are Parenchyma-Sparing Resections Really Appropriate for Small (<3 cm) Nonfunctional Pancreatic Neuroendocrine Tumors?

Have We Accounted for Asians? A Critical Analysis of Racial Cancer Disparity Amongst Asian Pancreatic Neuroendocrine Tumor Patients

Have We Accounted for Asians? A Critical Analysis of Racial Cancer Disparity Amongst Asian Pancreatic Neuroendocrine Tumor Patients

Have we accounted for asians? A disparity analysis amongst pancreatic neuroendocrine tumor patients

Have we accounted for asians? A disparity analysis amongst pancreatic neuroendocrine tumor patients

Bone Loss in Patients with Pancreatic Neuroendocrine Tumors.

Pancreatic diseases may affect nutritional status, which is one of the important associated factors of bone health. High prevalence of osteoporosis or osteopenia has been reported in patients with pancreatitis. The bone loss in pancreatic neuroendocrine tumors (PNETs) has not been reported. In this study, we showed the prevalence of bone loss and possible associated factors in PNET patients. A total of 91 PNET patients were included. Bone status was evaluated based on computed tomography (CT) attenuation (Housfield units, HU): &gt;160 HU, normal bone mineral density; osteopenia, 135 HU ≤ CT value ≤ 160 HU; osteoporosis, &lt;135 HU. Associated factors for bone loss were identified by logistic regression analyses. The average age was 55.76 years old in PNET patients. The prevalence of osteoporosis and low bone mass was 37.4% and 60.4%, respectively. Higher prevalence of osteoporosis was observed in patients older than 50 years (64.0%). Multivariate logistic analysis showed that age was an associated factor for low bone mass (odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.04-1.22) and osteoporosis (OR = 1.14, 95% CI: 1.03-1.20). Diabetes was also associated with bone loss in PNET patients after adjusting with confounders (OR = 13.56, 95% CI: 1.02-132.4). Our data show that bone loss is common in patients with PNETs. Age and diabetes are associated with bone loss in PNET patients.

RF19 | PSUN349 Histone Eraser and Reader Targeting Epigenetic Inhibitors Are Effective in Pancreatic Neuroendocrine Tumours

Abstract Background The 5-year survival for metastatic pancreatic neuroendocrine tumours (PNETs) is &amp;lt;50%, and current therapies are not effective. Thus, there is an unmet clinical need for new therapies for patients with PNETs. PNETs frequently have mutations in chromatin remodelling genes, including in Multiple Endocrine Neoplasia type 1 (MEN1), encoding menin, which is mutated in up to 40% of sporadic PNETs, and is part of multiple histone modifying complexes including the SET1/MLL methyltransferases. Aim To examine multiple classes of epigenetic inhibitors and determine which may be effective in treating PNETs. Methods BON1 and QGP1 PNET cell lines, the bronchial NET cell line H727, and the non-NET cell line HEK293T were utilised to assess &amp;gt;150 small molecule inhibitors targeting: histone deacetylases (HDACs); histone acetyltransferases; histone demethylases (KDMs); histone methyltransferases; bromodomain-containing proteins; menin; and DNA methyltransferases (DNMTs). MTOR inhibitors, already used clinically for PNET patients, as well as drugs targeting other tumorigenic pathways e.g. the proto-oncogene SRC, were used as comparators. Efficacy of compounds was evaluated using the Cell Titer Blue cell viability assay, and the Caspase Glo 3/7 apoptosis assay. Results At a dose of 1mM for 7 days, 26 compounds (including HDAC, KDM, bromodomain and mTOR inhibitors) significantly decreased the viability of both the BON1 and QGP1 cell lines by &amp;gt;50%, compared to DMSO control treated cells. Upon increasing the dose to 10mM for 7 days, 34 additional compounds, making a total of 60 compounds (including inhibitors of menin and DNMTs), decreased viability of both BON1 and QGP1 cells by &amp;gt;50%; and 56 and 46 compounds also reduced viability of H727 and HEK293 cells by &amp;gt;50%, respectively. Apoptosis assays utilising the 60 above compounds, at 10mM for 7 days, revealed that 25, 18, 14, and 9 of them could increase apoptosis by &amp;gt;4-fold of BON1, QGP1, H727 and HEK293 cells, respectively. Ten compounds (2 KDM, 5 HDAC and 3 bromodomain inhibitors) that were effective in reducing viability by &amp;gt;50% as well as increasing apoptosis by &amp;gt;4-fold of NET cells, were selected for further dosing (0.1-10mM) and time course investigations (3-7 days). All 10 compounds significantly reduced viability of BON1 and QGP1 cells (p&amp;lt;0.01) after 3 days of treatment. The KDM and HDAC inhibitors showed the greatest efficacy, by significantly (p&amp;lt;0.05) reducing BON1 and QGP1 cell viability at as low as 25nM treatment for 3 days. The efficacy of bromodomain inhibitors was not attained until 1000nM treatment, however these inhibitors had very little effect on the non-NET HEK293 cells. Conclusions Compounds targeting HDACs, KDMs or bromodomain-containing proteins are effective in reducing viability by &amp;gt;50% and increasing apoptosis by &amp;gt;4-fold of NET cells, and thus provide novel agents for studying anti-cancer mechanisms and potential therapeutic options for PNETs. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 1:12 p.m. - 1:17 p.m.

