Gastrointestinal neuroendocrine tumors in 2020

Innovative imaging approaches for neuroendocrine tumor characterization: Combined dual energy CT and perfusion protocol implementation

The article addresses the diagnostic value of the combined use of computed tomography (CT) perfusion and dual-energy CT (DECT) in patients with neuroendocrine tumors. It emphasizes the heterogeneity and complexity of these neoplasms, primarily affecting the gastrointestinal tract, bronchopulmonary system, and pancreas. While conventional CT is widely employed in their diagnosis, the combination of CT perfusion and dual-energy CT offers greater precision, particularly in detecting synchronous tumors and characterizing their vascularization. A clinical case of a patient with chronic abdominal symptoms, whose diagnosis was facilitated using both combined techniques, is presented. The discussion explores how CT perfusion assesses tumor vascularization and how dual-energy CT improves soft tissue differentiation, resulting in increased diagnostic accuracy. It is highlighted that this approach not only enhances detection rates but also positively impacts clinical management and healthcare costs. Therefore, the importance of considering these advanced tools in the diagnosis of neuroendocrine tumors to improve diagnostic precision and efficiency in patient care is underscored.

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.

Clinical outcomes after endoscopic resection and the risk of lymph node metastasis in rectal neuroendocrine tumors: a single-center retrospective study

BACKGROUND AND AIM

The incidence of rectal neuroendocrine tumors (R-NETs) has increased in recent years. However, the predictors of lymph node (LN) metastasis and clinical outcomes, particularly following endoscopic treatment, remain unclear. Our study aims to elucidate the potential risk factors for LN metastasis and the clinical outcomes of patients undergoing endoscopic resection in R-NETs.

METHODS

A total of 128 patients with R-NETs were retrospectively identified from a single center between June 2012 and December 2021. Risk factors for LN metastasis in R-NETs were analyzed using multivariate analysis. Additionally, the clinical outcomes of endoscopic resections in patients with R-NETs were assessed.

RESULTS

In our study, 128 patients with R-NETs were retrospectively analyzed. The risk factors for LN metastasis determined by multivariate analysis were tumor size and patient age at diagnosis. Among the 111 patients treated with endoscopic resection and with tumor margin records available, 92 underwent endoscopic submucosal dissection (ESD) and 19 underwent conventional endoscopic mucosal resection (EMR). There was no significant difference between the two groups regarding the positive rates of basal tumor margin and lateral tumor margin. Furthermore, 64 patients who underwent endoscopic resection for R-NETs were successfully followed up (range, 1.64-76.71 months), during which only one patient developed local recurrence.

CONCLUSION

Tumor size and age at diagnosis were predictors for LN metastasis of R-NETs. Both ESD and EMR are alternative techniques with a favorable prognosis for R-NETs, even in cases with positive resection margins. However, due to the relatively small number of patients undergoing EMR and missing data in follow-up protocols, definitive conclusions require further large-scale studies.

A population-based study on incidence trends of small intestine cancer in the United States from 2000 to 2020

BACKGROUND

Although rare, small intestine cancer is on the rise in the developed world. We aimed to investigate the incidence trends of small intestine cancer by sex, race/ethnicity, age, and histological subgroups in the United States (US) over 2000-2020. Also, we evaluated the COVID-19 impacts on the incidence trends of this cancer.

METHODS

Data were collected from the Surveillance, Epidemiology, and End Results 22 database. Both the average annual percent change (AAPC) and age-standardized incidence rates (ASIRs) were determined. The findings were expressed as counts and incidence rates adjusted for age per 100,000 people with 95% confidence intervals (CIs).

RESULTS

A total of 67,815 cases of small intestine cancer across all age groups were reported in the US between 2000 and 2019. Neuroendocrine carcinoma was the most often reported subtype (54.26%). The age group of 55 to 69 years (38.08%), men (53.10%), and Non-Hispanic Whites (69.07%) accounted for the majority of cases. Over 2000-2019, the ASIRs for small intestine cancer among men and women were 2.61 (95% CI: 2.59-2.64) and 1.92 (95% CI: 1.89-1.94) per 100,000, indicating a significant increase of 2.01% and 2.12%, respectively. Non-Hispanic Black men had the highest ASIR (4.25 per 100,000). Also, those aged 80-84 age group had the highest ASIR. During COVID-19, the ASIR of small intestine cancer decreased by 8.94% (5.06-12.81%).

CONCLUSIONS

Small intestine cancer incidence raised in all sexes and ethnicities. Following COVID-19, reported cases declined, possibly due to pandemic-related diagnostic challenges. The impact of underdiagnosis on patient survival needs further investigations.

The Investigation of B12 Deficiency Leading to the Serendipitous Diagnosis of Gastric Carcinoid Tumour

Gastric carcinoid is a rare type of gastric malignancy accounting for around 7% of all gastrointestinal neuroendocrine tumours (NETs). While most gastric NETs (gNETs) are readily visible through direct visualisation by upper endoscopy, around 25% of gastric carcinoids are invisible because they are located in the submucosal gastric regions of the body and fundus. gNETs located in the intra-mucosal areas can be identified by gastric mapping; this can be done by taking random gastric biopsies from the antrum, body and fundus. We report a case of a well-differentiated gastric NET type 1 with atrophic gastritis diagnosed on upper endoscopy and pathological immunohistochemistry staining.

LEARNING POINTS

The case highlights that not all gNETs are visible under direct endoscopic visualisation.It is essential to understand the different types of gNETs.Understand that both type and size of gNETs impact therapeutic implications and prognosis.

Gastroenteropancreatic neuroendocrine tumors in children and adolescents

BACKGROUND

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare in children and adolescents. Standard management of these tumors has not been well established due to their rarity in this age group. We aimed to report the clinical and pathological characteristics of patients with this rare disease followed and treated between the years 1993-2022.

MATERIALS AND METHODS

The medical records of patients with GEP-NETs were reviewed.

RESULTS

Fourteen patients (11 girls, 3 boys) were diagnosed with GEP-NET. The median age was 13 (9-18) years. Tumor localization was the appendix in 12, stomach in one and pancreas in one patient. Mesoappendix invasion was detected in four patients two of whom underwent right hemicolectomy (RHC) and lymph node dissection (LND). Of those, one patient had lymph node involvement. The other two had not further operations. Somatostatin was used in one with pancreatic metastatic disease and the other with gastric disease after surgery. No additional treatment was given in other patients. All patients are under follow-up without evidence of disease at a median follow-up of 85 months (7-226 months).

CONCLUSION

GEP-NETs should be considered in the differential diagnosis of acute appendicitis and in cases with persistent abdominal pain. In children, there is invariably a favorable prognosis, and additional surgical interventions other than simple appendectomies generally do not provide benefits. Mesoappendix invasion may not necessitate RHC and LND.

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.

