Early Gastroenteropancreatic Neuroendocrine Tumors: Endoscopic Therapy and Surveillance

Advances in Endoscopic Diagnosis and Treatment of Gastric Neuroendocrine Neoplasms

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

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

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

Understanding the increasing incidence of neuroendocrine tumors

INTRODUCTION

Neuroendocrine tumors (NETs) are a diverse group of tumors with origins from different primary sites such as gastro-entero-pancreatic, lung and endocrine tissue. Worldwide, their incidence has increased in recent decades. Advances in imaging and better clinical awareness are traditionally attributed to this trend; however, other factors such as genetic and environmental contributors are appreciated as well.

AREAS COVERED

The purpose of this article is to review the worldwide epidemiologic trends in incidence of NET through the decades and discuss the various factors potentially contributing to the observed changes in incidence trends.

EXPERT OPINION

Overall, the incidence of NET has increased across the globe over the last few decades. Although multiple genetics and environmental factors have been proposed, the majority of this increase in incidence is secondary to earlier detection. Future studies will help in more accurate assessments and an improved understanding of disease incidence among patients with different grades and differentiation.

Efficacy of Endoscopic Resection for Rectal Neuroendocrine Tumors Smaller than 15 mm

BACKGROUND

Local resection, including endoscopic resection, is recommended for rectal neuroendocrine tumors (NETs) < 15 mm in patients without risk factors for metastasis, though the short- and long-term outcomes are unclear.

AIMS

This study investigates the efficacy of endoscopic resection for rectal NETs < 15 mm.

METHODS

The short- and long-term outcomes of patients with rectal NETs < 15 mm who underwent endoscopic resection and the outcomes of each endoscopic technique were analyzed. The tumors were stratified as < 10 mm (small-size group, SSG) and 10-14 mm (intermediate-size group, IMG).

RESULTS

Overall, 139 lesions (SSG, n = 118; IMG, n = 21) were analyzed. All tumors were classified as G1 (n = 135) or G2 (n = 4) according to the 2019 World Health Organization grading criteria. The complete resection rate was not different between the groups (P = 0.151). Endoscopic submucosal dissection (ESD) and endoscopic submucosal resection with a ligation device (ESMR-L) achieved complete resection rates > 90% in the SSG. The ESMR-L procedure time (P < 0.001) and hospitalized period (P < 0.001) were significantly shorter than those of ESD. ESD achieved a complete resection rate of 80.0% in the IMG. The tumor size did not affect the overall survival or rate of lymph node/distant metastases.

CONCLUSIONS

Endoscopic resection is a feasible and effective treatment for patients with rectal NETs < 15 mm without the risk factors of metastasis. ESMR-L and ESD are optimal techniques for resecting tumors smaller than 10 mm and 10-14 mm, respectively.

Endoscopic techniques for gastric neuroendocrine tumors: An update

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

Endoscopic treatment and management of rectal neuroendocrine tumors less than 10 mm in diameter

Rectal neuroendocrine tumors (rNETs) measuring less than 10 mm in diameter are defined as small rNETs. Due to the low risk of distant invasion and metastasis, endoscopic treatments, including modified endoscopic mucosal resection, endoscopic submucosal dissection, and other transanal surgical procedures, are effective. This review article proposes a follow-up plan according to the size and histopathology of the tumor after operation.

Cytology as the guiding light: Prompt cytomorphologic diagnosis of cystic metastases from a jejunal neuroendocrine tumor masquerading as hepatic abscesses

Hepatic cystic lesions are commonly seen in radiology and can occur due to infective or neoplastic causes. It is imperative to determine the precise nature of these hepatic cysts owing to significant therapeutic and prognostic differences. Hepatic metastases from gastrointestinal neuroendocrine tumors (NETs) mostly present as solid hypervascular lesions. Cystic presentation of the metastatic NETs is extremely rare. A 64-year-old woman presented with an abdominal lump of 3 months duration and high-grade fever from the last 2 days. An ultrasound abdomen revealed multiple hypoechoic liver lesions suggestive of liver abscesses. An ultrasound-guided fine-needle aspiration (FNA) from the cystic liver lesions revealed a NET confirmed by immunocytochemistry. The Ki-67 index was 5%; hence, a final diagnosis of metastatic NET, grade 2, was given with advice to work up for localizing the primary tumor. Subsequently, a contrast-enhanced computerized tomography of the abdomen revealed a polypoidal lesion in the proximal jejunum, which showed intense expression on the whole-body DOTANOC scan (SUVmax-76.5), indicating it to be the likely primary tumor along with somatostatin receptor-expressing multiple lymph nodes and hypodense liver lesions. Thus, a final diagnosis of a jejunal NET with abdominal lymph node and liver metastases was made. The present report highlights the importance of FNA as a reliable modality in diagnosing metastatic NETs presenting as unusual cystic hepatic metastases masquerading as liver abscesses. Additionally, the cell block helps confirm the cytologic diagnosis and enables upfront tumor grading, thereby helping in prognostication and therapeutic decision-making.

