Principles of diagnosis and management of neuroendocrine tumours

Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs), also known as neuroendocrine tumors (NETs), are rare tumors derived from cells with characteristics of both nerve and endocrine cells. The clinical presentation, diagnosis, and treatment of NENs vary significantly depending on the type, location, whether the neoplasm is hormonally functional, how aggressive it is, and whether it has metastasized to other parts of the body. This article provides an overview of specific types of NETs, clinical presentations and related syndromes, diagnosis, and approach to management of common NENs.

Primary Hepatic Neuroendocrine Carcinoma: A Rare Entity

Neuroendocrine tumors are typically low-malignancy growths arising from neuroectodermal cells of neural crest origin. Neuroendocrine carcinoma, on the other hand, represents a high-malignancy form of these tumors. While rare in the liver, they often indicate metastasis when present. We present a unique case of incidentally discovered primary hepatic neuroendocrine carcinoma. Initially, the patient's management was based on misleading radiological findings. However, histopathology confirmed the diagnosis, with subsequent imaging ruling out an extrahepatic source. Despite this, the patient opted against surgical intervention, resulting in a fatal outcome. This case underscores the critical importance of prompt diagnosis and intervention to avert adverse outcomes.

The use of platelets as a clinical tool in oncology: opportunities and challenges

Platelets are small circulating anucleated cells mainly involved in thrombosis and hemostasis processes. Moreover, platelets play an active role in tumorigenesis and cancer progression, stimulating angiogenesis and vascular remodelling, and protecting circulating cancer cells from shear forces and immune surveillance. Several reports indicate that platelet number in the blood circulation of cancer patients is associated with prognosis and response to treatment. However, the mechanisms of platelets "education" by cancer cells and the crosstalk between platelets and tumor are still unclear, and the role of "tumor educated platelets" (TEPs) is achieving growing interest in cancer research. TEPs are a biological source of cancer-derived biomarkers, especially RNAs that are protected by platelets membrane from circulating RNases, and could serve as a non-invasive tool for tumor detection, molecular profiling and evolution during therapy in clinical practice. Moreover, short platelet lifespan offers the possibility to get a snapshot assessment of cancer molecular profile, providing a real-time tool. We review and discuss the potential and the clinical utility, in terms of cancer diagnosis and monitoring, of platelet count together with other morphological parameters and of the more recent and innovative TEP profiling.

Occult Pancreatic Neuroendocrine Tumor Presenting as Carcinoid Syndrome

We present a case of a 50-year-old male who initially presented to the clinic with complaints of palpitations, shortness of breath, dizziness, night sweats, headaches with associated intermittent episodes of diarrhea, episodes of flushing, and rash on the upper body. Laboratory testing revealed elevated chromogranin A levels. Initial imaging with computed tomography (CT) of the abdomen and pelvis with contrast was negative for any lesions. However, due to his clinical presentation and high suspicion of a neuroendocrine tumor (NET), a positron emission tomography-CT (PET-CT) scan with Gallium 68-DOTATATE was obtained, confirming and localizing his NET in the neck of the pancreas and the liver. Following confirmation and localization of his tumor, he was referred for surgical evaluation and treatment. Pancreatic neuroendocrine tumors are rare and difficult to diagnose, highlighted by unsuccessful initial efforts to localize and confirm the tumor. This case underscores the importance of clinical suspicion and acumen in diagnosing neuroendocrine tumors. Upcoming imaging modalities of PET-CT scans provide promising avenues to uncover neuroendocrine tumors.

Navigating the landscape of theranostics in nuclear medicine: current practice and future prospects

Theranostics refers to the combination of diagnostic biomarkers with therapeutic agents that share a specific target expressed by diseased cells and tissues. Nuclear medicine is an exciting component explored for its applicability in theranostic concepts in clinical and research investigations. Nuclear theranostics is based on the employment of radioactive compounds delivering ionizing radiation to diagnose and manage certain diseases employing binding with specifically expressed targets. In the realm of personalized medicine, nuclear theranostics stands as a beacon of potential, potentially revolutionizing disease management. Studies exploring the theranostic profile of radioactive compounds have been presented in this review along with a detailed explanation of radioactive compounds and their theranostic applicability in several diseases. It furnishes insights into their applicability across diverse diseases, elucidating the intricate interplay between these compounds and disease pathologies. Light is shed on the important milestones of nuclear theranostics beginning with radioiodine therapy in thyroid carcinomas, MIBG labelled with iodine in neuroblastoma, and several others. Our perspectives have been put forth regarding the most important theranostic agents along with emerging trends and prospects.

Predictive Nomogram and Propensity Score Matching in Neuroendocrine Carcinoma of the Tubular Gastrointestinal Tract: A US Population-Based Clinical Outcome Study

Background: Neuroendocrine carcinomas (NECs) of the tubular gastrointestinal tract (GI-NECs) are rare and associated with worse clinical outcomes. This population-based study aims to highlight key demographics, clinicopathological factors, and survival outcomes in the US population. Methods: Data from 10,387 patients with GI-NECs were extracted from the Surveillance, Epidemiology, and End Result (SEER) database from 2000 to 2020. Results: Most patients were >40 years old at the time of presentation with a median age of 63 years old, with almost equal ethnic distribution per US population data. The most common primary tumor site was the small intestine (33.6%). The metastatic spread was localized in 34.8%, regional in 27.8%, and distant in 37.3% of cases, and the liver was the most common site of metastasis (19.9%) in known cases of metastases. Most NEC patients underwent surgery, presenting the highest 5-year overall survival of 73.2% with a 95% confidence interval (CI) (95% CI 72.0-74.4%), while chemotherapy alone had the lowest 5-year survival of 8.0% (95% CI 6.4-10.0%). Compared to men, women had a superior 5-year survival rate of 59.0% (95% CI 57.6-60.5%). On multivariate analysis, age > 65 (HR 2.49, 95% CI 2.36-2.54%, p ≤ 0.001), distant metastasis (HR 2.57, 95% CI 2.52-2.62%, p ≤ 0.001), tumor size > 4 mm (HR 1.98, 95%, CI 1.70-2.31%, p ≤ 0.001), esophageal (HR 1.49, 95% CI 0.86-2.58%, p ≤ 0.001), transverse colon (HR 1.95, 95% CI 1.15-3.33%, p ≤ 0.01), descending colon (HR 2.12, 95% CI 1.12, 3.97%, p = 0.02) anorectal sites, and liver or lung metastases were associated with worse survival. Surgical intervention and tumors located in the small intestine or appendix showed a better prognosis. Conclusion: GI-NECs are a group of rare malignancies associated with a poor prognosis. Therefore, epidemiological studies analyzing national databases may be the best alternative to have a more comprehensive understanding of this condition, assess the impact of current practices, and generate prognosis tools.

Genetics-guided therapy in neuroendocrine carcinoma: response to BRAF- and MEK-inhibitors

Background

Metastatic neuroendocrine carcinoma (NEC) is associated with short survival. Other than platinum-based chemotherapy, there is no clear standard regimen. Current guidelines suggest that combination treatment with BRAF-inhibitors should be considered for patients with BRAF V600E-mutated NEC. However, since only eight such patients have been reported in the literature, our object was to confirm the validity of this recommendation.

Methods

This was a single-center retrospective cohort study conducted at Uppsala University Hospital. The included patients 1) had a histopathologically confirmed diagnosis of NEC, 2) were diagnosed between January 1st, 2018 and December 31st, 2023, 3) had tumor tissue genetically screened by a broad next-generation sequencing (NGS) panel, and 4) showed a tumor mutation for which there is a currently available targeted therapy.

Results

We screened 48 patients diagnosed with NEC between January 1st, 2018 and December 31st, 2023. Twelve had been analyzed with a broad NGS-panel, and two had a targetable mutation. Both these patients harbored a BRAF V600E-mutated colon-NEC and were treated with BRAF- and MEK-inhibitors dabrafenib and trametinib in second-line. At first radiological evaluation (RECIST 1.1), both patients had a reduction of tumor size, which decreased by 31 and 40%. Both had short response periods, and their overall survival was 12 and 9 months.

Conclusions

BRAF-mutated NEC is sensitive to treatment with BRAF- and MEK-inhibitor combination. These results further support that DNA sequencing should be considered as standard of care in NECs to screen for potential treatment targets.

