Gastroenteropancreatic Neuroendocrine Tumors Research Articles

Peptide Receptor Radionuclide Therapy Improves Survival in Patients Who Progress After Resection of Gastroenteropancreatic Neuroendocrine Tumors.

Peptide receptor radionuclide therapy (PRRT) is an effective treatment for advanced gastroenteropancreatic (GEP) neuroendocrine tumors (NETs). We investigated a 2-decade experience with PRRT to determine whether PRRT confers a survival advantage to patients who progress after surgery versus other therapies. We identified patients from our clinic who had resection/cytoreduction of GEP-NETs, then disease progression by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The Kaplan-Meier method assessed progression-free survival (PFS) and overall survival (OS), calculated from progression after surgery (no-PRRT group) or the start of PRRT. Cox regression with time-dependent covariates controlled for immortal time bias and other confounders. Overall, 237 patients progressed after surgery; 95 received PRRT and 142 did not. No differences existed in sex, T or Nstage, tumor grade/differentiation, primary site, or time to progression; 94% of PRRT patients had metastases at diagnosis versus 77% in the no-PRRT group. Median PFS was longer in the PRRT group versus the no-PRRT group (32.4 vs. 11.0 months, p<0.001), as was median OS (49.8 vs. 38.4 months; p=0.009). In subgroup analysis, the PRRT group had improved PFS in small bowel NETs and pancreatic NETs. Time-dependent covariate analysis revealed a lower risk of death associated with PRRT (hazard ratio 0.61, p=0.028) after adjusting for sex, age, Mstage, tumor grade, and primary site. Surgical resection and cytoreduction is an effective treatment for patients with GEP-NETs, but most patients with metastatic disease develop recurrent disease. Surgery followed by PRRT after progression conferred superior PFS and OS over no PRRT/other therapies, and is an effective strategy for managing patients with GEP-NETs.

A Novel Liver Metastasis Score for Patients Undergoing Surgical Resection of Gastroenteropancreatic Neuroendocrine Tumors: A Multi-institutional Study.

Liver metastasis impacts survival in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs); however, current guidelines lack consensus on post-resection surveillance and adjuvant therapy. A comprehensive risk stratification tool is needed to guide personalized management. We aimed to develop and validate a predictive model for liver metastasis risk after surgical resection of GEP-NETs that incorporates pathological factors and adjuvant therapy. Patients with GEP-NETs who underwent surgical resection with curative intent at three major Chinese hospitals (2010-2022) were identified. Univariable and multivariable Cox regression analysis identified independent risk factors of liver metastasis. The liver metastasis score (LMS) was developed using weighted risk factors and validated by tenfold cross-validation. Among the 724 patients included in the analytic cohort, liver metastasis occurred in 66 patients (9.1%) at a median of 36 months; patients with liver metastasis had a worse 5-year overall survival (no liver metastasis 63.6% vs. liver metastasis 95.8%; p<0.001). Independent predictors were Ki-67 index (hazard ratio [HR] 10.36 for Ki-67 3-20%, HR 18.30 for Ki-67 >20%, vs. <3%), vascular invasion (HR 5.03), lymph node metastases (HR 2.24), and lack of adjuvant therapy (HR 3.03). The LMS demonstrated excellent discrimination (C-index 0.888) and stratified patients into low, intermediate, and high-risk relative to 5-year risk of liver metastasis: 2.9%, 20.8%, and 49.7%, respectively (p<0.001). The novel LMS effectively predicted the risk of liver metastasis after surgical resection of GEP-NETs. This validated model can help guide personalized surveillance and adjuvant treatment strategies, potentially improving outcomes for high-risk patients.