Endoscopic techniques for diagnosis and treatment of gastro-entero-pancreatic neuroendocrine neoplasms: Where we are

BACKGROUND

The correct localization of the primary tumor site and a complete histological diagnosis represent the milestones for the proper management of gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs).

AIM

To analyze current evidence on the role of endoscopy in the diagnosis/treatment of GEP-NENs.

METHODS

An extensive bibliographical search was performed in PubMed to identify guidelines and primary literature (retrospective and prospective studies, systematic reviews, case series) published in the last 15 years, using both medical subject heading (MeSH) terms and free-language keywords: gastro-entero-pancreatic neuroendocrine neoplasms; endoscopy; ultrasound endoscopy; capsule endoscopy; double-balloon enteroscopy; diagnosis; therapy; staging.

RESULTS

In the diagnostic setting, endoscopic ultrasonography (EUS) represents the diagnostic gold standard for pancreatic NENs and the technique of choice for the locoregional staging of gastric, duodenal and rectal NENs. The diagnosis of small bowel NENs (sbNENs) has been improved with the advent of video capsule endoscopy and double-balloon enteroscopy, which allow for direct visualization of the entire small bowel; however, data regarding the efficacy/safety of these techniques in the detection of sbNENs are scanty and often inconclusive. From a therapeutic point of view, endoscopic removal is the treatment of choice for the majority of gastric NENs (type 1/2), for well-differentiated localized nonmetastatic duodenal NENs < 1 cm, confined to the submucosa layer and for < 10 mm, stage T1–T2, rectal NENs. EUS-guided pancreatic locoregional ablative treatments have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients.

CONCLUSION

Standard axial endoscopy and EUS still play a pivotal role in several GEP-NENs. Advanced techniques for increasing the rate of R0 resection should be reserved for high-volume referral centers.

Neuroendocrine tumour of the descending part of the duodenum complicated with schwannoma: A case report

BACKGROUND

No known case of neuroendocrine tumour (NET) with schwannoma has been reported.

CASE SUMMARY

A 63-year-old female presented to our hospital with nausea and vomiting. Upper gastrointestinal endoscopy revealed a mass in the descending part of the duodenum. Using ultrasound gastroscopy, we found that the tumour originated from the submucosa and showed low echo. We removed the tumour by electrocoagulation and sent it for pathological biopsy.

CONCLUSION

Immunohistochemical results showed that the mass was a rare NET with neurilemmoma.

Risk factors for metastasis and survival of patients with T1 gastric neuroendocrine carcinoma treated with endoscopic therapy versus surgical resection

Background

Gastrectomy with lymphadenectomy is recommended for early gastric Neuroendocrine carcinoma (G-NEC). We attempted to determine the prevalence and risk factors of metastasis of T1 G-NEC and compare the long-term survival of patients after receiving endoscopic therapy (ET) and radical surgery.

Methods

In this study, 205 patients in total with T1 G-NEC were collected from the Surveillance Epidemiology and End Result database. Independent predictors of metastasis were identified by Logistic regression analysis, followed by the calculation of both cancer-specific survival (CSS) and overall survival (OS).

Results

Twenty-five patients (12.2%) were burdened with metastasis at initial diagnosis, with a prevalence of 5.2% (3/58) in mucosa lesions and 16.2% (16/99) in submucosa lesions (P = 0.045). No metastasis was detected in lesions with mucosa involvement and tumors ≦ 20 mm (0%, 0/49). The most significant risk factor for metastasis was tumors > 20 mm [odds ratio (OR) 18.64; 95% confidence interval (CI) 4.01–86.68; P < 0.001]. For patients with T1N0M0 G-NEC who received ET or surgery, the 10-year OS was similar between the mucosa extension and submucosa extension groups, which was 91.56% in ET group vs 87.50% in surgery group (P = 0.62) and 57.33% vs 77.83% (P = 0.11), respectively. In addition, the 10-year CSS was also similar between the mucosa extension and submucosa extension groups with 97.30% in ET vs 100% in surgery (P = 0.51) and 97.62% vs 86.49% (P = 0.65).