Gastric Neuroendocrine Carcinoma Presenting as Ascites in a Young Female

Although neuroendocrine tumors (NETs) can occur in any organ, the majority of them occur in the gastrointestinal (GI) tract. We present the case of a 27-year-old female who presented with ascites. She underwent an ascitic fluid analysis, an esophagogastroduodenoscopy (EGDscopy) with biopsies, and a positron emission tomography (PET) scan, all of which culminated in a diagnosis of a poorly differentiated gastric NET (small cell type) with peritoneal metastasis. She was treated with cisplatin and etoposide. Depending on the differentiation and grade, NETs can manifest in a variety of ways. Definitive diagnosis requires histopathological examination and immunostaining. For smaller well-differentiated NETs, management is either endoscopic or surgical resection. For neuroendocrine carcinomas with metastasis, chemotherapy and symptomatic management are advised. This case report highlights the rare presentation of a neuroendocrine carcinoma as well as discusses its diagnostic approach and possible treatment options.

Biochemical Markers for Neuroendocrine Tumors: Traditional Circulating Markers and Recent Development-A Comprehensive Review

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms presenting unique challenges in diagnosis and management. Traditional markers such as chromogranin A (CgA), pancreatic polypeptide (PP), and neuron-specific enolase (NSE) have limitations in terms of specificity and sensitivity. Specific circulating markers such as serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) and various gastrointestinal hormones such as gastrin, glucagon, somatostatin, and vasoactive intestinal peptide (VIP) have a role in identifying functional NENs. Recent advances in molecular and biochemical markers, also accounting for novel genomic and proteomic markers, have significantly improved the landscape for the diagnosis and monitoring of NENs. This review discusses these developments, focusing on both traditional markers such as CgA and NSE, as well as specific hormones like gastrin, insulin, somatostatin, glucagon, and VIP. Additionally, it covers emerging genomic and proteomic markers that are shaping current research. The clinical applicability of these markers is highlighted, and their role in improving diagnostic accuracy, predicting surgical outcomes, and monitoring response to treatment is demonstrated. The review also highlights the need for further research, including validation of these markers in larger studies, development of standardized assays, and integration with imaging techniques. The evolving field of biochemical markers holds promise for improving patient outcomes in the treatment of NENs, although challenges in standardization and validation remain.

Same duodenal neuroendocrine tumors, different endoscopic resection methods: a case report and literature review

Duodenal neuroendocrine tumors (NETs), comprising 2-3% of all gastrointestinal NETs and 1-3% of all duodenal tumors, are remarkably uncommon. In this report, we described a patient diagnosed with two submucosal tumors in the duodenal bulb. We used two distinct endoscopic resection methods, including endoscopic submucosal dissection (ESD) and submucosal tunneling endoscopic resection (STER), to achieve en bloc resection of the lesions without complications. Pathological evaluation, involving hematoxylin-eosin staining and immunohistochemistry, confirmed the diagnosis of NET. Given the limited operative field and space in the duodenal bulb, STER proved to be a viable endoscopic resection technique.

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.

Automated AI-based grading of neuroendocrine tumors using Ki-67 proliferation index: comparative evaluation and performance analysis

Early detection is critical for successfully diagnosing cancer, and timely analysis of diagnostic tests is increasingly important. In the context of neuroendocrine tumors, the Ki-67 proliferation index serves as a fundamental biomarker, aiding pathologists in grading and diagnosing these tumors based on histopathological images. The appropriate treatment plan for the patient is determined based on the tumor grade. An artificial intelligence-based method is proposed to aid pathologists in the automated calculation and grading of the Ki-67 proliferation index. The proposed system first performs preprocessing to enhance image quality. Then, segmentation process is performed using the U-Net architecture, which is a deep learning algorithm, to separate the nuclei from the background. The identified nuclei are then evaluated as Ki-67 positive or negative based on basic color space information and other features. The Ki-67 proliferation index is then calculated, and the neuroendocrine tumor is graded accordingly. The proposed system's performance was evaluated on a dataset obtained from the Department of Pathology at Meram Faculty of Medicine Hospital, Necmettin Erbakan University. The results of the pathologist and the proposed system were compared, and the proposed system was found to have an accuracy of 95% in tumor grading when compared to the pathologist's report.

Elevated sortilin expression discriminates functional from non-functional neuroendocrine tumors and enables therapeutic targeting

A subset of neuroendocrine tumors (NETs) can cause an excessive secretion of hormones, neuropeptides, and biogenic amines into the bloodstream. These so-called functional NETs evoke a hormone-related disease and lead to several different syndromes, depending on the factors released. One of the most common functional syndromes, carcinoid syndrome, is characterized mainly by over-secretion of serotonin. However, what distinguishes functional from non-functional tumors on a molecular level remains unknown. Here, we demonstrate that the expression of sortilin, a widely expressed transmembrane receptor involved in intracellular protein sorting, is significantly increased in functional compared to non-functional NETs and thus can be used as a biomarker for functional NETs. Furthermore, using a cell line model of functional NETs, as well as organoids, we demonstrate that inhibition of sortilin reduces cellular serotonin concentrations and may therefore serve as a novel therapeutic target to treat patients with carcinoid syndrome.

Clinicopathologic features and diagnostic challenges of small cluster pattern appendiceal neuroendocrine tumors

Appendiceal neuroendocrine neoplasms (NENs) can present with various growth patterns including the traditional triad of histologic patterns-insular, trabecular and tubular. A small cluster pattern was also found in this study and the literature on this specific morphology is limited. In this study, we conducted a comprehensive review of appendiceal NENs from our institution over a ten-year period. Clinical and demographic data were obtained from medical records. Immunohistochemical stains were performed with antibodies specific for synaptophysin, chromogranin, INSM1, CD56, serotonin and peptide YY. The small cluster pattern was found in 29.4 % of all cases evaluated. The tumor cells in these cases were predominantly located at the distal tip of the appendix, associated with fibrous obliteration. These tumors were smaller in size and tended towards less advanced tumor stage, with reduced incidence of lymphovascular and/or perineural invasion. Chromogranin expression was identified in 76 % of these cases. There is a heterogeneous hormone profile with 46.7 % serotonin and 33.3 % peptide YY. In conclusion, the small cluster pattern NENs present with unique histological features and hormone expression profile. Among the various neuroendocrine markers, INSM1 showed superior diagnostic performance, with high sensitivity and minimal non-specific staining.

Comparing surgical and endoscopic resection approaches for colorectal neuroendocrine tumors within the diameter range of 10-20mm: an inverse probability weighting analysis based on the SEER database

Background

Currently, the primary treatment modalities for colorectal neuroendocrine tumors (CRNET) with a diameter between 10mm and 20mm are surgical resection (SR) and endoscopic resection (ER). However, it remains unclear which surgical approach yields the greatest survival benefit for patients.