Circulating Chromogranin A as Surveillance Biomarker in Patients with Carcinoids - The CASPAR Study.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are relatively indolent but can be more aggressive. The current recommendations for the use of serum CgA for GEP-NET patients are equivocal. This study was designed to validate an automated CgA immunofluorescence assay for monitoring disease progression in GEP-NET patients. A prospective, multi-center blinded observational study was designed to validate an automated chromogranin A (CgA) immunofluorescence assay for monitoring disease progression in GEP-NET patients. Tumor progression was evaluated with Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 by CT/MRI. An increase ≥ 50% above the prior CgA concentration to a value > 100 ng/mL in the following CgA concentration was considered positive. 153 GEP-NET patients were enrolled. Using the pre-specified cut-off of CgA change for tumor progression, specificity was 93·4% (95%-CI: 90·4%-95·5%, p < 0·001), sensitivity 34·4% (25·6%-44·3%), positive predictive value 57·9% (45·0-69·8), negative predictive value (NPV) 84·3% (80·5-87·6), and area under the curve 0·73 (0·67-0·79). Changes in serial measurements of serum CgA had a favorable specificity and NPV, making this test a useful adjunct to routine radiographic monitoring.

Comparative targeted genome profiling between solid and liquid biopsies in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs): a proof-of-concept pilot study.

Clinical presentation and genetic profile of gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) are highly variable, hampering their management. Sequencing of circulating tumor DNA (ctDNA) from liquid biopsy (LB) has been proposed as a less invasive alternative to solid biopsy (SB). Our aim is to compare the mutational profile (MP) provided by LB with that deriving from SB in GEP-NETs. SB and LB derived simultaneously from 6 GEP-NETs patients. A comparative targeted Next Generation Sequencing (NGS) analysis was performed on DNA from SB and LB to evaluate the mutational status of 11 genes (MEN1, DAXX, ATRX, MUTYH, SETD2, DEPDC5, TSC2, ARID1A, CHECK2, MTOR, PTEN). Patients (M:F =2:1; median age 64 yrs) included 3 with pancreatic and 3 with ileal NETs. NGS detected a median number of 55 variants/sample in SB and 66.5 variants/sample in LB specimens (mutational burden: 0.2-1.9 and 0.3-1.8 mut/Mb, respectively). Missense and nonsense mutations were prevalent in both, mainly represented by C&gt;T transitions. ARID1A, MTOR, and ATRX were consistently mutated in SB and ARID1A, TSC2, MEN1, PTEN, SETD2, and MUTYH were consistently mutated in LB. DAXX mutations were absent in LB. 17 recurrent mutations were shared between SB and LB; in particular, MTOR single nucleotide variants (SNVs) c.G4731A and c.C2997T were shared by 5 out of 6 patients. Hierarchical clustering supported genetic similarity between SB and LB. This pilot study explores the applicability of LB in GEP-NETs MP evaluation. Further studies with larger cohorts are needed to validate LB and to define the clinical impact.

Chinese multidisciplinary expert consensus on the rational use of surufatinib in clinical practice（2024 edition）

Neuroendocrine neoplasms are a group of heterogeneous tumors originating from the neuroendocrine system, which can occur in any part of the body. Pulmonary and gastroenteropancreatic neuroendocrine tumors are the most common. In recent years, the global incidence of neuroendocrine tumors has increased more significantly than other types of tumors, especially in the past 40 years. The drug treatment of neuroendocrine tumors includes somatostatin analogues, anti-angiogenesis targeting drugs, nuclide therapy and chemotherapy. Surufatinib is an oral tyrosine kinase receptor inhibitors that targets for vascular endothelial growth factor receptor (VEGFR1-3), fibroblast growth factor receptor 1 (FGFR1), and colony-stimulating factor-1 receptor (CSF-1R), has received approval in 2020 and 2021 for the treatment of locally advanced or metastatic, progressive nonfunctional, well-differentiated (G1, G2) neuroendocrine tumors (NETs) of both pancreatic and extrapancreatic origin that are unresectable. Ongoing exploratory studies are investigating its potential application in other tumor types. Common adverse reactions observed during surufatinib treatment include hypertension, proteinuria, bleeding events, and hepatic lab test abnormal and diarrhea. Chinese multidisciplinary expert consensus on the rational use of surufatinib in clinical practice (2024 edition) aims to provide standardized guidance for its rational use and enhance patient compliance to maximize therapeutic benefits.

