Neuroendocrine Tumors-Less Well Known, Often Misunderstood, and Rapidly Growing in Incidence

Single-cell sequencing reveals the heterogeneity of pancreatic neuroendocrine tumors under genomic instability and histological grading

Histological grading is the key factors affecting the prognosis and instructive in guiding treatment and assessing recurrence in non-functional pancreatic neuroendocrine tumor (NF-Pan-NET). Approximately one-third of patients without copy number variation (CNV) alteration and the prognosis of these patients are better than that of patients with CNV alteration. However, the difference between CNV and histological grading is unclear. Here, we analyzed the heterogeneity of tumor cells according to two classification criteria, genomic instability (including CNV alteration and tumor mutation burden) and histological grading. We revealed that the activated core pathways of tumor cells were significantly different under different histological grading's and genomic instability patterns. We also found that tip cells, lymphatic endothelial cells, macrophages, CD1A + dendritic cell, Treg, MAIT, ILC, and CAFs might participate in the process of hepatic metastases, which will facilitate the understanding of the patterns to decode the malignant potential and of NF-Pan-NET.

Incidence trend of neuroendocrine tumors and disparities by sex and race/ethnicity in adults from the United States, 2000-2020

OBJECTIVE

The incidence of neuroendocrine tumors (NET) has been increasing globally for several decades. The objective of the study was to examine the most recent trend in the incidence of NET as well as disparities by sex and race/ethnicity in adults in the USA.

METHODS

Patients with NET aged ≥20 years were identified from the SEER 22 Registries from 2000 to 2020. The age-adjusted incidence rate was calculated for overall NET and by primary site. The incidence trend was assessed by annual percent change. Disparities by sex and race/ethnicity were examined using the incidence rate ratio.

RESULTS

Age-adjusted incidence rate of overall NET in adults was 9.39 per 100 000 in 2000-2020. The incidence rate increased from 2000 but reached a plateau with no significant change since 2015. The lung and bronchus, small intestine, and rectum were the most common primary sites. Sex and racial/ethnic disparities in NET incidence varied by primary sites. For example, there was a female excess in NET of the lung and bronchus, stomach, and appendix; and there was a male excess in the small intestine, pancreas, colon, rectum and other/unknown NET. Compared to non-Hispanic white, non-Hispanic black had higher incidences of stomach, small intestine, liver, pancreas, colon, rectum, and other/unknown NET; they had lower incidences of lung and bronchus, and appendix NET than non-Hispanic white.

CONCLUSION

Age-adjusted incidence rate of overall NET has reached a plateau since 2015. However, there were sex and racial/ethnic disparities in such incidence, which varied depending on the primary site of NET.

A case of gallbladder neuroendocrine carcinoma complicated by ectopic adrenocorticotropic hormone syndrome and resulting in rapid fetal outcomes due to sepsis

A 52-year-old woman presented to our hospital with chief complaints of upper abdominal bloating and lower leg edema. Computed tomography (CT) revealed liver metastasis from a gallbladder tumor. This tumor was diagnosed as neuroendocrine carcinoma (NEC) on performing a biopsy. Physical examination revealed a moon face. Blood tests revealed hypokalemia and high levels of adrenocorticotropic hormone (ACTH) and cortisol. Dexamethasone suppression test revealed that cortisol secretion was not suppressed, and the patient was diagnosed with gallbladder NEC and ectopic ACTH syndrome (EAS). Metyrapone was administered to suppress cortisol production; however, she developed septic shock due to cellulitis in the lower leg and died on the 16th day of admission. A pathological autopsy was performed, which revealed disseminated intravascular coagulation and acute respiratory distress syndrome as the cause of death. Only a few cases of EAS due to NEC originating from the gallbladder have been reported. The patient reported here succumbed shortly after diagnosis, thereby highlighting the challenges in treating gallbladder NEC complicated by EAS.

