Follow-up Recommendations for Completely Resected Gastroenteropancreatic Neuroendocrine Tumors

A Novel Liver Metastasis Score for Patients Undergoing Surgical Resection of Gastroenteropancreatic Neuroendocrine Tumors: A Multi-institutional Study

BACKGROUND

Liver metastasis impacts survival in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs); however, current guidelines lack consensus on post-resection surveillance and adjuvant therapy. A comprehensive risk stratification tool is needed to guide personalized management.

OBJECTIVE

We aimed to develop and validate a predictive model for liver metastasis risk after surgical resection of GEP-NETs that incorporates pathological factors and adjuvant therapy.

METHODS

Patients with GEP-NETs who underwent surgical resection with curative intent at three major Chinese hospitals (2010-2022) were identified. Univariable and multivariable Cox regression analysis identified independent risk factors of liver metastasis. The liver metastasis score (LMS) was developed using weighted risk factors and validated by tenfold cross-validation.

RESULTS

Among the 724 patients included in the analytic cohort, liver metastasis occurred in 66 patients (9.1%) at a median of 36 months; patients with liver metastasis had a worse 5-year overall survival (no liver metastasis 63.6% vs. liver metastasis 95.8%; p < 0.001). Independent predictors were Ki-67 index (hazard ratio [HR] 10.36 for Ki-67 3-20%, HR 18.30 for Ki-67 >20%, vs. <3%), vascular invasion (HR 5.03), lymph node metastases (HR 2.24), and lack of adjuvant therapy (HR 3.03). The LMS demonstrated excellent discrimination (C-index 0.888) and stratified patients into low, intermediate, and high-risk relative to 5-year risk of liver metastasis: 2.9%, 20.8%, and 49.7%, respectively (p < 0.001).

CONCLUSIONS

The novel LMS effectively predicted the risk of liver metastasis after surgical resection of GEP-NETs. This validated model can help guide personalized surveillance and adjuvant treatment strategies, potentially improving outcomes for high-risk patients.

Management of Pancreatic Neuroendocrine Tumors: Surgical Strategies and Controversies

OBJECTIVE

Pancreatic neuroendocrine tumors (PNETs) are uncommon tumors which are increasing in incidence. The management of these tumors continues to evolve. This review examines the current role of surgery in the treatment of these tumors.

METHODS

Studies published over the past 10 years were identified using several databases including PubMed, MEDLINE, and Science Direct. Search terms included PNETs, treatment, and surgery. Clinical practice guidelines and updates from several major groups were reviewed.

RESULTS

Surgery continues to have a major role in the treatment of sporadic functional and nonfunctional PNETs. Pancreas-sparing approaches are increasingly accepted as alternatives to formal pancreatic resection in selected patients. Options such as watch and wait or endoscopic ablation may be reasonable alternatives to surgery for non-functional PNETs < 2 cm in size. Surgical decision-making in multiple endocrine neoplasia type 1 patients remains complex and in some situations such as gastrinoma quite controversial. The role of surgery has significantly diminished in patients with advanced disease due to the advent of more effective systemic and liver-directed therapies. However, the optimal treatments and sequencing in advanced disease remain poorly defined, and it has been suggested that surgery is underutilized in these patients.

CONCLUSIONS

Surgery remains a major treatment modality for PNETs. Given the plethora of available treatments, ongoing controversies and the changing landscape, management has become increasingly complex. An experienced multidisciplinary team which includes surgery is essential to manage these patients.

ASO Practice Guidelines Series: Surgical Management of Gastrointestinal (Midgut) Neuroendocrine Neoplasms

Gastrointestinal midgut neuroendocrine neoplasms (NENs) are a heterogeneous group of uncommon malignancies. For well-differentiated NENs, known as neuroendocrine tumors (NETs), surgery is a cornerstone of management in localized and metastatic disease. Because of heterogeneous tumor behaviour, association with endocrine syndrome, and prognosis, the management of NETs must be individualized to all these factors in addition to the primary site. With the fast pace of advancement in the field, both for therapies and understanding of tumoral etiology and behaviour, it is important for surgical oncologists to remain updated on guidelines recommendations and suggested treatment pathways. Those guidelines provide important guidance for management of NETs but are largely based on expert opinions and interpretation of retrospective evidence. This article reviews highlights of most recent practice guidelines for midgut (gastric, duodenal, small intestinal, and appendiceal) NETs.

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

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

Radiation Exposure from GEP NET Surveillance

BACKGROUND

Neuroendocrine tumors (NET) are neoplasms that secrete peptides and neuroamines. For gastroenteropancreatic (GEP) NET, surgical resection represents the only curative option. Ten-year imaging surveillance programs are recommended due to long time-to-recurrence following resection. We performed retrospective chart review evaluating radiation exposure and practice patterns from surveillance of completely resected GEP NET.

