Small Bowel Neuroendocrine Tumors Research Articles

Functional Copy-Number Alterations as Diagnostic and Prognostic Biomarkers in Neuroendocrine Tumors

Functional copy-number alterations (fCNAs) are DNA copy-number changes with concordant differential gene expression. These are less likely to be bystander genetic lesions and could serve as robust and reproducible tumor biomarkers. To identify candidate fCNAs in neuroendocrine tumors (NETs), we integrated chromosomal microarray (CMA) and RNA-seq differential gene-expression data from 31 pancreatic (pNETs) and 33 small-bowel neuroendocrine tumors (sbNETs). Tumors were resected from 47 early-disease-progression (<24 months) and 17 late-disease-progression (>24 months) patients. Candidate fCNAs that accurately differentiated these groups in this discovery cohort were then replicated using fluorescence in situ hybridization (FISH) on formalin-fixed, paraffin-embedded (FFPE) tissues in a larger validation cohort of 60 pNETs and 82 sbNETs (52 early- and 65 late-disease-progression samples). Logistic regression analysis revealed the predictive ability of these biomarkers, as well as the assay-performance metrics of sensitivity, specificity, and area under the curve. Our results indicate that copy-number changes at chromosomal loci 4p16.3, 7q31.2, 9p21.3, 17q12, 18q21.2, and 19q12 may be used as diagnostic and prognostic NET biomarkers. This involves a rapid, cost-effective approach to determine the primary tumor site for patients with metastatic liver NETs and to guide risk-stratified therapeutic decisions.

Functional Copy-Number Alterations as Diagnostic and Prognostic Biomarkers in Neuroendocrine Tumors

Functional copy-number alterations (fCNAs) are DNA copy-number changes with concordant differential gene expression. These are less likely to be bystander genetic lesions and could serve as robust and reproducible tumor biomarkers. To identify candidate fCNAs in neuroendocrine tumors (NETs), we integrated chromosomal microarray (CMA) and RNA-seq differential gene-expression data from 31 pancreatic (pNETs) and 33 small-bowel neuroendocrine tumors (sbNETs). Tumors were resected from 47 early-disease-progression (<24 months) and 17 late-disease-progression (>24 months) patients. Candidate fCNAs that accurately differentiated these groups in this discovery cohort were then replicated using fluorescence in situ hybridization (FISH) on formalin-fixed, paraffin-embedded (FFPE) tissues in a larger validation cohort of 60 pNETs and 82 sbNETs (52 early- and 65 late-disease-progression samples). Logistic regression analysis revealed the predictive ability of these biomarkers, as well as the assay-performance metrics of sensitivity, specificity, and area under the curve. Our results indicate that copy-number changes at chromosomal loci 4p16.3, 7q31.2, 9p21.3, 17q12, 18q21.2, and 19q12 may be used as diagnostic and prognostic NET biomarkers. This involves a rapid, cost-effective approach to determine the primary tumor site for patients with metastatic liver NETs and to guide risk-stratified therapeutic decisions.

The Clinicopathological Significance of Tumor Cell Subtyping in Appendiceal Neuroendocrine Tumors: A Series of 135 Tumors