Critical updates in neuroendocrine tumors: Version 9 American Joint Committee on Cancer staging system for gastroenteropancreatic neuroendocrine tumors

The American Joint Committee on Cancer (AJCC) staging system for all cancer sites, including gastroenteropancreatic neuroendocrine tumors (GEP-NETs), is meant to be dynamic, requiring periodic updates to optimize AJCC staging definitions. This entails the collaboration of experts charged with evaluating new evidence that supports changes to each staging system. GEP-NETs are the second most prevalent neoplasm of gastrointestinal origin after colorectal cancer. Since publication of the AJCC eighth edition, the World Health Organization has updated the classification and separates grade 3 GEP-NETs from poorly differentiated neuroendocrine carcinoma. In addition, because of major advancements in diagnostic and therapeutic technologies for GEP-NETs, AJCC version 9 advocates against the use of serum chromogranin A for the diagnosis and monitoring of GEP-NETs. Furthermore, AJCC version 9 recognizes the increasing role of endoscopy and endoscopic resection in the diagnosis and management of NETs, particularly in the stomach, duodenum, and colorectum. Finally, T1NXM0 has been added to stage I in these disease sites as well as in the appendix.

Optimization of Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection Strategies for Rectal Neuroendocrine Tumors Within 20 mm

AIMS

No consensus regarding the optimal endoscopic resection approach for rectal neuroendocrine tumors (R-NETs) measuring 10-20 mm, this study aims to investigate this issue.

METHODS

Patients with R-NETs underwent either endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). The primary endpoint was the complete resection rate, and the secondary endpoints were surgery-related complications and long-term outcomes.

RESULTS

96 patients met the inclusion criteria, 84 patients completed endoscopic resection, and 5 patients were excluded. 79 patients were enrolled and divided into EMR (n = 21) and ESD groups (n = 58). 100% of ESD excisions reached the primary endpoint, while 90.5% of EMR. Endoscopic submucosal dissection can achieve higher R0 rate and lower positive margin rate than EMR. The mean operative time of ESD and EMR was 35.22 ± 8.96 min and 13.14 ± 3.26 min, respectively. The complication rates of ESD and EMR were 3.4% and 4.8%, respectively. For R-NETs between 10 mm and 20 mm, the R0 rate of ESD was significantly higher than that of EMR (100% vs 71.4%, P = .01) and the margin positive rate of ESD was significant lower than that of EMR (4.8% vs 42.9%, P < .05). Both ESD and EMR obtained 100% R0 resection of less than 10 mm R-NET. The median follow-up was 13 months (3-84 months); 1 patient relapsed 25 months after EMR and was re-treated with ESD.

CONCLUSION

For R-NETs with a diameter less than 10 mm, both EMR and ESD were safe and effective and EMR is convenient and fast, with advantages. ESD offers superiority for R-NETs between 10 and 20 mm and can be considered as the preferred method.

Making progress against rare cancers: A case study on neuroendocrine tumors

In April 2023, the National Cancer Institute offered a roadmap for cancer research to achieve Cancer Moonshot goals. To reach these goals requires making progress for all cancers, not just those that are most common. Achieving progress against rare cancers, as well as common cancers, requires involvement of large clinical research networks. In 2020, the Patient-Centered Outcomes Research Institute (PCORI) launched an initiative on Conducting Rare Disease Research using PCORnet, the National Patient-Centered Clinical Research Network. The purpose of this commentary is to introduce the broader community of cancer researchers to the PCORnet NET-PRO study (comparing the effects of different treatment approaches for neuroendocrine tumors on patient-reported outcomes) thereby demonstrating how researchers can use the PCORnet infrastructure to conduct large-scale patient-centered studies of rare cancers.

Clinicopathological characteristics of gastric neuroendocrine neoplasms: A comprehensive analysis

OBJECTIVE

This study aimed to explore the clinicopathological characteristics and prognostic implications of gastric neuroendocrine neoplasms (g-NENs).

METHODS

A retrospective enrollment of 142 patients diagnosed with g-NENs was conducted at Zhejiang Cancer Hospital between January 1, 2007 and December 31, 2021. The study compared essential clinicopathological features and survival rates. Additionally, the prognosis of gastric neuroendocrine carcinomas/mixed neuroendocrine-non-neuroendocrine neoplasms (g-NEC/MiNEN) were contrasted with those of gastric adenocarcinoma (GAC) and signet ring cell carcinoma (SRCC).

RESULTS

The study comprised a total of 142 g-NENs cases, with a male-to-female ratio of approximately 2:1. The 5-year survival rates for g-NEC and g-MiNEN were 26.7% and 35.2%, respectively. Corresponding 5-year survival rates for G1 and G2 were observed at 100% and 80.0%, respectively. g-NEC/MiNEN showed a significantly worse prognosis compared to g-NET (p < 0.001). g-NEC/MiNEN exhibited a poor prognosis compared to GAC (p < 0.001), and within poorly differentiated GAC, g-NEC/MiNEN demonstrated a worse prognosis (p = 0.007). Additionally, patients receiving postoperative adjuvant therapy exhibited notably prolonged overall survival (OS) in the case of g-NEC/MiNEN (p = 0.010).