Conclusions

In G-NEC, tumors > 20 mm were considered as the most significant risk factor for metastasis. ET seemed adequate for the lesions with mucosa involvement and size ≦ 2 cm.

Endoscopic management of subepithelial lesions including neuroendocrine neoplasms: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends endoscopic ultrasonography (EUS) as the best tool to characterize subepithelial lesion (SEL) features (size, location, originating layer, echogenicity, shape), but EUS alone is not able to distinguish among all types of SEL.Strong recommendation, moderate quality evidence. 2: ESGE suggests providing tissue diagnosis for all SELs with features suggestive of gastrointestinal stromal tumor (GIST) if they are of size > 20 mm, or have high risk stigmata, or require surgical resection or oncological treatment.Weak recommendation, very low quality evidence. 3: ESGE recommends EUS-guided fine-needle biopsy (EUS-FNB) or mucosal incision-assisted biopsy (MIAB) equally for tissue diagnosis of SELs ≥ 20 mm in size.Strong recommendation, moderate quality evidence. 4: ESGE recommends against surveillance of asymptomatic gastrointestinal (GI) tract leiomyomas, lipomas, heterotopic pancreas, granular cell tumors, schwannomas, and glomus tumors, if the diagnosis is clear.Strong recommendation, moderate quality evidence. 5: ESGE suggests surveillance of asymptomatic esophageal and gastric SELs without definite diagnosis, with esophagogastroduodenoscopy (EGD) at 3-6 months, and then at 2-3-year intervals for lesions < 10 mm in size, and at 1-2-year intervals for lesions 10-20 mm in size. For asymptomatic SELs > 20 mm in size that are not resected, ESGE suggests surveillance with EGD plus EUS at 6 months and then at 6-12-month intervals.Weak recommendation, very low quality evidence. 6: ESGE recommends endoscopic resection for type 1 gastric neuroendocrine neoplasms (g-NENs) if they grow larger than 10 mm. The choice of resection technique should depend on size, depth of invasion, and location in the stomach.Strong recommendation, low quality evidence. 7: ESGE suggests considering removal of histologically proven gastric GISTs smaller than 20 mm as an alternative to surveillance. The decision to resect should be discussed in a multidisciplinary meeting. The choice of technique should depend on size, location, and local expertise.Weak recommendation, very low quality evidence. 8: ESGE suggests that, to avoid unnecessary follow-up, endoscopic resection is an option for gastric SELs smaller than 20 mm and of unknown histology after failure of attempts to obtain diagnosis.Weak recommendation, very low quality evidence. 9: ESGE recommends basing the surveillance strategy on the type and completeness of resection. After curative resection of benign SELs no follow-up is advised, except for type 1 gastric NEN for which surveillance at 1-2 years is advised.Strong recommendation, low quality evidence. 10: For lower or upper GI NEN with a positive or indeterminate margin at resection, ESGE recommends repeating endoscopy at 3-6 months and another attempt at endoscopic resection in the case of residual disease.Strong recommendation, low quality evidence.

Rectal neuroendocrine tumors: Current advances in management, treatment, and surveillance

Rectal neuroendocrine neoplasms (r-NENs) are considered among the most frequent digestive NENs, together with small bowel NENs. Their incidence has increased over the past few years, and this is probably due to the widespread use of endoscopic screening for colorectal cancer and the advanced endoscopic procedures available nowadays. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, well-differentiated r-NENs smaller than 10 mm should be endoscopically removed in view of their low risk of local and distant invasion. R-NENs larger than 20 mm are candidates for surgical resection because of their high risk of distant spreading and the involvement of the muscularis propria. There is an area of uncertainty regarding tumors between 10 and 20 mm, in which the metastatic risk is intermediate and the endoscopic treatment can be challenging. Once removed, the indications for surveillance are scarce and poorly codified by international guidelines, therefore in this paper, a possible algorithm is proposed.