Methods

This study included data from patients diagnosed with CRNET with tumor diameters ranging from 10mm to 20mm between the years 2004 and 2019, obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were categorized into ER and SR groups based on the respective surgical approaches. Inverse probability weighting (IPTW) was employed to mitigate selection bias. Kaplan-Meier analysis and log-rank tests were utilized to estimate overall survival (OS) and cancer-specific survival (CSS). Cox regression analysis (univariate and multivariate) was performed to evaluate potential factors influencing survival.

Results

A total of 292 CRNET patients were included in this study (ER group: 108 individuals, SR group: 184 individuals). Prior to IPTW adjustment, Kaplan-Meier analysis and Cox proportional hazard regression analysis demonstrated that the OS and CSS of the SR group were inferior to those of the ER group. However, after IPTW adjustment, no statistically significant differences in prognosis were observed between the two groups. Subgroup analyses revealed that patients with muscular invasion, positive lymph nodes, or distant metastasis derived greater survival benefits from SR. Significant differences in OS and CSS between the two groups were also observed across different age groups.

Conclusion

For patients with mucosal-limited lesions and without local lymph node or distant metastasis, ER is the preferred surgical approach. However, for patients with muscular invasion or positive lymph nodes/distant metastasis, SR offers a better prognosis. The choice of surgical approach should be based on the specific clinical characteristics of patients within different subgroups.

Gastric cancer with brain metastasis: from molecular characteristics and treatment

Gastric cancer is one of the cancers with increasing incidence and ranks fourth globally among the most frequent causes of cancer-related mortality. Early gastric cancer is often asymptomatic or presents with atypical symptoms, and the majority of patients present with advanced disease upon diagnosis. Brain metastases are present in approximately 1% of gastric cancer patients at the time of diagnosis, which significantly contributed to the overall mortality of the disease worldwide. Conventional therapies for patients with brain metastases remain limited and the median overall survival of patients is only 8 months in advanced cases. Recent studies have improved our understanding of the molecular mechanisms underlying gastric cancer brain metastases, and immunotherapy has become an important treatment option in combination with radiotherapy, chemotherapy, targeted therapy and surgery. This review aims to provide insight into the cellular processes involved in gastric cancer brain metastases, discuss diagnostic approaches, evaluate the integration of immune checkpoint inhibitors into treatment and prognosis, and explore the predictive value of biomarkers in immunotherapy.

A Clinicopathological Appraisal of Duodenal Neuroendocrine Tumors at a Racially Diverse Safety Net Hospital

INTRODUCTION

Significant knowledge gaps exist regarding clinicopathological profiling as well as treatment, surveillance, and survival of duodenal neuroendocrine tumors (dNETs).

METHODS

We clinicopathologically characterized and identified racial differences among patients with dNETs at a large safety net hospital. Tumor grades were updated based on the World Health Organization 2019 NET classification, and overall survival was determined.

RESULTS

We identified 17 dNETs and found no differences in clinicopathologic characteristics across racial groups. Pathological diagnosis was upgraded in 35% of dNETs, and age >65 years significantly shortened overall survival.

DISCUSSION

Larger-scale studies are needed to determine the significance of these findings.

Management of Gastric Neuroendocrine Tumors: A Review

Gastric neuroendocrine tumors (G-NET) are rare tumors arising from enterochromaffin-like cells of the gastric mucosa. They belong to a larger group called gastroenteropancreatic neuroendocrine tumors and are classified as low, intermediate, or high-grade tumors based on their proliferative indices. They are further categorized into three subtypes based on their morphologic characteristics, pathogenesis, and behavior. Types 1 and 2 tumors are characterized by elevated serum gastrin and are usually multifocal. They typically occur in the setting of atrophic gastritis or MEN1/Zollinger Ellison syndrome, respectively. Type 2 tumors are associated with the most symptoms, such as abdominal pain and diarrhea. Type 3 tumors are associated with normal serum gastrin, are usually solitary, and occur sporadically. This type has the most aggressive phenotype and metastatic potential. Treatment and prognosis for G-NET is dependent on their type, size, and stage. Type 1 has the best prognosis, and Type 3 has the worst. This review discusses the presentation, workup, and surgical management of these tumors.

Risk of metastasis and survival in patients undergoing different treatment strategies with T1 colonic neuroendocrine tumors

PURPOSE

The efficacy and safety of local excision (LE) for small (< 1‒2 cm) colonic neuroendocrine tumors (NETs) is controversial due to the higher metastasis risk when compared with rectal NETs. The study aimed to evaluate the metastasis risk of T1 colonic NETs and compare patients' long-term prognosis after LE or radical surgery (RS).

METHODS

The Surveillance Epidemiology and End Results database was used to identify patients with T1 colonic NETs (2004‒2015). Multivariable logistic regression was performed to assess factors associated with metastasis risk. Propensity score matching was used to balance the variables. Cancer-specific survival (CSS) and overall survival (OS) were calculated to estimate the prognosis of patients with T1N0M0 colonic NETs who underwent LE or RS.

RESULTS

Of the 610 patients with colonic NETs, 46 (7.54%) had metastasis at diagnosis. Tumor size (11-20 mm) (OR = 9.51; 95% confidence interval (CI): 4.32‒21.45; P < 0.001), right colon (OR = 15.79; 95% CI 7.20‒38.56; P < 0.001), submucosal infiltration (OR = 2.08; 95% CI 0.84‒5.57; P = 0.125) were independent risk factors associated with metastasis. Of the 515 patients with T1N0M0 colonic NETs, the overall long-term prognosis of LE was as good as that of RS groups (after matching, 5-year CSS: 97.9% vs. 94.6%, P = 0.450; 5-year OS: 92.7% vs. 85.6%, P = 0.009).

CONCLUSION

Tumor size (11‒20 mm) and site (right colon) are associated with metastasis in T1 colonic NETs. In the absence of metastasis, LE could be a viable option for 0‒10 mm T1 colonic NETs with well/moderate differentiation in the left colon in terms of long-term survival.

Virtual Care for Patients with Advanced Well Differentiated Gastroenteropancreatic Neuroendocrine Tumor (GEP-NET)

INTRODUCTION

The COVID-19 pandemic resulted in an unprecedent shift towards virtual cancer care, including the care of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). The aim of this study was to evaluate the use of virtual care for GEP-NETs during the COVID-19 pandemic at a high-volume academic cancer center.

METHODS

This retrospective, observational study performed at the Ottawa Hospital Cancer Center in Canada evaluated adult patients with GEP-NETs seen in consultation by medical oncology between 1 June 2019 and 31 December 2022. Demographic, clinicopathologic, cancer treatment and visit data were collected. Univariable and multivariable analyses assessed the relationship between patient characteristics and virtual care use.