CONCLUSION

In short, the prognosis of g-NEC/MiNEN was worse than that of g-NET, GAC and poorly differentiated GAC, but this group benefit from postoperative adjuvant therapy.

Analysis of the Genetic Characteristics and Metastatic Pathways of G1 and G2 Colorectal Neuroendocrine Neoplasms

Objective

G1 and G2 colorectal neuroendocrine neoplasms (NENs) are a group of rare and indolent diseases. We aimed to delineate their genetic characteristics and explore their metastatic mechanisms.

Methods

We used next-generation sequencing technology for targeted sequencing for 54 patients with G1 and G2 colorectal NENs. We delineated their genetic features and compared the genetic characteristics between metastatic NENs and nonmetastatic NENs. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was utilized to explore their abnormal pathways and study their potential metastatic mechanisms.

Results

We collected 23 metastatic NENs and 31 nonmetastatic NENs. In the whole cohort, the common mutated genes were NCOR2, BRD4, MDC1, ARID1A, AXIN2, etc. The common copy number variations (CNVs) included amplification of HIST1H3D, amplification of HIST1H3E, and loss of PTEN. The KEGG enrichment analysis revealed that PI3K-Akt, MAPK, and Rap1 were the major abnormal pathways. There were significantly different genetic features between metastatic NENs and nonmetastatic NENs. The metastatic NENs shared only 47 (22.5%) mutated genes and 6 (13.3%) CNVs with nonmetastatic NENs. NCOR2, BRD4, CDKN1B, CYP3A5, and EIF1AX were the commonly mutated genes in metastatic NENs, while NCOR2, MDC1, AXIN2, PIK3C2G, and PTPRT were the commonly mutated genes in nonmetastatic NENs. Metastatic NENs presented a significantly higher proportion of abnormal pathways of cell senescence (56.5% vs 25.8%, P = .022) and lysine degradation (43.5% vs 16.1%, P = .027) than nonmetastatic NENs.

Conclusion

G1 and G2 colorectal NENs are a group of heterogeneous diseases that might obtain an increased invasive ability through aberrant cell senescence and lysine degradation pathways.

Advances in Endoscopic Diagnosis and Treatment of Gastric Neuroendocrine Neoplasms

Gastric neuroendocrine neoplasms refer to a group of diseases that are relatively rare. They can be classified into three subtypes based on their clinical and histopathological features, and there are significant differences in diagnosis, treatment, and prognosis among the different subtypes. The incidence of gastric neuroendocrine neoplasms has been increasing globally in recent years with the localized disease being particularly evident. Gastrointestinal endoscopy is of irreplaceable importance for the diagnosis and management of g-NENs. Endoscopy with biopsy is the gold standard for the diagnosis of g-NENs. Ultrasound endoscopy can assess the depth of tumor invasion and the presence of lymphatic metastases, which is important for the development of treatment strategies. Meanwhile, for some small and low-risk lesions, endoscopic surveillance or endoscopic resection has satisfactory therapeutic results and prognosis. This means that even though the incidence has increased, advances in endoscopic techniques have allowed more patients to adopt a relatively conservative treatment strategy. However, the criteria for patients suitable for endoscopic surveillance or endoscopic resection remain controversial.

Gastroenteropancreatic Neuroendocrine Tumor Diagnosis: DOTATATE PET/CT

Gastroenteropancreatic neuroendocrine tumors(NETs), which arise from the small intestine, rectum, colon, appendix, or pancreas, have variable malignant potential with clinical behavior determined by proliferative activity according to the Ki-67 index and tumor differentiation. Somatostatin receptor (SSTR) expression by NETs allows SSTR imaging using 68Ga-DOTATATE PET/computed tomography (CT) and treatment with octreotide or SSTR-targeted peptide receptor radionuclide therapy (PRRT). 68Ga-DOTATATE PET/CT is indicated for localization of the primary tumor in select cases, staging patients with known NET, and selecting patients for PRRT. NCCN guidelines consider imaging with 68Ga-DOTATATE PET/CT appropriate for staging and receptor status assessment.

