Epidemiology of Cancers of the Small Intestine: Trends, Risk Factors, and Prevention

Advances and current concepts on Eph receptors and ephrins in upper digestive tract cancers

Erythropoietin-producing hepatocellular (Eph) receptors comprise the largest group of surface receptors and are responsible for cellular signals. Eph/ephrin signaling has been identified to play a role in key cancer development and progression processes, especially in the upper gastrointestinal tract. The Eph/ephrin system has been described as a tumor suppressor in duodenal cancer, while in esophageal, gastric, hepatic, and pancreatic cancer, the system has been related to tumor progression. For their significant role in developing a wide range of malignancies, Eph receptors and their ligands have proven to be an important target for new anticancer therapies. In this review, we present an overview of the literature and highlight evidence supporting the role of the Eph/ephrin system in upper digestive tract cancers. In addition, we discuss molecular findings that represent promising therapeutic targets for these cancers.

Diagnostic Challenges of Medullary Carcinoma of the Small Intestine During the COVID-19 Pandemic

Background: Medullary carcinoma of the small intestine is an exceptionally rare subtype of gastrointestinal cancer, characterized by its solid growth pattern and lack of glandular structures, which complicate timely diagnosis. During the COVID-19 pandemic, diagnostic delays for rare cancers became increasingly common due to the prioritization of COVID-related cases and patient reluctance to seek medical attention. Methods and Result: We present the case of a 70-year-old male initially misdiagnosed with COVID-19, whose persistent symptoms led to the eventual discovery of medullary carcinoma. Imaging studies revealed focal lesions in the liver, spleen, and thickened small intestinal walls, prompting surgical resection of a 16 cm intestinal segment. Histopathological examination confirmed medullary carcinoma with lymph node and liver metastases, supported by immunohistochemistry, which showed positive markers (calretinin, pancytokeratin, cytokeratin 7) and excluded other malignancies. Conclusions: The diagnostic delay, exacerbated by the pandemic, highlights the challenges of distinguishing rare cancers from more common conditions during global health crises. This case underscores the importance of advanced diagnostic techniques, such as immunohistochemistry, for accurate identification. Maintaining robust cancer diagnostic pathways during emergencies is crucial to avoid delays in treatment. Future research should focus on improving screening methods for rare cancers and developing resilient healthcare systems to mitigate similar challenges in future crises.

Clinical Characteristics and Outcomes of Small Bowel Neoplasms in Crohn's Disease: A Case-Control Study

Background

Patients with Crohn's disease (CD) who have ileal or any small bowel (SB) involvement are at increased risk of developing SB cancer. Due to the rarity of this complication of CD, we aimed to describe the clinical features, presentation, and of small bowel neoplasms (SBN) in patients with CD.

Methods

A case-control study was performed to include patients ≥18 years old with a diagnosis of CD with or without SBN at a single large referral center from January 1992 to May 2023. Patients were identified using bioinformatics and natural language processing tools, as well as anatomic pathology records. Two age- and sex-matched controls were identified for each case.

Results

In total, 54 patients with CD and SBN and 108 patients with CD without SBN were identified. Of the cases, most had ileal CD (55.6%) with stricturing (59.3%) phenotype. Median duration of CD prior to SBN diagnosis was 19.5 years. Nonpenetrating/nonstricturing behavior (odds ratio [OR], 9.23; 95% CI, 2.91-29.32; P = .0008) was significantly associated with an increased odds of SBN. History of tobacco use (OR, 0.27; 95% CI, 0.13-0.60; P = .0011) and IBD-associated colonic neoplasia (OR, 0.18; 95%, CI 0.4-0.85; P = .0303) were protective in development of SBN.

Conclusions

Nonpenetrating/nonstricturing CD appeared to raise SBN risk. History of tobacco use and colonic IBD-associated neoplasia are associated with reduced risk of SBN. Further studies with large sample sizes are needed to determine true incidence and risk factors associated with SBN in CD and assess potentially protective effects of early surgery.

The Role of Small-Bowel Endoscopy in the Diagnosis and Management of Small-Bowel Neuroendocrine Tumours

Neuroendocrine tumours (NETs) are relatively rare neoplasms but represent one of the most frequent types of primary small-bowel tumours. Their incidence is rising, and this is most likely because of their more frequent early-stage detection, physician awareness, and increasing availability and use of imaging and small-bowel endoscopic techniques, such as video capsule endoscopy and device-assisted enteroscopy, which enable the detection, localisation, and histological sampling of previously inaccessible and underdiagnosed small-bowel lesions. This review summarises the role of small-bowel endoscopy in the diagnosis and management of small-bowel NETs to assist clinicians in their practice. Small-bowel endoscopy may play a complementary role in the diagnosis of these tumours alongside other diagnostic tests, such as biomarkers, conventional radiology, and functional imaging. In addition, small-bowel enteroscopy may play a role in the preoperative setting for the identification and marking of these tumours for surgical resection and the management of rare complications, such as small-bowel variceal bleeding, in cases of portal hypertension due to the encasement of mesenteric vessels in fibrotic small-bowel NETs.

Primitive Resectable Small Bowel Cancer Clinical-Pathological Analysis: A 10-Year Retrospective Study in a General Surgery Unit

Introduction: Small bowel cancer is very rare; although the incidence of adenocarcinoma and other anatomopathological forms has increased recently, the diagnosis and treatment of this disease are still debatable because of the clinical heterogeneity and the absence of studies including a large number of patients. Materials and Methods: We performed a retrospective study over 10 years in which we analyzed the clinical, imaging, and anatomopathological data of 46 patients hospitalized in a surgery clinic and diagnosed with small bowel cancer (duodenum, jejunum, and ileum). Results: After clinical assessment of these patients, including complications (occlusion, bleeding, and perforation), the CT scan established the diagnosis in over 90% of the cases of the complicated form of the disease. Surgery has a curative role in localized cancers; tumor location, local invasion, the presence of locoregional lymph nodes, and the number of multiple tumors influence the type of surgery. The conventional pathological exam was completed via immunohistochemical staining. Adjuvant oncological treatment was performed after surgery (according to the guidelines); in patients with exceptional histopathological forms, the therapy was personalized. Conclusions: Most small bowel cancers were diagnosed with complications (occlusion and bleeding); the tumor type, location, and presence of multiple bowel cancers significantly influenced its management. Independently of the surgical resection (R0/R1 or R2), the prognosis of the disease depends on the tumor aggressivity, location (single/multiple), and locoregional node invasion.

Current Status of Immunotherapy in Management of Small Bowel Neuroendocrine Tumors

PURPOSE OF REVIEW

This study aims to present the current landscape of immunotherapy in the management of small bowel neuroendocrine tumors and identify ongoing and future targets for improved response.