RESULTS

A total of 103 patients with well-differentiated GEP-NETS were included. Overall, 18/103 (17.5%) consults and 594/781 (76.1%) follow-ups were performed virtually. All consultation visits returned to in-person assessment by 2022, while 67.0% and 41.4% follow-ups remained virtual in 2022 and 2023, respectively. The year of follow-up, sex, employment and Charlston comorbidity index were associated with virtual follow-up use in the multivariable analysis.

DISCUSSION

Virtual care remained a predominant method of GEP-NET patient assessment in the peri-pandemic period. These results highlight an opportunity to improve access to subspecialty neuroendocrine cancer care through the continued use of virtual care.

Gastric Neuroendocrine Tumor With Cystic Hepatic Metastases Mimicking Hepatic Echinococcosis: A Case Report

Metastatic gastrointestinal neuroendocrine tumors classically appear as contrast-enhancing lesions on computed tomography. However, in a small percentage of patients, these lesions can be cystic in nature, leading to false diagnoses of benign or infectious lesions such as echinococcosis. Hence, every cystic lesion of the liver must be carefully investigated before making the treatment plan. We report a patient with hematemesis caused by a large gastric ulcer with multiple cystic lesions in the left lobe of the liver abutting the stomach. The liver lesions were misdiagnosed as hepatic echinococcosis, and the patient was started on medical therapy. However, when medical therapy failed, the patient underwent surgical excision and the histopathology showed cystic metastases of a gastric neuroendocrine tumor.

A retrospective study comparing minimally invasive versus open surgical resection of small intestinal neuroendocrine neoplasms at a tertiary referral center

INTRODUCTION

Neuroendocrine neoplasms (SI-NEN) are the commonest malignancies of the small intestine. Traditionally, surgical treatment for SI-NEN has been open surgery.

PURPOSE

The purpose of this study was to compare minimally invasive surgery (MIS) with the traditional open surgery approach for treating SI-NEN in a Swedish population.

METHODS

Patients with histopathological confirmed SI-NEN who underwent open surgery or MIS resection within 2009-2021 were extracted from the hospital's medical records.

RESULTS

65 patients were included in this study, with 35 (54 %) undergoing MIS and 30 (46 %) undergoing open surgery. We found no statistically significant difference (p = 0.173) in the frequency of R0 resections (MIS group n = 34 (97 %), open surgery group n = 26 (87 %)). Nor was there a significant difference (p = 0.101) when comparing the median number of resected lymph nodes (MIS group n = 13.5, open surgery group n = 10). A post-operative paralytic ileus was more often reported (p = 0.052) in the MIS group (n = 9, 26 %) compared to the open surgery group (n = 2, 7 %). In light of this, the days of hospital stay did not differ significantly (MIS group median = 6, IQR (5-8), open surgery group median = 6, IQR (5-9)). The Kaplan-Meier analysis did not reveal differences concerning cancer-related deaths (p = 0.109).

CONCLUSION

The results from this study support that a MIS approach for the treatment of SI-NEN may not be inferior to open surgery. The higher number of resected lymph nodes and R0 resections may even speak in favor for a MIS approach. More studies with a longer time of observation are needed to further support this conclusion.

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.

Endoscopic Management of Gastro-Entero-Pancreatic Neuroendocrine Tumours: An Overview of Proposed Resection and Ablation Techniques

A literature search of MEDLINE/PUBMED was conducted with the aim to highlight current endoscopic management of localised gastro-entero-pancreatic NETs. Relevant articles were identified through a manual search, and reference lists were reviewed for additional articles. The results of the research have been displayed in a narrative fashion to illustrate the actual state-of-the-art of endoscopic techniques in the treatment of NETs. Localised NETs of the stomach, duodenum and rectum can benefit from advanced endoscopic resection techniques (e.g., modified endoscopic mucosal resection, endoscopic full thickness resection, endoscopic submucosal dissection) according to centre expertise. Radiofrequency thermal ablation can be proposed as an alternative to surgery in selected patients with localised pancreatic NETs.

Neuroendocrine tumour of the lesser omentum

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

Navigating Tumour Microenvironment and Wnt Signalling Crosstalk: Implications for Advanced Cancer Therapeutics

Cancer therapeutics face significant challenges due to drug resistance and tumour recurrence. The tumour microenvironment (TME) is a crucial contributor and essential hallmark of cancer. It encompasses various components surrounding the tumour, including intercellular elements, immune system cells, the vascular system, stem cells, and extracellular matrices, all of which play critical roles in tumour progression, epithelial-mesenchymal transition, metastasis, drug resistance, and relapse. These components interact with multiple signalling pathways, positively or negatively influencing cell growth. Abnormal regulation of the Wnt signalling pathway has been observed in tumorigenesis and contributes to tumour growth. A comprehensive understanding and characterisation of how different cells within the TME communicate through signalling pathways is vital. This review aims to explore the intricate and dynamic interactions, expressions, and alterations of TME components and the Wnt signalling pathway, offering valuable insights into the development of therapeutic applications.

Incidence trends and survival analysis of appendiceal tumors in the United States: Primarily changes in appendiceal neuroendocrine tumors

BACKGROUND

Appendiceal tumors are considered to be a relatively rare tumor of the gastrointestinal tract and the prognosis is unclear. This study comprehensively investigated trends in the epidemiology and survival of appendiceal tumors in the United States over the past approximately 20 years.

METHODS

Patients with pathologically confirmed appendiceal tumors from 2000 to 2017 were selected from the Surveillance, Epidemiology and End Results (SEER) database. Age-adjusted incidence rates were calculated by SEER*Stat 8.4.0. The Kaplan-Meier method was used to analyze survival and prognostic factors were investigated by a multivariate Cox proportional risk model.

RESULTS

Ultimately, 13,546 patients with appendiceal tumors between 2000 and 2017 were included. The annual incidence of colonic adenocarcinoma and mucinous adenocarcinoma remained relatively stable. Interestingly, the annual incidence of appendiceal neuroendocrine tumors (aNETs) increased significantly, from 0.03 to 0.90 per 100,000 person-years, with the most dramatic increase in the number of patients with localized disease. Patients with aNETs showed a significant improvement in survival between 2009-2017, compared to the period 2000-2008. Moreover, this improvement in survival over time was seen at all stages (localized, regional, distant) of aNETs. However, this improved survival over time was not seen in colonic and mucinous adenocarcinoma.

CONCLUSIONS

The incidence of appendiceal neoplasms has increased significantly over the past nearly two decades, which is mainly due to the increased incidence and significant migration to earlier stages in aNETs. We must note that despite the increased incidence of aNETs, survival rates have improved at different disease stages.