Treatment sequencing in gastroenteropancreatic neuroendocrine tumors

SummaryThe oncological treatment of neuroendocrine tumors (NET) has improved significantly in the last few years. Several informative clinical studies on NET have been conducted recently and updated NET guidelines have been published by the European Neuroendocrine Tumor Society (ENETS) in 2023 and 2024. With the growing number of positive phase III trials in NET, the main difficulty today is selecting the most appropriate treatment for a patient at the right time. The purpose of this short review is to delineate the main concepts and important changes in the therapy sequences for gastroenteropancreatic NET (gepNET) outlined in current European guidelines. In clinical practice, more individualized treatment decisions are often required that go beyond these general recommendations.

Immunohistochemical expression of ephrin receptors in neuroendocrine neoplasms: a case-series of gastroenteropancreatic neuroendocrine neoplasms and a systematic review of the literature.

Erythropoietin-producing hepatocellular (EPH) receptors are the largest known family of tyrosine kinases receptors (TKR) in humans, implicated in cell proliferation, adhesion, migration, tumor angiogenesis, invasion and metastasis. The aim of the present study is to assess the expression of EPHs in neuroendocrine neoplasms (NENs). Immunohistochemical staining of specimens of 30 patients with gastroenteropancreatic and lung NENs was performed for EPH-A1, EPH-A2, EPH-A4, EPH-A5 protein expression, in addition to ki-67 multiplication index and programmed death-ligand 1. Additionally, we performed a systematic review of the available literature in three different databases reporting on the expression of EPH in all neuroendocrine neoplasms. Positive expression was seen in 16/19 (84%) specimens for EPH-A1, 15/23 (65%) for EPH-A2, 21/24 (88%) for EPH-A4, 24/26 (92%) for EPH-A5. EPH-A1 was expressed in 9/9 pancreatic, 3/4 small intestine, but not in one lung NEN, EPH-A2 in 5/10 pancreatic, 3/4 small intestine and lung, and in one of each of gastric, appendix, colorectal, and cervical NENs, respectively. EPH-A4 showed positive expression in 9/11 pancreatic, 4/4 small intestine, 3/3 lung specimens and EPH-A5 in 10/11, 4/4 and 4/4, respectively. Data retrieved from the systematic review of the literature in combination with the data from the present study are suggestive of a frequent EPH expression in pituitary, thyroid, lung and gastroenteropancreatic NENs, yet, with varying expressions of the single receptor subtypes. EPHs may have a role in NEN tumorigenesis, prognosis as well as a role in the evolving molecular-targeted therapies.

Clinicopathological correlations in 38 cases of gastroenteropancreatic high-grade neuroendocrine neoplasms.

Diagnosis and treatment of gastroenteropancreatic high-grade neuroendocrine neoplasms (GEP-HG-NENs), particularly G3 well-differentiated neuroendocrine tumours (NETs) and poorly differentiated neuroendocrine carcinomas (NECs) relies on histopathological morphology, immunohistochemistry, and molecular biological markers, which are lacking especially in cases with ambiguous histomorphology. In this study to contribute to the development of more targeted treatment strategies, we examined various immunohistochemical and molecular biological markers and their association with clinicopathological features in GEP-HG-NENs. We included 38 patients with GEP-HG-NENs in this study, with their retrospective follow-up data. The expression of tumour protein p53 (TP53), RB transcriptional corepressor 1 (RB1), somatostatin receptor 2 (SSTR2), clusterin (CLU), and marker of proliferation Ki-67 (MKI67) was immunohistochemically analysed. KRAS proto-oncogene, GTPase (KRAS) and B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E expression was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). The relationships between immunohistochemical and molecular biological markers and clinicopathological characteristics were examined using a Cox risk regression model, receiver operating characteristic (ROC) curve, and Kaplan-Meier survival analyses. SSTR2, RB, TP53, and CLU expression differed between NET G3 and NECs, with variations among the NET G3 and small- and large-cell NEC (SCNEC and LCNEC, respectively) groups (p < 0.05). The median MKI67 proliferative index was approximately 40% and 70% in G3 NETs and NECs, respectively. The NET G3 group exhibited a median survival of 25 months, indicating a relatively better prognosis than that of the NECs group (median survival, 11 months). Both Kaplan-Meier survival analysis and the Cox risk regression model indicated a statistical correlation among treatment methods, CLU expression, and prognosis (p < 0.05). The BRAF V600E mutation rate was 32.4% in G3 NETs and SCNEC, demonstrating a significant difference between both types (p = 0.0086). Furthermore, ROC curve analysis highlighted the diagnostic significance of the positive expression of the immunohistochemical markers CLU, SSTR2, and RB in identifying NET G3. To guide more suitable treatment strategies, it is essential to develop and apply valuable and more targeted immunohistochemical and molecular pathological markers for a comprehensive analysis.