Diagnosis and Surgical Treatment of Gastroenteropancreatic Neuroendocrine Neoplasms: A Literature Review

This review aimed to highlight the characteristics and surgical treatments of tumours, and answer questions regarding the assessment of gastrointestinal neuroendocrine neoplasms (NENs) and optimal therapy. NENs comprise tumours that can produce hormones and cause a secretory syndrome. The diagnostic method and accuracy differ depending on the site of occurrence; hence, the relevant scientific society has created NEN treatment guidelines for each organ. Gastroenteric pancreatic (GEP) NENs have been unified and classified together according to the 2019 World Health Organization classification. Treatment is based on complete tumour resection, and when metastatic or primary lesions cannot be completely resected, lesions and symptoms are treated. Except for surgery for NENs, chemotherapy, molecularly targeted drugs, transarterial chemoembolization, etc., have also been confirmed as treatments. GEP NEN treatment methods will continue to advance and change because of surgery and other advances in treatment and diagnostic methods.

The new WHO classification of gastrointestinal neuroendocrine tumors and immunohistochemical expression of somatostatin receptor 2 and 5

The 2019 World Health Organization (WHO) classification of gastrointestinal tumors defines well-differentiated grade 3 neuroendocrine tumors, the mixed neuroendocrine-non-neuroendocrine tumors (MiNENs) and classifies goblet cell carcinoid as goblet cell adenocarcinoma. The expression of somatostatin receptors (SSTRs) is the foundation for somatostatin analogue therapy. At present, there are only a few studies that have analyzed the immunohistochemical reactivity of SSTRs in gastrointestinal neuroendocrine neoplasms (NENs). The aim of the present study was to evaluate the immunohistochemical expression of SSTR2 and SSTR5 in gastrointestinal NENs and goblet cell adenocarcinomas and the correlation of these markers with clinical and morphological factors. The study included 67 patients with NENs and 4 patients with adenocarcinoma ex-goblet cell carcinoid diagnosed between January 2008 and December 2018. Tumors were reclassified according to the 2019 WHO classification. Immunohistochemical staining for chromogranin A, synaptophysin, Ki-67, p53, SSTR2, and SSTR5 were performed in all the cases. The results showed that, G1 and G2 neuroendocrine tumors were more common SSTR2-positive in comparison with G3 carcinomas (P<0.0001). In addition, 33.3% of neuroendocrine carcinomas and 2 cases of low-grade adenocarcinoma ex-goblet cell carcinoid were SSTR2-positive. Neuroendocrine carcinomas had significantly lower SSTR2 and SSTR5 expression compared with well-differentiated neuroendocrine tumors (P=0.0130; P=0.0437, respectively). The SSTR2 expression in the early tumor stages was 100%, more often than in advanced stages (55.6%; P=0.0011). The results demonstrated the decrease in SSTR2 expression with increasing malignancy and tumor stage. The SSTR2-positive expression in neuroendocrine carcinomas and adenocarcinoma ex-goblet cell carcinoid provides evidence for the benefits of somatostatin analog treatment associated with surgery and chemotherapy.

Neuroendocrine Tumors of the Gastrointestinal Tract: A Focused Review and Practical Approach for Gastroenterologists

Neuroendocrine tumors (NETs) are rare tumors derived from the neuroendocrine cell system, and more commonly found in the gastrointestinal (GI) tract. Over the last decades, the incidence of GI-NETs has been steadily increasing, partly due to the expanding indications for endoscopy. Most patients with NETs are asymptomatic, and their NETs are noticed during screening examinations; thus, endoscopists are on the frontline of the diagnosis of GI-NETs. Since GI-NETs are less frequent than other malignancies, the natural history, diagnosis, and management of these tumors may not be fully understood. In this review, we aim to update the endoscopist on key clinical features and management of patients with gastric, duodenal, and rectal NETs.