RECENT FINDINGS

Somatostatin analogs and mTOR inhibitors remain cornerstones of non-surgical treatment, and applications of PRRT in SBNET are promising. Several efforts to replicate the success of immunotherapies in other solid tumors have been attempted in SBNET, with limited responses observed with current immune targets, such as PD-1/PD-L1 and CTLA-4. Epigenetic analyses have suggested a potential role for methylation and histone acetylation in SBNET tumorigenesis that warrant greater exploration. While the incidence of SBNET continues to increase, the number of effective therapies is few. Further elucidation of targetable components of the SBNET immune microenvironment with greater modulatory effects is necessary to improve outcomes in this growing patient population.

Should we perform regular surveillance capsule endoscopies in patients following small-bowel adenocarcinoma resection? A case report and discussion

Because small-bowel tumors are rare, prospective data on the utility of video capsule endoscopy (VCE) for their detection are limited. Current guidelines do not advocate for surveillance VCEs in patients following small-bowel tumor resection, which is mostly due to a lack of data. Here, we report an 81-year-old male patient who had undergone curative segmental ileal adenocarcinoma resection 15 years ago and another segmental jejunal adenocarcinoma resection (TNM-Classification: pT2 pN0 (0/2) G2M0) 7 years ago. He now presents with melena, progressive dyspnea, and decreased hemoglobin levels. VCE revealed local intestinal recurrence of the previously resected jejunal adenocarcinoma, leading to a second segmental jejunal resection (TNM-Classification: pT3 L1 pN0 (0/5) G2 M0). We believe that regular surveillance VCEs after the first jejunal adenocarcinoma resection might have facilitated earlier detection of tumor recurrence in this patient's case. Therefore, we suggest considering regular surveillance VCEs, at least in patients with recurrent small-bowel malignancies. However, future prospective studies are warranted to validate our findings.

Identification of TIMP1-induced dysregulation of epithelial-mesenchymal transition as a key pathway in inflammatory bowel disease and small intestinal neuroendocrine tumors shared pathogenesis

Inflammatory Bowel Disease (IBD) is believed to be a risk factor for Small Intestinal Neuroendocrine Tumors (SI-NET) development; however, the molecular relationship between IBD and SI-NET has yet to be elucidated. In this study, we use a systems biology approach to uncover such relationships. We identified a more similar transcriptomic-wide expression pattern between Crohn's Disease (CD) and SI-NET whereas a higher proportion of overlapping dysregulated genes between Ulcerative Colitis (UC) and SI-NET. Enrichment analysis indicates that extracellular matrix remodeling, particularly in epithelial-mesenchymal transition and intestinal fibrosis mediated by TIMP1, is the most significantly dysregulated pathway among upregulated genes shared between both IBD subtypes and SI-NET. However, this remodeling occurs through distinct regulatory molecular mechanisms unique to each IBD subtype. Specifically, myofibroblast activation in CD and SI-NET is mediated through IL-6 and ciliary-dependent signaling pathways. Contrarily, in UC and SI-NET, this phenomenon is mainly regulated through immune cells like macrophages and the NCAM signaling pathway, a potential gut-brain axis in the context of these two diseases. In both IBD and SI-NET, intestinal fibrosis resulted in significant metabolic reprogramming of fatty acid and glucose to an inflammatory- and cancer-inducing state. This altered metabolic state, revealed through enrichment analysis of downregulated genes, showed dysfunctions in oxidative phosphorylation, gluconeogenesis, and glycogenesis, indicating a shift towards glycolysis. Also known as the Warburg effect, this glycolytic switch, in return, exacerbates fibrosis. Corresponding to enrichment analysis results, network construction and subsequent topological analysis pinpointed 7 protein complexes, 17 hub genes, 11 microRNA, and 1 transcription factor related to extracellular matrix accumulation and metabolic reprogramming that are candidate biomarkers in both IBD and SI-NET. Together, these biological pathways and candidate biomarkers may serve as potential therapeutic targets for these diseases.

Bibliometrics analysis on the research status and trends of small bowel adenocarcinoma: 1923-2023

Objectives

The aim of this research is to discuss the research status, hotspots, frontiers, and development trends in the field of small bowel adenocarcinoma based on bibliometrics and visual analysis by CiteSpace software.

Methods

The relevant research articles on SBA from 1923 to 2023 were retrieved from the Web of Science Core Collection database. CiteSpace software was used to form a visual knowledge map and conduct analysis for the countries/regions, journals, authors, keywords, clusters, research hotspots and frontiers of the included articles.

Results

There were 921 articles included, and the number of articles published during 1923-2023 is increasing. The country with the highest number of articles published was the United States (443, 38.76%), followed by Japan (84, 9.12%) and France (72, 7.82%). The author with the highest number of publications is Ansell, Overman MJ (33, 3.58%), and the author with the highest co-citation frequency is Overman MJ (218). Journal of Clinical Oncology is the journal with the highest publication frequency. The top five cluster groups were "chemotherapy", "inflammatory bowel disease", "celiac disease", "tumor" and "small intestine". The related disease, chemotherapy drugs, and treatment regimens of SBA form the main research fields, and prognosis and diagnosis are the research hotspots and trends.

Conclusion

The global research field in SBA has expanded in the past 100 years. The prognosis and new diagnosis of SBA are hotspots in this field and require further study in the future.

Celiac Disease Deep Learning Image Classification Using Convolutional Neural Networks

Celiac disease (CD) is a gluten-sensitive immune-mediated enteropathy. This proof-of-concept study used a convolutional neural network (CNN) to classify hematoxylin and eosin (H&E) CD histological images, normal small intestine control, and non-specified duodenal inflammation (7294, 11,642, and 5966 images, respectively). The trained network classified CD with high performance (accuracy 99.7%, precision 99.6%, recall 99.3%, F1-score 99.5%, and specificity 99.8%). Interestingly, when the same network (already trained for the 3 class images), analyzed duodenal adenocarcinoma (3723 images), the new images were classified as duodenal inflammation in 63.65%, small intestine control in 34.73%, and CD in 1.61% of the cases; and when the network was retrained using the 4 histological subtypes, the performance was above 99% for CD and 97% for adenocarcinoma. Finally, the model added 13,043 images of Crohn's disease to include other inflammatory bowel diseases; a comparison between different CNN architectures was performed, and the gradient-weighted class activation mapping (Grad-CAM) technique was used to understand why the deep learning network made its classification decisions. In conclusion, the CNN-based deep neural system classified 5 diagnoses with high performance. Narrow artificial intelligence (AI) is designed to perform tasks that typically require human intelligence, but it operates within limited constraints and is task-specific.

Discordance Rate and Risk Factor of Other Diagnostic Modalities for Small Bowel Tumors Detected by Device-Assisted Enteroscopy: A Korean Association for the Study of Intestinal Disease (KASID) Multicenter Study

Background/Aims

Despite advances in imaging and endoscopic technology, diagnostic modalities for small bowel tumors are simultaneously performed. We investigated the discrepancy rate between each modality and predictive factors of discrepancy in patients with definite small bowel tumors.