The current status of somatostatin analogs in the treatment of neuroendocrine tumors and future perspectives.

Somatostatin analogs (SSAs) were developed as antisecretory agents to palliate hormonal symptoms in patients with functioning neuroendocrine tumors (NETs). Their antiproliferative activity has been established in the phase 3 PROMID and CLARINET trials. SSAs currently represent the standard first-line therapy for the majority of well-differentiated G1/G2 gastroenteropancreatic NETs as well as for pulmonary NETs. An update on the clinical applications of established SSAs for the treatment of NETs is provided. Perspectives on emerging nonpeptide SSAs such as paltusotine and innovative formulations of octreotide (CAM2029) are included. SSAs represent the cornerstone of treatment for both functioning and nonfunctioning NETs. While standard-dose SSAs have a defined place in the therapeutic algorithm of well-differentiated NETs, uncertainties remain on how to best integrate above-label doses of SSAs in the treatment sequence, particularly when tumor control is the goal. Octreotide and lanreotide appear to be clinically interchangeable, and no signs of superiority of one agent over the other has been observed so far. Whether SSAs may be exploited in the maintenance setting following more aggressive treatments, whether continuing SSAs beyond-progression after first-line therapy could be an effective treatment strategy, and whether new-generation SSAs such as pasireotide could overcome resistance to established SSAs are key areas of investigation.

Gastroenteropancreatic Neuroendocrine Tumor with Peritoneal Metastasis: A Review of Current Management.

Peritoneal metastasis in gastroenteropancreatic neuroendocrine tumors poses a significant clinical challenge, with limited data guiding management strategies. We review the existing literature on surgical and systemic treatment modalities for peritoneal metastasis from gastroenteropancreatic neuroendocrine tumors. Surgical interventions, including cytoreductive surgery, have shown promise in improving symptom control and overall survival-particularly in cases in which 70% cytoreduction can be achieved. Hyperthermic intraperitoneal chemotherapy remains controversial due to a paucity of high-level evidence and a lack of consensus for routine use. The use of systemic therapy in the setting of peritoneal metastasis from gastroenteropancreatic neuroendocrine tumors is extrapolated from high-quality evidence for its use in the setting of the solid organ metastasis of this disease. The use of somatostatin analogs for symptom control and some antiproliferative effects is supported by large clinical trials. Additional strong evidence exists for the use of interferon-alpha, everolimus, and sunitinib, particularly in pancreatic neuroendocrine tumors. Cytotoxic chemotherapy and peptide receptor radionuclide therapy may be used in select cases, though as an emerging treatment modality, the optimal sequence of peptide receptor radionuclide therapy within the existing algorithms is unknown. Significant gaps in understanding and standardized management exist, particularly for those patients presenting with peritoneal metastasis, and targeted research to optimize outcomes in this population is needed.

Radioligand therapy in the therapeutic strategy for patients with gastro-entero-pancreatic neuroendocrine tumors: a consensus statement from the Italian Association for Neuroendocrine Tumors (Itanet), Italian Association of Nuclear Medicine (AIMN), Italian Society of Endocrinology (SIE), Italian Association of Medical Oncology (AIOM).

