The Increasing Incidence of Neuroendocrine Neoplasms Worldwide: Current Knowledge and Open Issues

Predicting liver metastasis in pancreatic neuroendocrine tumors with an interpretable machine learning algorithm: a SEER-based study

Background

Liver metastasis is the most common site of metastasis in pancreatic neuroendocrine tumors (PaNETs), significantly affecting patient prognosis. This study aims to develop machine learning algorithms to predict liver metastasis in PaNETs patients, assisting clinicians in the personalized clinical decision-making for treatment.

Methods

We collected data on eligible PaNETs patients from the Surveillance, Epidemiology, and End Results (SEER) database for the period from 2010 to 2021. The Boruta algorithm and the Least Absolute Shrinkage and Selection Operator (LASSO) were used for feature selection. We applied 10 different machine learning algorithms to develop models for predicting the risk of liver metastasis in PaNETs patients. The model's performance was assessed using a variety of metrics, including the area under the receiver operating characteristic curve (AUC), the area under the precision-recall curve (AUPRC), decision curve analysis (DCA), calibration curves, accuracy, sensitivity, specificity, F1 score, and Kappa score. The SHapley Additive exPlanations (SHAP) were employed to interpret models, and the best-performing model was used to develop a web-based calculator.

Results

The study included a cohort of 7,463 PaNETs patients, of whom 1,356 (18.2%) were diagnosed with liver metastasis at the time of initial diagnosis. Through the combined use of the Boruta and LASSO methods, T-stage, N-stage, tumor size, grade, surgery, lymphadenectomy, chemotherapy, and bone metastasis were identified as independent risk factors for liver metastasis in PaNETs. Compared to other machine learning algorithms, the gradient boosting machine (GBM) model exhibited superior performance, achieving an AUC of 0.937 (95% CI: 0.931-0.943), an AUPRC of 0.94, and an accuracy of 0.87. DCA and calibration curve analyses demonstrate that the GBM model provides better clinical decision-making capabilities and predictive performance. Furthermore, the SHAP framework revealed that surgery, N-stage, and T-stage are the primary decision factors influencing the machine learning model's predictions. Finally, based on the GBM algorithm, we developed an accessible web-based calculator to predict the risk of liver metastasis in PaNETs.

Conclusion

The GBM model excels in predicting the risk of liver metastasis in PaNETs patients, outperforming other machine learning models and providing critical support for developing personalized medical strategies in clinical practice.

The radiologic spectrum of neuroendocrine tumors in emergent care

Neuroendocrine tumors (NETs) are a diverse group of neoplasms whose prevalence is increasing globally, primarily due to advancements in diagnostic techniques. NETs arise from cells of the diffuse endocrine system and can occur in various locations, with the gastrointestinal tract being the most common. Their diverse clinical presentations, which range from asymptomatic to severe hormone-induced syndromes, pose significant diagnostic challenges. In emergency care, prompt recognition and management of complications such as bowel obstruction, ischemic events, hormonal crises, and metastases are critical. This review discusses the radiologic spectrum of NETs in emergent care, emphasizing the role of imaging in timely diagnosis and intervention.

Towards a better registration of neuroendocrine neoplasms: The results of the Italian retrospective population-based study

BACKGROUND

The increasing incidence, rapidly evolving classification, rarity and heterogeneity of neuroendocrine neoplasms (NENs) pose challenges to NEN registration including difficulty in distinguishing neuroendocrine carcinoma (NEC) and neuroendocrine tumours (NETs). Thus, in Italy a higher NEC incidence was reported. Focusing on gastroenteropancreatic (GEP) NEN, we aimed to review GEP NEN, and in particular cases of neuroendocrine carcinoma, not otherwise specified (NOS) and estimate the incidence of NEN, NET and NEC of the GEP.MethodsWe launched a pilot study examining cases of neuroendocrine carcinomas NOS (ICD-O3 code 8246) of GEP incidents in the years 2012-2020. Cancer registries (CRs) reviewed information included in the pathology report regarding differentiation and tumour cells proliferation to decide whether to confirm the case as neuroendocrine carcinoma NOS or register it as NET or NEC. After the review, we estimated the GEP NEN, NET and NEC incidence.

RESULTS

Nine CRs contributed to the pilot study. After review, in all CRs, only 31% of GEP NOS neuroendocrine carcinomas were confirmed; 50% were recoded as NETs, and approximately 17% of cases were non-NENs. The IR of GEP NENs was 2.99/100,000, and the incidence of NETs was higher than that of NECs.

CONCLUSION

After the review, the incidence of GEP NEN, NET and NEC in the eight Italian CRs involved was comparable to that reported in other European countries.

IMPACT

Our results confirmed that heterogeneity of cancer registries in the registration of NEN requires collaborative work to define and promote a standard definition to be extended to all Italian registries.

Combined Neuroendocrine Carcinoma and Hepatocellular Carcinoma of the Liver: Systematic Literature Review Suggests Implementing Biological Characterization to Optimize Therapeutic Strategy

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine tumors (MINEN) of the liver are exceptionally rare, with limited data available regarding their clinical behavior, pathogenesis, and optimal management. The coexistence of hepatocellular carcinoma (HCC) and neuroendocrine carcinoma (NEC) within the liver presents diagnostic and therapeutic challenges.

METHODS

A systematic literature search was conducted on PubMed, identifying cases of primary mixed HCC and NEC in the liver. The search adhered to PRISMA guidelines, and relevant studies were critically analyzed. A total of 45 documented cases were reviewed, focusing on patient demographics, clinical characteristics, treatment strategies, and outcomes.