Development and validation of a contrast-enhanced CT-based radiomics nomogram for preoperative diagnosis in neuroendocrine carcinoma of digestive system

Objectives

To develop and validate a contrast-enhanced CT-based radiomics nomogram for the diagnosis of neuroendocrine carcinoma of the digestive system.

Methods

The clinical data and contrast-enhanced CT images of 60 patients with pathologically confirmed neuroendocrine carcinoma of the digestive system and 60 patients with non-neuroendocrine carcinoma of the digestive system were retrospectively collected from August 2015 to December 2021 at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, and randomly divided into a training cohort (n=84) and a validation cohort (n=36). Clinical characteristics were analyzed by logistic regression and a clinical diagnosis model was developed. Radiomics signature were established by extracting radiomic features from contrast-enhanced CT images. Based on the radiomic signature and clinical characteristics, radiomic nomogram was developed. ROC curves and Delong's test were used to evaluate the diagnostic efficacy of the three models, calibration curves and application decision curves were used to analyze the accuracy and clinical application value of nomogram.

Results

Logistic regression results showed that TNM stage (stage IV) (OR 6.8, 95% CI 1.320-43.164, p=0. 028) was an independent factor affecting the diagnosis for NECs of the digestive system, and a clinical model was constructed based on TNM stage (stage IV). The AUCs of the clinical model, radiomics signature, and radiomics nomogram for the diagnosis of NECs of the digestive system in the training, validation cohorts and pooled patients were 0.643, 0.893, 0.913; 0.722, 0.867, 0.932 and 0.667, 0.887, 0.917 respectively. The AUCs of radiomics signature and radiomics nomogram were higher than clinical model, with statistically significant difference (Z=4.46, 6.85, both p < 0.001); the AUC difference between radiomics signature and radiomics nomogram was not statistically significant (Z=1.63, p = 0.104). The results of the calibration curve showed favorable agreement between the predicted values of the nomogram and the pathological results, and the decision curve analysis indicated that the nomogram had favorable application in clinical practice.

Conclusions

The nomogram constructed based on contrast-enhanced CT radiomics and clinical characteristics was able to effectively diagnose neuroendocrine carcinoma of the digestive system.

Treatment Sequencing Strategies in Advanced Neuroendocrine Tumors: A Review

Neuroendocrine tumor (NET) incidence has grown. The treatment landscape for advanced NETs is rapidly evolving, but there are limited head-to-head data to guide treatment sequencing decisions. We assessed the available clinical data to aid practicing clinicians in their routine clinical decision-making. Clinical trials have demonstrated efficacy benefits for new therapies in advanced NETs. Emerging long-term data from these trials have enabled clinicians to make more accurate risk-benefit assessments, particularly for patients receiving multiple lines of therapy. However, clinical data specifically regarding treatment sequencing are limited. In lieu of definitive data, treatment sequencing should be based on disease-related factors (e.g., site of tumor origin, volume of disease) and patient-related characteristics (e.g., comorbidities, patient preferences). Clinical decision-making in advanced NETs remains highly individualized and complex; important evidence gaps regarding treatment sequencing remain. Given this, advanced NET management should be a joint effort of multidisciplinary teams at referring and high-volume centers. Additional clinical trial and real-world evidence are needed to meet the challenge of understanding how to sequence available NET therapies. Until these trials are conducted, the best practices provided in this review may serve as a guide for clinicians making treatment sequencing decisions based on the available data.

Pediatric Neuroendocrine Neoplasms: Rare Malignancies with Incredible Variability

Neuroendocrine neoplasms (NENs) encompass a variety of neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) which can arise anywhere in the body. While relatively rare in the pediatric population, the incidence of NENs has increased in the past few decades. These neoplasms can be devastating if not diagnosed and treated early, however, symptoms are variable and can be indolent for many years. There is a reported median of 10 years from the appearance of the first symptoms to time of diagnosis. Considering some of these neoplasms have a mortality rate as high as 90%, it is crucial healthcare providers are aware of NENs and remain vigilant. With better provider education and easily accessible resources for information about these neoplasms, awareness can be improved leading to earlier disease recognition and diagnosis. This manuscript aims to provide an overview of both the most common NENs as well as the rarer NENs with high lethality in the pediatric population. This review provides up to date evidence and recommendations, encompassing recent changes in classification and advances in treatment modalities, including recently completed and ongoing clinical trials.