Comparison of endoscopic resection techniques for duodenal neuroendocrine tumors: systematic review

Background and study aims  Regardless of size, duodenal neuroendocrine tumors (dNETs) should be considered potentially malignant. A complete resection without complications is essential to increase safety procedures. The aim of this review was to describe effectiveness and possible complications of endoscopic techniques resection for resectioning dNETs in patients with tumors ≤ 20 mm in diameter. Methods  An electronic bibliographic search was conducted using MEDLINE (via PubMed), Embase, Cochrane Central, and Google Scholar virtual databases. The types of intervention were endoscopic mucosal resection alone (EMR) or with cap (EMR-C), with a ligation device (EMR-L), with previous elevation of the tumor (EMR-I) or with endoscopic submucosal dissection (ESD); argon plasm coagulation (APC), and polypectomy. The outcome measures adopted were presence of free margin associated with tumor resection, tumor recurrence, complications (bleeding and perforation), and length of the procedure. Results  Ten publications were included with the result of 224 dNET resections. EMR alone and polypectomy resulted in the most significantly compromised margin. The most frequent complication was bleeding (n = 21), followed by perforation (n = 8). Recurrence occurred in 13 cases, the majority of those under EMR or EMR-I. Conclusions  EMR-C or EMR-I should be preferred for resectioning of dNETs. Polypectomy should not be indicated for resection of dNETs due to the high occurrence of incomplete resections. EMR alone must be avoided due a higher frequency of compromised margin and recurrent surgery. ESD was associated with no recurrence, however, but an increased occurrence of bleeding and perforation.

Endoscopic mucosal resection: still a reliable therapeutic option for gastrointestinal neuroendocrine tumors

Background

Neuroendocrine tumors (NETs), as a rare and heterogeneous category of solid tumors, feature various morphologies and behaviors. In recent years, the incidence of NETs has continued to increase. Endoscopic mucosal resection (EMR) is one of the therapeutic modalities for the treatment of gastric and rectal NETs.

Methods

We evaluated patients with well-differentiated NETs of the stomach, duodenum, or rectum between 2011 and 2018. In this study, all cases with tumors confined to the mucosal or submucosal layers and smaller than 20 mm were resected using the EMR technique. We used EUS, CT scan, or MRI to exclude patients with advanced disease. All patients were actively monitored for recurrence according to the recommended protocols.

Results

A total of 36 patients with NETs entered the study; 17 (47.2%) were female and the remaining 19 (52.8%) were male, with a total age range of 20–74 years (mean: 52.47 ± 13.47 years). Among the tumors, 31 cases (86.1%) were G1 and the remaining 5 (13.9%) were G2. Based on the pathology reports, 22 tumors (61.1%) were smaller than 1 cm, while the remaining 14 (38.9%) were between 1–2 cm. Twenty-two patients (61.1%) had a margin of specimen involved with the tumor. No recurrence was observed during the mean follow-up time of 63.5 ± 19.8 months (range: 39–103 months). All 36 cases survived during the study period.

Conclusion

Conventional EMR procedure provides low chance of R0 (complete resection) achievement in gastrointestinal NETs smaller than 20 mm and limited to the mucosa or sub mucosa. However, it could be an option if patients are closely followed. Postoperative marginal involvement is not a reliable predictor of disease recurrence, which may be explained by the deleterious effect of heat coagulation and cauterization applied during tumor removal.

Epidemiology, Diagnosis, Staging and Multimodal Therapy of Esophageal and Gastric Tumors

Gastric and esophageal tumors are diverse neoplasms that involve mucosal and submucosal tissue layers and include squamous cell carcinomas, adenocarcinomas, spindle cell neoplasms, neuroendocrine tumors, marginal B cell lymphomas, along with less common tumors. The worldwide burden of esophageal and gastric malignancies is significant, with esophageal and gastric cancer representing the ninth and fifth most common cancers, respectively. The approach to diagnosis and staging of these lesions is multimodal and includes a combination of gastrointestinal endoscopy, endoscopic ultrasound, and cross-sectional imaging. Likewise, therapy is multidisciplinary and combines therapeutic endoscopy, surgery, radiotherapy, and systemic chemotherapeutic tools. Future directions for diagnosis of esophageal and gastric malignancies are evolving rapidly and will involve advances in endoscopic and endosonographic techniques including tethered capsules, optical coherence tomography, along with targeted cytologic and serological analyses.

A "Watch and Wait" Strategy Involving Regular Endoscopic Surveillance Is Safe for Many Patients with Small, Sporadic, Grade 1, Non-Ampullary, Non-Functioning Duodenal Neuroendocrine Tumours

INTRODUCTION

Duodenal neuroendocrine tumours (d-NETs) are rare but are increasing in incidence. Current ENETS guidelines advocate resection of all localized d-NETs. However, "watch and wait" may be appropriate for some localized, small, grade 1, non-functioning, non-ampullary d-NETs. We evaluated whether patients with such d-NETs who chose "watch and wait" involving regular endoscopic surveillance had equivalent disease-related outcomes to patients undergoing endoscopic or surgical resection.