Multiomic sequencing of paired primary and metastatic small bowel carcinoids

Background: Small bowel carcinoids are insidious tumors that are often metastatic when diagnosed. Limited mutation landscape studies of carcinoids indicate that these tumors have a relatively low mutational burden. The development of targeted therapies will depend upon the identification of mutations that drive the pathogenesis and metastasis of carcinoid tumors. Methods: Whole exome and RNA sequencing of 5 matched sets of normal tissue, primary small intestine carcinoid tumors, and liver metastases were investigated. Germline and somatic variants included: single nucleotide variants (SNVs), insertions/deletions (indels), structural variants, and copy number alterations (CNAs). The functional impact of mutations was predicted using Ensembl Variant Effect Predictor. Results: Large-scale CNAs were observed including the loss of chromosome 18 in all 5 metastases and 3/5 primary tumors. Certain somatic SNVs were metastasis-specific; including mutations in ATRX, CDKN1B, MXRA5 (leading to the activation of a cryptic splice site and loss of mRNA), SMARCA2, and the loss of UBE4B. Additional mutations in ATRX, and splice site loss of PYGL, leading to intron retention observed in primary and metastatic tumors. Conclusions: We observed novel mutations in primary/metastatic carcinoid tumor pairs, and some have been observed in other types of neuroendocrine tumors. We confirmed a previously observed loss of chromosome 18 and CDKN1B. Transcriptome sequencing added relevant information that would not have been appreciated with DNA sequencing alone. The detection of several splicing mutations on the DNA level and their consequences at the RNA level suggests that RNA splicing aberrations may be an important mechanism underlying carcinoid tumors.

Therapeutic Challenges for Gastric Neuroendocrine Neoplasms: Take It or Leave It?

Background and Objectives: Gastric neuroendocrine neoplasms (gNENs) represent rare but increasingly recognized tumors. They are distinguished into three main clinical types (type-1, type-2, and type-3) according to gastrin level and at histological evaluation in well-differentiated G1, G2, or G3 lesions, as well as poorly-differentiated lesions. Small type-1 and type-2 neoplasms with low proliferation indices demonstrated excellent survival without progression during an extended follow-up period, and for these reasons, active endoscopic observation or endoscopic resection are feasible options. On the other hand, surgery is the treatment of choice for more aggressive type-3, G3, or infiltrating neoplasms. The present study aims to comprehensively review and compare the available therapeutic strategies for gNENs. Materials and Methods: A computerized literature search was performed using relevant keywords to identify all of the pertinent articles with particular attention to gNEN endoscopic treatment. Results: In recent years, different endoscopic resective techniques (such as endoscopic mucosal dissection, modified endoscopic mucosal resection, and endoscopic full-thickness resection) have been developed, showing a high rate of complete resection for advanced and more aggressive lesions. Conclusions: Overall, gNENs represent a heterogeneous group of lesions with varying behavior which require personalized management. The non-operative approach for small type-1 gNENs seems to be feasible and should be promoted. A step-up approach with minimally invasive endoscopic therapies might be proposed, particularly for type-1 gNEN. On the other hand, it is important to recognize the negative prognostic factors in order to identify those rare cases requiring more aggressive approaches. A possible therapeutic algorithm for localized gNEN management is provided.

Exploring Possible Diagnostic Precancerous Biomarkers for Oral Submucous Fibrosis: A Narrative Review

Oral submucous fibrosis (OSF) stands as a progressive oral ailment, designated as a potentially malignant disorder. OSF has gained widespread recognition as a significant precursor to malignant transformation. In the pursuit of dependable, straightforward, and non-invasive diagnostic measures for the early detection of oral malignant progression, research has delved into potential diagnostic biomarkers of OSF. This comprehensive review delves into current investigations that explore the correlation between various biomarkers and OSF. The molecular biomarkers of OSF are categorized based on cytology and sampling methods. Moreover, this review encompasses pertinent studies detailing how these biomarkers are acquired and processed. Within this scope, we scrutinize four potential biomarkers that hold the promise of facilitating the development of diagnostic tools for detecting early-stage OSF.

How the Radiologist Must Reason for a Correct Diagnosis in Patients With Small Bowel Mural Thickening Studied by CT or MRI: A Pictorial Review

Conditions that lead to small bowel mural thickening fall into a broad spectrum of diseases, including inflammatory, infectious, vascular or neoplastic. Computed tomography (CT) and Magnetic Resonance Imaging (MRI), especially CT-enterography and MR-enterography, permit evaluation of both entire small bowel and extraluminal structures. In CT/MR-enterography, the main prerequisite for the correct evaluation of small bowel is to obtain optimal intestinal distension. In fact, most errors are related to poor intestinal distension of the bowel which can lead to interpret as pathological a small bowel segment that is not very distended (false positive), or not to recognize presence of pathology in a collapsed segment (false negative). Once the examination has been performed, the images are analyzed in order to identify the presence of small bowel pathology. Pathology of the small bowel can manifest as endoluminal alteration and/or intestinal wall thickening. Once bowel wall thickening has been identified, the radiologist's first objective is trying to define benign or malignant nature of the alteration, using also patient's history and clinical features. Once the suspicion of benign or malignant pathology has been raised, the radiologist must try to formulate a diagnosis of nature. In this pictorial review we describe how the radiologist must reason for a correct diagnosis by answering a pattern of sequential questions in a patient with suspected small bowel disease studied by CT or MRI.

Exploring the spectrum of incidental gastric polyps in autoimmune gastritis

BACKGROUND

Gastric polyps represent an abnormal proliferation of the gastric mucosa. Chronic atrophic autoimmune gastritis (CAAG) targets parietal cells and results in hypo-achlorhydria and hypergastrinemia, which exerts a proliferative effect on the gastric mucosa.

AIMS

We investigate the incidence of gastric polyps in CAAG patients.

METHODS

This is a single-center retrospective study examining patients with confirmed CAAG from January 1990 until June 2022. Demographic, clinical, biochemical, and serological data were collected for each included patient. The histopathological characteristics of the detected polyps were recorded.

RESULTS

A total of 176 CAAG patients were included. Eighty-nine (50.5%) had 163 incidental polyps. Seventy-six patients (85%) had 130 non-endocrine lesions, among which 118 (90.7%) were inflammatory, 6 (4.6%) adenomatous, and 4 (3%) fundic; 33 patients (37%) had gastric neuroendocrine neoplasms (gNENs), and 21 (23.6%) both; one had MALToma and one gastric adenocarcinoma. Higher circulating levels of gastrin and chromogranin A were observed among patients with polyps (median 668 vs 893 pg/ml p = 0.0237, 146 vs 207 ng/ml p = 0.0027, respectively).

CONCLUSION

CAAG implies a high incidence of gNENs and exocrine lesions. Gastrin plays a possible trophic role on the mucosa. Further evidence is needed to validate its predictive role for increased polyp risk in CAAG.