RESULTS

Most patients (90%) were male, with a median age of 66.5 years. Hepatitis B or C infection was present in 74% of cases, and liver cirrhosis was reported in 38%. The combined type was the most frequently observed histological pattern (65%). Treatment modalities varied, including transarterial chemoembolization (TACE), radiofrequency ablation (RFA), surgery, and systemic therapies. The median overall survival was 10 months, highlighting the aggressive nature of these tumors.

CONCLUSIONS

Given the rarity and poor prognosis of hepatic MINEN tumors, multidisciplinary management is essential. Advanced molecular profiling may offer insights into tumor biology and potential therapeutic targets. Future research should explore novel systemic therapies, including immune checkpoint inhibitors, to improve patient outcomes.

Real-World Study of Lanreotide Autogel in Routine Practice in Patients with Gastroenteropancreatic Neuroendocrine Tumors (GEP-NETs) in Hong Kong and Taiwan

INTRODUCTION

There is a lack of data on the efficacy, effectiveness, and safety of lanreotide autogel in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) of Chinese ethnicity. This noninterventional, retrospective study evaluated the effectiveness and safety of lanreotide autogel in patients of Chinese ethnicity with GEP-NETs in clinical practice.

METHODS

Patients' charts were abstracted from five hospitals in Hong Kong and Taiwan (July-September 2021), where lanreotide autogel is approved for treating GEP-NETs. Included patients were adults with unresectable, metastatic, or locally advanced GEP-NETs who received a first injection (index) of lanreotide autogel 120 mg between 01 January 2017 and 30 June 2020 (planned sample size: N = 30). Follow-up ran from index to a maximum of 48 (± 4) weeks or until disease progression, start of new antitumor treatment, or death. The primary endpoint was progression-free survival (PFS) rate at week 48 (±4), and secondary endpoints included PFS rate at week 24 (±4), estimated using Kaplan-Meier analyses. All analyses were descriptive.

RESULTS

Of 27 patients enrolled, 22 (81.5%) had 48 weeks of follow-up. Tumors of pancreatic origin were the most common (73.9%). PFS rate was 0.96 (95% confidence interval: 0.72 - 0.99) at 24 weeks and 0.82 (0.53-0.94) at 48 weeks. Overall, 74.1% patients experienced ≥ 1 treatment-emergent adverse event; none were serious. No deaths were reported.

CONCLUSIONS

Lanreotide autogel was well tolerated and showed good tumor control rate in a real-world setting. These findings align with results from previous studies in Caucasian, Japanese, and Korean patients, thus supporting lanreotide autogel for treating patients with GEP-NETs of Chinese ethnicity.

Autoimmune Pancreatitis Mimicking a Pancreatic Neuroendocrine Tumor: A Case Report with a Literature Review

Autoimmune pancreatitis (AIP) is a rare chronic pancreatitis subtype that often mimics pancreatic cancer due to the overlapping clinical and radiological features, posing significant diagnostic challenges. Similarly, distinguishing AIP from pancreatic neuroendocrine neoplasms (PanNENs), which present with nonspecific symptoms, adds complexity to clinical evaluations. We present the case of a 46-year-old male with recurrent acute idiopathic pancreatitis. Abdominal computed tomography (CT) revealed a 25 mm hypodense mass in the pancreatic tail with mild arterial contrast enhancement. Magnetic resonance imaging (MRI) showed the mass to be hypointense on T2-weighted sequences, with no diffusion restriction and an enhancement pattern akin to normal pancreatic tissue. The endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) was inconclusive. Gallium-68 DOTATATE positron emission tomography-CT (Ga-68 DOTATATE PET-CT) showed an increased tracer uptake, leading to a distal pancreatectomy with a splenectomy. Histopathology demonstrated chronic sclerotic pancreatitis with inflammatory infiltrates. Elevated serum IgG4 levels confirmed the diagnosis of type 1 AIP Differentiating AIP from pancreatic malignancies, including PanNENs, is both critical and complex. This case highlights a misdiagnosis of PanNENs in a patient with focal AIP, where neuroendocrine hyperplasia and islet cell clusters within fibrotic areas mimicked PanNENs, even on Ga-68 PET-CT. The findings emphasize the potential for false positives with Ga-68 DOTATATE PET-CT and the importance of integrating clinical, radiological, and histological data for an accurate diagnosis.

Nutritional aspects in neuroendocrine neoplasms. bridging the gap between dietary interventions and cancer care strategies: a scoping review

PURPOSE

Neuroendocrine neoplasms (NENs) represent heterogeneous tumors arising from neuroendocrine cells in different organs. Despite growing interest in the nutritional aspects of NEN management, research in this area is limited. Aim of this review is to summarize the current state of knowledge, highlight research gaps, and underscore the significance of nutrition in the comprehensive care of NEN patients.

METHODS

We conducted an extensive bibliographic search focusing on studies (including retrospective and prospective studies, systematic reviews, case series, and guidelines) exploring the relationship between nutritional assessments, dietary interventions, micronutrient deficiencies, and their impact on NEN outcomes.

RESULTS

Significant gaps exist in current research, particularly in understanding the specific nutritional needs of NEN patients and how tailored nutritional interventions can improve clinical outcomes. Evidence suggests that a high-fat Western diet may promote the growth of NEN, while a Mediterranean diet may help lower insulin levels and strengthen the immune system, potentially preventing tumor development. The ketogenic diet and intermittent fasting may also have positive impacts. Addressing common micronutrient deficiencies, such as vitamin D and niacin, is crucial to mitigate disease progression. There's a crucial need for future studies to include a comprehensive nutritional assessment incorporating patient-reported outcomes, to fully capture the impact of nutritional strategies.

CONCLUSION

Nutritional management, an important but under-researched facet of NEN treatment, significantly improves patients' quality of life and survival. Integrating nutrition into personalized cancer care is essential, highlighting the role of nutritional strategies in optimizing patient outcomes.