METHODS

We performed a retrospective cohort study of cases with well-differentiated GEP NET from January 2005 to July 2020. Location of primary, modality of imaging, and duration of follow-up were collected. Dosimetry data was collected to calculate effective dose.

RESULTS

62 cases were included with 422 surveillance scans performed. Cross-sectional imaging was used in 82% and functional imaging was used in 18% of scans. Mean number of scans per year was 1.25 (0.42-3). Mean total effective dose was 56.05 mSv (SD 45.56; 0 to 198 mSv) while mean total effective dose per year was 10.62 mSv (SD 9.35; 0 to 45 mSv). Over the recommended ten years of surveillance the estimated total effective dose was 106 mSv.

CONCLUSIONS

Surveillance of completely resected GEP NET results in cumulative radiation doses in the range associated with secondary malignancy development. Strategies to minimize radiation exposure in surveillance should be considered in future guideline development.

Outlook for 615 Small Intestinal Neuroendocrine Tumor Patients: Recurrence Risk after Surgery and Disease-Specific Survival in Advanced Disease

BACKGROUND

Small intestinal neuroendocrine tumors (siNET) are one of the most common neuroendocrine neoplasms. Radical surgery is the only curative treatment.

METHOD

We utilized a single-center study including consecutive patients diagnosed from 2000 to 2020 and followed them until death or the end of study. Disease-specific survival and recurrence-free survival (RFS) were investigated by Cox regression analyses with the inclusion of prognostic factors. Aims/primary outcomes: We identified three groups: (1) disease specific-survival in the total cohort (group1), (2) RFS and disease-specific survival after intended radical surgery (group2), (3) disease specific-survival in patients with unresectable disease or residual tumor after primary resection (group3).

RESULTS

In total, 615 patients, with a mean age (SD) 65 ± 11 years were included. Median (IQR) Ki-67 index was 4 (2-7)%. Median disease-specific survival in group1 was 130 months. Median RFS in group2 was 138 months with 5- and 10-year RFS rates of 72% and 59% with age, plasma chromogranin A (p-CgA) and Ki-67 index as prognostic factors. The ten year disease-specific survival rate in group2 was 86%. The median disease-specific survival in group3 was 85 months with age, Ki-67 index, p-CgA and primary tumor resection as prognostic factors. When proliferation was expressed by WHO grade, no difference was observed between G1 vs. G2 for any of the primary outcomes.

CONCLUSIONS

Recurrence rates remained high 5-10 years after surgery (group2) supporting long-term follow-up. Median disease-specific survival in patient with unresectable disease (group3) was 7 years, with a favorable impact of primary tumor resection. Our data does not support the current grading system since no significant prognostic information was detected in G1 vs. G2 tumors.

Recurring Pancreatic Neuroendocrine Tumor: Timing and Pattern of Recurrence and Current Treatment

OBJECTIVE

The objective of this study was to describe the pattern of recurrence, treatments received, as well the oncological outcomes, of pancreatic neuroendocrine tumors (PanNETs) following curative surgery.

BACKGROUND

PanNETs recur in 10% to 15% of cases following surgery. Information on the natural history and management of recurring disease is lacking.

MATERIALS AND METHODS

Patients with PanNET that underwent curative surgery at 4 institutions between 2000 and 2019 were identified. Patients with poorly differentiated tumors, unknown tumor grade and differentiation, hereditary syndromes, unknown margin or R2 status, metastatic, and those that had neoadjuvant treatment or perioperative mortality were excluded. Clinical variables were assessed including first site of recurrence, treatment received, and survival outcomes.

RESULTS

A total of 1402 patients were included: 957 (74%) had grade 1, 322 (25%) had grade 2, and 13 (1%) had grade 3 tumors. Median follow-up was 4.8 years (interquartile range: 2-8.2 years). Cumulative incidence of recurrence at 5 years was 13% (95% CI: 11%-15.2%) for distant disease, 1.4% (95% CI: 0.8%-2.3%) for locoregional recurrence, and 0.8% (95% CI: 0.4%-1.5%) for abdominal nodal recurrence. Patients who recurred had 2.89 increased risk of death (95% CI: 2-4.1) as compared with patients who did not recur. Therapy postrecurrence included: somatostatin analogs in 111 (61.0%), targeted therapies in 48 (26.4%), liver-directed therapies in 61 (33.5%), peptide receptor radionuclide therapy in 30 (16.5%), and surgery in 46 (25.3%) patients. Multiple treatments were used in 103 (57%) cases. After the first recurrence, 5-year overall survival was 74.6% (95% CI: 67.4%-82.5%).

CONCLUSIONS

Recurrence following surgery is infrequent but reduces survival. Most recurrences are distant and managed with multiple therapies. Prospective studies are needed to establish strategies for surveillance and the sequence of treatment to control the disease and prolong survival.