Clinicopathological Findings and Treatment Outcomes of Patients with Primary Hepatobiliary Neuroendocrine Neoplasms: A Retrospective Single-institution Analysis

Objective Primary hepatobiliary neuroendocrine neoplasms (NENs) are rare tumors exhibiting several morphological and behavioral characteristics. Considering the lack of relevant data on this topic, we evaluated the clinicopathological features and treatment outcomes of patients with primary hepatobiliary NENs. Methods/Patients We examined 43 consecutive patients treated at the National Cancer Center Hospital with pathological diagnoses of primary hepatobiliary NEN between 1980 and 2016. Results Nine patients were diagnosed with neuroendocrine tumor (NET) G1, 9 with NET G2, and 25 with neuroendocrine carcinoma (NEC) based on the World Health Organization 2019 classification. Patients with NEC had primary sites across the hepatobiliary organs, although sites in patients with NET G1 and NET G2 only included the liver and ampulla of Vater. Patients with primary extrahepatic bile duct or ampulla of Vater NENs tended to be diagnosed earlier than patients with primary gallbladder NENs. The median survival times in the NET G1, NET G2, and NEC groups were 167.9, 97.4, and 11.1 months, respectively. A good performance status, absence of distant metastases, and low tumor grade were identified as independent predictors of a favorable prognosis. Conclusion The NET-to-NEC ratio and tumor stage distribution at the diagnosis differed depending on the primary site. Patients with G1 and G2 NETs who underwent surgical resection had good prognoses, whereas those with NEC exhibited more advanced disease and poorer prognoses. The performance status, staging classification, and tumor grade are important factors to consider when devising an appropriate treatment strategy and predicting the prognoses of patients with primary hepatobiliary NEN.

Altered CELF4 splicing factor enhances pancreatic neuroendocrine tumors aggressiveness influencing mTOR and everolimus response

Pancreatic neuroendocrine tumors (PanNETs) comprise a heterogeneous group of tumors with growing incidence. Recent molecular analyses provided a precise picture of their genomic and epigenomic landscape. Splicing dysregulation is increasingly regarded as a novel cancer hallmark influencing key tumor features. We have previously demonstrated that splicing machinery is markedly dysregulated in PanNETs. Here, we aimed to elucidate the molecular and functional implications of CUGBP ELAV-like family member 4 (CELF4), one of the most altered splicing factors in PanNETs. CELF4 expression was determined in 20 PanNETs, comparing tumor and non-tumoral adjacent tissue. An RNA sequencing (RNA-seq) dataset was analyzed to explore CELF4-linked interrelations among clinical features, gene expression, and splicing events. Two PanNET cell lines were employed to assess CELF4 function in vitro and in vivo. PanNETs display markedly upregulated CELF4 expression, which is closely associated with malignancy features, altered expression of key tumor players, and distinct splicing event profiles. Modulation of CELF4 influenced proliferation in vitro and reduced in vivo xenograft tumor growth. Interestingly, functional assays and RNA-seq analysis revealed that CELF4 silencing altered mTOR signaling pathway, enhancing the effect of everolimus. We demonstrate that CELF4 is dysregulated in PanNETs, where it influences tumor development and aggressiveness, likely by modulating the mTOR pathway, suggesting its potential as therapeutic target.

Surgery as a Principle and Technical Consideration for Primary Tumor Resection of Small Bowel Neuroendocrine Tumors

Small bowel neuroendocrine tumors (SB-NETs) are increasingly identified and have become the most frequent entity among small bowel tumors. An increasing incidence, a high prevalence, and a prolonged survival with optimal modern multidisciplinary management makes SB-NETs a unique set of tumors to consider for surgical oncologists. The major goals of surgical treatment in the setting of SB-NET include control of tumor volume, control of endocrine secretion, and prevention of locoregional complications. Key considerations include assessment of multifocality and resection of mesenteric nodal masses with the use of mesenteric-sparing approaches and acceptance of R1 margins if necessary to clear disease while avoiding short bowel syndrome. A description through eight steps for consideration is presented to allow for systematic surgical planning and execution of resection. Moreover, some controversies and evolving considerations to the surgical principles and technical procedures remain. The role of primary tumor resection in the presence of (unresectable) liver metastasis is still unclear. Reports of feasibility of minimally invasive surgery are emerging, with undetermined selection criteria for appropriateness or long-term outcomes. Resection of SB-NETs should be considered in all patients fit for surgery and should follow principles to achieve surgical oncological control that is appropriate for the stage and tumor burden, considering the age and comorbidity of the individual patient.

Obstructive Jaundice Caused by Metastatic Neuroendocrine Tumor of the Ampulla of Vater in a Young Adult: A Case Report

Introduction

Ampullary neuroendocrine tumors (NETs) are usually diagnosed in the 5th-6th decades of life, and no cases were reported in <20 years of age. We report a rare case, presenting at a very young age, of well-differentiated NET involving the ampulla of Vater with lymph node metastasis.

Case Presentation

An 18-year-old man presented with a 3-month history of upper abdominal pain and jaundice. Abdominal ultrasound showed a dilated common bile duct, and endoscopic retrograde cholangiopancreatography revealed two duodenal polypoid lesions, one of them overlying the ampulla of Vater, with an erythematous and ulcerated surface. Histopathological examination confirmed the diagnosis of NET grade 1. Octreotide scan revealed 2 para-aortic lymph nodes with intense radiotracer uptake. The patient had undergone Whipple surgery with para-aortic lymph node dissection. Histopathological examination of the surgical specimens was confirmatory of NET grade 2 and paraganglioma in a few of the dissected lymph nodes. Postoperatively, the patient was kept on monthly intramuscular octreotide. Follow-up gallium-68 DOTATATE is unremarkable apart from an avid left para-aortic lymph node which is showing stability over 12 months of follow-up.

Conclusion

This case demonstrates that NETs of the ampulla of Vater can present at a very young age. Radical surgical excision with extended lymph node dissection and postoperative octreotide is associated with better patient outcomes and survival.

The Role of Receptor-Ligand Interaction in Somatostatin Signaling Pathways: Implications for Neuroendocrine Tumors

Neuroendocrine tumors (NETs) arise from neuroendocrine cells and manifest in diverse organs. Key players in their regulation are somatostatin and its receptors (SSTR1-SSTR5). Understanding receptor-ligand interactions and signaling pathways is vital for elucidating their role in tumor development and therapeutic potential. This review highlights SSTR characteristics, localization, and expression in tissues, impacting physiological functions. Mechanisms of somatostatin and synthetic analogue binding to SSTRs, their selectivity, and their affinity were analyzed. Upon activation, somatostatin initiates intricate intracellular signaling, involving cAMP, PLC, and MAP kinases and influencing growth, differentiation, survival, and hormone secretion in NETs. This review explores SSTR expression in different tumor types, examining receptor activation effects on cancer cells. SSTRs' significance as therapeutic targets is discussed. Additionally, somatostatin and analogues' role in hormone secretion regulation, tumor growth, and survival is emphasized, presenting relevant therapeutic examples. In conclusion, this review advances the knowledge of receptor-ligand interactions and signaling pathways in somatostatin receptors, with potential for improved neuroendocrine tumor treatments.

Neuroendocrine tumour of the lesser omentum

A man in his early 20s presented to us in the outpatient department with a history of diarrhoea for 4 months. Investigations revealed elevated serum chromogranin levels and an intensely avid lesion in the gastrohepatic ligament in Gallium DOTATATE positron emission tomography (PET). The tumour was excised laparoscopically, and no other lesions were seen. The patient improved clinically and had a normal serum chromogranin level postoperatively. He is currently much improved at the 1year follow-up. We did an extensive workup to look for a primary tumour. It was concluded that it was a de novo tumour arising from the lesser sac. The recommended investigations in case of neuroendocrine tumour (NET) with unknown primary include blood investigations to look for the functional status of the tumour, histopathological examination, including immunohistochemistry, and radiological imaging, which must include a Gallium DOTATATE PET. An isolated NET of the lesser sac has not been reported in the literature.

Gastric variceal bleeding as a form of presentation of a pancreatic neuroendocrine tumor

NETs (neuroendocrine tumors) constitute a heterogeneous group of epithelial-type neoplasms with a predominantly neuroendocrine differentiation. Although the most common locations are the pancreas, digestive tract, and lung, this type of neoplasm can arise in virtually any organ in the body. They are rare tumors with a wide variety of clinical presentations. Symptomatic tumors are more frequent in younger patients and present at more advanced pathological stages. We present the case of a 42-year-old male with idiopathic splenomegaly and bicytopenia (anaemia and thrombocytopenia) under study by haematology department who was admitted due to an episode of melena and hemoglobin of 4.5 mg/dl. Isolated gastric varices (IGV1) with red spots were confirmed at gastroscopy and endoscopic variceal obturation using cyanoacrylate was performed in two sessions. An endoscopic ultrasonography was performed, showing thrombosis of the splenic vein extending towards the splenoportal confluence with anechoic serpiginous structures outside and inside the gastric wall suggestive of collateral circulation with gastric varices (GV). An increase in portal caliber was observed, with no signs of liver cirrhosis. Computed tomography confirms the findings. Two months/week/days later he was readmitted with rebleeding signs after starting anticoagulant treatment, so it was decided to perform a splenectomy due to failure of the endoscopic treatment. Histology revealed infiltration of the spleen by a well-differentiated neuroendocrine tumor (NET). Gallium PET/CT and Octreotid scan showed uptake in the body and tail of the pancreas with positivity for somatostatin receptors previously undetected by other means. Finally, treatment was completed with distal pancreatectomy and splenoportal axis trombectomy with vascular esplenic resection and the patient was discharged from hospital.