Phase II Study of Nanoliposomal Irinotecan (Nal-IRI) with 5-Fluorouracil and Leucovorin in Refractory Advanced High-Grade Neuroendocrine Cancer of Gastroenteropancreatic (GEP) or Unknown Origin

BACKGROUND

Neuroendocrine carcinomas (NECs) are treated with a frontline platinum-etoposide combination with no standard second-line therapies. We explored a novel combination of nanoliposomal irinotecan (Nal-IRI), 5-fluorouracil (5-FU), and leucovorin (LV) in advanced refractory NECs and investigated the impact of UGT1A1*28 polymorphism on treatment outcomes and toxicity.

METHODS

We conducted an open-label, single-arm, multi-center Phase 2 trial in advanced NEC patients of gastroenteropancreatic (GEP) or unknown origin with progression or intolerance to first-line therapy. Eligible patients received nal-IRI 70 mg/m2 and leucovorin 400 mg/m2, followed by 5-FU 2400 mg/m2 biweekly till disease progression or unacceptable toxicity. The primary endpoint was the objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. Next-generation sequencing (NGS) was performed on blood/tissue samples at baseline and during treatment.

RESULTS

Eleven patients were enrolled, with nine evaluable for the primary endpoint. Seven were male, the median age was 66.7 years, and the median Ki-67 was 90%. We observed partial response in one patient, stable disease in six patients, and progressive disease in two patients. The median OS was 9.4 months (95% CI 2.9-29.3), and the median PFS was 4.4 months (95% CI 1.7-6.7). The most common adverse events were diarrhea (45%), nausea (45%), vomiting (45%), and fatigue (45%). The most common genetic mutations on NGS were TP53 (88.9%), CHEK2 (88.9%), and APC (33.3%). Patients with CHEK2 and APC mutation had longer PFS (p = 0.005 and p = 0.013, respectively). UGT1A1*28 polymorphism was not associated with OS, PFS, or toxicity.

CONCLUSION

Nal-IRI with 5-FU/LV is a safe and effective treatment for refractory high-grade NECs of GEP or unknown origin. Future studies should explore novel combinations with Nal-IRI in high-grade NECs both in frontline and refractory settings.

Venous Thromboembolism in Patients with Neuroendocrine Neoplasms: A Systematic Review of Incidence, Types, and Clinical Outcomes

Background: Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with unique biological characteristics and complications, including thromboembolism. This systematic review evaluates the incidence, types, and clinical outcomes of venous thromboembolic events (VTEs) in NEN patients. Methods: A systematic search of PubMed, Scopus, and Embase was conducted to identify studies on TEs in NENs. Eligible studies included case reports, case series, and retrospective cohort studies reporting VTEs, including deep vein thrombosis (DVT), pulmonary embolism (PE), and visceral vein thrombosis (VVT). Data were extracted on tumor site, functionality, differentiation grade, and VTE type. Results: In total, 33 studies were included, comprising 26 case reports, 2 case series, and 5 retrospective cohort studies. VTE prevalence ranged from 7.5% to 33% across studies. The most common VTEs were DVT, PE, and portal vein thrombosis (PVT). A meta-analysis revealed a pooled VTE prevalence of 11.1% (95% CI: 9.07-13.53%). Pancreatic NENs exhibited the highest thrombotic burden, particularly in poorly differentiated and advanced-stage tumors. Functioning tumors, including glucagonomas and ACTH-secreting NENs, were strongly associated with VTEs, potentially related to their systemic effects on coagulation and inflammation. Conclusions: Venous thromboembolism is a significant complication in NEN patients, especially in advanced or poorly differentiated tumors. Early detection and targeted management are critical for improving outcomes. Further investigations are required to clarify the mechanisms underlying thromboembolism in NENs and to develop optimized prophylactic and therapeutic strategies tailored to this patient population.

miRNA profile in pancreatic neuroendocrine tumors: Preliminary results

OBJECTIVE

Our understanding of the pathophysiology of pancreatic neuroendocrine tumors (PanNETs) remains incomplete, largely due to their historically underestimated incidence and the perception of these tumors as rare and slow-growing cancers. Additionally, conventional reliance on histological examination alone is gradually being supplemented by the exploration and introduction of molecular biomarkers, such as microRNAs (miRNAs). As miRNAs modulate the expression of multiple genes and pathways involved in the tumorigenesis of PanNETs, these biomarkers hold considerable promise for diagnosis and prognosis applications. In this study, we aimed to identify miRNAs as tissue markers associated with the diagnosis of PanNETs.

METHODS

We conducted a case-control study including: 7 PanNETs and 19 nontumoral pancreatic tissues obtained from Romanian patients. The samples underwent miRNA profiling via quantitative RT-PCR to assess the expression of 84 miRNAs. Our results were compared with those obtained by reanalyzing a public dataset. Furthermore, we structured our miRNA expression data according to their targeted mRNAs and their roles in signaling pathways.

RESULTS

Fourteen miRNAs (miR-1, miR-133a-3p, miR-210-3p, miR-7-5p, miR-10a-5p, miR-92b-3p, miR-132-3p, miR-221-3p, miR-29b-3p, miR-107, miR-103a-3p, let-7b-5p, miR-148a-3p, and miR-202-3p) were identified as differentially expressed by comparing PanNETs with pancreatic nontumoral tissues, with six miRNAs (miR-7-5p, miR-92b-3p, miR-29b-3p, miR-107, miR-103a-3p, and miR-148a-3p) also found in the public dataset analyzed. Bioinformatic analysis revealed that the 14 identified miRNAs target 17 genes. Reanalyzing two public gene expression datasets, five of these genes have been found differentially expressed in PanNET compared to controls.