METHODS

Retrospective review of patients with histologically confirmed d-NETs at Liverpool ENETS Centre of Excellence 2007-2020.

RESULTS

Sixty-nine patients were diagnosed with d-NET of which 50 were sporadic, non-functioning, non-ampullary tumours. Patient treatment groups were similar in terms of age, gender, and tumour location and grade, but unsurprisingly, larger tumours (median diameter 17 mm [p < 0.0001]) were found in the surgically treated group. Five patients underwent surgical resection with no evidence of tumour recurrence or disease-related death. Twelve patients underwent endoscopic resection (ER), with 1 local recurrence detected during follow-up. Thirty patients (28 with d-NETs ≤10 mm) underwent "watch and wait" with resection only if tumours increased in size. The d-NETs in 28/30 patients remained stable or decreased in size over a median 27 months (IQR: 15-48, R: 3-98). In 7 patients, the d-NET was completely removed by avulsion during diagnostic biopsy and was not seen at subsequent endoscopies. Only 2 patients showed increased d-NET size during surveillance, of whom only one was fit for ER. No NET-related deaths were documented during follow-up.

CONCLUSIONS

All of the localized, ≤10 mm, grade 1, non-functioning, non-ampullary d-NETs in this cohort behaved indolently with very low risks of progression and no tumour-related deaths. "Watch and wait," therefore, appears to be a safe alternative management strategy for selected d-NETs.

The Neuroendocrine Neoplasms of the Digestive Tract: Diagnosis, Treatment and Nutrition

Nuroendocrine neoplasms (NENs) are a group of rare neoplasms originating from dispersed neuroendocrine cells, mainly of the digestive and respiratory tract, showing characteristic histology and immunoprofile contributing to classification of NENs. Some NENs have the ability to produce biogenic amines and peptide hormones, which may be associated with clinical syndromes like, e.g., the carcinoid syndrome caused by unmetabolized overproduced serotonin, hypoglycemic syndrome in case of insulinoma, or Zollinger-Ellison syndrome accompanying gastrinoma. Diagnostics for these include ultrasound with endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography/computed tomography (PET/CT). Different nuclear medicine procedures can also be used, like somatostatin analogues scintigraphy (SRS) and 68Ga-Dota-Peptide PET/CT, as well as biochemical methods to determine the level of general neuroendocrine markers, such as chromogranin A (CgA), 5-hydroxyindolacetic acid (5-HIAA), synaptopfysin and cell type-specific peptide hormones, and neurotransmitters like gastrin, insulin, serotonin, and histamine. NENs influence the whole organism by modulating metabolism. The treatment options for neuroendocrine neoplasms include surgery, somatostatin analogue therapy, radionuclide therapy, chemotherapy, molecular targeted therapies, alpha-interferon therapy, and inhibitors of serotonin production. In the case of hypersensitivity to biogenic amines, a diet that limits the main sources of amines should be used. The symptoms are usually connected with histamine, tyramine and putrescine. Exogenic sources of histamine are products that take a long time to mature and ferment. Patients with a genetic insufficiency of the diamine oxidase enzyme (DAO), and those that take medicine belonging to the group of monoamine oxidases (MAO), are particularly susceptible to the negative effects of amines. Diet plays an important role in the initiation, promotion, and progression of cancers. As a result of the illness, the consumption of some nutrients can be reduced, leading to nutritional deficiencies and resulting in malnutrition. Changes in metabolism may lead to cachexia in some patients suffering from NENs. The aim of this narrative review was to advance the knowledge in this area, and to determine possibilities related to dietary support. The authors also paid attention to role of biogenic amines in the treatment of patients with NENs. We can use this information to better understand nutritional issues faced by patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), and to help inform the development of screening tools and clinical practice guidelines.

Feasibility and Advantages of Transanal Minimally Invasive Surgery (TAMIS) for Various Lesions in the Rectum

Purpose

We report our experience in the use of transanal minimally invasive surgery (TAMIS) and the feasibility and safety of this surgical technique in operating for various rectal diseases that require a transanal approach.

Methods

Between 2013 and 2019, 30 patients underwent TAMIS for a rectal lesion at Seoul National University Boramae Medical Center. The clinical data including age, gender, body mass index, tumour size, distance from the anal verge, diagnosis, operation time, postoperative complications, duration of hospital stay, and post-operative margin status were obtained retrospectively from the electronic medical records.

