Small Bowel Neuroendocrine Tumors Research Articles

Race Affects Patients' Likelihood of Being Offered Surgical Resection for Small Bowel Neuroendocrine Neoplasms.

Race Affects Patients' Likelihood of Being Offered Surgical Resection for Small Bowel Neuroendocrine Neoplasms.

ASO Author Reflections: Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic Well-Differentiated Small Bowel Neuroendocrine Tumors.

ASO Author Reflections: Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic Well-Differentiated Small Bowel Neuroendocrine Tumors.

Correlation of cancer testis antigen expression with high type-I interferon signal and prognosis in small bowel neuroendocrine tumors.

596 Background: Patients with small bowel neuroendocrine tumors (SBNET) frequently present with metastatic disease, and efficacy of available therapies, including immune checkpoint inhibitors (ICI), is limited. Toward developing novel immunomodulatory strategies, we evaluated the tumor immune microenvironment of SBNETs using bulk transcriptional and digital spatial profiling (DSP). Methods: Patients with SBNET who underwent surgical resection at MD Anderson Cancer Center from 2003-2016 were retrospectively analyzed. Overall survival (OS) was assessed using the Kaplan-Meier method and Cox proportional hazards model was used for multivariate analysis (MVA). Bulk transcriptional profiling was performed using the Nanostring PanCancer-Immune Panel. DSP was performed with whole human transcriptome using PanCK to segment tumor and adjacent stroma; 88 distinct regions were analyzed using differential gene expression and Reactome pathway enrichment pipelines. Results: Resected SBNETs from 42 patients were selected for transcriptional analysis. Unsupervised clustering of gene expression demonstrated dichotomization into high and low cancer testis antigen (CTA) expression. CTA-high patients (n=12) demonstrated elevated expression of type-I interferons (IFN) and CTAs such as PRAME, GAGE1, and MAGEA3 and had significantly longer OS compared to CTA-low patients (n=30; median OS not reached vs 1975 days, p=0.008). MVA controlling for age, sex, metastatic disease, and Ki-67% confirmed CTA-high status as an independent predictor of longer OS (hazard ratio [HR] 0.2, 95% confidence interval [CI] 0.05-0.83). A pilot DSP experiment with 4 CTA-high and 4 CTA-low tumors revealed higher expression of epigenetic modification genes (e.g., H3C1, H2BC8, p<0.001) in CTA-high tumors with significant enrichment in epigenetic pathways (e.g., histone acetylation, DNA methylation). CTA-high tumors exhibited increased M2 macrophage presence (p=0.025) and increased stromal compartment NK cell activation (p=0.001). Conclusions: High expression of CTA and type-I IFN in resected SBNET is associated with longer survival, agnostic of stage or grade. While CTA expression has been implicated in tumor immunogenicity, this is the first work to identify a clinical signal in SBNET. Increased IFN in CTA-high tumors, corroborated by increased stromal NK cell activation, suggests an immune-mediated component of improved survival. Spatial transcriptomic analysis reveals epigenetic differences in CTA-high tumors and highlights the potential for combination epigenetic modifiers and immunotherapy in future trials.

Toll-like receptors 1-9 in small bowel neuroendocrine tumors-Clinical significance and prognosis.

Toll-like receptors (TLRs) are pattern recognition receptors of the innate immunity. TLRs are known to mediate both antitumor effects and tumorigenesis. TLRs are abundant in many cancers, but their expression in small bowel neuroendocrine tumors (SB-NETs) is unknown. We aimed to characterize the expression of TLRs 1-9 in SB-NETs and lymph node metastases and evaluate their prognostic relevance. The present study included 125 patients with SB-NETs, of whom 95 had lymph node metastases, from two Finnish hospitals. Tissue samples were stained immunohistochemically for TLR expression, assessed based on cytoplasmic and nucleic staining intensity and percentage of positively stained cells. Statistical methods for survival analysis included Kaplan-Meier method and Cox regression adjusted for confounding factors. Disease-specific survival (DSS) was the primary outcome. TLRs 1-2 and 4-9 were expressed in SB-NETs and lymph node metastases. TLR3 showed no positive staining. In primary SB-NETs, TLRs 1-9 were not associated with survival. For lymph node metastases, high cytoplasmic TLR7 intensity associated with worse DSS compared to low cytoplasmic intensity (26.4% vs. 84.9%, p = 0.028). Adjusted mortality hazard (HR) was 3.90 (95% CI 1.07-14.3). The expression of TLRs 1-6 and 8-9 in lymph node metastases were not associated with survival. SB-NETs and their lymph node metastases express cytoplasmic TLR 1-2 and 4-9 and nucleic TLR5. High TLR7 expression in SB-NET lymph node metastases was associated with worse prognosis. The current research has future perspective, as it can help create base for clinical drug trials to target specific TLRs with agonists or antagonists to treat neuroendocrine tumors.