Methods

Data of patients with definite small bowel tumors who underwent both device-assisted enteroscopy (DAE) and computed tomography (CT) were retrieved from web-based enteroscopy registry database in Korea. Predictive risk factors associated with discrepancy were analyzed using logistic regression analysis.

Results

Among 998 patients, 210 (21.0%) were diagnosed with small bowel tumor using DAE, in 193 patients with definite small bowel tumor, DAE and CT were performed. Of these patients, 12 (6.2%) showed discrepancy between examinations. Among 49 patients who underwent DAE and video capsule endoscopy (VCE) examination, 13 (26.5%) showed discrepancy between examinations. No significant independent risk factors were associated with concordance between DAE and CT in multivariate logistic regression analysis among the patients. In a multivariate logistic regression analysis, red blood cell transfusion was negatively associated with concordance between DAE and VCE in patients with small bowel tumor (odds ratio, 0.163; 95% confidence interval, 0.026 to 1.004; p=0.050).

Conclusions

For small bowel tumors, the discrepancy rate between DAE and CT was 6.2%, and 26.5% between DAE and VCE. Despite developments in cross-sectional imaging (VCE and DAE modalities), discrepancies still exist. For small bowel bleeding that require significant transfusion while showing insignificant VCE findings, DAE should be considered as the next diagnostic approach, considering the possibility of missed small bowel tumor.

An Unexpected Challenge: Marked Small Bowel Obstruction Arising From a Poorly Differentiated Metastatic Mucinous Adenocarcinoma of the Distal Ileum in a Risk-Free Healthy Patient

Adenocarcinoma, while constituting the predominant variant among small bowel cancers, is a component of the broader category of primary small bowel malignancies, which are notably infrequent in occurrence. The diagnosis of such malignancies is often markedly delayed, a consequence of their insidious onset and the nonspecific nature of the abdominal symptoms presented. A 69-year-old Caucasian male presented to the emergency department manifesting acute, sharp, and colicky abdominal pain accompanied by a single episode of vomiting, all developing over one day. His medical history was notable for gastroesophageal reflux disease (GERD) and regionally confined prostate adenocarcinoma, which was under meticulous surveillance by the urological team. The patient's lifestyle was characterized by abstention from alcohol and tobacco, adherence to a nutritious diet, and a commitment to regular physical activity. Subsequent examination and surgical excision of an abnormal mass, as delineated on computed tomography (CT), culminated in the diagnosis of a stage IV, poorly differentiated adenocarcinoma. We have reported this case to spark research regarding early diagnostic techniques for small bowel adenocarcinoma (SBA). In this case, a healthy individual presented with vague abdominal pain and a single episode of vomiting. Diagnosis required the surgical resection of the tumor, where metastasis was also visualized. Due to the rare nature of SBA, we believe different diagnostic measures and adjuvant therapy should be researched for earlier diagnosis and subsequently better patient outcomes.

Obscure Bleeding from a Metastatic Small Bowel Tumor Diagnosed Using Motorized Spiral Enteroscopy: A Case Study and a Literature Review

Small bowel tumors are relatively rare, representing only around 5% of all gastrointestinal neoplasms, with a progressively increasing incidence. Currently, there are no established guidelines for diagnostic approaches, screening procedures, or management strategies for small bowel tumors. We present here the case of a patient with a rare type of metastatic tumor of the small bowel originating from primary lung adenocarcinoma who presented with abdominal pain, severe iron-deficiency anemia, and melena. The initial investigations, gastroscopy and colonoscopy, failed to identify the bleeding source. The obscure bleeding source and diagnosis were achieved through power motorized spiral enteroscopy (MSE), which allowed the visualization and biopsy of the tumor. Histopathological examination established the presence of a poorly differentiated non-mucinous adenocarcinoma originating from the lung. This case is reported to provide evidence of the efficiency of MSE in the diagnosis of small bowel tumors, with the method providing higher insertion depth in a reduced amount of time.

Current Perspectives on Small Bowel Tumors: Overview of Prevalence, Clinical Manifestations, and Treatment Approaches

Small bowel tumors (SBTs) constitute a rare yet increasingly recognized group of gastrointestinal neoplasms, accounting for less than 5% of all gastrointestinal cancers. Despite their infrequency, the incidence of SBTs has exhibited a notable upward trend, underscoring the importance of understanding these diverse and complex tumors. This review consolidates current knowledge on SBTs, encompassing epidemiology, risk factors, clinical manifestations, diagnostic advancements, and treatment modalities. Data from various sources are analyzed to present a comprehensive overview of the evolving landscape of SBTs. Our findings indicate that adenocarcinomas, carcinoid tumors, lymphomas, and gastrointestinal stromal tumors (GISTs) are the common SBTs. While adenocarcinoma and neuroendocrine tumors are the common types of SBTs in the West, GIST and lymphoma are more common in Asia. Common risk factors include genetic syndromes and inflammatory bowel diseases. There is variability in clinical presentations depending on the type of tumors. Although diagnostic challenges persist, advancements in imaging and endoscopic techniques have improved detection rates. Treatment strategies are evolving; surgical resection remains the mainstay for localized disease, augmented by systemic therapies and targeted agents for advanced stages. This review emphasizes the importance of early detection and individualized treatment approaches in improving outcomes for SBT patients. It addresses the need for ongoing research and innovation in managing these tumors.

The Role of Capsule Endoscopy in the Diagnosis and Management of Small Bowel Tumors: A Narrative Review

Small bowel tumors (SBT) are relatively rare, but have had a steadily increasing incidence in the last few decades. Small bowel capsule endoscopy (SBCE) and device-assisted enteroscopy are the main endoscopic techniques for the study of the small bowel, the latter additionally providing sampling and therapeutic options, and hence acting complementary to SBCE in the diagnostic work-up. Although a single diagnostic modality is often insufficient in the setting of SBTs, SBCE is a fundamental tool to drive further management towards a definitive diagnosis. The aim of this paper is to provide a concise narrative review of the role of SBCE in the diagnosis and management of SBTs.

Management Strategies and Outcomes for Small Intestinal Neuroendocrine Tumours with Involvement of the Superior Mesenteric Vessels: A Systematic Review

Small intestinal neuroendocrine tumours (SI-NETs) are the most common small intestinal tumours. A particularly challenging subset of these tumours is those that involve the superior mesenteric artery or vein for which the role and feasibility of surgery are often questioned. This systematic review aimed to identify and evaluate the management strategies used for these complex SI-NETs. The identified studies showed positive outcomes with surgery and multimodality therapy.