Appendiceal neuroendocrine tumors (NETs) are common and often are identified as incidental lesions at the time of appendectomy. The guidelines for management are based on tumor size, degree of invasion, and the Ki67 proliferation index. Most small bowel NETs are composed of serotonin-producing EC-cells, but there are multiple other neuroendocrine cell types. In the rectum, there are L-cell tumors that express peptide YY (PYY), glucagon-like peptides (GLPs), and pancreatic polypeptide (PP); they are thought to have a better prognosis than serotonin-producing tumors. We investigated whether the appendix has distinct neuroendocrine tumor types based on cell type and whether that distinction has clinical significance. We collected 135 appendiceal NETs from the pathology archives of UHN Toronto and UHCMC (Cleveland). We analyzed the expression of biomarkers including CDX2, SATB2, PSAP, serotonin, glucagon (that detects GLPs), PYY, and pancreatic polypeptide (PP) and correlated the results with clinicopathologic parameters. Immunohistochemistry identified three types of appendiceal NETs. There were 75 (56%) classified as EC-cell tumors and 37 (27%) classified as L-cell tumors; the remaining 23 (17%) expressed serotonin and one of the L-cell biomarkers and were classified as mixed. EC-cell tumors were significantly larger with more extensive invasion involving the muscularis propria, subserosa, and mesoappendix compared with L-cell tumors. Mixed tumors were intermediate in all of these parameters. Both EC-cell and mixed tumors had lymphatic and/or vascular invasion while L-cell tumors had none. Unlike EC-cell NETs, L-cell tumors were not associated with lymph node metastasis. Tumor type correlated with pT stage and the only patient with distant metastatic disease in this series had an EC-cell tumor. Our study confirms that appendiceal NETs are not a homogeneous tumor population. There are at least three types of appendiceal NET, including EC-cell, L-cell, and mixed tumors. This information is important for surveillance of patients, as monitoring urinary 5HIAA levels is only appropriate for patients with serotonin-producing tumors, whereas measurement of GLPs and/or PP is more appropriate for patients with L-cell tumors. Our data also show that tumor type is of significance with EC-cell tumors exhibiting the most aggressive behavior.

Prognostic indicators of recurrence after surgical resection in non-pancreatic gastrointestinal neuroendocrine tumors.

e16287 Background: The incidence of gastrointestinal neuroendocrine tumors (GI-NETs) has continued to increase over the last two decades. In patients with locoregional disease, surgical resection of the primary tumor without additional therapies is considered standard of care. The frequency and risk factors associated with recurrence and survival in patients with non-pancreatic GI-NETs are poorly defined. We aimed to evaluate clinical and pathological factors associated with recurrence and survival in patients with resected non-pancreatic GI-NETs. Methods: We conducted a retrospective review of patients who presented to the Johns Hopkins Hospital between 2000-2019 with locoregional small bowel, colon, appendiceal, and rectal neuroendocrine tumors who underwent surgical resection with curative intent. We collected clinical and pathological data including tumor primary site, tumor differentiation, grade using Ki-67 labeling index (grade 1, 2, or 3), margin involvement, perineural or vascular invasion, time of recurrence, patterns of recurrence, and death. Patients with metastatic disease at the time of diagnosis and insufficient follow up were excluded. Results: A total of 133 patients met inclusion criteria. Most patients had tumors originating from the small bowel (n = 87, 66%), followed by the appendix (n = 19, 15%), rectum (n = 18, 14%), and colon (n = 7, 5%). With a median follow-up of 35 months, 23 patients (17%) had tumor progression after curative-intent surgery, with the liver (n = 13, 57%) as the most common site. In the majority of patients, tumors were well-differentiated (n = 118, 97%) and grade 1 (n = 78, 75%). Intermediate/high grade tumors (grade 2/3) occurred in 26 (25%) of patients. Median progression-free survival was 226 months (18.8 years). Age (greater than 60) and intermediate/high grade tumors (grade 2 or 3) were associated with worse overall survival HR = 5.5 (95% CI: 1.5, 19.6), p = 0.009, and HR = 3.3 (95% CI: 1.1, 10.2), p = 0.034, respectively. Tumor grade (2 or 3) and positive nodes were associated with worse progression-free survival HR = 4.5 (95% CI: 2.0, 10.1), p = 4e-04, and HR = 3.1 (95% CI: 1.4, 6.8), p = 0.009, respectively. Conclusions: A significant number of patients (17%) with non-pancreatic GI-NETs had tumor progression after curative-intent surgery. Risk factors for recurrence include intermediate/high-grade tumors and positive lymph nodes. Further studies are needed to evaluate the role of adjuvant therapy in patients at higher risk of recurrence following surgical resection for non-pancreatic GI-NETs.