CONCLUSIONS

Our preliminary results, albeit limited by a small sample size, highlighted a specific miRNA expression pattern able to distinguish tumoral from normal pancreatic tissue. The diagnostic performance of these miRNAs, matching with circulating miRNAs and validated in more homogeneous and large cohorts, could represent a starting point for improving the diagnostic accuracy of PanNETs.

"Vascular tuft sign" in neuroendocrine tumors of the pancreas

The often well-developed microvasculature in pancreatic neuroendocrine tumors (PanNETs) has been studied from different perspectives. However, some detailed structural findings have received less attention. Our objective is to study an overlooked event in PanNETs: "enclosed vascular tufts" (EVTs). For this purpose, 39 cases of PanNETs were examined with conventional (including serial sections) and immunochemistry procedures. In typical EVTs, the results show: 1) an insulated terminal vascular area, with a globular (glomeruloid) aspect, formed by a cluster of coiled microvessels, presenting CD31-, CD34-positive endothelial cells, αSMA-positive pericytes, and perivascular CD34-positive stromal cells/telocytes, separated by a pseudoglandular space from the surrounding trabeculae of tumor neuroendocrine cells; and 2) a pedicle joining the insulated terminal vascular area, with connective tissue tracts around the enclosing tumor trabeculae. EVTs predominate in the trabecular and nested gyriform pattern of PanNETs, with tumor trabeculae that follow a ribbon coil (winding ribbon pattern) around small vessels, which acquire a tufted image. In EVTs, secondary modifications may occur (fibrosis, hyalinization, myxoid changes, and calcification), coinciding or not with those of the connective tracts. In conclusion, the typical characteristics of unnoticed EVTs allow them to be considered as a morphological sign of PanNETs (a vascular tuft sign). Further in-depth studies are required, mainly to assess the molecular pathways that participate in vascular tuft formation and its pathophysiological implications.

Adverse Events of Radioligand Therapy in Patients with Progressive Neuroendocrine Neoplasms: The Biggest Eastern European Prospective Study

BACKGROUND

Neuroendocrine neoplasms (NENs) are neoplastic tumors developing in every part of the body, mainly in the gastrointestinal tract and pancreas. Their treatment involves the surgical removal of the tumor and its metastasis, long-acting somatostatin analogs, chemotherapy, targeted therapy, and radioligand therapy (RLT).

MATERIALS AND METHODS

A total of 127 patients with progressive neuroendocrine neoplasms underwent RLT-4 courses, administered every 10 weeks-with the use of 7.4 GBq [177Lu]Lu-DOTA-TATE or tandem therapy with 1.85 GBq [177Lu]Lu-DOTA-TATE and 1.85 GBq [90Y]Y-DOTA-TATE. Assessment of short- and long-term complications, as well as the calculation of progression-free survival (PFS) and overall survival (OS) were performed.

RESULTS

RLT caused a statistically but not clinically significant decrease in blood morphology parameters during both short- and long-term observations. Glomerular filtration rate (GFR) significantly decreased only in a long-term observation after RLT; however, it was clinically acceptable. Computed predictions of progression-free survival (PFS) and overall survival (OS) indicated that five years post-RLT, there is a 74% chance of patients surviving, with only a 58.5% likelihood of disease progression.

CONCLUSIONS

Computed predictions of PFS and OS confirmed treatment efficiency and good patient survival. RLT should be considered a safe and reliable line of treatment for patients with progressive NENs as it causes only a low number of low-grade adverse events.

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.

Factors associated with gastric and duodenal neuroendocrine tumors: A multicenter case-control study

BACKGROUND AND AIMS

The incidence of gastric and duodenal neuroendocrine tumors (GNET and DNET, respectively) is increasing, however associated factors of these diseases are not well known. Here, we investigated the factors associated with GNET and DNET.

METHODS

Patients with GNET and DNET presenting at eight tertiary referral centers between 2001 and 2020 were included and compared with healthy controls who underwent upper endoscopic screening. Clinical factors and laboratory data were analyzed to determine associated factors of GNET and DNET.

RESULTS

Overall, 396 patients with GNET and 193 patients with DNET were included and compared with 1725 healthy controls. Multivariate analysis showed that age (odds ratio [OR] 0.98), diabetes (OR 1.72), hypertension (OR 1.97), low serum high-density lipoprotein cholesterol (HDL-C) levels (OR 2.54), and past/present H. pylori infection (OR 1.46) were significantly associated with GNET. In contrast, DNET was significantly associated with diabetes (OR 1.80), hypertension (OR 1.68), low serum HDL-C levels (OR 2.29), and past/present H. pylori infection (OR 5.42). In the sex-based subgroup analysis in GNET, current smoking was strongly associated in women (OR 9.85), but not in men.

CONCLUSIONS

This study identified several common metabolic factors associated with GNET and DNET. Additionally, some factors had sex-specific associations.

An Overview of Altered Pathways Associated with Sensitivity to Platinum-Based Chemotherapy in Neuroendocrine Tumors: Strengths and Prospects

Neuroendocrine neoplasms (NENs) are a diverse group of malignancies with a shared phenotype but varying prognosis and response to current treatments. Based on their morphological features and rate of proliferation, NENs can be classified into two main groups with a distinct clinical behavior and response to treatment: (i) well-differentiated neuroendocrine tumors (NETs) or carcinoids (with a low proliferation rate), and (ii) poorly differentiated small- or large-cell neuroendocrine carcinomas (NECs) (with a high proliferation rate). For certain NENs (such as pancreatic tumors, higher-grade tumors, and those with DNA damage repair defects), chemotherapy is the main therapeutic approach. Among the different chemotherapic agents, cisplatin and carboplatin, in combination with etoposide, have shown the greatest efficacy in treating NECs compared to NETs. The cytotoxic effects of cisplatin and carboplatin are primarily due to their binding to DNA, which interferes with normal DNA transcription and/or replication. Consistent with this, NECs, which often have mutations in pathways involved in DNA repair (such as Rb, MDM2, BRCA, and PTEN), have a high response to platinum-based chemotherapy. Identifying mutations that affect molecular pathways involved in the initiation and progression of NENs can be crucial in predicting the response to platinum chemotherapy. This review aims to highlight targetable mutations that could serve as predictors of therapeutic response to platinum-based chemotherapy in NENs.