A Novel Mutation of MSH2 Gene in a Patient with Lynch Syndrome Presenting with Thirteen Metachronous Malignancies

Lynch syndrome (LS), also known as hereditary nonpolyposis colorectal cancer (HNPCC), accounts for 2-3% of all colorectal cancers. This autosomal dominant disorder is associated with a predisposition to endometrial, stomach, small bowel, pancreatic, biliary tract, ovary, urinary tract, brain, and skin tumors. Lynch syndrome is caused by the mutation of the MLH1, MSH2 (EPCAM), MSH6, and PMS2 genes. In this article, a case study of a 70-year-old female patient with Lynch syndrome is presented. Over a span of 30 years, the patient underwent multiple surgical procedures for a total of thirteen different malignancies. She was found to have a deleterious pathogenic gene MSH2 (NM_000251.2) variant (mutation) c.1774_1775insT in the 12th exon. This variant, c.1774_1775insT, represents a novel finding, as it has not been previously reported in existing databases or literature. No other case of 13 metachronous tumors in a patient with Lynch syndrome was found in the literature.

Detection of Neuroendocrine Tumours by Enteroscopy: A Case Report

We present the case of a 62-year-old patient who developed melenas and in whom conventional endoscopic tests could not detect any bleeding lesion. In our case, capsule endoscopy and enteroscopy were the pivotal elements in establishing the diagnosis of a neuroendocrine tumour with an atypical location. As a result, it was possible to surgically remove the lesions at an early stage of the malignancy without metastatic disease and without the need for adjuvant therapy. Our case demonstrates the need for these new techniques in tumours of atypical location and aggressive course. Otherwise, this malignancy may be underdiagnosed until an advanced stage.

Case Report of a Missed Small Bowel Adenocarcinoma on an Upper Endoscopy-A Review of Small Bowel Diagnostic Modalities

Background

Small bowel neoplasms (SBN) are rare but pose a significant diagnostic challenge. The routine upper endoscopy delays the diagnosis, and most cases require multiple investigations increasing the health care burden.

Case summary

A 74-year-old man presented with two months of progressively worsening postprandial bilious emesis and epigastric abdominal pain. He underwent outpatient evaluation with upper endoscopy and a computed tomographic enterography. The first endoscopy did not enable us to recognize the small bowel mass, leading to a diagnostic delay of two months. He subsequently developed a complete intestinal obstruction. A Second look upper endoscopy done with a push enteroscopy showed an apple core-like mass suggestive of a possible malignant neoplasm at the distal duodenum/proximal jejunum.

Conclusion

Therefore, more sensitive, and specific diagnostic modalities like push enteroscopy, capsule endoscopy, and deep enteroscopy should be considered in case upper endoscopy is not conclusive.

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.

Survival in Colon, Rectal and Small Intestinal Cancers in the Nordic Countries through a Half Century

Background: Survival studies in intestinal cancers have generally shown favorable development, but few studies have been able to pinpoint the timing of the changes in survival over an extended period. Here, we compared the relative survival rates for colon, rectal and small intestinal cancers from Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE). Design: Relative 1-, 5- and 5/1-year conditional survival data were obtained from the NORDCAN database for the years 1971-2020. Results: The 50-year survival patterns were country-specific. For colon and rectal cancers, the slopes of survival curves bended upwards for DK, were almost linear for NO and bended downwards for FI and SE; 5-year survival was the highest in DK. Survival in small intestinal cancer was initially below colon and rectal cancers but in FI and NO it caught up toward the end of the follow-up. Conclusions: Relative survival in intestinal cancers has developed well in the Nordic countries, and DK is an example of a country which in 20 years was able to achieve excellent survival rates in colon and rectal cancers. In the other countries, the increase in survival curves for colon and rectal cancer has slowed down, which may be a challenge posed by metastatic cancers.

Duodenal Mucinous Adenocarcinoma in a Patient With Immunodeficiency: A Case Report

Duodenal mucinous adenocarcinoma is a rare type of small bowel carcinoma. It is not commonly encountered; hence little knowledge exists about its presentation, diagnosis, and management. The diagnosis is mostly made by either esophagogastroduodenoscopy (EGD) or intra-operatively. Some of the main symptoms are abdominal pain, nausea, vomiting, weight loss, or signs and symptoms of upper gastrointestinal bleeding. Therefore, this is a serious condition that healthcare providers and patients should be aware of to reduce its severity and improve prognosis. We present a case of duodenal mucinous adenocarcinoma in a patient with immunodeficiency virus.

Malignancies in Patients with Celiac Disease: Diagnostic Challenges and Molecular Advances

Celiac disease (CD) is a multiorgan autoimmune disorder of the chronic intestinal disease group characterized by duodenal inflammation in genetically predisposed individuals, precipitated by gluten ingestion. The pathogenesis of celiac disease is now widely studied, overcoming the limits of the purely autoimmune concept and explaining its hereditability. The genomic profiling of this condition has led to the discovery of numerous genes involved in interleukin signaling and immune-related pathways. The spectrum of disease manifestations is not limited to the gastrointestinal tract, and a significant number of studies have considered the possible association between CD and neoplasms. Patients with CD are found to be at increased risk of developing malignancies, with a particular predisposition of certain types of intestinal cancer, lymphomas, and oropharyngeal cancers. This can be partially explained by common cancer hallmarks present in these patients. The study of gut microbiota, microRNAs, and DNA methylation is evolving to find the any possible missing links between CD and cancer incidence in these patients. However, the literature is extremely mixed and, therefore, our understanding of the biological interplay between CD and cancer remains limited, with significant implications in terms of clinical management and screening protocols. In this review article, we seek to provide a comprehensive overview of the genomics, epigenomics, and transcriptomics data on CD and its relation to the most frequent types of neoplasms that may occur in these patients.

Characteristics and outcomes of small bowel adenocarcinoma: 14 years of experience at a single tertiary hospital in Saudi Arabia

Small bowel adenocarcinoma (SBA) is an extremely rare cancer type. In the present study, the patient characteristics and clinical outcomes of patients diagnosed and treated for SBA at a single tertiary hospital were reported. All patients diagnosed and managed between 2007 and 2020 were reviewed. Regression analysis was used to assess variables associated with the metastatic stage at diagnosis. The Kaplan-Meier method was used to estimate survival and the log-rank test was used to determine factors associated with survival outcomes. Out of 137 cases of small bowel primary tumor, 43 consecutive patients with SBA were diagnosed with a median age of 53 years and the majority (76.7%) were males. The common initial presenting symptoms were abdominal pain (58.8%) and bowel obstruction (30.2%). The most common primary site was the duodenum (60.5%) and the majority (65.1%) were diagnosed with stage III/IV disease. Patients with a high neutrophil-lymphocyte ratio (NLR) (≥0.85) were more likely to be in the metastatic stage at diagnosis (P=0.01). The 3-year overall survival (OS) rates based on stage were 100% (I), 85% (II), 53% (III) and 33.9% (IV) (P=0.001). In addition to the stage, the Eastern Cooperative Oncology Group Performance Status (P<0.001), NLR (P<0.001), hypoalbuminemia (P=0.02) and chemotherapy in a metastatic setting (P=0.02) were prognostic factors for OS. In conclusion, NLR is a potential prognostic biomarker for a metastatic stage at diagnosis. Advanced stage, lower performance status score, low albumin level and high NLR are associated with short OS.