Optimal surgical approach for digestive neuroendocrine neoplasia primaries: Oncological benefits versus short and long-term complications

The rising incidence and the accumulating prevalence of neuroendocrine neoplasia (NEN) in the population makes this a common, prevalent and a clinically relevant disease group. Surgical resection represents the only potentially curative treatment for digestive NENs. Thus, resection should in principle be considered for all patients with NEN, although taking the patients age, relevant comorbidity, and performance status into account for operability. Patients with insulinomas, NEN of the appendix and rectal NENs are usually cured by surgery alone. However, less than a third of patients are amendable to curative surgery alone at time of diagnosis. Furthermore, recurrence is common and may occur years after primary surgery, hence the long follow-up time recommended in most NENs (>10 years). As many patients with NENs present with locoregional or metastatic disease, there is considerable debate regarding the role of debulking surgery in these settings. However, good long-term survival can be achieved in a considerable proportion of patients, with 50-70% alive up to 10 years after surgery. Location and grade are the main determinants of long-term survival. Here we present considerations to surgery for primary neuroendocrine tumors in the digestive tract.

SEOM-GETNE clinical guidelines for the diagnosis and treatment of gastroenteropancreatic and bronchial neuroendocrine neoplasms (NENs) (2022)

Neuroendocrine neoplasms (NENs) are a heterogeneous family of tumors of challenging diagnosis and clinical management. Their incidence and prevalence continue to rise mainly due to an improvement on diagnostic techniques and awareness. Earlier detection, along with steadfast improvements in therapy, has led to better prognosis over time for advanced gastrointestinal and pancreatic neuroendocrine tumors. The aim of this guideline is to update evidence-based recommendations for the diagnosis and treatment of gastroenteropancreatic and lung NENs. Diagnostic procedures, histological classification, and therapeutic options, including surgery, liver-directed therapy, peptide receptor radionuclide therapy, and systemic hormonal, cytotoxic or targeted therapy, are reviewed and discussed, and treatment algorithms to guide therapeutic decisions are provided.

Imaging of Small-Bowel Neuroendocrine Neoplasms: AJR Expert Panel Narrative Review

Neuroendocrine neoplasms (NENs) of the small bowel are typically slow-growing lesions that remain asymptomatic until reaching an advanced stage. Imaging modalities for lesion detection, staging, and follow-up in patients with known or suspected NEN include CT enterography, MR enterography, and PET/CT using a somatostatin receptor analog. FDG PET/CT may have a role in the evaluation of poorly differentiated NENs. Liver MRI, ideally with a hepatocyte-specific contrast agent, should be used in the evaluation of hepatic metastases. Imaging informs decisions regarding both surgical approaches and systematic therapy (specifically, peptide receptor radionuclide therapy). This AJR Expert Panel Narrative Review describes the multimodality imaging features of small-bowel NENs; explores the optimal imaging modalities for their diagnosis, staging, and follow-up; and discusses how imaging may be used to guide therapy.

Evaluating the Presence of a Stage IV Low-Grade Well-Differentiated Neuroendocrine Tumor of the Ileocecum: A Case Report with Evaluation of Staging Protocol of Neuroendocrine Tumors and Treatment Options Based on Current Available Evidence

Neuroendocrine tumors (NET) are rare neoplasms that can originate throughout the human body. An initial treatment option includes upfront surgical resection of the primary tumor (pT) if the tumor can be localized. Current systemic therapy options following resection of the pT or with evidence of metastatic disease include somatostatin analogs, evorlimus, peptide receptor radionuclide therapy, cytotoxic chemotherapy, and interferon alpha among other less common therapy options. We present a case of a patient with a NET that originated in the ileocecal region. The patient underwent upfront surgical resection with a right hemicolectomy due to the location of the tumor. The pT was notable for extensive invasion into the visceral peritoneum and metastasis to nearby lymph nodes. However, despite being diagnosed as a stage IV NET, the Ki67 index was less than 1%, categorizing it as a low-grade well-differentiated tumor. Following resection of the tumor, there was no evidence of metastasis to the liver on the follow-up magnetic resonance imaging and recurrent somatostatin receptor overexpressing neoplasm on the Gallium-68 DOTATE PET/CT scan. Due to the juxtaposition of the low grade of the tumor and the high staging, several different treatment options were discussed with the main distinction being whether to base these options off of the stage or the grade of the tumor in the case. Low-grade well-differentiated NET have a good prognosis. On the other hand, stage IV NET and tumors that have metastasized to nearby lymph nodes and organs have an increased likelihood to reoccur and worse outcomes. Recommendations for NET based on current evidence have a lack of clarity in terms of when to undergo observation versus systemic therapy.

Predicting the survival of patients with pancreatic neuroendocrine neoplasms using deep learning: A study based on Surveillance, Epidemiology, and End Results database

BACKGROUND

The study aims to evaluate the performance of three advanced machine learning algorithms and a traditional Cox proportional hazard (CoxPH) model in predicting the overall survival (OS) of patients with pancreatic neuroendocrine neoplasms (PNENs).