Small Bowel Imaging from Stepchild of Roentgenology to MR Enterography, Part II: The Reliable Disclosure of Crohn's Disease and Non-Inflammatory Small Bowel Disorder Plot through MRI Findings

MRE has become a standard imaging test for evaluating patients with small bowel pathology, but a rigorous methodology for describing and interpreting the pathological findings is mandatory. Strictures, abscess, inflammatory activity, sinus tract, wall edema, fistula, mucosal lesions, strictures, and mesentery fat hypertrophy are all indicators of small bowel damage in inflammatory and non-inflammatory small bowel disease, and they are all commonly and accurately explained by MRE. MRE is a non-invasive modality that accurately assesses the intra-luminal, parietal, and extra-luminal small bowel. Differential MRE appearance allows us to distinguish between Crohn's disease and non-inflammatory small bowel disorder. The purpose of this paper is to present the MRE pathological findings of small bowel disorder.

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.

A Comprehensive Review on Neuroendocrine Neoplasms: Presentation, Pathophysiology and Management

Neuroendocrine neoplasms (NENs) are a group of heterogeneous tumors with neuroendocrine differentiation that can arise from any organ. They account for 2% of all malignancies in the United States. A significant proportion of NEN patients experience endocrine imbalances consequent to increased amine or peptide hormone secretion, impacting their quality of life and prognosis. Over the last decade, pathologic categorization, diagnostic techniques and therapeutic choices for NENs-both well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs)-have appreciably evolved. Diagnosis of NEN mostly follows a suspicion from clinical features or incidental imaging findings. Hormonal or non-hormonal biomarkers (like serum serotonin, urine 5-HIAA, gastrin and VIP) and histology of a suspected NEN is, therefore, critical for both confirmation of the diagnosis and classification as an NET or NEC. Therapy for NENs has progressed recently based on a better molecular understanding, including the involvement of mTOR, VEGF and peptide receptor radionuclide therapy (PRRT), which add to the growing evidence supporting the possibility of treatment beyond complete resection. As the incidence of NENs is on the rise in the United States and several other countries, physicians are more likely to see these cases, and their better understanding may support earlier diagnosis and tailoring treatment to the patient. We have compiled clinically significant evidence for NENs, including relevant changes to clinical practice that have greatly updated our diagnostic and therapeutic approach for NEN patients.

A novel nomogram and risk stratification system predicting the cancer-specific survival of patients with gastric neuroendocrine carcinoma: a study based on SEER database and external validation

BACKGROUND

Gastric neuroendocrine carcinoma (GNEC) is a rare histology of gastric cancer. The retrospective study was designed to construct and validate a nomogram for predicting the cancer-specific survival (CSS) of postoperative GNEC patients.

METHODS

Data for 28 patients from the Hangzhou TCM Hospital were identified as the external validation cohort. A total of 1493 patients were included in the SEER database and randomly assigned to the training group (1045 patients) and internal validation group (448 patients). The nomogram was constructed using the findings of univariate and multivariate Cox regression studies. The model was evaluated by consistency index (C-index), calibration plots, and clinical net benefit. Finally, the effect between the nomogram and AJCC staging system was compared by net reclassification index (NRI) and integrated discrimination improvement (IDI).

RESULTS

Age, gender, grade, T stage, N stage, metastasis, primary site, tumor size, RNE, and chemotherapy were incorporated in the nomogram. The C-indexes were 0.792 and 0.782 in the training and internal verification sets. The 1-, 3-, and 5-year CSS predicted by the nomogram and actual measurements had good agreement in calibration plots. The 1-, 3-, and 5-year NRI were 0.21, 0.29, and 0.37, respectively. The 1-, 3-, and 5-year IDI values were 0.10, 0.12, and 0.13 (P < 0.001), respectively. In 1-, 3-, and 5-year CSS prediction using DCA curves, the nomogram outperformed the AJCC staging system. The nomogram performed well in both the internal and external validation cohorts.

CONCLUSION

We developed and validated a nomogram to predict 1-, 3-, and 5-year CSS for GNEC patients after surgical resection. This well-performing model could help doctors enhance the treatment plan.

Comparable long-term survival outcomes of endoscopic therapy versus surgical therapy for T1-2N0M0 duodenal neuroendocrine tumors

BACKGROUND AND STUDY AIMS

The optimal treatment modality for T1-2N0M0 duodenal neuroendocrine tumors (DNETs) is still controversial. In this study, long-term survival outcomes were compared between the endoscopic therapy and surgical therapy for T1-2N0M0 DNETs using the Surveillance, Epidemiology, and End Results (SEER) database.

PATIENTS AND METHODS

Patients with DNETs from the SEER database were selected from 2004 to 2015. We used the Kaplan-Meier method and log-rank test to compare long-term survival results between the endoscopic therapy and surgical therapy. An analysis of the multivariable Cox proportional hazards model was performed to identify risk factors for patient prognoses. The 1:1 propensity score matching (PSM) was performed to balance baseline data.

RESULTS

A total of 816 patients with DNETs were included, of which 578 patients (70.8%) received endoscopic therapy and 238 patients (29.2%) received surgical therapy. Before the PSM, there was no difference between the two groups of patients with DNETs on long-term survival [5-year OS (86.1% vs. 87.9%, P = 0.45), 10-year OS (72.5% vs. 72.3%, P = 0.45)]. After adjusting covariates, we found endoscopic therapy and surgical therapy groups had comparable risks of overall survival (HR 0.86, 95% CI 0.60-1.23, P = 0.409) and cancer-specific survival (HR 1.68, 95% CI 0.74-3.83, P = 0.214). In the post-PSM analysis, there was no discernible difference between the endoscopic therapy and surgical therapy group.

CONCLUSIONS

Our study found that for T1-2N0M0 DNETs patients, whose long-term OS and CSS results were similar for the endoscopic and surgical therapy groups. For these patients, endoscopic resection might be an optimal therapy modality.

Risk Factors for Lymph Node Metastasis of Rectal Neuroendocrine Tumor and Its Prognostic Impact: A Single-Center Retrospective Analysis of 195 Cases with Radical Resection

PURPOSE

The incidence of rectal neuroendocrine tumors (NETs) has been steadily increasing. The risk factors for and prognostic impact of lymph node (LN) metastasis were analyzed in 195 patients with stage I-III rectal NET who underwent radical surgery.

METHODS

This retrospective, single-center study analyzed risk factors for LN metastasis focusing on previously identified factors and a novel risk factor: multiple rectal NETs. The association between LN metastasis and the prognosis was also analyzed.

RESULTS

Pathologically, the LN metastasis rate (also the rate of stage III disease) was 39%, which was higher than the clinical LN metastasis rate of 14%. Tumor size > 10 mm, presence of central depression, tumor grade G2, depth of invasion, LN swelling on preoperative imaging (cN1), venous invasion and multiple NETs were identified as risk factors for LN metastasis. As the tumor size and risk factors increased, the rate of LN metastasis increased. Among these 7 factors, venous invasion, cN1, and multiple NETs were identified as independent predictors of LN metastasis. LN metastasis of rectal NETs was associated with significantly poor disease-free and disease-specific survival.