Differential to Terminal Ileitis: Terminal Ileum Neuroendocrine Tumor Identified on Screening Colonoscopy

Background: Asymptomatic patients at average risk of developing colorectal cancer are encouraged to undergo screening colonoscopy beginning at age 45 years. While ileal intubation is often considered the gold standard for a complete colonoscopy, the relatively low diagnostic yield has prevented widespread adoption. Small bowel cancers, including neuroendocrine tumors, may present incidentally as terminal ileitis on routine colonoscopy with terminal ileum intubation. Neuroendocrine tumors, the most common primary neoplasm of the small intestine, are often asymptomatic or present as nonspecific abdominal pain in the sixth or seventh decade of life. Case Report: A 51-year-old asymptomatic male with unremarkable physical examination underwent screening colonoscopy that revealed scattered ulcerations of the terminal ileum. Immunohistochemistry of the lesion was consistent with well-differentiated neuroendocrine tumor, World Health Organization Grade I. DOTATATE positron emission tomography/computed tomography demonstrated avid adjacent right mesenteric lymph node and avid focal pancreatic body lesion. Fine-needle biopsy and immunohistochemistry of the pancreatic lesion confirmed neuroendocrine tumor, while the mesenteric lymph node was found to be benign. The patient underwent robotic-assisted ileocolic resection and has ongoing surveillance of the pancreatic lesion. Conclusion: Terminal ileitis encompasses a host of pathologic processes, including inflammatory states, infectious disease, malignancy, and vasculitis. Importantly, small bowel cancer is an increasing cause of terminal ileitis. Screening colonoscopy with ileal intubation can be a valuable tool for early detection of these lesions.

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in small bowel adenocarcinoma with peritoneal metastasis: a systematic review

Objectives

Small bowel adenocarcinoma (SBA) with peritoneal metastasis (PM) is rare and despite treatment with systemic chemotherapy, the prognosis is poor. However, there is emerging evidence that cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) may offer a survival benefit over systemic therapy alone. This systematic review will assess the effectiveness of CRS-HIPEC for SBA-PM.

Content

Three databases were searched from inception to 11/10/21. Clinical outcomes were extracted and analysed.

Summary

A total of 164 cases of SBA-PM undergoing CRS-HIPEC were identified in 12 studies. The majority of patients had neoadjuvant chemotherapy (87/164, 53%) and complete cytoreduction (143/164, 87%) prior to HIPEC. The median overall survival was 9-32 months and 5-year survival ranged from 25 to 40%. Clavien-Dindo grade III/IV morbidity ranged between 19.1 and 50%, while overall mortality was low with only 3 treatment-related deaths.

Outlook

CRS-HIPEC has the potential to improve the overall survival in a highly selected group of SBA-PM patients, with 5-year survival rates comparable to those reported in colorectal peritoneal metastases. However, the expected survival benefits need to be balanced against the intrinsic risk of morbidity and mortality associated with the procedure. Further multicentre studies are required to assess the safety and feasibility of CRS-HIPEC in SBA-PM to guide best practice management for this rare disease.

Small Bowel Adenocarcinoma: 10-Year Experience in a Cancer Center-The Ottawa Hospital (TOH)

(1) Background: Small bowel adenocarcinoma (SBA) is one of the predominant primary small bowel cancers that has a dismal outcome. We aim to report 10 years of experience in SBA management at a regional cancer centre in Canada.; (2) Methods: We retrospectively analysed clinical and pathological data of patients diagnosed with an SBA between 2011 and 2021 at the Ottawa Hospital (TOH), Ottawa, Canada. We describe the clinicopathological features and outcomes, including survival. Potential prognostic factors were analysed using the Cox proportional hazard model for multivariate analysis.; (3) Results: We identified 115 patients with SBA. The duodenum was the most common SBA location representing 61% (70) of the total patients, followed by the jejunum (17%) and ileum (10%). Around 24% (27) of cases presented with bowel obstructions. The majority of patients (56%, 64) had stage IV disease on presentation. Seven patients had MSI-high tumours, while 24% (27) were MS-stable. In terms of management, 48 patients underwent curative surgical resection, 17 of whom received adjuvant chemotherapy. On the other hand, 57 patients (49.5%) with the advanced disease received palliative systemic therapy, and 18 patients (16%) had supportive care only. Over a median follow-up of 21.5 months (range 0-122), the median overall survival was 94, 61, and 34 months for stages II, III, and IV, respectively (p < 0.05). The median recurrence-free survival was 93 and 23 months for stages II and III, respectively. However, there was no statistically significant difference between TNM stages in RFS, p = 0.069. Multivariate Cox regression analysis showed only poor performance status at diagnosis as a predictor for shorter overall survival (p < 0.05). The univariate analysis didn't show any significant correlation between RFS and covariants.; (4) Conclusions: SBA remains one of the most aggressive tumours with a dismal prognosis even after surgical resection. The optimal chemotherapy regimen has not been established. Further studies are needed to explore the role of adjuvant chemotherapy for stages I-III SBA.

Diagnosis and management of small bowel neuroendocrine tumors: A state-of-the-art

This review provides an update on the epidemiology, pathophysiology, symptoms, diagnosis and treatment of neuroendocrine neoplasms (NENs) of the small bowel (SB). These NENs are defined as a group of neoplasms deriving from neuroendocrine cells. NENs are currently the most common primary tumors of the SB, mainly involving the ileum, making the SB the most frequently affected part of the gastrointestinal tract. SB NENs by definition are located between the ligament of Treitz and the ileocecal valve. They are characterized by small size and induce an extensive fibrotic reaction in the small intestine including the mesentery, resulting in narrowing or twisting of the intestine. Clinical manifestations of bowel functionality are related to the precise location of the primary tumor. The majority of them are non-functional NENs and generally asymptomatic; in an advanced stage, NENs present symptoms of mass effect by non-specific abdominal pain or carcinoid syndrome which appears in patients with liver metastasis (around 10%). The main manifestations of the carcinoid syndrome are facial flushing (94%), diarrhea (78%), abdominal cramps (50%), heart valve disease (50%), telangiectasia (25%), wheezing (15%) and edema (19%). Diagnosis is made by imaging or biochemical tests, and the order of request will depend on the initial diagnostic hypothesis, while confirmation will always be histological. All patients with a localized SB NEN with or without near metastasis in the mesentery are recommended for curative resection. Locoregional and distant spread may be susceptible to several therapeutic strategies, such as chemotherapy, somatostatin analogs and palliative resection.