METHOD

The clinicopathological dataset obtained from the Surveillance, Epidemiology, and End Results database was randomly assigned to the training set and testing set at a ratio of 7:3. The concordance index (C-index) and integrated Brier score (IBS) were used to compare the predictive performance of the models. The accuracy of the model in predicting the 5-year and 10-year survival rates was compared using the receiver operating characteristic curve, decision curve analysis (DCA) and calibration curve.

RESULTS

This study included 3239 patients with PNENs in total. The DeepSurv model had the highest C-index of 0.7882 in the testing set and training set and the lowest IBS of 0.1278 in the testing set compared with the CoxPH, neural multitask logistic and random survival forest models (C-index = 0.7501, 0.7616, and 0.7612, respectively; IBS = 0.1397, 0.1418, and 0.1432, respectively). Moreover, the DeepSurv model had the highest accuracy in predicting 5- and 10-year OS rates (area under the curve: 0.87 and 0.90). DCA showed that the DeepSurv model had high potential for clinical decisions in 5- and 10-year OS models. Finally, we developed an online application based on the DeepSurv model for clinical use (https://whuh-ml-neuroendocrinetumor-app-predict-oyw5km.streamlit.app/).

CONCLUSIONS

All four models analyzed above can predict the prognosis of PNENs well, among which the DeepSurv model has the best prediction performance.

Association between surveillance imaging and survival outcomes in small bowel neuroendocrine tumors

BACKGROUND

Surveillance guidelines following the resection of small bowel neuroendocrine tumors (SB-NETs) are inconsistent. We evaluated the impact of surveillance imaging on SB-NET recurrence and overall survival (OS).

METHODS

Patients with completely resected SB-NETs referred to a provincial cancer center (2004-2015) were reviewed. Associations between imaging frequency, recurrence, post-recurrence treatment, and OS were determined using univariate and Cox-regression analyses.

RESULTS

Among 195 completely resected SB-NET patients, 31% were ≥70 years, 43% were female, and 80% had grade 1 disease. Imaging frequency was predictive of recurrence (hazard ratio 2.52, 95% confidence interval 1.84-3.46, p < 0.001). 72% underwent interventions for recurrent disease. Patients who were treated for the recurrent disease had comparable OS to those who did not recur (median 152 vs. 164 months; p = 0.25). Imaging frequency was not associated with OS in those with treated recurrent disease (p = 0.65). Patients who recurred underwent more computerized tomography (CT) scans than those who did not recur (CT: 1.47 ± 0.89 vs. 1.02 ± 0.81 scans/year, p < 0.001). Detection of disease recurrence was 5%-7% per year during the first 6 years of surveillance and peaked at 17% in Year 9.

CONCLUSION

Less frequent imaging over a longer duration should be emphasized to capture clinically relevant recurrences that can be treated to improve OS.

Role of Chromogranin A in the Diagnosis and Follow-up of Neuroendocrine Tumors: Real-World Experience

OBJECTIVE

The aim of this study was to assess the utility of serum chromogranin A (CgA) along the clinical pathway of patients with neuroendocrine tumors (NETs).

METHODS

A retrospective review of medical records was conducted of patients with NET who had at least 1 measurement of CgA between January 2015 and April 2021 at a large metropolitan Australian hospital. Chromogranin A was classified as increased or decreased if there was at least a 25% change in sequential levels and was compared with disease response by anatomical or functional imaging if within 6 weeks (considered concurrent).

RESULTS

Of 102 patients with NETs, 67 had at least 1 serum CgA level: 50 had been ordered during diagnostic workup, of which 33 were elevated (sensitivity: 66%; 95% confidence interval, 51%-79%). Of 129 CgA results concurrent with imaging, the sensitivity for detecting progressive disease was 28% (95% confidence interval, 15%-44%).

CONCLUSIONS

Our findings support previous concerns that CgA adds little value in clinical decision-making.

Survival and Incidence Patterns of Pancreatic Neuroendocrine Tumors Over the Last 2 Decades: A SEER Database Analysis

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs) are rare cancers with outcomes determined by multiple factors including grade, stage, and clinical presentation. In this study, we aimed to determine the prognosis of patients with pNETs using a large population-based database.

MATERIALS AND METHODS

In this population-based study, we identified patients with pNETs from the SEER 18 registry (2000-2016) using a combination of ICD-O-3 and histology codes. We calculated age-adjusted incidence rates using SEER*Stat 8.3.5. In addition, we analyzed overall survival (OS) using the Kaplan-Meier method, and investigated prognostic factors using a multivariable Cox proportional hazards model.

RESULTS

A total of 8944 pNETs patients were identified. Annual incidence rates increased from 0.27 to 1.00 per 100 000. This was largely explained by an increase in number of patients diagnosed with localized disease in more recent years (2012-2016). Median OS was 68 months (95% CI [64, 73]) and 5-year OS rates in localized, regional, and metastatic disease were 83%, 67%, and 28%, respectively. There was a significant improvement in OS for patients diagnosed between 2009 and 2016 (median OS 85 months) compared with those diagnosed between 2000 and 2008 (median OS 46 months) (HR 0.66; 95% CI [0.62, 0.70]). This improvement in OS was consistent across all stages.