This paper outlines the consensus of the Italian Association for Neuroendocrine Tumors(Itanet), the Italian Association of Nuclear Medicine (AIMN), the Italian Society of Endocrinology (SIE), and the Italian Association of Medical Oncology (AIOM) on treating neuroendocrine neoplasms (NENs)with radioligand therapy (RLT). A list of 10 questions regarding using RLT ingastroenteropancreatic neuroendocrine tumors (GEP-NETs) was addressed after a careful review of theavailable literature. compiling information from the MEDLINE database, augmented with expert opinionsand recommendations, aligns with the latest scientific research and the author's extensive knowledge.The recommendations are evaluated using the GRADE system, showcasing the level of evidence andthe strength of the recommendations. Specifically, this paper focuses on thesubcategories of well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs) thatexpress somatostatin receptors and are considered suitable for RLT, according to internationalguidelines.

To Perform, or Not to Perform Interim PET: Questioning the Impact of Midtherapy Evaluation During PRRT in GEP-NET Patients.

This study aimed to analyze the impact of interim evaluation on the continuation of 177Lu-based peptide receptor radionuclide therapy (PRRT) in gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and to survey its usage across German university hospitals. In 119 GEP-NET patients who underwent PRRT, we retrospectively assessed the results and therapeutic impact of restaging performed after 2 cycles using MRI/CT/somatostatin receptor imaging. Therapeutic decisions based on interim PET results were made in multidisciplinary tumor board meetings. Additionally, an online survey was conducted among 37 German university hospitals regarding their interim evaluation practices, focusing on the change in management. Of 119 patients, 83 completed 4 PRRT cycles; 36 stopped after 2: 27 showed PD, 3 had PR leading to surgery, 5 experienced toxicity, and 1 died. Those completing 4 cycles showed a median PFS of 38.0 months (95% confidence interval, 32.2-43.8). Seventeen of 37 surveyed hospitals routinely used interim evaluation. In a survey among 37 German university hospitals, 62% reported offering PRRT for GEP-NET patients, with 74% of these performing a routinely interim evaluation after 2 cycles of PRRT, primarily using PET/CT imaging techniques. Interim PET after 2 PRRT cycles helps to identify early progression in GEP-NET patients. Standardizing interim evaluation practices could enhance the comparability of clinical outcomes and optimize patient management.

Updated Morphological and Immunohistochemical Profile of Neuroendocrine Tumors Developing in Ovarian Teratomas: A Large Series of a Rare and Heterogeneous Disease.

Ovarian neuroendocrine tumors are rare and often arise within mature teratoma of the ovary. No recent re-evaluation of the immunophenotype of these tumors with the new markers available in the field of neuroendocrine neoplasms has been performed. The objectives were to describe the morphologic and immunohistochemical characteristics of neuroendocrine tumors (NETs) arising from ovarian teratomas, to correlate them with the type of teratomatous epithelial components present and to evaluate their proliferative activity using the WHO recommendations for gastroenteropancreatic NETs. This is a bi-centric retrospective study using a panel of markers (chromogranin-A, chromogranin-B, synaptophysin, CDX2, SATB2, TTF1, PAX8, islet-1, serotonin and calcitonin) and Ki-67 proliferation index. The 34 NETs studied were unilateral and presented when it's done four distinct immunophenotypic profiles: 8 NETs expressed serotonin and CDX2 (small intestinal profile), 12 SATB2 (colorectal profile), one TTF1 (thoracic profile) and 4 "null" tumors expressed none of the above markers. The Ki-67 index ranged from 0 to 19.82% (median: 1.51%). 28 tumors were grade 1 (85%), 5 tumors were grade 2 (15%). They were associated with squamous (n = 26), respiratory (n = 23), thyroid (n = 10) and gastrointestinal (n = 5) components. The main type of NET is intestinal phenotype, but rarely accompanied with digestive tissue. This suggests that the cell of origin may be a neuroendocrine precursor present in the teratoma, and confirms that primary NETs arising in ovarian teratomas should not be classified or named according to the type of the surrounding teratoma tissue.