Results

The mean operation time was 52.1±33.5 and the mean duration of hospital stay after surgery was 4.3±4.2 days. Most of the patients had undergone TAMIS for neuroendocrine tumor (NET) (60%) followed by an adenoma (16.7%) and rectal cancer (13.3%). 4 patients (13.3%) had minor complications after TAMIS. 2 patients (50%) had complained of diarrhea, 1 patient (25%) complained of fecal incontinence and 1 patient (25%) been diagnosed fluid in the operation bed.

Conclusion

TAMIS is a useful method for local excision of rectal lesion located in mid to upper rectum as well as other rectal pathologies that require a transanal approach.

Surgical resection for duodenal neuroendocrine neoplasia: Outcome, prognostic factors and risk of metastases

BACKGROUND

Clinical management of duodenal neuroendocrine neoplasms (dNEN) is controversial. The aim of this study was to assess the outcome of surgical management and to identify risk factors for metastatic disease.

METHODS

Patients undergoing surgery for dNEN were retrospectively analysed. Clinicopathologic features, perioperative outcome and survival were assessed. A literature review with focus on risk factors for metastatic disease was additionally performed.

RESULTS

24 patients were identified. Out of 22 patients presenting with their primary tumour, 20 patients underwent curative resection and 18 patients received curative resection with systematic lymphadenectomy. 17 patients underwent formal oncological resection. Surgical mortality was 1 out of 24 patients. The 5-year overall survival rate was 67% in the entire cohort, 71% in patients undergoing resection for their primary tumour, 72% for patients undergoing curative resection with systematic lymphadenectomy, 75% for pN0 and 70% for pN1 tumours. Lymph node metastases were identified in 15 patients undergoing systematic lymphadenectomy, including 9 of 14 patients with tumours smaller than 2 cm, and 6 of 10 patients with G1 tumours. Literature review confirmed a high risk of metastases in small (58%) or G1 (24%) tumours. Tumour grade and angioinvasion were significantly associated with overall and disease-free survival.

CONCLUSION

Even well differentiated or small dNEN harbour a considerable risk of metastases. These data challenge the concepts of surveillance, local resection and endoscopic management for dNEN based on size and grading. Angioinvasion was identified as a strong negative predictor of overall and disease-free survival in dNEN.

[Neuroendocrine tumors : Classification, clinical presentation and imaging]

CONTEXT

Neuroendocrine tumors (NET) are a heterogeneous group of neoplasms found in all organs. They often present with characteristic clinical syndromes due to hormone hypersecretion.

DIAGNOSTICS

In addition to hormone diagnostics molecular-genetic work-up can play an important role.

IMAGING

Morphological imaging comprises ultrasound, endoscopy, computed tomography (CT) and magnetic resonance imaging (MRI) scans. Functional imaging of NET relies on radioligands that bind to specific receptors or transporters (Ga-68-DOTATATE-PET-CT, Tc-99-tektrotyd-SPECT/CT, F‑18-DOPA-PET/CT).

THERAPY

Somatostatin analogs either native or coupled to radionuclides are potent drugs for treating various neuroendocrine tumors.

CONCLUSION

The requirements of imaging are determined by clinical presentation, laboratory findings, tumor stage, the presence of a tumor syndrome and the need of a personalized systemic treatment modality.

Contemporary surgical management of the Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1

About 30% of patients with MEN1 develop a Zollinger-Ellison syndrome. Meanwhile it is well established that the causative gastrinomas are almost exclusively localized in the duodenum and not in the pancreas, MEN1 gastrinomas occur multicentric and are associated with hyperplastic gastrin cell lesions and tiny gastrin-producing micro tumors in contrast to sporadic duodenal gastrinomas. Regardless of the high prevalence of early lymphatic metastases, the survival is generally good with an aggressive course of disease in only about 20% of patients. Symptoms can be controlled medically. The indication, timing, type, and extent of surgery are highly controversial and are discussed in detail in this article by a thorough and critical review of literature. More radical procedures, like partial pancreaticoduodenectomy, are weighed against less aggressive local excision of gastrinomas and the pros and cons of both approaches are discussed in terms of long-term morbidity, biochemical cure, and survival.