CONCLUSIONS AND RELEVANCE

This study shows a steady increase pNETs incidence with notable stage migration to earlier stages in recent years. This increase in incidence is accompanied by a significant improvement in survival across different disease stages.

Clinical Management of Neuroendocrine Neoplasms in Clinical Practice: A Formal Consensus Exercise

Simple Summary

Well-structured international guidelines are currently available regarding the management of patients with neuroendocrine neoplasms (NENs). However, in relation to the multiplicity of treatments and the relative rarity and heterogeneity of NENs, there are many controversial issues in which clinical evidence is insufficient and for which expert opinion can be of help. A group of experts selected 14 relevant topics and formulated relative statements concerning controversial issues in several areas on diagnosis, prognosis, therapeutic strategies, and patient follow-up. Specific statements have also been formulated regarding patient management on radioligand therapy (RLT), as well as in the presence of co-morbidities or bone metastases. All the statements were drafted, discussed, modified, and then approved. The Nominal Group Technique (NGT) method was used to obtain consensus. The results of this paper can facilitate the clinical approach of patients with NENs in daily practice in areas where there is scarcity or absence of clinical evidence.

Abstract

Many treatment approaches are now available for neuroendocrine neoplasms (NENs). While several societies have issued guidelines for diagnosis and treatment of NENs, there are still areas of controversy for which there is limited guidance. Expert opinion can thus be of support where firm recommendations are lacking. A group of experts met to formulate 14 statements relative to diagnosis and treatment of NENs and presented herein. The nominal group and estimate-talk-estimate techniques were used. The statements covered a broad range of topics from tools for diagnosis to follow-up, evaluation of response, treatment efficacy, therapeutic sequence, and watchful waiting. Initial prognostic characterization should be based on clinical information as well as histopathological analysis and morphological and functional imaging. It is also crucial to optimize RLT for patients with a NEN starting from accurate characterization of the patient and disease. Follow-up should be patient/tumor tailored with a shared plan about timing and type of imaging procedures to use to avoid safety issues. It is also stressed that patient-reported outcomes should receive greater attention, and that a multidisciplinary approach should be mandatory. Due to the clinical heterogeneity and relative lack of definitive evidence for NENs, personalization of diagnostic–therapeutic work-up is crucial.

Current updates and future directions in diagnosis and management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms are a heterogenous group of rare neoplasms that are increasingly being discovered, often incidentally, throughout the gastrointestinal tract with varying degrees of activity and malignant potential. Confusing nomenclature has added to the complexity of managing these lesions. The term carcinoid tumor and embryonic classification have been replaced with gastroenteropancreatic neuroendocrine neoplasm, which includes gastrointestinal neuroendocrine and pancreatic neuroendocrine neoplasms. A comprehensive multidisciplinary approach is important for clinicians to diagnose, stage and manage these lesions. While histological diagnosis is the gold standard, recent advancements in endoscopy, conventional imaging, functional imaging, and serum biomarkers complement histology for tailoring specific treatment options. In light of developing technology, our review sets out to characterize diagnostic and therapeutic advancements for managing gastroenteropancreatic neuroendocrine tumors, including innovations in radiolabeled peptide imaging, circulating biomarkers, and endoscopic treatment approaches adapted to different locations throughout the gastrointestinal system.

Prognostic validity of the American joint committee on cancer eighth edition staging system for well-differentiated pancreatic neuroendocrine tumors

BACKGROUND

The American Joint Committee on Cancer (AJCC) made improvements for staging pancreatic neuroendocrine tumors (pNETs) in its 8th Edition; however, multicenter studies were not included.

METHODS

We collected multicenter datasets (n = 1,086, between 2004 and 2018) to validate the value of AJCC 8 and other coexisting staging systems through univariate and multivariate analysis for well-differentiated (G1/G2) pNETs.

RESULTS

Compared to other coexisting staging systems, AJCC 7 only included 12 (1.1%) patients with stage III tumors. Patients with European Neuroendocrine Tumor Society (ENETS) stage IIB disease had a higher risk of death than patients with stage IIIA (hazard ratio [HR]: 4.376 vs. 4.322). For the modified ENETS staging system, patients with stage IIB disease had a higher risk of death than patients with stage III (HR: 6.078 vs. 5.341). According to AJCC 8, the proportions of patients with stage I, II, III, and IV were 25.7%, 40.3%, 23.6%, and 10.4%, respectively. As the stage advanced, the median survival time decreased (NA, 144.7, 100.8, 72.0 months, respectively), and the risk of death increased (HR: II = 3.145, III = 5.925, and IV = 8.762).