Gastrointestinal Tract Microbiome Effect and Role in Disease Development

In recent years, it has been shown that gastrointestinal microflora has a substantial impact on the development of a large number of chronic diseases. The imbalance in the number or type of microbes in the gastrointestinal tract can lead to diseases and conditions, including autism spectrum disorder, celiac disease, Crohn’s disease, diabetes, and small bowel cancers. This can occur as a result of genetics, alcohol, tobacco, chemotherapeutics, cytostatics, as well as antibiotic overuse. Due to this, essential taxa can be lost, and the host’s metabolism can be severely affected. A less known condition called small intestine bacterial overgrowth (SIBO) can be seen in patients who suffer from hypochlorhydria and small intestine cancers. It is characterized as a state in which the bacterial population in the small intestine exceeds 10⁵–10⁶ organisms/mL. The latest examination methods such as double-balloon enteroscopy and wireless capsule endoscopy have the potential to increase the accuracy and precision of diagnosis and provide better patient care. This review paper aims to summarize the effect of the gastrointestinal environment on chronic disease severity and the development of cancers.

The gut microbiome and the immune system

The human body contains trillions of microbes which generally live in symbiosis with the host. The interaction of the gut microbiome with elements of the host immune system has far-reaching effects in the development of normal gut and systemic immune responses. Disturbances to this intricate relationship may be responsible for a multitude of gastrointestinal and systemic immune mediated diseases. This review describes the development of the gut microbiome and its interaction with host immune cells in both health and disease states.

Concomitant Kinase-Dead BRAF and Oncogenic KRAS Lead to an Aggressive Biologic Behavior and Tumor Lysis Syndrome: A Case Report

Tumor lysis syndrome (TLS) is a life-threatening oncological emergency rarely seen in solid tumors and is a complication of cancer therapy for rapidly proliferating tumors with devastating outcomes. BRAF and KRAS are two key oncogenes in the MAPK signaling pathway that are routinely examined for mutations to predict resistance to anti-EGFR therapy. Concomitant KRAS and BRAF mutations in GI tumors are rare, occurring in less than 0.001% of cases and are associated with an aggressive tumor behavior. We report an unusual case of a young male patient diagnosed with locally advanced duodenal mucinous adenocarcinoma harboring concomitant KRAS and BRAF mutations. This unique genetic profile generated hyperactivation of the EGFR signaling pathway. Following day-1 of mFOLFOX-6 chemotherapy protocol, the patient developed TLS. Clinical resolution was achieved using high volume hydration. Unfortunately, the patient passed away 10 days later during anesthesia induction.

Comparative Study of the Role of Interepithelial Mucosal Mast Cells in the Context of Intestinal Adenoma-Carcinoma Progression

Mast cells (MCs) are crucial players in the relationship between the tumor microenvironment (TME) and cancer cells and have been shown to influence angiogenesis and progression of human colorectal cancer (CRC). However, the role of MCs in the TME is controversially discussed as either pro- or anti-tumorigenic. Genetically engineered mouse models (GEMMs) are the most frequently used in vivo models for human CRC research. In the murine intestine there are at least three different MC subtypes: interepithelial mucosal mast cells (ieMMCs), lamina proprial mucosal mast cells (lpMMCs) and connective tissue mast cells (CTMCs). Interepithelial mucosal mast cells (ieMMCs) in (pre-)neoplastic intestinal formalin-fixed paraffin-embedded (FFPE) specimens of mouse models (total lesions n = 274) and human patients (n = 104) were immunohistochemically identified and semiquantitatively scored. Scores were analyzed along the adenoma-carcinoma sequence in humans and 12 GEMMs of small and large intestinal cancer. The presence of ieMMCs was a common finding in intestinal adenomas and carcinomas in mice and humans. The number of ieMMCs decreased in the course of colonic adenoma-carcinoma sequence in both species (p < 0.001). However, this dynamic cellular state was not observed for small intestinal murine tumors. Furthermore, ieMMC scores were higher in GEMMs with altered Wnt signaling (active β-catenin) than in GEMMs with altered MAPK signaling and wildtypes (WT). In conclusion, we hypothesize that, besides stromal MCs (lpMMCs/CTMCs), particularly the ieMMC subset is important for onset and progression of intestinal neoplasia and may interact with the adjacent neoplastic epithelial cells in dependence on the molecular environment. Moreover, our study indicates the need for adequate GEMMs for the investigation of the intestinal immunologic TME.

Morbid Obesity in Women Is Associated with an Altered Intestinal Expression of Genes Related to Cancer Risk and Immune, Defensive, and Antimicrobial Response

Background: Little is known about the relation between morbid obesity and duodenal transcriptomic changes. We aimed to identify intestinal genes that may be associated with the development of obesity regardless of the degree of insulin resistance (IR) of patients. Material and Methods: Duodenal samples were assessed by microarray in three groups of women: non-obese women and women with morbid obesity with low and high IR. Results: We identified differentially expressed genes (DEGs) associated with morbid obesity, regardless of IR degree, related to digestion and lipid metabolism, defense response and inflammatory processes, maintenance of the gastrointestinal epithelium, wound healing and homeostasis, and the development of gastrointestinal cancer. However, other DEGs depended on the IR degree. We mainly found an upregulation of genes involved in the response to external organisms, hypoxia, and wound healing functions in women with morbid obesity and low IR. Conclusions: Regardless of the degree of IR, morbid obesity is associated with an altered expression of genes related to intestinal defenses, antimicrobial and immune responses, and gastrointestinal cancer. Our data also suggest a deficient duodenal immune and antimicrobial response in women with high IR.

Risk and Prognostic Factors for Small Bowel Adenocarcinoma: A Multicenter Retrospective Observational Study in China

Background

Small bowel adenocarcinoma (SBA) is a rare malignancy that accounts for 3% of all gastrointestinal tumors. We evaluated the clinical characteristics, outcomes, and prognostic factors of primary SBAs.

Methods

We retrospectively analyzed the clinicopathological features and clinical outcomes of 300 patients with SBA from three institutions in China between January 2003 and July 2020. Overall survival (OS) was analyzed using the Kaplan-Meier method and it was statistically compared using the log-rank test. Single-variable and multivariate analyses were used to identify the significant correlates of OS.

Results

The primary tumor was on the duodenal papilla in 156 patients (52%), in the duodenum in 60 patients (20%), and in the jejunum-ileum in 84 patients (28%). The median OS of the entire cohort was 32.5 months (range, 0-213 months), with a 1-year OS rate of 78.0%. For jejunoileal adenocarcinoma, advanced age, advanced T stage, advanced N stage, more positive lymph nodes, distant metastasis, high carcinoembryonic antigen (CEA), and lymphocyte-to-monocyte ratio < 2.32 predicted worse survival on single-variable analysis. Multivariate analysis showed that advanced age, advanced tumor node metastases (TNM) stage, high CEA level, high alpha fetoprotein (AFP) level, and low prealbumin level were independent prognostic factors for non-ampullary SBA. The independent prognostic factors for duodenal papilla adenocarcinoma included TNM Stage III, nerve invasion, low platelet/lymphocyte ratio, and high CA19-9.