CONCLUSIONS

As risk factors increase, the potential for rectal NETs to metastasize to the LNs increases and LN metastasis is associated with a poor prognosis. This is the first study to report multiple NETs as a risk factor for LN metastasis. A future study examining the survival benefit of radical surgery accompanying LN dissection compared with local resection is warranted.

NET-02: a randomised, non-comparative, phase II trial of nal-IRI/5-FU or docetaxel as second-line therapy in patients with progressive poorly differentiated extra-pulmonary neuroendocrine carcinoma

Background

The prognosis for patients with poorly-differentiated extra-pulmonary neuroendocrine carcinoma (PD-EP-NEC) is poor. A recognised first-line (1L) treatment for advanced disease is etoposide/platinum-based chemotherapy with no standard second-line (2L) treatment.

Methods

Patients with histologically-confirmed PD-EP-NEC (Ki-67 > 20%; Grade 3) received IV liposomal irinotecan (nal-IRI) (70 mg/m2 free base)/5-FU (2400 mg/m2)/folinic acid, Q14 days (ARM A), or IV docetaxel (75 mg/m2), Q21 days (ARM B), as 2L therapy. Primary endpoint was 6-month progression-free survival (PFS) rate (80% power to demonstrate one-sided 95% lower confidence interval excluded 15% (target level of efficacy: 30%)). Secondary endpoints: objective response rate (ORR), median PFS, overall survival (OS), toxicity and patient-reported quality-of-life (QoL) (ClinicalTrials.gov: NCT03837977).

Findings

Of 58 patients (29 each arm); 57% male, 90% ECOG PS 0/1, 10% PS 2, 89.7% Ki-67 ≥ 55%, primary site: 70.7%-gastrointestinal, 18.9%-other, 10.3%-unknown, 91.4%/6.9%/1.7% were resistant/sensitive/intolerant to 1L platinum-based treatment, respectively. The primary end-point of 6-month PFS rate was met by ARM A: 29.6% (lower 95% Confidence-Limit (CL) 15.7), but not by ARM B: 13.8% (lower 95%CL:4.9). ORR, median PFS and OS were 11.1% (95%CI:2.4-29.2) and 10.3% (95%CI:2.2-27.4%); 3 months (95%CI:2-6) and 2 months (95%CI:2-2); and 6 months (95%CI:3-10) and 6 months (95%CI:3-9) in ARMS A and B, respectively. Adverse events ≥ grade 3 occurred in 51.7% and 55.2% (1 and 6 discontinuations due to toxicity in ARMS A and B), respectively. QoL was maintained in ARM A, but not ARM B.

Interpretation

nal-IRI/5-FU/folinic acid, but not docetaxel, met the primary endpoint, with manageable toxicity and maintained QoL, with no difference in OS. ORR and median PFS were similar in both arms. This study provides prospective efficacy, toxicity and QoL data in the 2L setting in a disease group of unmet need, and represents some of the strongest evidence available to recommend systemic treatment to these patients.

Funding

Servier.

Non-specific Symptoms of Small Bowel Neuroendocrine Tumor and the Diagnostic Challenges: A Case Report

Neuroendocrine tumors (NETs) are considered the most frequent tumors that affect the small bowels. Despite diagnostic modalities, the diagnosis of small bowel NETs is not straightforward and poses a high challenge to most physicians, due to poor accessibility to this area and the patient's non-specific presentations. We reported a case of a 60-year-old male patient, who presented with severe postprandial epigastric pain of one-month duration, loss of appetite, and weight loss. Investigations revealed no definite diagnosis. Therefore, exploratory laparoscopy was attempted along with multiple biopsies that led to the diagnosis of small bowel NET. We conclude that NETs require a high index of suspicion in patients with recurrent abdominal pain.

Circulating hsa-miR-5096 predicts 18F-FDG PET/CT positivity and modulates somatostatin receptor 2 expression: a novel miR-based assay for pancreatic neuroendocrine tumors

Gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) are rare diseases encompassing pancreatic (PanNETs) and ileal NETs (SINETs), characterized by heterogeneous somatostatin receptors (SSTRs) expression. Treatments for inoperable GEP-NETs are limited, and SSTR-targeted Peptide Receptor Radionuclide Therapy (PRRT) achieves variable responses. Prognostic biomarkers for the management of GEP-NET patients are required. ¹⁸F-FDG uptake is a prognostic indicator of aggressiveness in GEP-NETs. This study aims to identify circulating and measurable prognostic miRNAs associated with ¹⁸F-FDG-PET/CT status, higher risk and lower response to PRRT.

Methods

Whole miRNOme NGS profiling was conducted on plasma samples obtained from well-differentiated advanced, metastatic, inoperable G1, G2 and G3 GEP-NET patients enrolled in the non-randomized LUX (NCT02736500) and LUNET (NCT02489604) clinical trials prior to PRRT (screening set, n= 24). Differential expression analysis was performed between ¹⁸F-FDG positive (n=12) and negative (n=12) patients. Validation was conducted by Real Time quantitative PCR in two distinct well-differentiated GEP-NET validation cohorts, considering the primary site of origin (PanNETs n=38 and SINETs n=30). The Cox regression was applied to assess independent clinical parameters and imaging for progression-free survival (PFS) in PanNETs. In situ RNA hybridization combined with immunohistochemistry was performed to simultaneously detect miR and protein expression in the same tissue specimens. This novel semi-automated miR-protein protocol was applied in PanNET FFPE specimens (n=9). In vitro functional experiments were performed in PanNET models.

Results

While no miRNAs emerged to be deregulated in SINETs, hsa-miR-5096, hsa-let-7i-3p and hsa-miR-4311 were found to correlate with ¹⁸F-FDG-PET/CT in PanNETs (p-value:<0.005). Statistical analysis has shown that, hsa-miR-5096 can predict 6-month PFS (p-value:<0.001) and 12-month Overall Survival upon PRRT treatment (p-value:<0.05), as well as identify ¹⁸F-FDG-PET/CT positive PanNETs with worse prognosis after PRRT (p-value:<0.005). In addition, hsa-miR-5096 inversely correlated with both SSTR2 expression in PanNET tissue and with the ⁶⁸Gallium-DOTATOC captation values (p-value:<0.05), and accordingly it was able to decrease SSTR2 when ectopically expressed in PanNET cells (p-value:<0.01).

Conclusions

hsa-miR-5096 well performs as a biomarker for ¹⁸F-FDG-PET/CT and as independent predictor of PFS. Moreover, exosome-mediated delivery of hsa-miR-5096 may promote SSTR2 heterogeneity and thus resistance to PRRT.