Neuroendocrine Tumors: An Analysis of Prevalence, Incidence, and Survival in a Hospital-Based Study in Ecuador

Neuroendocrine tumors (NETs) represent a heterogeneous malignancy group of neoplasms, with a limited amount of data from Latin America. Thus, this observational study aimed to provide data about the prevalence, incidence, and survival rates for NET in Ecuadorian hospitals. The study was conducted using data from the Society for the Fight Against Cancer (SOLCA). We evaluated patients with NETs (2000−2020) using the HJ-Biplot method and Cox proportional hazards. Annual age-adjusted incidence and limited-duration prevalence in multivariable analyses as well as hazard ratios (HRs) for mortality and survival were obtained. In the years 2000−2020, the age-adjusted incidence rate increased by 9-fold in the stomach and by 7-fold in the breast. The incidence rates were 1.38 per 100,000 persons in the lung and at 1.79 per 100,000 persons in gastroenteropancreatic sites (rectum, stomach, and pancreas). The prevalence increased from 0.0027% in 2000 to 0.0736% in 2019 and 0.0245% in 2020. Overall survival was worse for metastatic NETs (HR, 4.061; 95% CI, 1.932−8.540; p < 0.001) and advanced local NETs (HR, 2.348; 95% CI, 1.007−5.475 p < 0.048) than for localized NETs. In conclusion, the NET incidence increased in the last 20 years and survival decreased over time, especially for metastatic tumors in the pancreas and the nostril.

The clinical and prognostic factors for biliary neuroendocrine neoplasm: a study based on the SEER database

Background

In this study, we aimed at elucidating the postoperative survival and prognostic factors in patients with biliary neuroendocrine neoplasm (NEN).

Methods

Cases of biliary system NEN and adenocarcinoma from 1975 to 2016 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. A propensity score matching (PSM) method was used to adjust baseline differences in clinicopathological characteristics in our analysis. The Kaplan–Meier analysis was carried out for survival analysis.

Results

A total of 233 patients with biliary system NEN were enrolled in this study, of which 119 patients’ lesions located in gallbladder, while the others’ located in bile duct. The postoperative overall survival of bile duct NEN is significantly longer than that of gallbladder NEN (P < 0.001). For gallbladder NENs, surgery method (P = 0.020) and lymph node metastasis (P = 0.018) were identified as independent prognostic factors. In terms of ampulla of vater (AOV) NENs, age (P = 0.017) and lymph node metastasis (P = 0.006) were identified as independent prognostic factors, while grade (P = 0.002) and lymph node metastasis (P = 0.036) were identified as independent prognostic factors for extrahepatic bile duct (EBD) NENs. PSM analysis indicated that patients with biliary duct NENs have a better postoperative prognosis than biliary duct adenocarcinoma.

Conclusions

Patients with NEN have better overall survival than patients with adenocarcinoma. Gallbladder NEN has an adverse prognosis than that of biliary tract NEN. The pathological subtype, differentiation, lymph node metastasis, surgery method, and lymph node resection could affect the postoperative prognosis of the gallbladder and biliary tract NEN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01689-7.

hPG80 (Circulating Progastrin), a Novel Blood-Based Biomarker for Detection of Poorly Differentiated Neuroendocrine Carcinoma and Well Differentiated Neuroendocrine Tumors

Simple Summary

Current blood-based biomarkers for neuroendocrine neoplasms (NENs) lack both sensitivity and specificity. Human circulating progastrin (hPG₈₀) can be easily measured in plasma by ELISA. This study is the first to examine hPG₈₀ in NENs. The study demonstrated increased levels of hPG₈₀ in all sub-types of NENs, with a high sensitivity and specificity demonstrated. Plasma hPG₈₀ in NENs may be a diagnostic blood biomarker for both low- and high-grade NENs; further study is warranted. A prospective multi-center trial is ongoing in NET to evaluate hPG₈₀ as a means of monitoring disease (NCT04750954).