9220 Machine Learning Methods In Differential Diagnosis Of Genetically Confirmed Multiple Endocrine Neoplasia Type 1 And Its Phenocopies

Abstract Disclosure: D. Trukhina: None. K. Voronov: None. E. Mamedova: None. A. Solodovnikov: None. Z. Belaya: None. Background. MEN-1 is a rare autosomal dominant disorder caused by mutations in the MEN1 gene encoding the menin protein (gMEN1). This syndrome is characterised by the occurrence of parathyroid tumours, gastroenteropancreatic neuroendocrine tumours, pituitary adenomas, and other endocrine and non-endocrine neoplasms. If a patient with the MEN-1 phenotype does not have any mutation in the MEN1 gene, the condition is considered a phenocopy of the syndrome (phMEN1). The goal of this study was to develop a machine learning algorithm to estimate the probability of gMEN-1 vs phMEN-1 based on easily available clinical features at first line differential diagnostics. Materials and methods. A single-center, one-stage, cohort, retrospective study was carried out. Patients were randomly stratified into 2 cohorts: training (80%) and test (20%). Eight machine learning algorithms were used to develop predictive models: Logistic Regression, k-nearest neighbors (kNN), Naive Bayes, binary decision tree (CART), C5.0 decision tree algorithms, Bagged CART, Random Forest, Gradient Boosting (Stochastic Gradient Boosting, GBM). Results. The study included 95 patients with genetically confirmed gMEN-1 syndrome and 60 patients with its phenocopies. As a result of preliminary data processing and selection for the most informative features, the final variables for the classification and prediction of gMEN-1 syndrome were identified: the number of affected parathyroid glands, age at diagnostics, pancreatic tumour existence, heredity, type of pituitary adenoma secretion, and gender. The kNN algorithm demonstrated the best diagnostic performance in a training sample (ROC-AUC - 0.96, sensitivity - 84%, specificity - 100%), which was confirmed in a test sample (ROC-AUC - 1.0; sensitivity - 94.4%, specificity - 100%) to determine genetically confirmed MEN-1 syndrome. Conclusion. The k-nearest neighbours (kNN) algorithm may be used as a first-line differential diagnostics method to select patients to be refered for genetic testing for gMEN-1. Presentation: 6/1/2024

7845 Machine Learning Methods In Differential Diagnosis Of Genetically Confirmed Multiple Endocrine Neoplasia Type 1 And Its Phenocopies

Abstract Disclosure: D. Trukhina: None. K. Voronov: None. E. Mamedova: None. A. Solodovnikov: None. Z. Belaya: None. Background. MEN-1 is a rare autosomal dominant disorder caused by mutations in the MEN1 gene encoding the menin protein (gMEN1). This syndrome is characterised by the occurrence of parathyroid tumours, gastroenteropancreatic neuroendocrine tumours, pituitary adenomas, and other endocrine and non-endocrine neoplasms. If a patient with the MEN-1 phenotype does not have any mutation in the MEN1 gene, the condition is considered a phenocopy of the syndrome (phMEN1).The goal of this study was to develop a machine learning algorithm to estimate the probability of gMEN-1 vs phMEN-1 based on easily available clinical features at first line differential diagnostics. Materials and methods. A single-center, one-stage, cohort, retrospective study was carried out. Patients were randomly stratified into 2 cohorts: training (80%) and test (20%). Eight machine learning algorithms were used to develop predictive models: Logistic Regression, k-nearest neighbors (kNN), Naive Bayes, binary decision tree (CART), C5.0 decision tree algorithms, Bagged CART, Random Forest, Gradient Boosting (Stochastic Gradient Boosting, GBM). Results. The study included 95 patients with genetically confirmed gMEN-1 syndrome and 60 patients with its phenocopies. As a result of preliminary data processing and selection for the most informative features, the final variables for the classification and prediction of gMEN-1 syndrome were identified: the number of affected parathyroid glands, age at diagnostics, pancreatic tumour existence, heredity, type of pituitary adenoma secretion, and gender. The kNN algorithm demonstrated the best diagnostic performance in a training sample (ROC-AUC - 0.96, sensitivity - 84%, specificity - 100%), which was confirmed in a test sample (ROC-AUC - 1.0; sensitivity - 94.4%, specificity - 100%) to determine genetically confirmed MEN-1 syndrome. Conclusion. The k-nearest neighbours (kNN) algorithm may be used as a first-line differential diagnostics method to select patients to be refered for genetic testing for gMEN-1. Presentation: 6/1/2024

Cardiac Neuroendocrine Tumor Metastases on 68Ga-DOTATATE PET/CT: Identification and Prognostic Significance.