Synchronous Early Gastric Cancer/Neuroendocrine Tumor Associated with Autoimmune Gastritis Completely Resected with Endoscopic Submucosal Dissection

Synchronous early gastric cancer/neuroendocrine tumor (NET) associated with autoimmune gastritis is rare, and its endoscopic and pathological features remain poorly described. Screening esophagogastroduodenoscopy performed on a 71-year-old man revealed a whitish, superficial elevated lesion and a submucosal tumor with redness that appeared slightly centrally depressed. Endoscopic submucosal dissection (ESD) allowed these lesions to be resected with negative margins, and they were diagnosed as tubular adenocarcinoma, well-differentiated type (tub1), pT1a (M) and NET G1, pT1b (SM). To our knowledge, this is the first report describing the endoscopic and pathological findings of synchronous early gastric cancer/NET that was amenable to complete resection with ESD.

Clinical characteristics of early neuroendocrine carcinoma in stomach: A case report and review of literature

INTRODUCTION

Gastric neuroendocrine carcinoma (NEC) is rare. It is considered to be aggressive and has a poor prognosis since the diagnosis is usually made at its advanced stage. However, the survival rate is increased in some early gastric NECs. This study showed a case and reviewed the clinical characteristics of early NECs in stomach.

PATIENT CONCERNS

A 38-year-old man displayed no symptoms and underwent the gastric endoscopy test for his health examination, which showed a red slightly depressed lesion 1.0 cm in size on the lesser curvature of gastric cardia. Magnifying endoscopy with narrow-band imaging (NBI) revealed a clear demarcation and an irregular mesh in vessels within the depressed area. The background mucosa was negative for atrophic gastritis and Helicobacter Pylori infection. A contrast-enhanced computed tomography (CT) scan disclosed no obvious thickening of stomach and lymphadenopathy. Blood tests and physical examination were unremarkable. He had not received any surgical treatment and denied a family history of cancer and any genetic disorders. The pathologic result of biopsy from the lesion was suspicious of superficial carcinoma. Then endoscopic submucosal dissection (ESD) was performed.

DIAGNOSIS

Gastric NEC G3 in the early stage (T1aN0M0).

INTERVENTIONS

Concerning this patient's situation, we considered the ESD as a curable treatment. And no radical surgery or adjuvant chemotherapy was arranged.

OUTCOMES

The patient is doing well and displays no recurrence for 11 months, who is still in follow-up.

LESSONS SUBSECTIONS AS PER STYLE

The early diagnosis and effective treatment by endoscopy would contribute to improve the prognosis of gastric NECs.

Safety and efficacy of over-the-scope clip-assisted full thickness resection of duodenal subepithelial tumors: A case report

BACKGROUND

Over-the-scope clip-assisted endoscopic full thickness resection (eFTR) of subepithelial tumors is a novel and promising endoscopic technique. Recently, there have been prospective studies investigating its use for colonic masses, but data regarding its use and efficacy in the duodenum are limited to a few reports.

CASE SUMMARY

A 65-year-old African American female presents for evaluation of persistent gastroesophageal reflux disease not responsive to medical treatment. A 1 cm nodule was incidentally found in the duodenum and biopsies revealed a low grade well differentiated neuroendocrine tumor. The nodule was removed using over-the-scope clip-assisted eFTR and pathology revealed clear margins. We review the available literature with a discussion on the efficacy and safety of clip-assisted eFTR s of subepithelial lesions in the duodenum.

CONCLUSION

Clip assisted eFTR appears to be a safe and efficacious treatment approach to duodenal subepithelial lesions. Further prospective studies are needed to investigate the long-term utility and safety of clip-assisted eFTR in the management of subepithelial duodenal lesions.

Analysis of risk factors of lymph node metastasis in rectal neuroendocrine neoplasms using multicenter data

Aim: This study was conducted to analyze the risk factors associated with lymph node metastasis in rectal neuroendocrine neoplasms (NENs). Materials & methods: A total of 419 patients with rectal NENs were enrolled. A univariate analysis of risk factors of lymph node metastasis was conducted using a χ2 test, and a multivariate analysis was conducted using a logistic regression analysis. Results: Univariate and multivariate regression analysis revealed that tumor size, G grade and the depth of tumor invasion were independent risk factors for lymph node metastasis (p < 0.05). Conclusion: Rectal NENs patients with a larger tumor size, deeper tumor invasion or a higher G grade had a higher risk of regional lymph node metastasis.