Epidemiology of Neuroendocrine Neoplasms and Results of Their Treatment with [177Lu]Lu-DOTA-TATE or [177Lu]Lu-DOTA-TATE and [90Y]Y-DOTA-TATE-A Six-Year Experience in High-Reference Polish Neuroendocrine Neoplasm Center

Neuroendocrine neoplasms (NENs) are a group of neoplasms arising from neuroendocrine cells. The worldwide incidence and prevalence of the NENs are estimated to be 6/100,000 and 35/100,000, respectively. Those numbers are increasing every decade, requiring higher and higher diagnosis and treatment costs. Radioligand therapy (RLT) using beta-emitting radioisotopes is an efficient and relatively safe method of treatment, typically used as a second-line treatment. RLT tolerability is higher than other available pharmacotherapies (chemotherapy or tyrosine kinase inhibitors). Recent studies show an increase in overall survival among patients treated with RLT. The present study aimed to learn the epidemiology of NENs in Poland and assess the effectiveness of RLT in a high-reference center. A prospective analysis of 167 patients treated with RLT in one of Poland's highest-reference NEN centers was performed. The analysis covered 66 months of observation (1 December 2017-30 May 2023), during which 479 RLT single administrations of radioisotope were given. The standard procedure was to give four courses of [177Lu]Lu-DOTA-TATE alone, or tandem therapy-[177Lu]Lu-DOTA-TATE and [90Y]Y-DOTA-TATE. Grading analysis showed that most patients had non-functioning G2 NEN with a mean Ki-67 of 6.05% (SD ± 6.41). The most common primary tumor location was the pancreas. Over two-thirds of patients did undergo surgery due to primary tumors or distant metastases. The majority of patients were using lanreotide as a chronically injected somatostatin analog. Median progression-free survival (PFS) on somatostatin analogs was 21.0 (IQR = 29.0) months. Directly after the last course of RLT, disease stabilization was noted in 69.46% of patients, partial regression was noted in 20.36% of patients, complete regression was noted in 0.60% of patients, and progression was noted in 9.58% of patients. In long-term follow-up, the median observation time among patients who underwent four treatment cycles (n = 108) was 29.8 (IQR = 23.9) months. Stabilization of the disease was observed in 55.56% of the patients and progression was observed in 26.85% of the patients, while 17.59% of patients died. Median PFS was 29.3 (IQR 23.9), and the median OS was 34.0 months (IQR 16.0). The mean age of NEN diagnosis is the sixth decade of life. It takes almost three years from NEN diagnosis to the start of RLT. In long-term observation, RLT leads to disease stabilization in over half of the patients with progressive disease. No differences in PFS or OS depend on the radioisotope used for RLT. In Poland, organized coordination of NEN treatment in high-reference centers ensures the continuity of patient care.

Pituitary adenoma or neuroendocrine tumour: the need for an integrated prognostic classification

In the 2022 fifth edition of the WHO Classification of Endocrine Tumours and of Central Nervous System Tumours, pituitary adenomas are reclassified as neuroendocrine tumours (NETs). This change confers an oncology label to neoplasms that are overwhelmingly benign. A comprehensive clinical classification schema is required to guide prognosis, therapy and outcomes for all patients with pituitary adenomas. Pituitary adenomas and NETs exhibit some morphological and ultrastructural similarities. However, unlike NETs, pituitary adenomas are highly prevalent, yet indolent and rarely become malignant. This Perspective presents the outcomes of an interdisciplinary international workshop that addressed the merit and clinical implications of the classification change of pituitary adenoma to NET. Many non-histological factors provide mechanistic insight and influence the prognosis and treatment of pituitary adenoma. We recommend the development of a comprehensive classification that integrates clinical, genetic, biochemical, radiological, pathological and molecular information for all anterior pituitary neoplasms.

Metastatic primary breast neuroendocrine neoplasms: a case series

BACKGROUND

Breast neuroendocrine neoplasms represent a rare subtype of breast cancer which have not been well studied or characterised, particularly in the metastatic setting.

AIM

To present clinicopathological characteristics, treatment and outcomes of a series of patients with metastatic neuroendocrine carcinoma of the breast and review the current literature.

METHODS

We performed a retrospective review to identify and describe patients with metastatic neuroendocrine carcinoma of the breast at our centre between 2011 and 2021. Medical records, pathology and imaging results were examined to evaluate the clinical and histopathological features as well as the treatment pathways and prognosis of these patients.

RESULTS

We present a series of seven female patients with metastatic neuroendocrine carcinoma of the breast, as defined by the World Health Organization classification, over a period of 10 years (2011-2021) from a single centre. Median age at diagnosis was 48 years (range 39-63). Six of seven tissue samples expressed synaptophysin and chromogranin and were also oestrogen and progesterone receptor positive; median Ki-67 index was 50% (range 20-90%). All seven patients had demonstrated avidity on 18 F-FDG PET imaging, and the six who underwent 68 Ga-DOTATATE PET all had significant avidity. Treatment modalities and sequencing varied, but all patients received chemotherapy during their disease course. Six patients received three or more lines of treatment. Median overall survival was 31.8 months (range 3.7-108.6). Median progression-free survival (PFS) with first-line therapy for metastatic disease was 5.8 months (range 1.8-37.8).

CONCLUSIONS

This series shows the use of multiple modalities in treating this disease, with different sequencing in different patients. Despite multiple modalities used in the first-line setting, first-line PFS remains short. Larger series and further molecular characterisation are required to aid clinicians in managing this condition and to guide optimal treatment sequencing to improve outcomes in this rare patient group.

Diagnostic accuracy of SSR-PET/CT compared to histopathology in the identification of liver metastases from well-differentiated neuroendocrine tumors

BACKGROUND

Histopathology is the reference standard for diagnosing liver metastases of neuroendocrine tumors (NETs). Somatostatin receptor-positron emission tomography / computed tomography (SSR-PET/CT) has emerged as a promising non-invasive imaging modality for staging NETs. We aimed to assess the diagnostic accuracy of SSR-PET/CT in the identification of liver metastases in patients with proven NETs compared to histopathology.

METHODS

Histopathologic reports of 139 resected or biopsied liver lesions of patients with known NET were correlated with matching SSR-PET/CTs and the positive/negative predictive value (PPV/NPV), sensitivity, specificity, and diagnostic accuracy of SSR-PET/CT were evaluated. PET/CT reading was performed by one expert reader blinded to histopathology and clinical data.

RESULTS

133 of 139 (95.7%) liver lesions showed malignant SSR-uptake in PET/CT while initial histopathology reported on 'liver metastases of NET´ in 127 (91.4%) cases, giving a PPV of 91.0%. Re-biopsy of the initially histopathologically negative lesions (reference standard) nevertheless diagnosed 'liver metastases of NET' in 6 cases, improving the PPV of PET/CT to 95.5%. Reasons for initial false-negative histopathology were inadequate sampling in the sense of non-target biopsies. The 6 (4.3%) SSR-negative lesions were all G2 NETs with a Ki-67 between 2-15%.

CONCLUSION

SSR-PET/CT is a highly accurate imaging modality for the diagnosis of liver metastases in patients with proven NETs. However, we found that due to the well-known tumor heterogeneity of NETs, specifically in G2 NETs approximately 4-5% are SSR-negative and may require additional imaging with [18F]FDG PET/CT.

Optimal surgical approach for digestive neuroendocrine neoplasia primaries: Oncological benefits versus short and long-term complications

The rising incidence and the accumulating prevalence of neuroendocrine neoplasia (NEN) in the population makes this a common, prevalent and a clinically relevant disease group. Surgical resection represents the only potentially curative treatment for digestive NENs. Thus, resection should in principle be considered for all patients with NEN, although taking the patients age, relevant comorbidity, and performance status into account for operability. Patients with insulinomas, NEN of the appendix and rectal NENs are usually cured by surgery alone. However, less than a third of patients are amendable to curative surgery alone at time of diagnosis. Furthermore, recurrence is common and may occur years after primary surgery, hence the long follow-up time recommended in most NENs (>10 years). As many patients with NENs present with locoregional or metastatic disease, there is considerable debate regarding the role of debulking surgery in these settings. However, good long-term survival can be achieved in a considerable proportion of patients, with 50-70% alive up to 10 years after surgery. Location and grade are the main determinants of long-term survival. Here we present considerations to surgery for primary neuroendocrine tumors in the digestive tract.