A Rare Complication: Aortic Thrombosis Complicating A Carcinoid Syndrome Secondary to Small Bowel Neuroendocrine Tumor: Case report

Despite advancements in managing metastatic neuroendocrine tumors (NETs), cardiovascular complications remain a significant cause of morbidity and mortality in patients with carcinoid syndrome. We present a rare case of aortic thrombosis complicating carcinoid syndrome secondary to a small bowel neuroendocrine tumor. A 69-year-old male chronic smoker presented with treatment-resistant diarrhea, febrile sensations, and facial erythema. Imaging revealed a tissue mass in the right iliac fossa, infiltrating the ileocecal angle. Preoperative assessment was unremarkable, and the patient underwent open surgery for right ileocolectomy. Postoperatively, he developed chest pain and dyspnea, with elevated D-dimer levels and a floating aortic thrombus detected on angioscan. Management included unfractionated heparin, vitamin K antagonists, and octreotide. Pathological examination confirmed the neuroendocrine tumor. At 1-year follow-up, the patient showed no cardiovascular anomalies. This case highlights the need for further research on antithrombotic prophylaxis in NETs and underscores the complexity of managing paraneoplastic embolism.

ASO Visual Abstract: Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic, Well-Differentiated, Small-Bowel Neuroendocrine Tumors.

ASO Visual Abstract: Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic, Well-Differentiated, Small-Bowel Neuroendocrine Tumors.

Small Bowel Neuroendocrine Neoplasms-A Review.

Neuroendocrine neoplasms (NENs) are rapidly evolving small bowel tumors, and the patients are asymptomatic at the initial stages. Metastases are commonly observed at the time of presentation and diagnosis. This review addresses the small bowel NEN (SB-NEN) and its molecular, histological, and imaging features, which aid diagnosis and therapy guidance. Somatic cell number alterations and epigenetic mutations are studied to be responsible for sporadic and familial SB-NEN. The review also describes the grading of SB-NEN in addition to rare histological findings such as mixed neuroendocrine-non-NENs. Anatomic and nuclear imaging with conventional computed tomography, magnetic resonance imaging, computed tomographic enterography, and positron emission tomography are adopted in clinical practice for diagnosing, staging, and follow-up of NEN. Along with the characteristic imaging features of SB-NEN, the therapeutic aspects of imaging, such as peptide receptor radionuclide therapy, are discussed in this review.

Cancer testis antigen and interleukin expression correlates with survival in small bowel neuroendocrine tumors

Cancer testis antigen and interleukin expression correlates with survival in small bowel neuroendocrine tumors

Accuracy of DOTATATE PET imaging in the preoperative planning of small bowel neuroendocrine tumor resection

Accuracy of DOTATATE PET imaging in the preoperative planning of small bowel neuroendocrine tumor resection

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

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

Morbidity and Outcomes of Primary Tumor Management in Patients with Widely Metastatic Well-Differentiated Small Bowel Neuroendocrine Tumors.

The benefit of primary tumor resection in distant metastatic small bowel neuroendocrine tumors (SBNETs) is controversial, with treatment-based morbidity not well-defined. We aimed to determine the impact of primary tumor resection on development of disease-specific complications in patients with metastatic well-differentiated SBNETs. A retrospective analysis was performed of patients diagnosed with metastatic well-differentiated jejunal/ileal SBNETs at a single tertiary care cancer center from 1980 to 2016. Outcomes were compared on the basis of treatment selected at diagnosis between patients who underwent initial medical treatment or primary tumor resection. Among 180 patients, 71 underwent medical management and 109 primary tumor resection. Median follow-up was 116 months. Median event-free survival did not differ between treatment approaches (log-rank p = 0.2). In patients medically managed first, 16/71 (23%) required surgery due to obstruction, perforation, or bleeding. These same complications led to resection at presentation in 31/109 (28%) surgically treated patients. Development of an obstruction from the primary tumor was not associated with disease progression/recurrence (HR 1.14, 95% CI 0.75-1.75) with all patients recovering postoperatively. Ongoing tumor progression requiring secondary laparotomy was associated with worse mortality (HR 7.51, 95% CI 3.3-16.9; p < 0.001) and occurred in 20/109 (18%) primary tumor resection and 7/16 (44%) initially medically treated patients. Rates of event-free survival among patients with metastatic SBNETs do not differ on the basis of primary tumor management. The development of an obstruction from the primary tumor was not associated with worse outcomes with all patients salvaged. Regardless of initial treatment selected, patients with metastatic SBNET should be closely followed for early signs of primary tumor complications.