Feasibility of home parenteral nutrition in patients with intestinal failure due to small bowel neuroendocrine tumours: a systematic review

Feasibility of home parenteral nutrition in patients with intestinal failure due to small bowel neuroendocrine tumours: a systematic review

Safety and efficacy of peptide receptor radionuclide therapy in neuroendocrine tumors: A single center experience.

Peptide receptor radionucleotide therapy (PRRT) with 177Lu-dotatate is widely used for the treatment of patients with neuroendocrine tumors (NETs). We analyzed data from 104 patients with NETs treated with 177Lu -dotatate at a US academic center between December 2017 and October 2020 to better understand patterns of long-term efficacy, safety, and toxicity in the real-world setting. 177Lu-dotatate (200 mCi) was administered every eight weeks for four doses. The most common sites of primary disease were small intestine NETs (n = 49, 47%), pancreatic NETs (n = 32, 31%), and lung NETs (n = 7, 7%). Twenty-seven percent had Ki-67 <3%, 49% had Ki-67 between 3-20%, and 13.5% had Ki-67 >20%. The cohort had been pretreated with a median of two prior lines of treatment. Forty percent had received prior liver-directed treatment. Seventy-four percent of patients completed all four doses of treatment. The objective response rate was 18%. The median time-to-treatment failure/death was significantly longer for small-bowel NETs when compared to pancreatic NETs (37.3 months vs. 13.2 months, p = 0.001). In a multivariate model, Ki-67, primary site, and liver tumor burden ≥50% were found to independently predict time-to-treatment failure/death. Around 40% of patients experienced adverse events of ≥grade 3 severity. Treatment-related adverse events leading to discontinuation of therapy happened in 10% of patients. Preexisting mesenteric/peritoneal disease was present in 33 patients; seven of these patients developed bowel-related toxicities including two grade 5 events. We also report two cases of delayed-onset minimal change nephrotic syndrome, which occurred 14 and 27 months after the last dose of PRRT. Lastly, we describe six patients who developed rapid tumor progression in the liver leading to terminal liver failure within 7.3 months from the start of PRRT, and identify potential risk factors associated with this occurrence, which will need further study.

Surgery for advanced neuroendocrine tumours of the small bowel: recommendations based on a consensus meeting of the European Society of Endocrine Surgeons (ESES).

Small bowel neuroendocrine tumours often present with locally advanced or metastatic disease. The aim of this paper is to provide evidence-based recommendations regarding (controversial) topics in the surgical management of advanced small bowel neuroendocrine tumours. A working group of experts was formed by the European Society of Endocrine Surgeons. The group addressed 11 clinically relevant questions regarding surgery for advanced disease, including the benefit of primary tumour resection, the role of cytoreduction, the extent of lymph node clearance, and the management of an unknown primary tumour. A systematic literature search was performed in MEDLINE to identify papers addressing the research questions. Final recommendations were presented and voted upon by European Society of Endocrine Surgeons members at the European Society of Endocrine Surgeons Conference in Mainz in 2023. The literature review yielded 1223 papers, of which 84 were included. There were no randomized controlled trials to address any of the research questions and therefore conclusions were based on the available case series, cohort studies, and systematic reviews/meta-analyses of the available non-randomized studies. The proposed recommendations were scored by 38-51 members and rated 'strongly agree' or 'agree' by 64-96% of participants. This paper provides recommendations based on the best available evidence and expert opinion on the surgical management of locally advanced and metastatic small bowel neuroendocrine tumours.