Neuroendocrine tumor (NET) metastases to the heart are found in 1%-4% of NET patients and have been reported primarily in the form of individual cases. We investigated the prevalence, clinical characteristics, imaging features, and outcomes of NET patients with cardiac metastases on 68Ga-DOTATATE PET/CT. Methods: 68Ga-DOTATATE PET/CT of 490 consecutive patients from a single institution were retrospectively reviewed for sites of metastases. The cumulative cardiovascular event rate and overall survival of patients with cardiac NET metastases (CNMs) were compared with those of a control group of metastatic NET patients without cardiac metastases. In patients with CNMs, the cardiac SUVmax with and without normalization to the myocardial background uptake was compared with a separate cohort of 11 patients with active cardiac sarcoidosis who underwent 68Ga-DOTATATE PET/CT for research purposes. Results: In total, 270 patients with metastatic NETs were identified, 9 (3.3%) of whom had CNMs. All 9 patients had grade 1-2 gastroenteropancreatic NETs, most commonly from the small intestine (7 patients). The control group consisted of 140 patients with metastatic grade 1-2 gastroenteropancreatic NETs. On Kaplan-Meier analysis, there was no significant difference in the risk of cardiovascular adverse events (P = 0.91 on log-rank test) or mortality (P = 0.83) between the metastatic NET patients with and without cardiac metastases. The degree of cardiac DOTATATE uptake was significantly higher in CNMs than in patients with cardiac sarcoidosis without overlap, in terms of both cardiac SUVmax (P = 0.027) and SUVmax-to-myocardial background ratio (P = 0.021). Conclusion: Routine 68Ga-DOTATATE PET/CT can be used to identify CNMs in 3% of patients with metastatic NETs. CNMs do not confer added cardiovascular or mortality risk. A distinguishing feature of CNMs is their high degree of DOTATATE uptake compared with focal myocardial inflammation.

Surgery enhances the effectiveness of peptide receptor radionuclide therapy in metastatic gastroenteropancreatic neuroendocrine tumors

BackgroundWith the advent of peptide receptor radionuclide therapy, the timing and sequence of surgery in the treatment of metastatic gastroenteropancreatic neuroendocrine tumors merits further study. We hypothesized that surgery before peptide receptor radionuclide therapy might enhance its effectiveness in patients with metastatic gastroenteropancreatic neuroendocrine tumors. MethodsEighty-nine patients with metastatic well-differentiated gastroenteropancreatic neuroendocrine tumors treated with 177Lutetium-dotatate peptide receptor radionuclide therapy between 2018 and 2023 were included. Fifty-six patients underwent surgery (primary tumor resection and/or liver debulking) before peptide receptor radionuclide therapy and 33 patients did not. Primary outcome was progression-free survival according to Response Evaluation Criteria in Solid Tumors. Pretreatment dotatate positron emission tomography/computed tomography was used to calculate tumor volumes. ResultsThe surgery and no-surgery groups were well-matched. Median progression-free survival after peptide receptor radionuclide therapy was 15.6 months (interquartile range, 9.1–22.7 months) in the no-surgery group compared with 26.1 months (interquartile range, 12.7–38.1 months) in the surgery group (P = .04). On subgroup analysis, median progression-free survival was 18.1 months (interquartile range, 11.9–38.4 months) in patients who underwent primary tumor resection only compared with 26.2 months (interquartile range, 14.0–38.1 months) in patients who underwent liver debulking (P = .04). Tumor volume was lowest in patients who underwent liver debulking (median 146.07 mL3) compared with no surgery (median 626.42 mL3) (P = .001). On univariable analysis, a tumor volume <138.8 mL3 was associated with longer progression-free survival (hazard ratio, 2.03; 95% confidence interval, 0.95–4.34, P = .05), with a median progression-free survival of 38.1 months (interquartile range, 16.9–41.3 months) compared with 17.8 months (interquartile range, 10.8–28.7 months). ConclusionSurgery may enhance the effectiveness of 177Lutetium-dotatate in the treatment of metastatic well-differentiated gastroenteropancreatic neuroendocrine tumors. This positive effect may be the result of a lower tumor volume in patients after surgery. Our findings fortify the concept of using surgical debulking to improve systemic therapies such as peptide receptor radionuclide therapy.