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

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

Peptide Receptor Radionuclide Therapy Performed Shortly After Administration of Long-Acting Octreotide.

We present a case of a 68-year-old man with metastatic small bowel neuroendocrine tumor who underwent 4 cycles of peptide receptor radionuclide therapy with 177Lu-DOTATATE. For his first 3 cycles, therapy was performed approximately 4 weeks after his last dose of octreotide LAR. Because of miscommunication in scheduling, his fourth cycle was performed only 48 hours after his last full dose of octreotide LAR. Despite this, we found that the tumoral uptake was not reduced at all, which may add to the increasing evidence on the nonnecessity of stopping somatostatin analogs before peptide receptor radionuclide therapy.

Pancreatic metastasis from small bowel neuroendocrine tumor.

Pancreatic metastasis from small bowel neuroendocrine tumor.

Management of Small Bowel Neuroendocrine Tumours: 10 Years' Experience at a Tertiary Referral Centre.

Neuroendocrine tumours (NET) arising from the small bowel are clinically challenging and are often diagnosed at advanced stages. Disease control with surgery alone can be demanding. Multimodal treatment concepts integrating surgery and non-surgical modalities could be of benefit. Retrospective review of consecutive adult patients with SB NET treated at Imperial College Healthcare NHS Trust between 1 January 2010 and 31 December 2019. Data regarding clinicopathological characteristics, treatments, and disease trajectory were extracted and summarised. Overall and progression/recurrence-free survival were estimated at 5 and 10 years. 154 patients were identified, with a median age of 64 years (range 33-87); 135/154 (87.7%) had stage III/IV disease at diagnosis. Surgery was used in 125 individuals (81.2%), typically with either segmental small bowel resection (60.8%) or right hemicolectomy (33.6%) and mesenteric lymphadenectomy for the primary tumour. Systemic and/or liver-directed therapies were used in 126 (81.8%); 60 (47.6%) had more than one line of non-surgical treatment. Median follow-up was 67.2 months (range 3.1-310.4); overall survival at 5 and 10 years was 91.0% (95% CI: 84.9-94.7%) and 82.5% (95% CI: 72.9-88.9%), respectively. Imaging-based median progression-free survival was 42.7 months (95% CI: 24.7 to 72.4); 5-year progression-free survival was 63.4% (95% CI: 55.0-70.6%); 10-year progression-free survival was 18.7% (95% CI: 12.4-26.1). Nineteen patients (12.3%) reached 10 years follow-up without disease recurrence and therefore were considered cured. Most patients with SB NET present in a metastasised stage. Multimodal treatment concepts may be associated with excellent clinical outcomes. Future work should explore optimal approaches to treatment sequencing and patient selection.

Socioeconomic disparities in patients with small bowel neuroendocrine tumors.

Demographic and socioeconomic disparities affect cancer specific outcomes in numerous malignancies, but the impact of these for patients with small bowel neuroendocrine tumors (SBNETs) is not well understood. The primary objective was to investigate the impact of demographic and socioeconomic factors on overall survival (OS) for patients with SBNETs. We performed a retrospective cohort study utilizing the National Cancer Database to assess patients diagnosed with SBNET between 2004 and 2015. Patients were stratified by demographics, socioeconomic factors, insurance status, and place of living. The 5-year OS for the entire cohort was 78.5%. The 5-year survival was worse in patients with lower income (p < 0.0001), lower education (p < 0.0001), not in proximity to a metro area (p = 0.0004), and treatment at a community cancer center (p < 0.0001). Adjusting for age and sex, factors associated with worse OS were lower income (<$38 000) (hazard ratio[HR]: 1.16, 95% confidence interval[CI]: 1.04-1.28), lower education (>20% no HSD) (HR: 1.14, 95% CI: 1.02-1.26), no insurance (HR: 1.66, 95% CI: 1.33-2.06), and not living in proximity to a metro area (HR: 1.27, 95% CI: 1.10-1.47). Patient demographics and socioeconomic factors play an important role in survival of patients with SBNETs, specifically proximity to a metro area, median income, education level, and type of treatment center. Strategies to improve access to care must be considered in this at-risk population.

Feasibility of Home Parenteral Nutrition in Patients with Intestinal Failure Due to Neuroendocrine Tumours: A Systematic Review.