Conclusion

We found different independent prognostic factors for tumors at different locations. This finding warrants further investigation to ensure more effective management strategies for SBA.

Development and validation of prognostic nomograms for patients with metastatic small bowel adenocarcinoma: a retrospective cohort study

We aimed to explore factors associated with prognosis in patients with metastatic small bowel adenocarcinoma (SBA) as well as to develop and validate nomograms to predict overall survival (OS) and cancer-specific survival (CSS). Relevant information of patients diagnosed between 2004 and 2016 was extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Nomograms for predicting 1- and 3-year OS and CSS were established with potential risk factors screened from multivariate cox regression analysis. The discrimination and accuracy of the nomograms were assessed by concordance index (C-index), calibration plots, and the area under receiver operating characteristic curve (AUC). In total, 373 SBA patients with M1 category were enrolled. Multivariate analysis revealed that age, size and grade of primary tumor, primary tumor surgery, and chemotherapy were significant variables associated with OS and CSS. The C-index values of the nomogram for OS were 0.715 and 0.687 in the training and validation cohorts, respectively. For CSS, it was 0.711 and 0.690, respectively. Through AUC, decision curve analysis (DCA) and calibration plots, the nomograms displayed satisfactory prognostic predicted ability and clinical application both in the OS and CSS. Our models could be served as a reliable tool for prognostic evaluation of patients with metastatic SBA, which are favorable in facilitating individualized survival predictions and clinical decision-making.

Small bowel adenocarcinoma in Crohn's disease: a systematic review and meta-analysis of the prevalence, manifestation, histopathology, and outcomes

BACKGROUND AND AIMS

Small bowel adenocarcinoma (SBA) is a rare neoplasm that is associated with Crohn's disease (CD). This study aims to quantify the prevalence of CD-SBA, review the current evidence of histopathology and molecular analysis findings, and identify the clinical presentation and outcomes of CD-SBA.

METHODS

Electronic databases Medline and Embase were searched for articles describing SBA in inflammatory bowel disease patients. The histopathology, molecular analysis findings, clinical presentation, prevalence, and outcomes of CD-SBA were extracted, and results were pooled with random effects.

RESULTS

In total, 33 articles were included in the analysis. Prevalence of SBA was 1.15 (CI: 0.31-2.33) per 1000 CD patients. Only 11% (CI: 0.04-0.21) of CD-SBA patients had observable radiological features. CD-SBA was most commonly found in the ileum (84%), diagnosed at stage 2 (36%), with main presenting complaints including obstruction, weight loss, and abdominal pain. Significant histopathological findings included adjacent epithelial dysplasia, and an equal distribution of well-differentiated (49%) and poorly differentiated subtypes (46%). Most prevalent genetic mutation was KRAS mutation (18%), followed by mismatch repair deficiency (9.7%). The 5-year overall survival for CD-SBA patients was 29% (CI: 0.18-0.41), and 33% (CI: 0.26-0.41) for de novo SBA. No statistically significant increase in risk for CD-SBA was noted for treatment with thiopurines, steroids, and 5-ASA.

CONCLUSION

Our meta-analysis found the prevalence of CD-SBA to be 1.15 per 1000 CD patients. The 5-year overall survival for CD-SBA was poor. The presenting symptoms were non-specific, and therefore the diagnosis requires a high index of suspicion.

Systemic Therapy for Microsatellite Instability Small Bowel Adenocarcinoma With Mesenteric Vascular Embolism as Initial Symptom: A Case Report

Background: Small bowel adenocarcinoma are relatively rare tumors of the digestive system. Due to the lack of specific screening methods, patients are often diagnosed at an advanced stage. At present, there is no specific surgical guidance and chemotherapy regimen for small bowel adenocarcinoma. Here, we report a rare small bowel adenocarcinoma case with mesenteric vascular embolization and microsatellite instability, in which palliative surgery combined with chemotherapy and anti-Programmed cell death protein 1(PD-1) therapy resulted in complete remission.

Case Presentation: The patient was a 55-year-old man who was admitted for suspected small bowel adenocarcinoma combined with incomplete ileus, mesenteric vascular occlusion and distant metastasis. We performed palliative surgery to remove adenocarcinoma as well as relieve obstruction. Then according to the pathological and immunohistochemical results (Stage IV and microsatellite instability), we used XELOX regimen combined with anti-PD-1 therapy. In last 2 years follow up, this patient achieved complete remission.

Conclusions: The possibility of small intestinal tumor should be considered in patients with mesenteric vascular obstruction. PD-1 blockade is an effective therapy for small bowel adenocarcinoma with microsatellite instability.

Metachronous small bowel adenocarcinoma after rectal adenocarcinoma: A case report

RATIONALE

Small bowel adenocarcinoma (SBA), an uncommon gastrointestinal malignant tumor, is difficult to diagnose at an early stage because of its non-specific disease presentation. Metachronous SBA is a special type of SBA that is rarely reported. We herein report a case of metachronous primary SBA following resection of rectal adenocarcinoma.

PATIENT CONCERNS

A 65-year-old man presented to our hospital after having experienced recurrent bowel obstruction for 6 months. He had undergone a Dixon operation 30 months previously followed by adjuvant chemotherapy with capecitabine plus oxaliplatin.

DIAGNOSIS

Abdominal computed tomography showed thickened bowel walls in the right lower abdomen, and the patient was initially misdiagnosed with intestinal adhesion. After the operation, he was diagnosed with primary SBA (T3N0M0, stage IIA).

INTERVENTIONS

Treatment with a transnasal ileus tube was ineffective. Therefore, we performed small intestinal segmental resection and side-to-side anastomosis through open surgery.

OUTCOMES

The patient completed all postoperative adjuvant chemotherapy, and posttreatment surveillance revealed no further abnormalities.

LESSONS

This case suggests that patients with colorectal adenocarcinoma may have an increased risk of metachronous SBA. Corresponding symptoms in high-risk patients should raise clinicians' suspicion for SBA, and further detailed examinations are imperative. Early screening for SBA may help to improve the patients' prognosis.