Incidental intraoperative finding of jejunal neuroendocrine tumors during elective ventral hernia repair

Neuroendocrine tumors (NETs) constitute ~0.5% of all diagnosed malignancies. In our case, a 72-year-old male, who was asymptomatic aside from mild left lower abdominal pain, was scheduled for elective ventral hernia repair, evident on computed tomography. The laparoscopic ventral hernia repair necessitated the conversion to laparotomy due to extensive adhesions and the incorporation of surgical mesh into the small bowel wall. The patient suffered from delayed small bowel injury resulting in the second emergent laparotomy when numerous calcified lesions were incidentally noted in the small bowel wall. Pathology confirmed Grade 1 well-differentiated NETs of the jejunum. This case highlights the importance of considering NETs as part of a differential diagnosis in patients with nonspecific symptoms and negative imaging studies. This case also emphasizes the importance of early detection of this rare pathology to improve prognosis and outcome.

New horizon of radiopharmaceuticals in management of neuroendocrine tumors

Neuroendocrine neoplasms are rare and heterogenous group of tumors with varying degrees of clinical presentations and involvement of multiple organ systems in the body. In the modern clinical practice somatostatin receptor molecular imaging and targeted radioligand therapy plays a vital role in the diagnosis and management of the disease. Several new and promising radiotracers for NET imaging and theranostics, belonging to various groups and classes are being studied and investigated. This exponential growth of radiotracers poses concerns about the indication, clinical benefit, and safety profile of the agents. We discuss the basis behind these radiotracers clinical use, receptor targeting and intra and inter tumor heterogeneity. Furthermore, role of dual tracer imaging, combination therapy and potential applications of dosimetry in predicting treatment outcome and safety profile is reviewed. Individualized precision medicine with better tumor characterization, maximum therapeutic benefit and minimum toxicity is the way forward for future medicine.

An Overview of Circulating Biomarkers in Neuroendocrine Neoplasms: A Clinical Guide

Neuroendocrine neoplasms (NENs) are a heterogeneous group of diseases that are characterized by different behavior and clinical manifestations. The diagnosis and management of this group of tumors are challenging due to tumor complexity and lack of precise and widely validated biomarkers. Indeed, the current circulating mono-analyte biomarkers (such as chromogranin A) are ineffective in describing such complex tumors due to their poor sensitivity and specificity. In contrast, multi-analytical circulating biomarkers (including NETest) are emerging as more effective tools to determine the real-time profile of the disease, both in terms of accurate diagnosis and effective treatment. In this review, we will analyze the capabilities and limitations of different circulating biomarkers focusing on three relevant questions: (1) accurate and early diagnosis; (2) monitoring of disease progression and response to therapy; and (3) detection of early relapse.

Radioligand Therapy with [177Lu]Lu-DOTA-TATE or [177Lu]Lu-DOTA-TATE and [90Y]Y-DOTA-TATE in Patients with Neuroendocrine Neoplasms of Unknown Locations, or Locations Other Than the Midgut and Pancreas as Primaries in a G1, G2 and G3 Grade

BACKGROUND

Neuroendocrine neoplasms (NENs) are a rare group of tumors with a different clinical course, prognosis and location. Radioligand therapy (RLT) can be used as a first or second line of treatment. It is registered in gastroenteropancreatic NENs (GEP-NENs) as grades G1 and G2. Tumors with an unknown point of origin, diagnosed outside the gastrointestinal tract and pancreas (non-GEP) or at the G3 grade, remain in the "grey area" of treatment.

MATERIALS AND METHODS

Analysis of 51 patients with NENs who underwent RLT in a single highest reference center from 2018 to 2023 was performed. Treatment was administrated to the patients with neoplasms of unknown origin, non-GEP-NENs, and ones with G3 grade. In total, 35 patients received 177-Lutetium (7.4 GBq), while 16 received 177-Lutetium and 90-Yttrium with equal activities (1.85 + 1.85 GBq).

RESULTS

The progression-free survival (PFS) before RLT qualification was 34.39 ± 35.88 months for the whole study group. In subgroups of patients with an unknown tumor location (n = 25), the median PFS was 19 months (IQR = 23), with "other" locations (n = 21) at 31 months (IQR = 28), and with NEN G3 (n = 7) at 18 months (IQR = 40). After RLT, disease stabilization or regression was observed in 42 (87.5% of) patients. RLT did not cause statistical changes in creatinine or GFR values. Hematological parameters (RBC, WBC, PLT, HGB) as well as chromogranin A concentration decreased significantly. There were no statistical differences between both subgroups regarding the type of radioisotope (177-Lutetium vs. 177-Lutetium and 90-Yttrium). After RLT in long-term observation, the median observation time (OT) was 14 months (IQR = 18 months). In patients with progression (n = 8), the median PFS was 20 months (IQR = 16 months), while in patients with confirmed death (n = 9), the median overall survival (OS) was 8 months (IQR = 14 months).

CONCLUSIONS

Our study showed that 87.5% of NEN patients with unknown origin, non-GEP-NENs, and those with GEP-NEN G3 grade had benefited from the radioligand therapy. There were no significantly negative impacts on renal parameters. The decrease of bone marrow parameters was acceptable in relation to beneficial disease course. The decrease of chromogranin concentration was confirmed as a predictive factor for disease stabilization or regression.

Virus-associated neuroendocrine cancers: Pathogenesis and current therapeutics

Neuroendocrine neoplasms (NENs) comprise malignancies involving neuroendocrine cells that often lead to fatal pathological conditions. Despite escalating global incidences, NENs still have poor prognoses. Interestingly, research indicates an intricate association of tumor viruses with NENs. However, there is a dearth of comprehension of the complete scenario of NEN pathophysiology and its precise connections with the tumor viruses. Interestingly, several cutting-edge experiments became helpful for further screening of NET for the presence of polyomavirus, Human papillomavirus (HPV), Kaposi sarcoma-associated herpesvirus (KSHV), Epstein Barr virus (EBV), etc. Current research on the neuroendocrine tumor (NET) pathogenesis provides new information concerning their molecular mechanisms and therapeutic interventions. Of note, scientists observed that metastatic neuroendocrine tumors still have a poor prognosis with a palliative situation. Different oncolytic vector has already demonstrated excellent efficacies in clinical studies. Therefore, oncolytic virotherapy or virus-based immunotherapy could be an emerging and novel therapeutic intervention. In-depth understanding of all such various aspects will aid in managing, developing early detection assays, and establishing targeted therapeutic interventions for NENs concerning tumor viruses. Hence, this review takes a novel approach to discuss the dual role of tumor viruses in association with NENs' pathophysiology as well as its potential therapeutic interventions.

The Latest Advancements in Diagnostic Role of Endosonography of Pancreatic Lesions

Endosonography, a minimally invasive imaging technique, has revolutionized the diagnosis and management of pancreatic diseases. This comprehensive review highlights the latest advancements in endosonography of the pancreas, focusing on key technological developments, procedural techniques, clinical applications and additional techniques, which include real-time elastography endoscopic ultrasound, contrast-enhanced-EUS, EUS-guided fine-needle aspiration or EUS-guided fine-needle biopsy. EUS is well established for T-staging and N-staging of pancreaticobiliary malignancies, for pancreatic cyst discovery, for identifying subepithelial lesions (SEL), for differentiation of benign pancreaticobiliary disorders or for acquisition of tissue by EUS-guided fine-needle aspiration or EUS-guided fine-needle biopsy. This review briefly describes principles and application of EUS and its related techniques.

Neuroendocrine Tumor Metastases to the Breast: A Case Report and Review of the Literature

Breast metastases from neuroendocrine neoplasms (NENs) are considered infrequent. We report a case of a patient with ileocecal neuroendocrine tumor (NET) metastases to both breasts, for whom the initial clinical presentation was chronic diarrhea. Breast metastasis was initially suspected by a 68-Gallium DOTANOC positron emission tomography (PET)/CT and was confirmed by histopathology. We also performed a literature review in which we identified 116 cases of NENs metastatic to the breast reported so far. Most cases occurred in older women, were caused by NETs, and had the gastrointestinal tract as the primary site.