CONCLUSION

These findings suggest that AJCC 8 had a more reasonable proportional distribution and the risk of death was better correlated with disease stage.

Discovery and Validation of Methylated DNA Markers From Pancreatic Neuroendocrine Tumors

Background and Aims

Methylated DNA markers (MDMs) accurately identify several different cancer types, but there are limited data for pancreatic neuroendocrine tumors (pNETs). We aimed to identify MDM candidates in tissue that differentiate pNETs from normal pancreas.

Methods

wUsing DNA from frozen normal pancreas (13) and pNET (51) tissues, we performed reduced representation bisulfite sequencing for MDM discovery. Validation in independent formalin fixed paraffin embedded tissues used pNET cases (67; solid = 50, cystic = 17), normal pancreas (24), and buffy coat (36) controls. Primary pNET MDM distributions were compared with lung (36), small bowel (36) NETs, and metastatic pNET (25) tissues. The discrimination accuracy was summarized as the area under the receiver operator characteristic curve (AUC) with corresponding 95% confidence intervals (CIs). Fisher's linear discriminant analysis was performed to estimate a linear discriminate score (LDS) differentiating normal from pNET tissue and applied to all patient groups; discrimination accuracy of the LDS was summarized as the bootstrap cross-validated AUC.

Results

Median AUC for distinguishing normal pancreas from pNET tissue was 0.91 (interquartile range: 0.80-0.93). The cross-validated AUC for the LDS discriminating normal pancreatic tissue from primary and metastatic pNETs was 0.957 (95% CI 0.858-1.0, P < .0001) and 0.963 (95% CI 0.865-1.0, P < .0001), respectively. The LDS for the MDM panel was significantly higher for primary pNET, metastatic pNET, lung NET, and small bowel NET, each compared with normal pancreas tissue (P < .0001). There was no statistical difference between primary pNET and metastatic pNET (P = .1947).

Conclusion

In independent tissue validation, MDMs accurately discriminate pNETs from normal pancreas. These results provide scientific rationale for exploration of these tissue MDMs in a plasma-based assay for clinical application.

Predictors of disease recurrence after curative surgery for nonfunctioning pancreatic neuroendocrine neoplasms (NF-PanNENs): a systematic review and meta-analysis

PURPOSE

Patients submitted to curative surgery for non-functioning pancreatic neuroendocrine neoplasms (NF-PanNENs) exhibit a variable risk of disease relapse. Aims of this meta-analysis were to estimate the rate of disease recurrence and to investigate the risk factors for disease relapse in patients submitted to curative surgery for NF-PanNENs.

METHODS

Medline/Pubmed and Web of Science databases were searched for relevant studies. A meta-regression analysis was performed to investigate the source of recurrence rate heterogeneity. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CI) were used to assess the effect of each possible prognostic factor on disease-free survival.

RESULTS

Fifteen studies, involving 2754 patients submitted to curative surgery for NF-PanNENs, were included. The pooled rate of disease recurrence was 21% (95% CI 15-26%). Study quality (Odds ratio, OR 0.94, P = 0.016) and G3-PanNENs rate (OR 2.18, P = 0.040) independently predicted the recurrence rate variability. Nodal metastases (HR 1.63, P < 0.001), tumor grade G2-G3 (G1 versus G2: HR 1.72, P < 0.001, G1 versus G3 HR 2.57, P < 0.001), microvascular (HR 1.25, P = 0.046) and perineural (HR 1.29, P = 0.019) invasion were identified as significant prognostic factors. T stage (T1-T2 versus T3-T4, P = 0.253) and status of resection margins (R0 versus R1, P = 0.173) did not show any significant relationship with NF-PanNENs recurrence.

CONCLUSION

Disease relapse occurs in approximately one out of five patients submitted to curative surgery for NF-PanNENs. Nodal involvement, tumor grade, microvascular and perineural invasion are relevant prognostic factors, that should be taken into account for follow-up and for possible trials investigating adjuvant or neoadjuvant treatments.

Expression Patterns and Prognostic Value of DNA Damage Repair Proteins in Resected Pancreatic Neuroendocrine Neoplasms

OBJECTIVE

This study aimed to examine the expression profiles and prognostic value of multiple DDR proteins in resected PanNENs.

BACKGROUND

DDR proteins play important roles in various cancers, including pancreatic ductal adenocarcinoma. However, the expression patterns and prognostic value of DDR proteins in PanNENs remain unclear.

METHODS

This retrospective analysis included PanNEN patients who underwent resection at the Fudan University Shanghai Cancer Center from 2012 to 2018. Immunohistochemical staining was performed for 12 DDR proteins in tissue microarrays. The associations of DDR protein expression and clinicopathological features with recurrence-free survival (RFS) were examined via a Cox regression model and random survival forest. A recurrence signature was constructed using recursive partitioning analysis.