Time toxicity of lutetium-177 treatment in gastroenteropancreatic neuroendocrine tumours

Objectives: We aim to investigate the time toxicity of patients with gastroenteropancreatic-neuroendocrine tumours treated with lutetium-177 Dotatate in a single institution. Design: This is a retrospective cohort study. Methods: All patients with gastroenteropancreatic-neuroendocrine tumours treated with lutetium-177 Dotatate in the Alexander Fleming Institute were included. Our primary endpoint was to evaluate time toxicity, which accounted for every day that the patient had contact with any department of any healthcare institution. Results: Our cohort included 21 patients with metastatic disease, female sex 86%, and had a median age of 55 (IQR 44-63). The primary tumour site was small intestine in 47.6% of the cases. The median number of previous systemic treatments for advanced disease was 2 (IQR 2 - 3). The overall response rate was 19%, and 66.6% had disease clinical benefit. The median calculated 'time toxicity' was 11 days (IQR 8-18), representing 5.7% of the total treatment duration. The main contributors to time-toxicity included infusion days, blood draws, radiological scans, and hospitalizations (median 4 days for each). Conclusion: Lutetium-177 Dotatate treatment for gastroenteropancreatic-neuroendocrine tumours was associated with a low time toxicity, excellent tolerability, good response and a prolonged PFS, of which the median was not reached in the short follow-up we present. Newer treatments with different mechanisms of action provide longer survivals and widen the landscape of choices. Understanding new clinical endpoints is important for the transition into a more modern clinical practice, strengthening personalised and patient-oriented strategies.

The Role of Liquid Biopsy in Gastroenteropancreatic Neuroendocrine Neoplasms.

Neuroendocrine neoplasms incidence has been increasing, arising the need for precise and early diagnostic tools. Liquid biopsy (LB) offers a less invasive alternative to tissue biopsy, providing real-time molecular information from circulating tumour components in body fluids. The aim of this review is to analyse the current evidence concerning LB in NENs and its role in clinical practice. We conducted a systematic review in July 2024 focusing on LB applications in NENs, including circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), micro RNA (miRNA), messenger RNA (mRNA) and extracellular vesicles. Sixty-five relevant articles were analysed. The LB showed potential in diagnosing and monitoring NENs. While CTCs face limitations due to low shedding, ctDNA provides valuable information on high-grade neoplasms. MiRNA and mRNA (e.g., the NETest) offer high sensitivity and specificity for diagnosis and prognosis, outperforming traditional markers like chromogranin A. The LB has significant potential for NEN diagnosis and monitoring but lacks widespread clinical integration due to limited prospective studies and guidelines, requiring further validation. Advances in sequencing technologies may enhance the clinical utility of LB in NENs. Future research should focus on refining LB methods, standardising protocols and exploring applications in high-grade NENs.

Gastroenteropancreatic neuroendocrine neoplasms: epidemiology, genetics, and treatment.

The incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP NEN) is increasing at a rapid pace and is becoming an increasingly important consideration in clinical care. Epidemiological data from multiple countries indicate that the incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP NEN) exhibits regional, site-specific, and gender-based variations. While the genetics and pathogenesis of some GEP NEN, particularly pancreatic NENs, have been investigated, there are still many mechanisms that require further investigation. The management of GEP NEN is diverse, but surgery remains the primary option for most cases. Peptide receptor radionuclide therapy (PRRT) is an effective treatment, and several clinical trials are exploring the potential of immunotherapy and targeted therapy, as well as combination therapy.