Global challenges in access to diagnostics and treatment for neuroendocrine tumor (NET) patients

SCAN, an online survey, measured access to diagnosis, treatments and monitoring of neuroendocrine tumor (NET) patients globally. Between September and November 2019, NET patients and healthcare professionals (HCPs) completed an online, semi-standardized survey with 54 patient questions and 33 HCP questions. A total of 2359 patients with NETs and 436 HCPs responded. Misdiagnosis was common (44% [1043/2359]). Mean time to diagnosis was 4.8 years (standard deviation [SD], 6.2). Compared with global figures (60% [1407/2359]), the availability of 68 Ga-DOTA positron emission tomography (PET)/computed tomography (CT) was significantly lower in Asia (45% [126/280]) and higher in Oceania (86% [171/200]). HCPs reported that 68 Ga-DOTA PET/CT was free/affordable to fewer patients in Emerging and Developing Economies (EDE) than Advanced Economies (AE; 17% [26/150] and 59% [84/142], respectively). Compared with global data (52% [1234/2359]), patient-reported availability of peptide receptor radionuclide therapy (PRRT) was significantly lower in Asia (31% [88/280]) and higher in Oceania (61% [122/200]). Significant differences were observed in average annual NET specialist costs between AE and EDE ($1081 and $2915, respectively). Compared with AE, patients in EDE traveled further for NET specialists (1032 [SD, 1578] and 181 [SD, 496] km, respectively). Patients and HCPs both recommended referral to HCPs that were more knowledgeable in the field of NETs and had better access to NET experts/specialist centers. National care pathways, enhancing HCP NET knowledge and ensuring effective diagnostics and access to appropriate treatments are crucial to improving patient survival and NET care worldwide.

Urinary Neuroendocrine Neoplasms Treated in the "Modern Era": A Multicenter Retrospective Review

BACKGROUND

Primary urinary neuroendocrine neoplasms (U-NENs) are extremely rare thus optimal treatment is unknown. Grading and treatment are typically extrapolated from other primary sites. Since 2010, the clinical landscape for NENs has changed substantially. We performed a retrospective review of U-NENs to assess treatment patterns and oncologic outcomes of patients treated in the recent era of NEN therapy.

PATIENTS AND METHODS

A multicenter retrospective review of patients diagnosed after 2005 and alive after 2010. Time to treatment failure (TTF) was used to evaluate progression and toxicity for systemic therapy. Tumors were categorized as having either well-differentiated neuroendocrine tumor (WDNET) or poorly differentiated neuroendocrine carcinoma (PDNEC) histology.

RESULTS

A total of 134 patients from 6 centers were included in our analysis, including 94 (70%) bladder, 32 (24%) kidney, 2 (1.5%) urethra and 4 other urinary primaries (3.0%). Poorly-differentiated neuroendocrine carcinoma was more common in bladder (92%) than non-bladder tumors (8%). Median Ki-67 available in bladder primary was 90% (n = 24), kidney 10% (n = 23), ureter 95% (n = 1), urethra 54% (n = 2), and others 90% (n = 3). Patients received a median of 2 therapies (range 0-10). Median time to death was not reached in locoregional WDNETs versus 8.2 years (95% CI, 3.5-noncalculable) in metastatic WDNETs (predominantly renal primary). Median time to death was 3.6 years (95% CI, 2.2-9.2) in locoregional PDNECs versus 1 year (95% CI, 0.8-1.3) in metastatic PDNECs (predominantly bladder primary).

CONCLUSION

This is the most extensive series examining treatment patterns in patients with U-NENs in the recent era of NEN therapy. The apparent inferior survival for bladder NENs is likely due to the preponderance of PDNECs in this group. As predicted, treatments for U-NENs mirrored that of other more common NENs. In our retrospective cohort, we observed that patients with WD-UNETs treated with peptide receptor radionuclide therapy (PRRT) and everolimus suggested potential activity for disease control in WD-UNETs. Prospective studies are needed to assess the activity of new oncology drugs in UNENs.

Patterns of emergency department visits before diagnosis with digestive neuroendocrine neoplasms

OBJECTIVE

To evaluate the patterns of emergency department visits before diagnosis with digestive neuroendocrine neoplasms (NENs).

METHODS

Linked administrative databases from the province of Alberta, Canada, were examined, and patients diagnosed with digestive NENs from 2004 to 2019 were reviewed. Incidents of emergency department visits in the 3 months before histological diagnosis were reviewed. Multivariable logistic regression analyses were used to examine factors associated with at least one emergency department (ED) visit as well as factors associated with more than one ED visit. The impact of pre-diagnosis ED visits on overall survival was further assessed in a multivariable Cox regression model, which included (in addition to ED visits), age at diagnosis, sex, histology, Charlson comorbidity index, and stage.

RESULTS

A total of 2120 patients were considered eligible for the study, and they were included in the analysis (including 1041 patients (49.1%) with at least one ED visit in the 3 months before diagnosis). The following factors were associated with a higher likelihood of an ED visit prior to diagnosis: younger age (OR with increasing age: 0.983; 95% CI: 0.977-0.989), higher comorbidity index (OR: 1.332; 95% CI: 1.215-1.460), female sex (OR: 1.292; 95% CI: 1.084-1.540), and stage IV (OR: 1.515; 95% CI: 1.106-2.075). Likewise, the following factors were associated with more than one ED visit within 3 months before diagnosis: younger age (OR with increasing age: 0.985; 95% CI: 0.979-0.992), higher comorbidity index (OR: 1.280; 95% CI: 1.167-1.405), and female sex (OR: 1.516; 95% CI: 1.230-1.868). Using multivariable Cox regression modeling, the following factors were associated with worse overall survival (higher risk of death): older age (HR: 1.050; 95% CI: 1.043-1.056), higher comorbidity index (HR: 1.280; 95% CI: 1.209-1.356), stage IV (HR: 3.163; 95% CI: 2.562-3.905), neuroendocrine carcinoma histology (HR: 1.645; 95% CI: 1.350-2.003), pre-diagnosis ED visit (HR: 1.784; 95% CI: 1.529-2.083).

CONCLUSION

Almost one-half of patients with NENs visit the ED within 3 months before diagnosis. ED visits were associated with younger age, female sex, advanced disease, and higher comorbidity. Moreover, pre-diagnosis ED visit(s) were associated with worse overall survival in the current cohort.

Renal Disturbances during and after Radioligand Therapy of Neuroendocrine Tumors-Extended Analysis of Potential Acute and Chronic Complications

Neuroendocrine tumors (NEN) are a group of neoplasms that arise from hormonal and neural cells. Despite a common origin, their clinical symptoms and outcomes are varied. They are most commonly localized in the gastrointestinal tract. Targeted radioligand therapy (RLT) is a treatment option which has proven to be successful in recent studies. However, the possible outcomes and true safety profile of the treatment need to be fully determined, especially by new, more sensitive methods. Our study aimed to present an extended analysis of acute and chronic renal complications during and after radioligand therapy using, for the first time in the literature, innovative and complex renal parameters. Forty patients with neuroendocrine tumors underwent four courses of radioligand therapy with [¹⁷⁷Lu]Lu-DOTATATE or [¹⁷⁷Lu]Lu/[⁹⁰Y]Y-DOTATATE. Radioisotopes were administrated in intervals of 8-12 weeks, with concurrent intravenous nephroprotection. New detailed and sensitive renal parameters were used to determine the renal safety profile during and after radioisotope therapy for standard treatment of NEN. During the first and fourth courses of RLT, no change in the glomerular filtration rate (GFR) was observed. However, long-term observations one year after the treatment showed a 10% reduction in the GFR. During the first course of treatment, the fractional urea and calcium excretions increased, while the fractional potassium concentration decreased. The fractional calcium excretion remained highly increased in long-term observations. Decreases in urine IL-18, KIM-1 and albumin concentrations were observed during RLT. The concentrations of IL-18 and KIM-1 remained low even a year after therapy. The ultrasound parameters of renal perfusion changed during treatment, before partially returning to the baseline one year after therapy, and were correlated with the biochemical parameters of renal function. A permanent increase in diastolic blood pressure was correlated with the decrease in the GFR observed during the study. In this innovative and complex renal assessment during and after RLT, we found a permanent 10% per year decrease in the GFR and noticeable disturbances in renal tubule function. The diastolic blood pressure also increased.

Neuroendocrine carcinoma of cervix and review literature

INTRODUCTION

Neuroendocrine carcinoma of the cervix (NECC) is a rare variant of cervical cancer with poor prognosis and high mortality. Recurrence is seen with multi-organ metastasis including liver.

CASE PRESENTATION

A 65 year old female presented with vaginal bleeding for the past one year. Cervical cancer screening and biopsy demonstrated poorly differentiated squamous carcinoma. Immunohistochemistry showed positive expression of chromogranin, synaptophysin, pancytokeratin, TTP1, and CEA and negative expression of p40 and estrogen receptors. An adenocarcinoma with neuroendocrine tumor was suggested. Hysterectomy with bilateral salpingo-oophrectomy was performed. This was followed by carboplatin and etoposide therapy to have clinical remission for a year. Then recurrence was observed to start same drugs again resulting in to partial improvement. It was followed by radiotherapy. The patient succumbed to death approximately after three months.