RESULTS

In total, 131 PanNEN patients were included, with 32 (24.4%) cases of recurrence. Among the 12 DDR proteins, low checkpoint kinase 2 (CHK2) expression (P = 0.020) and loss of ataxia-telangiectasia-mutated (ATM) (P = 0.0007) significantly correlated with recurrence. Multivariable Cox regression analysis identified tumor size ≥3 cm, lymph node (LN) metastasis, high tumor grade, low CHK2 expression, and ATM loss as independent risk factors for recurrence. A recurrence signature was established based on the importance of recurrence-specific risk factors; patients with the LNnegTumorSize<3cm signature had a 5-year RFS rate of 96.8%, whereas patients with the LNposCHK2low signature had the worst 5-year RFS rate (0%). Discrimination (concordance index: 0.770) and calibration plots indicated that the recurrence signature had a good ability to identify patients at risk for recurrence.

CONCLUSIONS

By analyzing large-scale tissue microarrays of PanNENs, we evaluated 12 DDR protein expression profiles. We developed a recurrence signature that can identify distinct subpopulations according to RFS, which may help refine individual follow-up.

Prognosis of rectal neuroendocrine tumors after endoscopic resection: a single-center retrospective study

BACKGROUND

The efficacy of endoscopic resection in patients with rectal neuroendocrine tumors (NETs) which are less than 20 mm in diameter remains unclear. This study aimed to investigate the efficacy and outcomes of different types of endoscopic resection in patients with NETs.

METHODS

We performed a retrospective analysis and follow-up on 98 patients who underwent endoscopic resection for rectal NETs between August 2010 and October 2019 at Guangdong Provincial People's Hospital, China. The lesions were preoperatively classified according to their endoscopic morphology and measured by endoscopic ultrasound. Patients were divided into modified endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) groups depending on the endoscopic treatment they received. The en bloc resection rate, histopathological complete resection rate, and the complication rate of the 2 groups were evaluated after the operation. The risk factors for incomplete resection were also analyzed.

RESULTS

The average diameter of the 98 NETs was 6.29±2.90 mm (range, 2-15 mm). The en bloc resection rate of the modified EMR and ESD treatment groups was 97.2% (35/36) and 100% (62/62), respectively. The histopathological complete resection rate was 86.1% (31/36) and 87.1% (54/62), respectively. No tumor recurrence or tumor-related death occurred. There were no statistically significant differences in the rate of histopathological complete resection, perforation, or delayed hemorrhage between the 2 groups (P>0.05). Multivariate analysis demonstrated that the depth of tumor invasion (P=0.007) and tumor diameter (P<0.001) were independent risk factors for histopathological complete resection.

CONCLUSIONS

Modified EMR and ESD are safe and effective endoscopic approaches for the resection of rectal NETs ≤15 mm in diameter. Endoscopic resection requires a comprehensive preoperative evaluation of risk factors including the depth of tumor invasion and tumor diameter.

CIRSE Standards of Practice on Hepatic Transarterial Chemoembolisation

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing transarterial chemoembolisation. It has been developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It will encompass all technical details reflecting European practice of different TACE procedures (Lp-TACE, DEM-TACE, DSM-TACE, b-TACE) as well as revising the existing literature on the various clinical indications (HCC, mCRC, ICC, NET). Finally, new frontiers of development will also be discussed.

Time to give up traditional methods for the management of gastrointestinal neuroendocrine tumours

Neuroendocrine tumors (NETs) are a rare and heterogeneous disease group and constitute 0.5% of all malignancies. The annual incidence of NETs is increasing worldwide. The reason for the increase in the incidence of NETs is the detection of benign lesions, incidental detection due to the highest use of endoscopic and imaging procedures, and higher recognition rates of pathologists. There have been exciting developments regarding NET biology in recent years. Among these, first of all, somatostatin receptors and downstream pathways in neuroendocrine cells have been found to be important regulatory mechanisms for protein synthesis, hormone secretion, and proliferation. Subsequently, activation of the mammalian target of rapamycin pathway was found to be an important mechanism in angiogenesis and tumor survival and cell metabolism. Finally, the importance of proangiogenic factors (platelet-derived growth factor, vascular endothelial growth factor, fibroblastic growth factor, angiopoietin, and semaphorins) in the progression of NET has been determined. Using the combination of biomarkers and imaging methods allows early evaluation of the appropriateness of treatment and response to treatment.

Patterns and predictors of pancreatic neuroendocrine tumor prognosis: Are no two leaves alike?