Abstract 3578: A systematic NEN spheroid drug screen reveals a novel drug resistance mechanism in small bowel NETs

Abstract Neuroendocrine neoplasms (NENs) are rare cancers that arise from neuroendocrine cells. NENs are classified as well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Small bowel NETs (SBNETs) and pancreatic NETs (PNETs) are generally slow growing but they commonly metastasize to the liver and can become aggressive cancers. NECs are rapidly growing, and patients have poor prognosis. Little is known about the drug sensitivity profile of SBNETs, PNETs and NECs due to a paucity of cellular and animal models of these malignancies. We have successfully cultured NEN cells from clinical samples as patient-derived spheroids (PDS) and showed that they express appropriate tumor markers. We systematically screened 20 NEN (12 SBNET, 5 PNET, and 3 NEC) spheroid cultures against a library of 175 compounds (147 FDA-approved anti-cancer drugs, 8 lab selected compounds, and 20 structurally diverse molecules) and compared their drug sensitivity profiles to identify the most effective drug classes and to better understand the biology of each NEN subtype. Top drug hits were validated for their anti-tumor properties in NEN PDS and patient-derived xenograft (PDX) mouse models. Our NEN PDS cultures identified common and unique drug sensitivity profiles for each type of NEN. SBNET spheroids were more resistant to many classes of anti-cancer drugs, which was due to overexpression of cytochrome P450 genes. Consistent with clinical findings, PNET spheroids showed increased sensitivity to tyrosine kinase and mTOR/PI3K inhibitors compared to SBNET &amp; NEC spheroids. NEC spheroids showed the broadest sensitivity to many anti-neoplastic compounds. The top candidate drug identified from our screen was romidepsin, a histone deacetylase inhibitor. Romidepsin displayed anti-tumor properties in vitro and in vivo for all 3 NEN models and was highly synergistic with rapamycin, an mTOR inhibitor similar to the SBNET approved drug everolimus. Excitingly, low-dose romidepsin effectively inhibited tumor growth when combined with low-dose rapamycin in an SBNET PDX mouse model. These NEN PDS drug screens enabled direct drug testing in primary tumor cultures to identify promising drugs that could be used alone or in combination with currently approved-NEN therapies. Histone deacetylase inhibitors, such as romidepsin, may be effective against SBNETs. NEN PDS models also serve as a valuable resource for understanding the unique biology and mechanisms of drug resistance for specific NEN subtypes. Citation Format: Catherine G. Tran, Luis C. Borbon, Dane H. Tow, Jonathan Shilyansky, Guiying Li, James Egan, Scott K. Sherman, Ellen Abusada, Jing Tang, Ramaswamy govindan, Ryan C. Fields, Terry A. Braun, Carlos HF Chan, Chandrikha Chandrasekharan, Douglas Spitz, Dawn E. Quelle, Andrew M. Bellizzi, James R. Howe, Po Hien Ear. A systematic NEN spheroid drug screen reveals a novel drug resistance mechanism in small bowel NETs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3578.

Abstract 3574: Cancer testis antigen expression correlates with stromal natural killer cell activation and longer overall survival in small bowel neuroendocrine tumors

Abstract Background: Patients with small bowel neuroendocrine tumors (SBNET) frequently present with metastatic disease and the efficacy of available therapies, including immune checkpoint blockade (ICB), is limited. Toward developing novel immunomodulatory strategies, we interrogated the tumor immune microenvironment of SBNETs using bulk transcriptional and digital spatial profiling (DSP). Methods: Patients with SBNET who underwent resection at MD Anderson Cancer Center from 2003-2016 were retrospectively analyzed. Overall survival (OS) was assessed using the Kaplan-Meier method and the Cox proportional hazards model was used for multivariate analysis (MVA). Bulk transcriptional profiling was performed using the Nanostring PanCancer-Immune Panel. DSP with whole human transcriptome was performed using PanCK to segment tumor and adjacent stroma; 88 distinct regions were analyzed using differential gene expression and Reactome pathway enrichment pipelines. Results: Resected SBNET 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, stage, 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, p=0.014). A pilot DSP experiment on 4 CTA-high and 4 CTA-low tumors confirmed differential gene expression in the PanCK+ tumor compartment of these samples (R2=0.09, p=0.001). In particular, epigenetic modification genes (e.g., H2BC8, H4C8, H3C1, p&amp;lt;0.001) and epigenetic pathways (e.g., DNA methylation, histone acetylation) were enriched in CTA-high tumors. CTA-high tumors exhibited increased M2 macrophage presence (p=0.025) and increased NK cell activation within the PanCK- stromal compartment (p=0.001). Conclusions: High CTA and type-I IFN expression in resected SBNET identifies patients 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 clinically relevant signal in SBNET. Increased IFN in CTA-high tumors, corroborated by increased stromal NK cell activation, suggests that enhanced immunogenicity may drive this survival difference. Spatial transcriptomic analysis reveals epigenetic differences in CTA-high tumors and highlights the potential for combination epigenetic modifiers and immunotherapy in future trials. Citation Format: Reed I. Ayabe, Yongwoo D. Seo, Brenda Melendez, Rossana Lazcano, Brittany C. Fields, Khalida Wani, Sarah Johnson, Manoj Chelvanambi, Courtney Hudgens, Sharia D. Hernandez, Nadim J. Ajami, Jennifer A. Wargo, Alexander J. Lazar, Daniel M. Halperin, Jeannelyn S. Estrella, Jessica E. Maxwell. Cancer testis antigen expression correlates with stromal natural killer cell activation and longer overall survival in small bowel neuroendocrine tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3574.