Maintaining adequate nutritional status can be a challenge for patients with small bowel neuroendocrine tumours (NETs). Surgical resection could result in short bowel syndrome (SBS), whilst without surgical resection there is a considerable risk of ischemia or developing an inoperable malignant bowel obstruction (IMBO). SBS or IMBO are forms of intestinal failure (IF) which might require treatment with home parenteral nutrition (HPN). Limited data exist regarding the use of HPN in patients with small bowel neuroendocrine tumours, and it is not frequently considered as a possible treatment. A systematic review was performed regarding patients with small bowel NETs and IF to report on overall survival and HPN-related complications and create awareness for this treatment. Five articles regarding patients with small bowel NETs or a subgroup of patients with NETs could be identified, mainly case series with major concerns regarding bias. The studies included 60 patients (range 1-41). The overall survival time varied between 0.5 and 154 months on HPN. However, 58% of patients were alive 1 year after commencing HPN. The reported catheter-related bloodstream infection rate was 0.64-2 per 1000 catheter days. This systematic review demonstrates the feasibility of the use of HPN in patients with NETs and IF in expert centres with a reasonable 1-year survival rate and low complication rate. Further research is necessary to compare patients with NETs and IF with and without HPN and the effect of HPN on their quality of life.

Debating Deposits, Redux: Substantial Interobserver Agreement Exists in Distinguishing Tumor Deposits From Nodal Metastases in Small Bowel Neuroendocrine Tumors.

Recent data suggest mesenteric tumor deposits (MTDs) indicate poor prognosis in small bowel well-differentiated neuroendocrine tumors (SB-NETs), including compared to positive lymph nodes, making their distinction crucial. To study interobserver agreement in distinguishing SB-NET MTDs from positive nodes. Virtual slides from 36 locally metastatic SB-NET foci were shared among 7 gastrointestinal pathologists, who interpreted each as an MTD or a positive node. Observers ranked their 5 preferred choices among a supplied list of potentially useful histologic features, for both options. Diagnostic opinions were compared using Fleiss multirater and Cohen weighted κ analyses. Preferred criteria for MTD included irregular shape (n = 7, top choice for 5), perineural invasion/nerve entrapment (n = 7, top choice for 2), encased thick-walled vessels (n = 7), and prominent fibrosis (n = 6). Preferred criteria for positive nodes included peripheral lymphoid follicles (n = 6, top choice for 4), round shape (n = 7, top choice for 2), peripheral lymphocyte rim (n = 7, top choice for 1), subcapsular sinuses (n = 7), and a capsule (n = 6). Among 36 foci, 10 (28%) each were unanimously diagnosed as MTD or positive node. For 13 foci (36%), there was a diagnosis favored by most observers (5 or 6 of 7): positive node in 8, MTD in 5. Only 3 cases (8%) had a near-even (4:3) split. Overall agreement was substantial (κ = .64, P < .001). Substantial interobserver agreement exists for distinguishing SB-NET MTDs from lymph node metastases. Favored histologic criteria in making the distinction include irregular shape and nerve/vessel entrapment for MTD, and peripheral lymphocytes/lymphoid follicles and round shape for positive nodes.

Genetic and epigenetic prognosticators of neuroendocrine tumours of the GI tract, liver, biliary tract and pancreas: A systematic review and meta-analysis.

Multiple recurrent genetic and epigenetic aberrations have been associated with worse prognosis in multiple studies of neuroendocrine tumours (NETs), but these have been mainly small cohorts and univariate analysis. This review and meta-analysis will focus upon the literature available on NETs of the gastrointestinal (GI) tract, liver, biliary tract and pancreas. PubMed and Embase were searched for publications that investigated the prognostic value of (epi)genetic changes of neuroendocrine tumours. A meta-analysis was performed assessing the association of the (epi)genetic alterations with overall survival (OS), disease-free survival (DFS) or locoregional control (LRC). In the pancreas DAXX/ATRX [hazard ratio (HR) = 3.29; 95% confidence interval (CI) = 2.28-4.74] and alternative lengthening telomeres (ALT) activation (HR = 8.20; 95% CI = 1.40-48.07) showed a pooled worse survival. In the small bowel NETs gains on chromosome 14 were associated with worse survival (HR 2.85; 95% CI = 1.40-5.81). NETs from different anatomical locations must be regarded as different biological entities with diverging molecular prognosticators, and epigenetic changes being important to the pathogenesis of these tumours. This review underpins the prognostic drivers of pancreatic NET which lie in mutations of DAXX/ATRX and ALT pathways. However, there is reaffirmation that prognostic molecular biomarkers of small bowel NETs should be sought in copy number variations (CNVs) rather than in single nucleotide variations (SNVs). This review also reveals how little is known about the prognostic significance of epigenetics in NETs.

Metastatic small bowel neuroendocrine tumours: surgical management of the primary.

Metastatic small bowel neuroendocrine tumours: surgical management of the primary.