An update on the safety of lanreotide autogel for the treatment of patients with neuroendocrine tumors

INTRODUCTION

Neuroendocrine neoplasms (NENs) are a rare group of tumors originating from neuroendocrine cells in various organs. They include neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs), which differ in biological behavior and prognosis. NETs are usually well-differentiated and slow-growing, while NECs are poorly differentiated and more aggressive. Management of NETs often involves somatostatin analogs like octreotide and lanreotide to control tumor growth and alleviate symptoms, especially in well-differentiated NETs. Lanreotide is used to control tumor growth, and both lanreotide and octreotide alleviate symptoms. Treatment approaches may vary depending on the specific type and grade of the neuroendocrine neoplasm.

AREAS COVERED

This review provides an update on the safety of lanreotide autogel in treating patients with NETs, through a comprehensive review of clinical trials, post-marketing surveillance, real-world evidence, and its safety profile. Specific adverse events, side effects, and potential risks associated with lanreotide autogel are discussed, along with risk mitigation strategies and recommendations for patient monitoring.

EXPERT OPINION

The findings highlight the overall safety of lanreotide autogel in managing NETs, focusing on its efficacy in controlling hormone secretion, tumor progression, and symptom management. New safety concerns and precautions are also addressed to help healthcare providers make informed decisions when prescribing lanreotide autogel.

Outcome of Endoscopic Resection of Rectal Neuroendocrine Tumors ≤ 10 mm

BACKGROUND AND AIM

Guidelines suggest endoscopic resection for rectal neuroendocrine tumors (rNETs) < 10 mm, but the most appropriate resection technique is unclear. In real-life clinical practice, the endoscopic removal of unrecognized rNETs can take place with "simple" techniques and without preliminary staging. The aim of the current study is to report our own experience at a referral center for both neuroendocrine neoplasms and endoscopy.

METHODS

Retrospective analyses of polypectomies were performed at the Humanitas Research Hospital for rNETs (already diagnosed or previously unrecognized).

RESULTS

A total of 19 patients were included, with a median lesion size of 5 mm (range 3-10 mm). Only five lesions were suspected as NETs before removal and underwent endoscopic ultrasound (EUS) before resection, being removed with advanced endoscopic techniques. Unsuspected rNETs were removed by cold polypectomy in eleven cases, EMR in two, and biopsy forceps in one. When described, the margins were negative in four cases, positive in four (R1), and indeterminate in one. The median follow-up was 40 months. A 10 mm polypoid lesion removed with cold snare polypectomy (G2 R1) needed subsequent surgery. Eighteen patients underwent EUS after a median time of 6.5 months from resection. The EUS identified local recurrence after 14 months in a 7 mm polypoid lesion removed with cold snare polypectomy (G1 R1); the lesion was treated with cap-assisted EMR. For all the other lesions, the follow-up was negative.

CONCLUSIONS

When rNETs are improperly removed without prior staging, caution must be exercised. The data from our cohort suggest that even if inappropriate resection had happened, patients may be safely managed with early EUS evaluation.

Improvements and future perspective in diagnostic tools for neuroendocrine neoplasms

INTRODUCTION

Neuroendocrine neoplasms (NENs) represent a complex group of tumors arising from neuroendocrine cells, characterized by heterogeneous behavior and challenging diagnostics. Despite advancements in medical technology, NENs present a major challenge in early detection, often leading to delayed diagnosis and variable outcomes. This review aims to provide an in-depth analysis of current diagnostic methods as well as the evolving and future directions of diagnostic strategies for NENs.

AREA COVERED

The review extensively covers the evolution of diagnostic tools for NENs, from traditional imaging and biochemical tests to advanced genomic profiling and next-generation sequencing. The emerging role of technologies such as artificial intelligence, machine learning, and liquid biopsies could improve diagnostic precision, as could the integration of imaging modalities such as positron emission tomography (PET)/magnetic resonance imaging (MRI) hybrids and innovative radiotracers.

EXPERT OPINION

Despite progress, there is still a significant gap in the early diagnosis of NENs. Bridging this diagnostic gap and integrating advanced technologies and precision medicine are crucial to improving patient outcomes. However, challenges such as low clinical awareness, limited possibility of noninvasive diagnostic tools and funding limitations for rare diseases like NENs are acknowledged.

Clinical Outcome of Patients with Gastric, Duodenal, or Rectal Neuroendocrine Tumors after Incomplete Endoscopic Resection

Objectives: Our aim was to investigate the clinical outcome of patients with well-differentiated gastric, duodenal, and rectal neuroendocrine tumors after treatment with incomplete endoscopic resection due to the finding of microscopic positive resection margins (R1). Methods: This is a retrospective analysis of consecutive patients with type 1 gastric, non-ampullary non-functioning duodenal, or rectal neuroendocrine neoplasms with positive R1 margins after endoscopic resection. The rate of tumor recurrence and progression-free survival were considered to be the study's main endpoints. Statistical analysis was performed using MedCalc® v.17 software and a p-value of <0.05 was considered significant. A Cox proportional-hazard regression was performed to identify risk factors for disease recurrence/progression. Results: After evaluating 110 patients, a total of 58 patients were included in the final analysis (15 gastric NENs, 12 duodenal NENs, and 31 rectal NENs). After evidence of endoscopic R1 resection had been gathered, 26 patients (44.8%) underwent an endoscopic/surgical extension of the previous resection. Tumor progression (all local recurrences) occurred in five out of fifty-eight patients (8.6%) with a median PFS of 36 months. There were no tumor-related deaths. G2 grading and the gastric primary tumor site were the only features significantly associated with the risk of recurrence of the disease (HR: 11.97 [95% CI: 1.22-116.99], HR: 12.54 [95% CI: 1.28-122.24], respectively). Conclusions: Tumor progression rarely occurs in patients with microscopic positive margin excision (R1) after endoscopic resection and does not seem to affect patients' clinical outcomes.