CONCLUSION

A metastatic lesion in liver may be a case of Neuroendocrine tumor of cervix, a rare condition that can be easily missed on histopathological examination. More studies are required to establish a standard therapeutic protocol.

Evaluating home injection compared with healthcare-setting injection of somatostatin analogs: a systematic literature review

PURPOSE

A systematic literature review was conducted to assess the use of home injections (self/partner/healthcare provider [HCP]-administered) of somatostatin analogs (SSAs) as an alternative to healthcare-setting injections in patients with acromegaly and neuroendocrine tumors (NETs).

METHODS

MEDLINE/Embase/the Cochrane Library (2001-September 2021), key congresses (2019-2021), and bibliographies of relevant systematic reviews were searched. Eligible studies reported on efficacy/effectiveness, safety, adherence, patient-reported outcomes (PROs), and economic outcomes in populations receiving home injections of SSAs.

RESULTS

Overall, 12 studies were included, all reporting on SSAs (lanreotide Autogel/Depot or octreotide long-acting release) in acromegaly or NETs. Across four studies, home injection was associated with similar disease control in patients with acromegaly/NETs compared with healthcare-setting administration. High rates of treatment adherence were shown in two studies of patients with acromegaly receiving lanreotide injections at home. Two studies reported non-serious adverse events; incidence of adverse reactions was similar in both the home and healthcare administration settings. Preference for injection setting varied between studies and indications; nonetheless, higher satisfaction/convenience (>75% patients) was reported for home injections. Self- or partner-injection was associated with economic savings compared with administration in the healthcare setting across five studies.

CONCLUSION

Efficacy/effectiveness, adherence, and safety outcomes of SSAs in the home injection setting were similar to those in the healthcare setting, with high reported satisfaction and convenience. Self/partner injection also resulted in cost savings. These findings provide a basis to understand outcomes related to home injection and encourage healthcare providers to discuss optimal treatment choices with their patients.

The hidden potential of glycomarkers: Glycosylation studies in the service of cancer diagnosis and treatment

Changes in the glycosylation process appear early in carcinogenesis and evolve with the growth and spread of cancer. The correlation of the characteristic glycosylation signature with the tumor stage and the appropriate therapy choice is an important issue in translational medicine. Oncologists also pay attention to extracellular vesicles as reservoirs of new cancer glycomarkers that can be potent for cancer diagnosis/prognosis. In this review, we recall glycomarkers used in oncology and show their new glycoforms of improved clinical relevance. We summarize current knowledge on the biological functions of glycoepitopes in cancer-derived extracellular vesicles and their potential use in clinical practice. Is glycomics a future of cancer diagnosis? It may be, but in combination with other omics analyses than alone.

Incidental Finding of a Periampullary Neuroendocrine Tumor: A Case Report

A 63-year-old male with multiple co-morbidities presented with a diabetic foot infection which was treated surgically. During admission to the hospital, he developed melena and underwent an endoscopic assessment which revealed an incidental finding of an ampullary mass. The histological analysis of the biopsy revealed ampullary carcinoma with mixed intestinal-type and pancreatobiliary-type features. A magnetic resonance imaging (MRI) of the liver with contrast presented the tumor as an ill-defined small soft tissue lesion measuring 8 x 9 mm in the ampullary region, with multiple lymph nodes in the periportal, peripancreatic, and para-aortic regions. There was no evidence of biliary obstruction. The patient underwent a Whipple procedure with no complications. The final histology report of the specimens taken stated that the tumor is predominantly in the duodenum and focally in the ampulla, and is a well-differentiated neuroendocrine tumor confirmed to be submucosal. The histopathologic and radiologic workup determined the pathological stage classification to be pT3N1, Mx G1.

An Intestinal Type Gastric Neuroendocrine Tumor: A Case Report

Neuroendocrine tumors (NETs) represent a diverse set of malignancies, originating from the neuroendocrine cells dispersed throughout the body. Their symptoms are associated with the secretion of bioactive peptides by tumor cells. Five-year survival rates depend on the disease stage: 93% for local, 74% for regional, and 19% for metastatic disease. This report describes a case involving a 64-year-old male patient, who was enduring high blood pressure and anemia. His symptomatology included frequent fainting and bloody vomiting without prior bleeding, coupled with persistent abdominal pain and weight loss. A complete blood count revealed microcytic anemia. His condition improved postoperatively after the transfusion of two units of packed red blood cells, normalizing all parameters. Further biochemistry and serology tests did not provide significant insights. However, an upper endoscopy unveiled a deep ulcer below the gastroesophageal junction with ulcer desquamation. A combination of clinical, laboratory, and radiographic data initially indicated a gastric carcinoma of the intestinal type, characterized by extensive extracellular mucin secretion. The surgical intervention led to the extraction of multiple tumors from lymph nodes, culminating in a postoperative diagnosis of a gastrointestinal (GI) mesenchymal tumor. NETs predominantly manifest in the GI tract, initiating primarily in the small intestine but can also originate in the stomach, appendix, colon, and other parts of the GI tract. Their development from neuroendocrine cells enables them to produce high concentrations of hormone-like substances such as neuropeptides and amines.

Preclinical Models of Neuroendocrine Neoplasia

Neuroendocrine neoplasia (NENs) are a complex and heterogeneous group of cancers that can arise from neuroendocrine tissues throughout the body and differentiate them from other tumors. Their low incidence and high diversity make many of them orphan conditions characterized by a low incidence and few dedicated clinical trials. Study of the molecular and genetic nature of these diseases is limited in comparison to more common cancers and more dependent on preclinical models, including both in vitro models (such as cell lines and 3D models) and in vivo models (such as patient derived xenografts (PDXs) and genetically-engineered mouse models (GEMMs)). While preclinical models do not fully recapitulate the nature of these cancers in patients, they are useful tools in investigation of the basic biology and early-stage investigation for evaluation of treatments for these cancers. We review available preclinical models for each type of NEN and discuss their history as well as their current use and translation.

Lanreotide Depot to Treat Gastroenteropancreatic Neuroendocrine Tumors in a US Community Oncology Setting: A Prospective, Observational Study

INTRODUCTION

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) can result in symptoms such as diarrhea, flushing, abdominal pain, and fatigue and are often associated with a significant disease burden and poor prognosis. This non-interventional, prospective, observational study evaluated the real-world safety and effectiveness of lanreotide depot, a somatostatin analog (SSA) used to treat GEP-NETs, in a community setting.

METHODS

In this prospective, non-interventional study (NCT02730104), adult patients with locally advanced (inoperable), metastatic GEP-NETs treated with lanreotide depot were evaluated by their physician every 6 months from enrollment for 24 months. Clinically defined time to disease progression (TTDP) and overall survival (OS) were estimated for the total population and by primary tumor type (gastrointestinal [GI], pancreatic, unknown origin), and an exploratory analysis determined the rate of progression-free survival (PFS) at 12 and 24 months. Patient satisfaction was evaluated via the Treatment Satisfaction Questionnaire for Medication (TSQM-9), and safety information was recorded.

RESULTS

Of 99 patients, the 24-month PFS rate was 73.7% (95% confidence interval [CI] 63.1-81.7) and 24-month OS rate was 84.2% (95% CI 74.0-90.7). Median TTDP was not reached because few patients experienced disease progression during the study period. The majority of responding patients expressed satisfaction with treatment on each domain of the TSQM-9. Treatment-related adverse events (AEs) occurred in 19.2% of patients, while no serious AEs (SAEs) were related to the study drug.

CONCLUSIONS

Lanreotide depot is an effective and well-tolerated treatment for GEP-NETs in the real-world community setting.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02730104.

Specific classification and new therapeutic targets for neuroendocrine prostate cancer: A patient-based, diagnostic study

Objective: Neuroendocrine prostate cancer (NEPC) is an aggressive variant of prostate cancer (PC) that may arise de novo or in patients previously treated with hormonal therapies for prostate adenocarcinoma as a mechanism of resistance. In our investigation, there appeared to be a strong correlation between neuroendocrine differentiation prostate cancer (NEDPC) and NEPC. The objectives of this study included exploring whether NEDPC is an intermediate stage in the progression of high-risk prostate cancer (HRPC) to NEPC and identifying risk factors and new targets associated with survival in the treatment of NEPC.

Methods: The selected prostate cancer patients were progressed to high-risk and characterized by neuroendocrine. We collected the clinical data and characteristics of patients with three types of cancer: the incidence of metastasis, site and time of metastasis, recurrence rate, related treatment methods, etc. The similarity and differences of the three groups were compared through experiment and database.

Results: By analyzing the clinical data and immunohistochemical results, we found that there seems to be a clinical feature of neuroendocrine differentiation (NED) status in between when patients progress from PC to NEPC. Finding novel treatment targets would therefore be beneficial by taking into account NEDPC as the stage of PC progression prior to NEPC. The metastasis-free survival curve and the immunohistochemical results are informing us that NEDPC can be a pre-state for diagnosing NEPC.