Abstract

Current blood-based biomarkers for neuroendocrine neoplasms (NENs) lack both sensitivity and specificity. Human circulating progastrin (hPG₈₀) is a novel biomarker that can be easily measured in plasma by ELISA. This study is the first to examine hPG₈₀ in NENs. Plasma hPG₈₀ was quantified from 95 stage IV NEN patients, using DxPG₈₀ technology (ECS Progastrin, Switzerland) and compared with hPG₈₀ concentrations in two cohorts of healthy donor controls aged 50–80 (n = 252) and 18–25 (n = 137). Median hPG₈₀ in NENs patients was 5.54 pM compared to 1.5 pM for the 50–80 controls and 0.29 pM the 18–25 cohort (p < 0.0001). Subgroup analysis revealed median hPG₈₀ levels significantly higher than for either control cohort in neuroendocrine carcinoma (NEC; n = 25) and neuroendocrine tumors (NET; n = 70) including the small-cell lung cancer (SCLC) sub-cohort (n = 13). Diagnostic accuracy, estimated by AUCs, was high for NENs, as well as both sub-groups (NEC/NET) when compared to the younger and older control groups. Plasma hPG₈₀ in NENs may be a diagnostic blood biomarker for both low- and high-grade NENs; further study is warranted. A prospective multi-center trial is ongoing in NET to evaluate hPG₈₀ as a means of monitoring disease (NCT04750954).

Efficacy of Immune Checkpoint Inhibitors against Advanced or Metastatic Neuroendocrine Neoplasms: A Systematic Review and Meta-Analysis

We performed a systematic review and meta-analysis of the treatment efficacy of immune checkpoint inhibitors (ICIs) in advanced/metastatic neuroendocrine neoplasms (NENs). MEDLINE and EMBASE were searched to identify studies that provide data on treatment response and/or survival outcomes of advanced/metastatic NEN patients treated with ICIs. The overall response rate (ORR) was pooled using a random-effects model. Meta-regression was performed to explore factors influencing the ORR. Individual patient data (IPD) meta-analysis of survival was performed using stratified Cox regression. Ten studies (464 patients) were included. The overall pooled ORR was 15.5% (95% confidence interval (CI), 9.5-24.3%), and it varied according to the primary site (thoracic, 24.7%; gastro-entero-pancreatic, 9.5%), tumor differentiation (poorly differentiated, 22.7%; well-differentiated, 10.4%), and drug regimen (combination, 25.3%; monotherapy, 10.1%). All these variables significantly influenced the ORR. Tumor differentiation was associated with both overall survival and progression-free survival (hazard ratio of poorly differentiated tumors, 4.2 (95% CI, 2.0-8.7) and 2.6 (95% CI, 1.6-4.4), respectively). Thus, the treatment efficacy of ICIs for advanced/metastatic NENs varied according to primary site, tumor differentiation, and drug regimen. Poorly differentiated NENs showed a better ORR than well-differentiated NENs but had a negative impact on survival.

HRAS overexpression predicts response to Lenvatinib treatment in gastroenteropancreatic neuroendocrine tumors

INTRODUCTION

Neuroendocrine neoplasms (NENs) are a rare group of tumors exceptionally heterogeneous, with clinical presentation ranging from well differentiated more indolent tumors to poorly differentiated very aggressive forms. Both are often diagnosed after the metastatic spread and require appropriate medical treatment. A high priority need in the management of this disease is the identification of effective therapeutic strategies for advanced and metastatic patients. The recent TALENT trial demonstrated the efficacy of lenvatinib, a multi-tyrosine kinase inhibitor, in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) with no other treatment indication. Further development of this drug in advanced NETs is warranted.

METHODS

We investigated potential clinical and molecular determinants of lenvatinib response in human primary cultures derived from patients with GEP-NET of different grades and sites of origin. We correlated response to treatment with patient clinical characteristics, with the mutational status of 161-cancer associated genes and with the expression levels of MKI-related genes.

RESULTS

Lenvatinib exerted a significant antitumor activity in primary GEP-NET cells, with median survival inhibitions similar or higher than those of standard frontline treatments. Of the 11 primary cultures analyzed in our case series, 6 were classified as responder showing a significant survival inhibition, and 5 as non-responder. We observed that the overexpression of HRAS in the original tumor tissue compared to the matched healthy tissue significantly correlated with responsiveness of primary cells to lenvatinib (p=.048). All 5 non-responder cultures showed normal HRAS expression, while of the 6 responder cultures, 4 had HRAS overexpression. Overexpression of HRAS was not associated with gene mutation. None of the other evaluated clinical variables (grade, Ki67, site of origin and syndromic disease) or molecular markers correlated with response.

DISCUSSION

Lenvatinib appears to be a highly effective drug for the treatment of NETs. The evaluation of HRAS expression in the tumor tissue might improve patient selection and optimize therapeutic outcome.