Abstract 5953: DUSP6 is a novel target in neuroendocrine tumors

Abstract Background: Neuroendocrine tumors (NETs) are rare malignancies derived from enterochromaffin cells of the diffuse neuroendocrine system and most frequently observed in the gastrointestinal tract and bronchopulmonary system. Surgery is the major treatment for localized NETs. In high-grade NETs, treatment opportunities include chemotherapeutic drugs such as temozolomide (TEM), and capecitabine and small-molecule targeted therapies such as everolimus or sunitinib. Despite promising initial responses, most patients develop therapy resistance by unknown mechanisms. Therefore, there is a pressing need to apprehend the mechanisms of resistance to improve the therapeutic efficacy of the current treatments. Phosphatases are emerging and novel targets in human malignancies and their modulation yields significant anti-tumor activities. Dual specificity phosphatase 6 (DUSP6) is a MAPK phosphatase and mainly binds to and dephosphorylates extracellular signal-regulated kinase (ERK)1/2. DUSP6 expression is increased in several malignancies, correlating with distant metastases and a worse clinical outcome. Moreover, DUSP6 mediates resistance to certain chemotherapeutics and small molecular tyrosine kinase inhibitors and its blockade increases therapeutic sensitivity. The current study aimed to investigate the contribution of DUSP6 to therapy resistance in the NET models. Material and Methods: Using Western blot analysis, the expression of DUSP6 was measured in 8 clinical samples of small bowel neuroendocrine tumors, the NET cell lines BON-1, H69, IMR-32, QGP and H524 and two PDX models, 1452 (rectal neuroendocrine) and 913 (pancreatic neuroendocrine). The effects of DUSP6 depletion on cell viability were explored using a pharmacological inhibitor, BCI, and its siRNA-mediated knockdown. Moreover, BCI-mediated apoptotic cell death was measured by an annexin V/PI staining assay. Results: DUSP6 expression was positive in 5 out of 8 clinical samples, 4 NET cell lines and both the PDX models. BCI treatment induced an apoptotic response in the NET models and synergistically increased sensitivity to TMZ and cisplatin in 1452 cells., RNAi-mediated depletion of DUSP6 also increased sensitivity to sunitinib and triggered TMZ-induced apoptotic cell death in 1452 cells, which was associated with changes in (O6-Methylguanine-DNA-methyltransferase) MGMT expression. These findings suggest that DUSP6 is an important therapeutic target in neuroendocrine tumors and its blockade is a promising therapeutic approach to enhance the therapeutic index of current treatments. Citation Format: Majid Momeny, Vahid Khalaj, Solmaz AghaAmiri, Po Hien Ear, Servando Hernandez Vargas, Sukhen Ghosh, Ali Azhdarinia. DUSP6 is a novel target in neuroendocrine tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5953.

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&lt;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.

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.