De-escalating chemotherapy for stage I-II gastric neuroendocrine carcinoma? A real-world competing risk analysis

BACKGROUND

The role of adjuvant chemotherapy in gastric neuroendocrine neoplasms (GNEC) has not been well clarified yet. The study was designed to investigate the potential effect of adjuvant chemotherapy in stage I-II GNEC patients and construct a predictive nomogram.

METHOD

Stage I-II GNEC patients were included in the Surveillance, Epidemiology, and End Results (SEER) database and divided into chemotherapy and no-chemotherapy groups. We used Kaplan-Meier survival analyses, propensity score matching (PSM), and competing risk analyses. The predictive nomogram was then built and validated.

RESULTS

Four hundred four patients with stage I-II GNEC were enrolled from the SEER database while 28 patients from Hangzhou TCM Hospital were identified as the external validation cohort. After PSM, similar 5-year cancer-specific survival was observed in two groups. The outcomes of competing risk analysis indicated a similar 5-year cumulative incidence of cancer-specific death (CSD) between the two cohorts (35.4% vs. 31.4%, p = 0.731). And there was no significant relation between chemotherapy and CSD in the multivariate competing risks regression analysis (HR, 0.79; 95% CI, 0.48-1.31; p = 0.36). Furthermore, based on the variables from the multivariate analysis, a competing event nomogram was created to assess the 1-, 3-, and 5-year risks of CSD. The 1-, 3-, and 5-year area under the receiver operating characteristic curve (AUC) values were 0.770, 0.759, and 0.671 in the training cohort, 0.809, 0.782, and 0.735 in the internal validation cohort, 0.786, 0.856, and 0.770 in the external validation cohort. Furthermore, calibration curves revealed that the expected and actual probabilities of CSD were relatively consistent.

CONCLUSION

Stage I-II GNEC patients could not benefit from adjuvant chemotherapy after surgery. De-escalation of chemotherapy should be considered for stage I-II GNEC patients. The proposed nomogram exhibited excellent prediction ability.

Small Cell Carcinoma of the Gallbladder

Primary neuroendocrine carcinoma of the gallbladder (GB) is a rare, highly dismal lethal disease with a fatal prognosis. A 45-year-old female presented with right upper abdomen pain and multiple vomiting episodes. Imaging studies showed diffuse thickening of the wall of the GB with locoregional invasion into the nearby structures with extensive abdominal lymph node metastasis and arteriovenous encasements. Ultrasound-guided fine-needle aspiration was done, which was diagnostic of small cell carcinoma of the GB. The patient was planned for palliative chemotherapy. A small cell variant of neuroendocrine carcinoma of the GB is a rare entity with a moribund lethality associated with it. Patients are diagnosed in advanced stages with not many treatment modalities to offer. Usually, patients are treated with palliative chemotherapy.

Endoscopic techniques for gastric neuroendocrine tumors: An update

Gastric neuroendocrine neoplasms (gNENs) are a rare type of gastric neoplasm, even if their frequency is increasing according to the latest epidemiologic revisions of the main registries worldwide. They are divided into three main subtypes, with different pathogeneses, biological behaviors, and clinical characteristics. GNEN heterogeneity poses challenges, therefore these neoplasms require different management strategies. Update the knowledge on the endoscopic treatment options to manage g-NENs. This manuscript is a narrative review of the literature. In recent years, many advances have been made not only in the knowledge of both the pathogenesis and the molecular profiling of gNENs but also in the endoscopic expertise towards innovative treatment options, which proved to be less aggressive without losing the capability of being radical. The endoscopic approach is increasingly applied in the field of gastrointestinal (GI) luminal neoplasms, and this is true not only for adenocarcinomas but also for gNENs. In particular, different techniques have been described for the endoscopic removal of suspected lesions, ranging from classical polypectomy (cold or hot snare) to endoscopic mucosal resection (both with “en bloc” or piecemeal technique), endoscopic submucosal dissection, and endoscopic full-thickness resection. GNENs comprise different subtypes of neoplasms with distinct management and prognosis. New endoscopic techniques offer a wide variety of approaches for GI localized neoplasms, which demonstrated to be appropriate and effective also in the case of gNENs. Correct evaluation of size, site, morphology, and clinical context allows the choice of tailored therapy in order to guarantee a definitive treatment.

Emerging Immunotherapeutic and Diagnostic Modalities in Carcinoid Tumors

Evasion of innate immunity represents a frequently employed method by which tumor cells survive and thrive. Previously, the development of immunotherapeutic agents capable of overcoming this evasion has realized pronounced clinical utility across a variety of cancer types. More recently, immunological strategies have been investigated as potentially viable therapeutic and diagnostic modalities in the management of carcinoid tumors. Classic treatment options for carcinoid tumors rely upon surgical resection or non-immune pharmacology. Though surgical intervention can be curative, tumor characteristics, such as size, location, and spread, heavily limit success. Non-immune pharmacologic treatments can be similarly limited, and many demonstrate problematic side effects. Immunotherapy may be able to overcome these limitations and further improve clinical outcomes. Similarly, emerging immunologic carcinoid biomarkers may improve diagnostic capabilities. Recent developments in immunotherapeutic and diagnostic modalities of carcinoid management are summarized here.

Incidental Finding of a Periampullary Neuroendocrine Tumor: A Case Report

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

Ga-68-Edotreotide Positron Emission Tomography/Computed Tomography Somatostatin Receptors Tumor Volume Predicts Outcome in Patients With Primary Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

We retrospectively aimed to assess the prognostic significance of somatostatin receptor (SSTR) standardized uptake value (SUVmax_sstr), SSTR representative tumor volume (RTV_sstr) and total lesion SSTR expression (TL_sstr) obtained by [⁶⁸Ga]Ga-edotreotide PET/CT ([⁶⁸Ga]Ga-SSTR PET/CT) in patients with primary gastroenteropancreatic neuroendocrine tumors (GEP-NET) before surgery.

MATERIAL AND METHODS

We analyzed patients who underwent [⁶⁸Ga]Ga-SSTR PET/CT 3-6 weeks before surgery from February 2020 to April 2022. The mean SUVmax_sstr value, the RTV_sstr (cm3; 42% threshold) and the TL_sstr (g) were registered. Thereafter the patients were followed up 10.3 months (range 3-27). The PET/CT results were compared to the event free survival (EFS).

RESULTS

Forty-two patients (61 ± 13 years) have been enrolled. At multivariate analysis only RTV_sstr values were predictive. The Kaplan-Meier survival analysis for RTV_sstr showed a significant better EFS in patients presenting lower values as compared to those having greater (P = .003, log-rank test). SUVmax_sstr was not suitable for predicting EFS, TL_sstr mildly.

CONCLUSION

RTV_sstr represents a valuable volumetric parameter able to predict the outcome in GEP-NET patients who underwent surgery. The magnitude of the SSTR representative tumor burden holds a predominant value for determining the response to therapy in GEP-NET patients before surgery, rather than the maximal SSTR representation at single voxel.