Simultaneous detection of multiple neuroendocrine tumor markers in patient serum with an ultrasensitive and antifouling electrochemical immunosensor

Neuroendocrine tumors (NETs) are rare heterogeneous tumors that are often misdiagnosed and mistreated. Most NETs patients are diagnosed as advanced. Early on-time detection of NETs is significant for precision therapy. Here, an ultrasensitive and antifouling label-free electrochemical immunosensor was constructed for simultaneous analysis of NETs biomarkers chromogranin A (CgA) and chromogranin B (CgB). The metal ion functionalized porous magnesium silicate/gold nanoparticles/polyethylene glycol/chitosan (PMS-M²⁺/AuNPs/PEG/CS) composites were employed as the sensing platforms. By combining PEG and CS with good hydrophilicity, the sensing interface exhibited outstanding antifouling ability in complex biological systems. PMS with high surface area and the porous structure can efficiently load Cu²⁺ and Pb²⁺, which could directly generate independent electrochemical peak currents that reflected the concentrations of CgA and CgB. Under optimal conditions, this immunosensor can detect CgA and CgB with good linearity from 0.1 pg mL^-1 to 100 ng mL^-1 as low as 5.3 and 2.1 fg mL^-1, respectively. Moreover, this immunosensor can accurately detect CgA and CgB levels in clinical serum, which were well consistent with the enzyme-linked immunosorbent assay (ELISA). This strategy provided a sensitive, simple and low-cost platform for clinical screening and point-of-care diagnosis of NETs.

Frequency of Neuroendocrine Tumor Studies: Using Latent Dirichlet Allocation and HJ-Biplot Statistical Methods

Background: Neuroendocrine tumors (NETs) are severe and relatively rare and may affect any organ of the human body. The prevalence of NETs has increased in recent years; however, there seem to be more data on particular types, even though, despite the efforts of different guidelines, there is no consensus on how to identify different types of NETs. In this review, we investigated the countries that published the most articles about NETs, the most frequent organs affected, and the most common related topics. Methods: This work used the Latent Dirichlet Allocation (LDA) method to identify and interpret scientific information in relation to the categories in a set of documents. The HJ-Biplot method was also used to determine the relationship between the analyzed topics, by taking into consideration the years under study. Results: In this study, a literature review was conducted, from which a total of 7658 abstracts of scientific articles published between 1981 and 2020 were extracted. The United States, Germany, United Kingdom, France, and Italy published the majority of studies on NETs, of which pancreatic tumors were the most studied. The five most frequent topics were t_21 (clinical benefit), t_11 (pancreatic neuroendocrine tumors), t_13 (patients one year after treatment), t_17 (prognosis of survival before and after resection), and t_3 (markers for carcinomas). Finally, the results were put through a two-way multivariate analysis (HJ-Biplot), which generated a new interpretation: we grouped topics by year and discovered which NETs were the most relevant for which years. Conclusions: The most frequent topics found in our review highlighted the severity of NETs: patients have a poor prognosis of survival and a high probability of tumor recurrence.

Novel therapeutics for patients with well-differentiated gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) represent the most common subtype of NETs. The incidence of all NETs, and specifically GEP NETs, has risen exponentially over the last three decades. Only within the past several years have these tumors been appropriately classified, allowing for meaningful drug development. Broadly, some of the most exciting drug classes being developed for patients with well-differentiated GEP NETs include newer types of peptide receptor radionuclide therapy (PRRT) or combinations which increase the potency of lutetium-177 (177Lu)-Dotatate, novel multi-target receptor tyrosine kinase inhibitors (RTKIs) and immunotherapy modalities, beyond checkpoint inhibitors, which seek to unleash the immune system against NETs. Specifically looking at newer types of PRRT, somatostatin receptor antagonists and alpha-emitter radionuclides each have demonstrated the ability to elicit greater DNA damage than 177Lu-Dotatate in preclinical models. Early clinical experiences with each of these agents suggest they may be more cytotoxic than 177Lu-Dotatate. Other approaches seeking to build upon the DNA damage created by 177Lu-Dotatate include combinations of PRRT with radiosensitizers such as heat shock protein 90 inhibitors, hedgehog inhibitors, chemotherapy combinations, and triapine. Many of these combinations have just begun to be tested clinically. With regards to novel RTKIs, some of the ones which have demonstrated potent cytoreductive potential include cabozantinib and lenvatinib. Other RTKIs which are further along the clinical development spectrum and have demonstrated benefit in randomized trials include surufatinib and pazopanib. And though single-agent immune checkpoint inhibitors have not demonstrated significant anti-tumor activity in patients with GEP NETs, outside of certain biomarker selected subsets, somatostatin receptor-directed chimeric antigen receptor (CAR) T cells and vaccines such as SurVaxM, which targets survivin, represent two means through which NET-directed immunity may be modulated. The potential of these agents, if clinically realized, will likely improve outcomes for patients with well-differentiated GEP NETs.