Conclusion: NEPC is a late PC symptom that is frequently disregarded and has a bad prognosis. Finding novel treatment targets would therefore be beneficial by taking into account NEDPC as the stage of PC progression prior to NEPC.

Survival Benefit of Surgical Resection for Pancreatic Neuroendocrine Tumors With Oligometastatic Liver Metastasis: A Retrospective and Propensity Score-Matching Analysis

Background

Pancreatic neuroendocrine tumors (PanNETs) are a heterogeneous group of pancreatic malignancies. Surgical resection is the only curative treatment option for patients with localized PanNETs, yet the role of cancer-directed surgery (CDS) in the setting of oligometastatic liver metastasis remains a controversy.

Methods

All patients diagnosed with PanNETs and liver-only metastasis from 2010 to 2018 were identified from the SEER database. The biases of baseline characteristics between CDS and no-CDS cohorts were reduced by the propensity score-matching (PSM) method, and the prognostic role of CDS was estimated using the Kaplan–Meier method and Cox regression models. Logistic regression analysis was utilized to identify factors associated with patients who underwent CDS.

Results

A total of 1,270 PanNET patients with oligometastatic liver metastasis were included and analyzed. Of these patients, 283 (22.3%) patients underwent CDS of the primary tumor, while the remaining 987 (77.7%) did not. The OS and CSS were significantly better in the CDS cohort regardless of the propensity score analysis. Multivariate analysis revealed that age, tumor differentiation, tumor location, and lymph node status were significantly associated with patients who were more likely to receive CDS.

Conclusion

Our study demonstrated that CDS was associated with survival benefits in selected patients with PanNETs and liver-only metastasis based on a large population database.

Unique Finding of a Primary Central Nervous System Neuroendocrine Carcinoma in a 5-Year-Old Child: A Case Report

Neuroendocrine tumors (NETs) are rare neoplasms predominantly arising in the gastrointestinal-tract or the lungs of adults. To date, only ten cases of primary central nervous system (CNS) NETs have been reported, with just three of them describing a neuroendocrine carcinoma (NECA) and none occurring in a child. We report on a previously healthy 5-year-old boy, who presented with headaches, nausea and vomiting, and was diagnosed with a left cerebellar solid mass with a cystic component. After gross-total resection, histology revealed a neuroendocrine carcinoma. Molecular analysis of the tumor tissue showed a KRAS-splice-site mutation (c451-3C &gt; T). The KRAS-mutation was discovered to be a maternal germline mutation, previously described as likely benign. After extensive search for an extracranial primary tumor, including Ga-68 DOTANOC-PET-CT, the diagnosis of a primary CNS NECA was established, and proton irradiation was performed. Unfortunately, the patient developed an in-field recurrence just 5 weeks after the end of radiotherapy. The tumor was re-resected with vital tumor tissue. Six cycles of chemotherapy were initiated, consisting of cisplatin, carboplatin, etoposide and ifosfamide. The patient remains disease free 22 months after the end of treatment, supporting the beneficial effect of platinum- and etoposide-based chemotherapy for this tumor entity.

An update on the diagnosis of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) arise from neuroendocrine cells found throughout the gastrointestinal tract and islet cells of the pancreas. The incidence and prevalence of GEP-NENs have been increasing each year due to higher awareness, improved diagnostic modalities, and increased incidental detection on cross-sectional imaging and endoscopy for cancer screening and other conditions and symptoms. GEP-NENs are a heterogeneous group of tumors and have a wide range in clinical presentation, histopathologic features, and molecular biology. Clinical presentation most commonly depends on whether the GEP-NEN secretes an active hormone. The World Health Organization recently updated the classification of GEP-NENs to introduce a distinction between high-grade neuroendocrine tumors and neuroendocrine carcinomas, which can be identified using histology and molecular studies and are more aggressive with a worse prognosis compared to high-grade neuroendocrine tumors. As our understanding of the biology of GEP-NENs has grown, new and improved diagnostic modalities can be developed and optimized. Here, we discuss clinical features and updates in diagnosis, including histopathological analysis, biomarkers, molecular techniques, and radiology of GEP-NENs. We review established diagnostic tests and discuss promising novel diagnostic tests that are currently in development or require further investigation and validation prior to broad utilization in patient care.

Neuroendocrine Tumor with Metachronous Gastrointestinal Stromal Tumor in a Patient: A Case Report

Neuroendocrine tumors (NETs) that arise from neuroendocrine cells can develop in most organs; however, it is rarely found in the duodenal papilla. Conversely, gastrointestinal stromal tumors (GISTs), which are mostly asymptomatic and detected incidentally, are usually found in the stomach and very rarely occur metachronously with NETs. A 42-year-old female with no specific underlying disease underwent gastroscopy due to epigastric pain. Biopsy of enlarged major and minor duodenal papilla confirmed the diagnosis of a NET. Endoscopic papillectomy of the major and minor papillae was performed. Multiple duodenal and jejunal submucosal nodules were seen on biliary CT performed at the 30 months follow-up. Pylorus-preserving pancreaticoduodenectomy was performed due to the suspicion of multiple recurrent NETs and muscularis propria involvement on endoscopic ultrasound. Surgical specimen biopsy confirmed the diagnosis of multiple duodenal and jejunal GIST lesions and a metastatic NET in the duodenal lymph node. We report a rare case of a GIST detected in the duodenum during follow-up after the diagnosis and papillectomy of duodenal papilla NET.

Ampullary and Pancreatic Neuroendocrine Tumors: A Series of Cases and Review of the Literature

The ampulla of Vater is a unique, highly vascularized pouch. Its anatomic transition is halfway along the second part of the duodenum from the foregut to the midgut. According to the World Health Organization’s (WHO) latest nomenclature, carcinoid tumors are now called neuroendocrine tumors (NETs). Knowledge of NETs is important because of their rarity, reclassification, prognosis, and management. NETs involving the ampulla of Vater are extremely rare, constituting <0.05% of gastrointestinal NETs, and involving the pancreas are rare to our knowledge. There are only a few reports of ampullary NETs.

We report two rare NET cases involving the ampulla and pancreas and review the relevant literature. A 71-year-old patient with neurofibromatosis and multiple comorbidities presented with chronic intermittent abdominal pain. Abdominal imaging studies showed a suspicious mass at the level of the ampulla. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound revealed bulging papillae. Histopathology of the biopsied mass revealed a low-grade NET. Given his multiple comorbidities, the patient was scheduled for endoscopic resection. Our second patient was an 83-year-old lady presenting with nausea and vomiting. Abdominal imaging studies revealed a lobular mass over the body of the pancreas. Histopathological examination of fine-needle aspiration of the mass confirmed a well-differentiated low-grade NET. Octreoscan and dotatate scans showed pancreatic, multiple hepatic and metastatic lesions in the left lung and left shoulder. The patient is currently stable after completing peptide receptor radioligand therapy at a tertiary oncology center. Because of the patients’ comorbidities and staging, their management has taken different approaches.

More data and more research are needed for accurate assessment of prognosis; however, a review of the latest literature recommends Whipple resection with lymphadenectomy for all ampullary NETs provided patients can tolerate the procedure. Endoscopic resection or surgical ampullary resection should be performed on contraindicated patients. The majority of ampullary and pancreatic NETs would have metastasized by the time patients sought treatment. Because of their rarity and ill-defined and highly variable presentation, NET diagnosis is always delayed and sometimes incidental; therefore, we emphasize the importance of early diagnosis and management to reduce mortality and morbidity.

From chronic pruritus to neuroendocrine tumor: A case report

Chronic pruritus is a major and distressing symptom of many diseases of dermatological, neurological, psychogenic or systemic origin. This chronic itch could be a presenting sign of malignancy; therefore, paraneoplastic pruritus has also been associated with neuroendocrine tumors (NETs). This article focuses on a patient presenting with chronic pruritus for the past 12 months and who received numerous treatment schemes with very poor clinical improvement, that presented in the hospital for worsening of the chronic pruritus associated with skin rash and significant weight loss (approximately 6 kg over a 2-month period). The laboratory tests showed iron deficiency anemia, eosinophilia and negative tumor markers. In order to investigate the hypoanabolic and anemic syndromes, upper gastrointestinal endoscopy and colonoscopy, which showed no lesions or tumors, were employed. Skin biopsy was performed and antihistaminic and local steroid treatment was initiated. The patient's status worsened within a week and the patient was started on systemic steroid treatment with poor results. Computer tomography was performed to identify any tumor(s) located either in the pelvis or abdomen. A lesion was found in the terminal ileum, identified as a hypervascularized associating bulky lymphadenopathy. The patient was transferred to the surgical ward where right hemicolectomy with manual ileotransverse anastomosis L-L was performed. The histopathological result confirmed NET G2. The patient clinically improved, the skin lesions resolved and the itchiness disappeared. The general status improved significantly. NET G2 diagnosing was possible due to the atypic paraneoplastic sign: chronic pruritus. This case study highlights the association between itch and malignancy and presents an atypical way of NET presentation when all tumor markers remain negative.