Neuroendocrine neoplasms: Consensus on a patient care pathway

People with neuroendocrine neoplasms (NENs) face a multitude of challenges, including delayed diagnosis, low awareness of the cancer among healthcare professionals and limited access to multidisciplinary care and expert centres. We have developed the first patient care pathway for people living with NENs in England to guide disease management and help overcome these barriers. The pathway was developed in two phases. First, a pragmatic review of the literature was conducted, which was used to develop a draft patient care pathway. Second, the draft pathway was then updated following semi-structured interviews with carefully selected expert stakeholders. After each phase, the pathway was discussed among a multidisciplinary, expert advisory group (which comprised the authors and the Deputy Chief Operating Officer, West Suffolk NHS Foundation Trust), who reached a consensus on the ideal care pathway. This article presents the outputs of this research. The pathway identified key barriers to care and highlighted how these may be addressed, with many of the findings relevant to the rest of the UK and international audiences. NENs are increasing in incidence and prevalence in England, compounding pre-existing inequities in diagnosis and disease management. Effective integration of this pathway within NHS England will help achieve optimal, equitable care provision for all people with NENs, and should be feasible within the existing expert multidisciplinary teams across the country.

Type 3 gastric neuroendocrine neoplasms: the rising promise of conservative endoscopic management

Gastric neuroendocrine neoplasms (g-NENs) are rare tumors arising from the gastric enterochromaffin-like cells. Recent data suggests an increased detection rate, attributed to more frequent esophagogastroduodenoscopies. While type 3 g-NENs were historically deemed aggressive, emerging research indicates potential for conservative management, especially endoscopic resection, in well-differentiated, small tumors. European guidelines now advocate for endoscopic intervention in selected cases, but North American guidelines remain more conservative. Key factors influencing outcomes are tumor size, grading, and depth of gastric wall infiltration. Endoscopic resection has shown promise for tumors confined to submucosal layers without lymphovascular invasion. Given the complexities, a multidisciplinary team approach is essential for management decisions. Current insights are largely based on retrospective studies, underscoring the need for prospective research to optimize endoscopic approaches.

Management of type 1 gastric neuroendocrine tumors: an 11-year retrospective single-center study

BACKGROUND

Type 1 gastric neuroendocrine tumors (NETs) are relatively rare to the extent that some physicians have little experience in diagnosing and treating them. The purpose of this study was to increase the understanding of the disease by analyzing and summarizing the management and prognoses of patients with type 1 gastric NETs at our center.

METHODS

The data of 229 patients (59.4% female) with type 1 gastric NETs who were treated at our center during 2011-2022 were retrospectively analyzed.

RESULTS

The average patient age was 50.5 ± 10.8 years. Multiple tumors affected 72.5% of the patients; 66.4% of the tumors were < 1 cm, 69.4% were NET G1, and 2.2% were stage III-IV. A total of 76.9% of the patients had received endoscopic management, 60.7% had received traditional Chinese medicine treatment, 10.5% received somatostatin analogues treatment, and 6.6% underwent surgical resection. Seventy patients (41.2%) experienced the first recurrence after a median follow-up of 31 months (range: 2-122 months), and the median recurrence-free time was 43 months. The 1-, 2-, and 3-year cumulative recurrence-free survival rates were 71.8%, 56.8%, and 50.3%, respectively. During a median follow-up of 39 months (range: 2-132 months), one patient had bilateral pulmonary metastasis, and no disease-related deaths were observed.

CONCLUSION

Type 1 gastric NETs have a high recurrence rate and a long disease course, underscoring the importance of long-term and comprehensive management.

Prioritization of Fluorescence In Situ Hybridization (FISH) Probes for Differentiating Primary Sites of Neuroendocrine Tumors with Machine Learning

Determining neuroendocrine tumor (NET) primary sites is pivotal for patient care as pancreatic NETs (pNETs) and small bowel NETs (sbNETs) have distinct treatment approaches. The diagnostic power and prioritization of fluorescence in situ hybridization (FISH) assay biomarkers for establishing primary sites has not been thoroughly investigated using machine learning (ML) techniques. We trained ML models on FISH assay metrics from 85 sbNET and 59 pNET samples for primary site prediction. Exploring multiple methods for imputing missing data, the impute-by-median dataset coupled with a support vector machine model achieved the highest classification accuracy of 93.1% on a held-out test set, with the top importance variables originating from the ERBB2 FISH probe. Due to the greater interpretability of decision tree (DT) models, we fit DT models to ten dataset splits, achieving optimal performance with k-nearest neighbor (KNN) imputed data and a transformation to single categorical biomarker probe variables, with a mean accuracy of 81.4%, on held-out test sets. ERBB2 and MET variables ranked as top-performing features in 9 of 10 DT models and the full dataset model. These findings offer probabilistic guidance for FISH testing, emphasizing the prioritization of the ERBB2, SMAD4, and CDKN2A FISH probes in diagnosing NET primary sites.