Epidemiology, Incidence, and Prevalence of Neuroendocrine Neoplasms: Are There Global Differences?

PURPOSE OF REVIEW

The purpose of our review is to explore global epidemiologic trends of gastroenteropancreatic (GEP) neuroendocrine tumors (NETs). Specifically, we sought to examine whether there are differences in incidence, prevalence, distribution (by primary tumor site, tumor grade, tumor stage at presentation), and overall survival of GEP NETs between different regions of the world.

RECENT FINDINGS

GEP NET incidence rates are rising steadily in North America, Asia, and Europe, though this rise appears to be most profound in North America. The distribution of GEP NETs differs regionally as in North America small intestinal and rectal NETs are most prevalent, in Asia rectal and pancreatic NETs are most prevalent, and in Europe small intestinal and pancreatic NETs are most prevalent. Overall survival for patients with GEP NETs appears to be improving with time. Some of the global increase in GEP NET incidence can be explained by increased health care utilization. This factor alone, however, does not explain the rise completely. Population-based studies utilizing uniform data collection instruments and a standard pathologic grading system are needed to identify other factors which may be contributing to this phenomenon.

Somatostatin receptor radionuclide therapy in neuroendocrine tumors

Peptide receptor radionuclide therapy (PRRT) using 177Lu-DOTATATE has been approved for the treatment of gastroenteropancreatic NETs. An understanding of benefits and risks is important for the appropriate implementation of this therapy. This review summarizes study data supporting the use of radiolabeled somatostatin analogs for the treatment of advanced NETs and highlights risks, including potential toxicities in specific populations. Key ongoing clinical trials, including randomized studies, are designed to better define the position of PRRT within the broader therapeutic landscape. Preclinical and early-phase human studies are focused on the development of novel somatostatin-receptor agonists and antagonists, new radionuclides, and radiosensitizing combination therapies.

A system for classifying cancers diagnosed in adolescents and young adults

Cancer types in adolescents and young adults form a unique distribution. A system for classifying them is presented.

A proof-of-concept methodology to validate the in situ visualization of residual disease using cancer-targeted molecular agents in fluorescence-guided surgery

Introduction

The clinical need for improved intraoperative tumor visualization has led to the development of targeted contrast agents for fluorescence-guided surgery (FGS). A key characteristic of these agents is their high tumor specificity, which could enable detection of residual lesions that would likely be missed by visual inspection. Here, we examine the utility of a promising somatostatin receptor subtype-2 (SSTR2)-targeted fluorescent agent for detecting residual disease in mouse xenografts using FGS and post-operative histopathological validation.

Methods

Mice (n=2) implanted with SSTR2 overexpressing tumors were injected with 2 nmol of the dual-labeled somatostatin analog, ⁶⁷Ga-MMC(IR800)-TOC, and tumors were resected 48 h post-injection using traditional white light reflectance and palpation. Tumors underwent gamma counting and histopathology analysis. The wide-field FGS imaging platform (OnLume) was used to evaluate residual disease in situ under ambient light representative of an operating room.

Results

The tumor was resected with grossly negative margins using conventional inspection and palpation; however, additional in situ residual disease was found in the tumor cavity using FGS imaging. In situ fluorescent tumor contrast-to-noise ratios (CNRs) were 3.0 and 5.2. Agent accumulation was 7.72 and 8.20 %ID/g in tumors and 0.27 and 0.20 %ID/g in muscle. Fluorescence pixel values and gamma counts were highly correlated (r = 0.95, P < 0.048). H&E and IHC staining confirmed cancer positivity and SSTR2-overexpression, respectively.

Conclusion

Our findings demonstrate that the use of clinically relevant fluorescence imaging instrumentation enhances the evaluation of promising FGS agents for in situ visualization of residual disease.