Small and Large Intestine (II): Inflammatory Bowel Disease, Short Bowel Syndrome, and Malignant Tumors of the Digestive Tract

The small intestine is key in the digestion and absorption of macro and micronutrients. The large intestine is essential for the absorption of water, to allow adequate defecation, and to harbor intestinal microbiota, for which their nutritional role is as important as it is unknown. This article will describe the causes and consequences of malnutrition in patients with inflammatory bowel diseases, the importance of screening and replacement of micronutrient deficits, and the main indications for enteral and parenteral nutrition in these patients. We will also discuss the causes of short bowel syndrome, a complex entity due to anatomical or functional loss of part of the small bowel, which can cause insufficient absorption of liquid, electrolytes, and nutrients and lead to complex management. Finally, we will review the causes, consequences, and management of malnutrition in patients with malignant and benign digestive tumors, including neuroendocrine tumors (present not only in the intestine but also in the pancreas).

Adenocarcinoma of the Jejunum: A Case Report and Literature Review

Small intestine cancers account for 1-3% of all gastrointestinal tumors, with only 11-25% of these tumors located in the jejunum. We report the case of a woman who has been experiencing abdominal pain for the last six months, accompanied by nausea, vomiting and appearance of dark-colored stools, who has lost 20 kg in weight during the last few months. Laboratory findings indicated anemia and no significant changes were identified in the abdominal ultrasound. By endoscopic examination of the stomach and duodenum and by colonoscopy, no infiltrations were found. Serum markers were elevated and CT scan of the abdomen showed thickening of a part of the jejunum wall with swollen lymph nodes in the mesentery, along the inferior vena cava and abdominal aorta, in the retroperitoneal space. By opening the abdominal cavity, we observed an infiltration in the initial part of the jejunum with an infiltration of the entire wall. Resection of the jejunum with related mesenthery, vessels and lymph nodes therein was performed. Histopathology revealed an invasive adenocarcinoma of the small intestine, with an invasion of all layers of the wall and mesentery. Adjuvant FOLFOX chemotherapy was introduced, 6 cycles in total, and following each cycle, tumor markers have been constantly decreasing. No relapse has been identified after nine months. Due to often deep position in the small intestine, atypical symptomatology and lack of screening, an early diagnosis is difficult. Surgical resection of the affected small intestine followed by an additional chemotherapy is the optimal treatment strategy.

Update on Incidence, Prevalence, Treatment and Survival of Patients with Small Bowel Neuroendocrine Neoplasms in the Netherlands

BACKGROUND

Small bowel neuroendocrine neoplasms (SB-NEN) are rare cancers, population-based studies are needed to study this rare indolent disease. The aim of this study was to explore trends in epidemiology, treatment and survival outcomes of patients with SB-NEN based on Dutch nationwide data.

PATIENTS AND METHODS

Patients with grade 1 or 2 SB-NEN diagnosed between 2005 and 2015 were retrieved from the Netherlands Cancer Registry and linked to The Nationwide Network and Registry of Histo- and Cytopathology in the Netherlands. Age-adjusted incidence rates were calculated based using the direct standardization method. Survival analyses were performed with the Kaplan-Meier method.

RESULTS

A total of 1132 patients were included for epidemiological analyses. The age-adjusted incidence rate of SB-NEN increased from 0.52 to 0.81 per 100.000 person-years between 2005 and 2015. Incidence was higher for males than females (0.93 vs. 0.69 in 2015). Most patients had grade 1 tumours (83%). Surgery was performed in 86% of patients, with resection of the primary tumour in 99%. During the study period, administration of somatostatin analogues (SSAs) increased from 5 to 22% for stage III and from 27 to 63% for stage IV disease. Mean follow-up was 61 (standard deviation 38) months. Survival data were complete for 975/1132 patients and five-year overall survival was 75% for stage I-II, 75% for stage III and 57% for stage IV.

CONCLUSIONS

This study shows an increase in the incidence of SB-NEN in the Netherlands. A predominant role of surgery was found in all disease stages. Use of SSAs has increased over time.

Gastrointestinal epithelial innate immunity-regionalization and organoids as new model

The human gastrointestinal tract is in constant contact with microbial stimuli. Its barriers have to ensure co-existence with the commensal bacteria, while enabling surveillance of intruding pathogens. At the centre of the interaction lies the epithelial layer, which marks the boundaries of the body. It is equipped with a multitude of different innate immune sensors, such as Toll-like receptors, to mount inflammatory responses to microbes. Dysfunction of this intricate system results in inflammation-associated pathologies, such as inflammatory bowel disease. However, the complexity of the cellular interactions, their molecular basis and their development remains poorly understood. In recent years, stem cell-derived organoids have gained increasing attention as promising models for both development and a broad range of pathologies, including infectious diseases. In addition, organoids enable the study of epithelial innate immunity in vitro. In this review, we focus on the gastrointestinal epithelial barrier and its regional organization to discuss innate immune sensing and development.

Roles of Capsule Endoscopy and Device-Assisted Enteroscopy in the Diagnosis and Treatment of Small-Bowel Tumors

With the development of capsule endoscopy (CE) and device-assisted enteroscopy (DAE), the incidence of small-bowel tumors has increased and the characteristics of these tumors have changed. In addition, the diagnostic and therapeutic approaches for small-bowel tumors have diversified. CE is a simple, noninvasive method that aid in the visualization the entire small bowel. CE is considered the initial approach for small-bowel tumors. DAE can be used to perform endoscopic procedures such as bleeding control, polypectomy, stent insertion, and tattooing, as well as for diagnosis through visualization or tissue sampling. Therapeutic intervention with DAE is particularly useful in polyposis syndromes such as familial adenomatous polyposis and Peutz-Jeghers syndrome. This review will discuss the roles of CE and DAE in the diagnosis and treatment of small-bowel tumors.

Esophagogastroduodenoscopy: how far should we go? A point of view

N.A.

Management of Small Bowel Neuroendocrine Tumors

Several important landmark trials have reshaped the landscape of non-surgical management of small bowel neuroendocrine tumors over the last few years, with the confirmation of the antitumor effect of somatostatin analogue therapy in PROMID and CLARINET trials as well as the advent of therapies with significant potential such as mammalian target of rapamycin inhibitor (mTor) everolimus (RADIANT trials) and peptide receptor radionuclide therapy (PRRT) with 177-Lutetium (NETTER-1 trial). This narrative summarizes the recommended management strategies of small bowel neuroendocrine tumors. We review the main evidence behind each recommendation as well as compare and contrast four major guidelines, namely the 2016 Canadian Consensus guidelines, the 2017 North American Neuroendocrine Tumor Society guidelines, the 2018 National Comprehensive Cancer Network guidelines, and the 2016 European Neuroendocrine Tumor Society guidelines. Different clinical situations will be addressed, from loco-regional therapy to metastatic unresectable disease. Carcinoid syndrome, which is mostly managed by somatostatin analogue therapy and the serotonin antagonist telotristat etiprate for refractory diarrhea, as well as neuroendocrine carcinoma will be reviewed. However, several questions remain unanswered, such as the optimal management of neuroendocrine carcinomas or the effect of combining and sequencing of the aforementioned modalities where more randomized controlled trials are needed.