Diagnosing pancreatic neuroendocrine tumors in patients with multiple endocrine neoplasia type 1 in daily practice.

BackgroundIn multiple endocrine neoplasia type 1 (MEN1), pancreatic neuroendocrine tumors (PanNETs) have a high prevalence and represent the main cause of death. This study aimed to assess the diagnostic accuracy of the currently used conventional pancreatic imaging techniques and the added value of fine needle aspirations (FNAs).MethodsPatients who had at least one imaging study were included from the population-based MEN1 database of the DutchMEN Study Group from 1990 to 2017. Magnetic resonance imaging (MRI), computed tomography (CT), endoscopic ultrasonography (EUS), FNA, and surgical resection specimens were obtained. The first MRI, CT, or EUS was considered as the index test. For a comparison of the diagnostic accuracy of MRI versus CT, patients with their index test taken between 2010 and 2017 were included. The reference standard consisted of surgical histopathology or radiological follow-up.ResultsA total of 413 patients (92.8% of the database) underwent 3,477 imaging studies. The number of imaging studies per patient increased, and a preference for MRI was observed in the last decade. Overall diagnostic accuracy was good with a positive (PPV) and negative predictive value (NPV) of 88.9% (95% confidence interval, 76.0–95.6) and 92.8% (89.4–95.1), respectively, for PanNET in the pancreatic head and 92.0% (85.3–96.0) and 85.3% (80.5–89.1), respectively, in the body/tail. For MRI, PPV and NPV for pancreatic head tumors were 100% (76.1–100) and 87.1% (76.3–93.6) and for CT, 60.0% (22.9–88.4) and 70.4% (51.3–84.3), respectively. For body/tail tumors, PPV and NPV were 91.3% (72.0–98.8) and 87.0% (75.3–93.9), respectively, for MRI and 100% (74.9–100) and 77.8% (54.3–91.5), respectively, for CT. Pathology confirmed a PanNET in 106 out of 110 (96.4%) resection specimens. FNA was performed on 34 lesions in 33 patients and was considered PanNET in 24 [all confirmed PanNET by histology (10) or follow-up (14)], normal/cyst/unrepresentative in 6 (all confirmed PanNET by follow-up), and adenocarcinoma in 4 (2 confirmed and 2 PanNET). Three patients, all older than 60 years, had a final diagnosis of pancreatic adenocarcinoma.ConclusionAs the accuracy for diagnosing MEN1-related PanNET of MRI was higher than that of CT, MRI should be the preferred (non-invasive) imaging modality for PanNET screening/surveillance. The high diagnostic accuracy of pancreatic imaging and the sporadic occurrence of pancreatic adenocarcinoma question the need for routine (EUS-guided) FNA.

Evolutionary Trajectories of Primary and Metastatic Pancreatic Neuroendocrine Tumors Based on Genomic Variations.

Liver metastases are common in pancreatic neuroendocrine tumors (PanNETs) patients and they are considered a poor prognostic marker. This study aims to analyze the spatiotemporal patterns of genomic variations between primary and metastatic tumors, and to identify the key related biomolecular pathways. We performed next-generation sequencing on paired tissue specimens of primary PanNETs (n = 11) and liver metastases (n = 12). Low genomic heterogeneity between primary PanNETs and liver metastases was observed. Genomic analysis provided evidence that polyclonal seeding is a prevalent event during metastatic progression, and may be associated with the progression-free survival. Besides this, copy number variations of BRCA1/BRCA2 seem to be associated with better prognosis. Pathways analysis showed that pathways in cancer, DNA repair, and cell cycle regulation-related pathways were significantly enriched in primary PanNETs and liver metastases. The study has shown a high concordance of gene mutations between the primary tumor and its metastases and the shared gene mutations may occur during oncogenesis and predates liver metastasis, suggesting an earlier onset of metastasis in patients with PanNETs, providing novel insight into genetic changes in metastatic tumors of PanNETs.

Predictors of post-operative pancreatic fistula formation in pancreatic neuroendocrine tumors: A national surgical quality improvement program analysis

BackgroundPost-operative pancreatic fistula (POPF) is a serious complication following pancreas surgery. We aimed to establish factors associated with POPF specifically in patients with pancreatic neuroendocrine tumors (PNET). MethodsThe 2014–2018 American College of Surgeons National Surgical Quality Improvement Program database was querried for patients undergoing resection for PNET. The impact of patient, tumor, and operative factors on POPF formation was evaluated. Results3532 patient underwent resections for PNET. The POPF rate was significantly higher in patients with PNET (24.8%) versus non-PNET (16.4%) (p < 0.0001). Male sex (OR 1.45, 95% CI 1.11–1.89), enucleation (OR 3.14, 95% CI 1.10–8.98), pancreaticoduodenectomy (OR 1.51, 95% CI 1.13–2.03), small duct size <3 mm (OR 3.24, 95% CI 1.62–6.48), and soft gland texture (OR 1.81, 95% CI 1.18–2.77) were independently associated with POPF in PNET patients on multivariable analysis. ConclusionsPOPF is more common in patients undergoing resection for PNET and is dictated primarily by surgical approach and gland characteristics.