Pancreatic Neuroendocrine Tumor (Pan-NET) Presented by Abdominal Pain: A Case Report and Literature Review

A pancreatic neuroendocrine tumor (Pan-NET) is a rare neoplasm originating in the neuroendocrine system. Carcinoid syndrome occurs in approximately 19% of patients with functional Pan-NETs, typically when liver metastases occur. In this paper, we describe the case of a patient with a low-grade non-functional Pan-NET, but with a typical clinical presentation of carcinoid syndrome. An 81-year-old male was admitted to our Department of Internal Medicine at Cannizzaro Hospital (Catania, Italy) because of the onset of abdominal pain with nausea, loose stools, and episodic flushing. Firstly, an abdominal contrast-enhanced CT scan showed a small pancreatic hyper-vascular mass; then, a gallium-68 DOTATOC integrated PET/CT revealed an elevated expression of SSTR receptors. Serum chromogranin A and urinary 5-HIAA measurements were negative. We performed an endoscopic ultrasonography (EUS) by a fine-needle biopsy (EUS-FNB), allowing the immunostaining of a small mass (0.8 cm) and the diagnosis of a low-grade (G1) non-functional Pan-NET (NF-Pan-NET). Surgery was waived, while a follow-up strategy was chosen. The early recognition of Pan-NETs, although rare, is necessary to improve the patient's survival. Although helpful to allow for immunostaining, EUS-FNB needs to be warranted in future studies comparing EUS-FNB to EUS-FNA (fine-needle aspiration), which is, to date, reported as the tool of choice to diagnose Pan-NETs.

Site-specific trends in gastroenteropancreatic neuroendocrine neoplasms in Bavaria, Germany

INTRODUCTION

Neuroendocrine neoplasms (NEN) are rare and heterogeneous epithelial tumors, occurring throughout the body. For gastroenteropancreatic (GEP)-NEN, rising incidence rates were reported for the last decades, with underlying causes remaining largely unexplained. We evaluated NEN trends stratifying by their histologic subtypes.

METHODS

Incident cases of GEP-NEN diagnosed between 2005 and 2019 were retrieved from the prospective, population-based Bavarian Cancer Registry. GEP-NEN were divided in their histologic subtypes, that is, neuroendocrine tumors (NET) G1, NET G2/G3, other NET versus small-cell neuroendocrine carcinoma (NEC), large-cell NEC, and other NEC. We calculated annual age-standardized incidence rates (ASIRs) per 100,000 persons for the total of GEP-NEN, NEN histologic subtypes, and tumor sites. We used an annual percentage change (APC) approach including a joinpoint analysis to investigate NEN incidence trends.

RESULTS

ASIR of GEP-NEN rose from 2.2 in 2005 to 4.8 in 2019, characterized by a significant increase until 2012 (APC 2005-2012: 10.1%), followed by modest rise (APC 2012-2019: 1.5%). In the last decade, this increase was mainly driven by the rise of NET G1 and G2/G3, while incidence for NEC declined. Over the study period, ASIR increased significantly for all GEP-sites except the colon. APCs were largest for the stomach, the appendix, the pancreas, and the rectum.

CONCLUSIONS

This study found a significant increase in the incidence of GEP-NET. Though this development may partially be attributable to the increased use of advanced detection techniques and changes in NEN classification, further research should also focus on the identification of NEN risk factors.

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.

Evaluating the Presence of a Stage IV Low-Grade Well-Differentiated Neuroendocrine Tumor of the Ileocecum: A Case Report with Evaluation of Staging Protocol of Neuroendocrine Tumors and Treatment Options Based on Current Available Evidence

Neuroendocrine tumors (NET) are rare neoplasms that can originate throughout the human body. An initial treatment option includes upfront surgical resection of the primary tumor (pT) if the tumor can be localized. Current systemic therapy options following resection of the pT or with evidence of metastatic disease include somatostatin analogs, evorlimus, peptide receptor radionuclide therapy, cytotoxic chemotherapy, and interferon alpha among other less common therapy options. We present a case of a patient with a NET that originated in the ileocecal region. The patient underwent upfront surgical resection with a right hemicolectomy due to the location of the tumor. The pT was notable for extensive invasion into the visceral peritoneum and metastasis to nearby lymph nodes. However, despite being diagnosed as a stage IV NET, the Ki67 index was less than 1%, categorizing it as a low-grade well-differentiated tumor. Following resection of the tumor, there was no evidence of metastasis to the liver on the follow-up magnetic resonance imaging and recurrent somatostatin receptor overexpressing neoplasm on the Gallium-68 DOTATE PET/CT scan. Due to the juxtaposition of the low grade of the tumor and the high staging, several different treatment options were discussed with the main distinction being whether to base these options off of the stage or the grade of the tumor in the case. Low-grade well-differentiated NET have a good prognosis. On the other hand, stage IV NET and tumors that have metastasized to nearby lymph nodes and organs have an increased likelihood to reoccur and worse outcomes. Recommendations for NET based on current evidence have a lack of clarity in terms of when to undergo observation versus systemic therapy.

Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

BACKGROUND

The incidence of type I gastric neuroendocrine neoplasms (gNENs) has increased significantly over the past 50 years. Although autoimmune gastritis (AIG) increases the likelihood of developing gNENs, the exact incidence and prevalence of this association remain unclear.

AIM

To evaluate the incidence and prevalence of type I gNENs in a cohort of patients with a histological diagnosis of AIG.

METHODS

Patients with a histological diagnosis of AIG were enrolled between October 2020 and May 2022. Circulating levels of CgA and gastrin were assessed at enrollment. Included patients underwent regular endoscopic follow-up to detect gastric neoplastic lesions, enterochromaffin-like (ECL) cell hyperplasia, and the development of gNEN.