Temozolomide in Grade 3 Gastroenteropancreatic Neuroendocrine Neoplasms: A Multicenter Retrospective Review

BACKGROUND

Grade 3 gastroenteropancreatic neuroendocrine neoplasms (G3 GEPNENs) are often aggressive, and the optimal treatment is unclear for this subgroup of neuroendocrine neoplasms (NENs). Temozolomide (TEM)-based regimens have been increasingly used to treat grade 1-2 NENs, but their efficacy in G3 NENs remains undetermined. We aimed to assess the clinical efficacy of TEM-containing regimens in advanced grade 3 GEPNENs.

MATERIALS AND METHODS

A multicenter retrospective review (2008-2018) of patients with metastatic/unresectable G3 GEPNENs who received a TEM-containing regimen was undertaken within a North American partnership to pool data. The primary endpoint was time to treatment failure (TTF). Radiologic response was extracted from local reports.

RESULTS

One hundred and thirty patients in six high-volume NEN centers were included (median age 55, 64% male, 18% functional, 67% pancreatic NEN). Forty-nine percent were well-differentiated, 35% poorly differentiated, and 15% unknown based on local pathology reports. The regimen used was capecitabine and temozolomide (CAPTEM) in 92% and TEM alone in 8%. Radiological response by local assessment was seen in 36% of patients. Median TTF was 3.6 months and median overall survival (OS) 19.2 months. Six percent of patients required discontinuation of therapy due to adverse events. TTF was longer in first-line treatment (7.8 months vs. 2.9 months; hazard ratio, 1.62; 95% confidence interval, 1.11-2.36; p = .015) and in patients with pancreatic NENs (panNENs) compared with gastrointestinal NENs (5.8 months vs 1.8 months; p = .04). The overall response rate was higher in the first-line setting (51% vs 29%; p = .02) and in panNEN (41% vs 23%; p = .04).

CONCLUSION

This is the largest TEM treatment series in G3 NEN, involving collaboration of several major North American NEN centers as a partnership. Thirty-six percent of patients showed some degree of radiographic response, and treatment was generally well tolerated, although the median duration of response was short. Response rates and time to treatment failure were superior in the first-line setting. CAPTEM should be considered a viable treatment option in this setting. Further randomized trials are warranted.

IMPLICATIONS FOR PRACTICE

Neuroendocrine neoplasms (NENs) are heterogeneous, and optimal treatment for aggressive grade 3 (G3) NENs remains undetermined. The capecitabine and temozolomide (CAPTEM) regimen has been used in low-grade pancreas NENs but there are few data for its safety and efficacy in the G3 setting. This article reports on the efficacy of temozolomide-containing regimens, particularly CAPTEM, in management of G3 NENs. The good tolerance and response rate show that CAPTEM should be considered a viable regimen in treatment of G3 NENs pending confirmatory prospective studies.

Weight Maintenance up to 48 Weeks in Patients With Carcinoid Syndrome Treated With Telotristat Ethyl: Pooled Data From the Open-Label Extensions of the Phase III Clinical Trials TELESTAR and TELECAST

Reported incidences of neuroendocrine tumors (NETs) appear to be increasing, possibly due to greater disease awareness and increased accuracy of diagnosis. Approximately 20% of patients with NETs develop carcinoid syndrome (CS), which arises from elevated secretion of bioactive compounds, including serotonin, from NETs. This leads to symptoms including diarrhea and flushing, which result in weight loss and are associated with considerable negative impact on patients' quality of life. We previously reported significant weight gain and improved nutritional status in patients with NETs who were treated with telotristat ethyl (TE) for 12 weeks. In this follow-up analysis, using pooled data from the 36-week open-label extensions of the TELESTAR (NCT01677910) and TELECAST (NCT02063659) phase III trials, we demonstrate that improvements in weight and nutritional parameters were sustained or further improved in patients with CS through to week 48 of treatment with TE. At week 48/end of study, 68.7% of all patients maintained a stable weight or had weight gain and the mean changes from baseline in cholesterol and albumin levels in patients treated with TE were +0.41 mmol/L and -0.34 g/L, respectively. These results indicate that TE, alongside routine clinical practice, may provide long-term benefits in nutritional intake and weight evolution in patients with CS.

Comparing the Effect of Multiple Histone Deacetylase Inhibitors on SSTR2 Expression and [111In]In-DOTATATE Uptake in NET Cells

Simple Summary

Patients diagnosed with neuroendocrine tumors (NETs) are often treated with peptide receptor radionuclide therapy (PRRT). This therapy targets the somatostatin type-2 receptors (SSTR2) frequently overexpressed on these types of tumors. Although this therapy has proven to be effective, complete responses are rare and therapy improvement is desirable. We aimed to increase SSTR2 expression on NET cells, potentially increasing the number of patients eligible for SSTR2-targeted PRRT and improving clinical outcomes. We used histone deacetylase inhibitors (HDACis) to manipulate the epigenetic machinery and hereby aimed to increase SSTR2 gene transcription. Our results showed that the HDACis increased SSTR2 expression in several NET cell lines. Moreover, the uptake of radiolabeled DOTATATE, the tracer used for PRRT, was enhanced. The observed reversibility profile after HDACi withdrawal of the induced effects suggests that proper timing of HDACi treatment is likely essential.

Abstract

The aim of this study was to increase somatostatin type-2 receptor (SSTR2) expression on neuroendocrine tumor (NET) cells using histone deacetylase inhibitors (HDACis), potentially increasing the uptake of SSTR2-targeted radiopharmaceuticals and subsequently improving treatment efficacy of peptide receptor radionuclide therapy (PRRT). Human NET cell lines BON-1, NCI-H727, and GOT1 were treated with HDACis (i.e., CI-994, entinostat, LMK-235, mocetinostat, panobinostat, or valproic acid (VPA); entinostat and VPA were the HDACis tested in GOT1 cells) to examine SSTR2 mRNA expression levels and uptake of SSTR2-targeting radiotracer [¹¹¹In]In-DOTATATE. Reversibility of the induced effects was examined after drug-withdrawal. Finally, the effect of VPA on radiosensitivity was investigated. A strong stimulatory effect in BON-1, NCI-H727, and GOT1 cells was observed after HDACi treatment, both on SSTR2 mRNA expression levels and [¹¹¹In]In-DOTATATE uptake. The effects of the HDACis were largely reversible over a period of seven days, demonstrating largest reductions within the first day. The reversibility profile of the induced effects suggests that proper timing of HDACi treatment is most likely essential for a beneficial outcome. In addition to increasing SSTR2 expression levels, VPA enhanced the radiosensitivity of all cell lines. In conclusion, HDACi treatment increased SSTR2 expression, and radiosensitivity was also enhanced upon VPA treatment.

Opportunities to Improve Symptom Control with Somatostatin Congeners in GEP-NETs: A Review of Key Issues

Octreotide acetate (octreotide) is the most prescribed and most studied somatostatin congener, or analog, for gastroenteropancreatic neuroendocrine tumors (GEP‐NETs) and carcinoid syndrome, the latter of which may be characterized by debilitating diarrhea and flushing. Approved in the U.S. more than 30 years ago, octreotide is widely used to control the symptoms of carcinoid syndrome and has been shown to demonstrate antiproliferative activity. The two formulations available in the U.S. include a subcutaneous immediate‐release (IR) injection introduced in 1989 and a long‐acting repeatable (LAR) intramuscular injection approved in 1999. Lanreotide depot (lanreotide), a more recent somatostatin congener, has been available in the U.S. since 2014.

Despite widespread use of octreotide LAR, several key challenges exist with the current depot‐based treatment paradigm. Studies indicate that LAR formulations are associated with continued unmet patient needs, owing in part to a loss of bioactivity over time that may necessitate progressive supplemental treatment with IR octreotide to adequately control symptoms. Clinicians should understand the key differences in the pharmacokinetic profiles of the LAR and IR formulations that may contribute to bioactivity loss and somatostatin receptor desensitization. In addition, there is a need to re‐evaluate the role of IR octreotide in combination with depot therapy to provide consistent bioavailability and better control of carcinoid syndrome symptoms.

The purpose of this review is to explore all these issues and to re‐establish a rationale for the IR formulation, particularly with respect to novel use cases and its use during the COVID‐19 pandemic.

This review explores key challenges with depot‐based treatment of gastroenteropancreatic neuroendocrine tumors with octreotide and the key differences between the LAR and IR formulations.