RESULTS

We included 176 patients [142 women (80.7%), median age 64 years, interquartile range (IQR) 53-71 years] diagnosed with AIG between January 1990 and June 2022. At enrollment. One hundred and sixteen patients (65.9%) had ECL hyperplasia, of whom, 29.5% had simple/linear, 30.7% had micronodular, and 5.7% had macronodular type. The median follow-up time was 5 (3-7.5) years. After 1032 person-years, 33 patients developed a total of 50 type I gNENs, with an incidence rate of 0.057 person-years, corresponding to an annual cumulative incidence of 5.7%. Circulating CgA levels did not significantly differ between AIG patients who developed gNENs and those who did not. Conversely, gastrin levels were significantly higher in AIG patients who developed gNENs [median 992 pg/mL IQR = 449-1500 vs 688 pg/mL IQR = 423-1200, P = 0.03]. Calculated gastrin sensitivity and specificity were 90.9% and 1.4%, respectively, with an overall diagnostic accuracy of 30% and a calculated area under the gastrin receiver operating characteristic curve (AUROC or AUC) of 0.53.

CONCLUSION

Type I gNENs are a significant complication in AIG. Gastrin's low diagnostic accuracy prevents it from serving as a marker for early diagnosis. Effective strategies for early detection and treatment are needed.

Small Bowel Neuroendocrine Tumors-10-Year Experience of the Ottawa Hospital (TOH)

(1) Aim: The prevalence and incidence of small bowel NETs have increased significantly over the past two decades. This study aims to report the 10-year experience of SB-NET management at a regional cancer center in Canada. (2) Materials and methods: We conducted a retrospective study of the clinical and pathological data of patients diagnosed with biopsy-proven SB-NET at The Ottawa Hospital (TOH), Ottawa, Canada between 2011 and 2021. We report the clinicopathological characteristics of these patients, as well as their outcomes data, including survival rates. (3) Results: Between 2011 and 2021, a total of 177 SB-NET cases were identified with 51% (n = 91) of cases being males. The most common sites of the tumors were the ileum 53% (n = 94), followed by the duodenum 9% (n = 16) and jejunum 7% (n = 12). Approximately 24% (n = 42) of the patients had symptoms for over six months prior to diagnosis and 18% (n = 32) had functioning SB-NET during the course of the disease. The majority of patients had locally advanced or metastatic disease at the time of presentation with stage III, and stage IV representing 42% (n = 75), and 41% (n = 73) respectively. The majority of patients 84% (n = 148) had well-differentiated histology. One hundred twenty patients underwent surgical resection of the primary tumor including 28 patients (16%) with limited metastatic disease. A total of 21 patients (18%) had recurrence after curative surgery. A total of 62 patients (35%) received first-line somatostatin analog (SSA) therapy for unresectable disease and seven patients had PRRT after progression on SSA. Five years OS was 100%, 91%, 97%, and 73% for stages I, II, III, and IV respectively. In univariate analysis, carcinoid symptoms, T stage, and differentiation were significant predictors for worse overall survival, but not RFS. (4) Conclusions: Compared to published historical controls, our study suggests improvement in the 5-year survival rate of SB-NETs over the last 10 years.

The risk and prognostic factors for G1 pancreatic neuroendocrine tumors: A retrospective analysis of the SEER database

Background

Pancreatic neuroendocrine tumors (pNETs) are rare neuroendocrine neoplasms (NENs) for which little is known about their clinical features, treatment options, and survival prognosis. The purpose of this study is to evaluate the risk factors affecting the overall survival (OS) and cancer-specific survival (CSS) in patients with grade 1 pNETs (G1 pNETs) and to provide a new theoretical basis for clinical diagnosis and treatment.

Methods

A retrospective analysis of individuals with G1 pNETs registered in the Surveillance, Epidemiology, End Results (SEER) database was performed. Risk factors affecting OS and CSS were analyzed using Kaplan-Meier analysis, Cox proportional hazards model, and Fine-Gray competing-risk model.

Results

A total of 751 patients were included, most of whom were white (77.2%) women (53.9%) under the age of 60 years (54.9%), of whom 66 died of pNETs (8.78%) and 34 died of other causes (4.52%). Patients who were older than 60 years at diagnosis (hazard ratio [HR] = 1.866, 95% confidence interval [CI]: 1.242-2.805) had worse OS. And stage in the regional extent (HR = 1.777, 95% CI: 1.006-3.137) or distance extent (HR = 4.540, 95% CI: 2.439-8.453) had worse OS. Patients who delayed treatment after diagnosis had shorter CSS (delayed treatment < 1 month: HR = 1.933, 95% CI: 0.863-4.333; delayed treatment ≥ 1 month: HR = 2.208; 95% CI:1.047-4.654). Patients with lymph node metastasis (HR = 1.989, 95% CI: 1.137-3.479) or distant metastasis (HR = 5.625, 95% CI: 1.892-16.726) had worse CSS. Acceptance of surgery can significantly improve the patient’s OS and CSS. OS (partial pancreatectomy [PP]: HR = 0.350, 95% CI: 0.182-0.672; pancreatectomy and duodenectomy [PD]: HR = 0.426, 95% CI: 0.222-0.815; total pancreatectomy [TP]: HR = 0.495, 95% CI: 0.193-1.267). CSS(PP: HR = 0.148, 95% CI: 0.0054-0.401; PD: HR = 0.332, 95% CI: 0.150-0.730; TP: HR = 0.69, 95% CI: 0.254-1.872).

Conclusion

Age and stage were identified as independent risk factors for OS. Delayed treatment, N stage and M stage were independent risk factors for CSS. Only surgery was identified as independent protective factors for OS and CSS.