Pancreatic neuroendocrine tumors (PanNETs) are heterogeneous; thus, individual prognostic prediction is important. Clinicopathological features, like TNM stage, grade, and differentiation, are independent clinical predictors. However, single predictors are insufficient, as patients sharing similar clinicopathological features usually show distinct prognoses. Accordingly, novel nomograms and risk stratifications have been developed for more accurate PanNET prognostic prediction. Moreover, the exploration of molecular mechanisms has identified novel prognostic predictors for PanNET. Multi-analyte assays of molecular biomarkers provide a deeper understanding of PanNET features; however, the priority, and the optimal combination of classic and novel predictors for PanNET prognosis prediction remain unclear. In this review, we summarized the patterns and predictors of PanNET prognosis and discussed their clinical utility; we emphasized that PanNET at different stages have different superior predictor, and that multi-analyte assays are more sensitive than mono-analyte biomarkers. Therefore, combined biomarkers improve the accuracy of surveillance and optimize decision-making in clinical practice.

Making Sense of a Complex Disease: A Practical Approach to Managing Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are a heterogeneous clinical entity with a broad range of grade, pace of disease, functional status, and primary sites. Pathologic classification, diagnostic modalities, and therapeutic options for NETs have evolved considerably in the past decade. In part driven by these advances, incidence and prevalence of NETs are rising in the United States and the practicing oncologist is likely to encounter these in the clinic. However, there are no clear lines of therapy for unresectable or metastatic NETs, and sequencing of systemic therapies depends on consideration of patient and tumor characteristics including extent of disease, grade, pace of growth, functional status, primary site, somatostatin receptor status, performance status, and comorbidities. Familiarity with ongoing clinical trials will guide therapeutic decision making as well. In this review, we seek to provide a framework to formulate and tailor an individualized treatment plan for each patient with a NET.

Nuclear Imaging of Neuroendocrine Tumors

Consensus guidelines acknowledge the role of gallium Ga-68 (⁶⁸Ga) 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic (DOTA) somatostatin receptor (SSTR) positron emission tomography/computed tomography (PET/CT) in management of neuroendocrine tumor (NET) patients. ⁶⁸Ga-DOTA-SSTR PET/CT demonstrates superior performance to conventional imaging in initial detection, staging, detection of recurrent tumor, and detection of unknown primary in known metastatic disease. ⁶⁸Ga-DOTA-SSTR PET/CT is low yield for NET detection in the setting of symptoms or elevated biomarkers when conventional imaging is negative, but may still guide management. The role of ⁶⁸Ga-DOTA-SSTR PET/CT is not established in monitoring response to systemic therapy but may identify progression through detection of new metastases.

Multifocal Small Bowel Neuroendocrine Tumours

In contemporary surgical series, the incidence of multifocal tumours (MFT) in small bowel neuroendrocrine tumours (SBNET) is as high as 50%. Familial forms of SBNET appear to have an even higher rate of MFTs in the range of 80%. Multifocal disease poses several challenges and questions for the operating surgeon, including the cause of the disease whether it is local metastases or a genetic field defect, the extent of the resection, and the prognosis. The etiology of these multiple tumours appears to be multifactorial and may represent localized metastases in some, a genetic mutation resulting in the rare familial form of this disease in others, or the integration of genetic and epigenetic events within the bowel. Contrary to historical series, recent data suggest that MFT are not associated with a poorer prognosis. The challenge remains on the long-term surveillance of these unique tumours.

Risk of Cancer-Specific Death for Patients Diagnosed With Neuroendocrine Tumors: A Population-Based Analysis

BACKGROUND

Although patients with neuroendocrine tumors (NETs) are known to have prolonged overall survival, the contribution of cancer-specific and noncancer deaths is undefined. This study examined cancer-specific and noncancer death after NET diagnosis.

METHODS

We conducted a population-based retrospective cohort study of adult patients with NETs from 2001 through 2015. Using competing risks methods, we estimated the cumulative incidence of cancer-specific and noncancer death and stratified by primary NET site and metastatic status. Subdistribution hazard models examined prognostic factors.

RESULTS

Among 8,607 included patients, median follow-up was 42 months (interquartile range, 17-82). Risk of cancer-specific death was higher than that of noncancer death, at 27.3% (95% CI, 26.3%-28.4%) and 5.6% (95% CI, 5.1%-6.1%), respectively, at 5 years. Cancer-specific deaths largely exceeded noncancer deaths in synchronous and metachronous metastatic NETs. Patterns varied by primary tumor site, with highest risks of cancer-specific death in bronchopulmonary and pancreatic NETs. For nonmetastatic gastric, small intestine, colonic, and rectal NETs, the risk of noncancer death exceeded that of cancer-specific deaths. Advancing age, higher material deprivation, and metastases were independently associated with higher hazards, and female sex and high comorbidity burden with lower hazards of cancer-specific death.

CONCLUSIONS

Among all NETs, the risk of dying of cancer was higher than that of dying of other causes. Heterogeneity exists by primary NET site. Some patients with nonmetastatic NETs are more likely to die of noncancer causes than of cancer causes. This information is important for counseling, decision-making, and design of future trials. Cancer-specific mortality should be included in outcomes when assessing treatment strategies.

Gastrointestinal Disease-Specific Survivorship Care: A New Personalized Model Integrating Onco-Wellness

Although the number of gastrointestinal (GI) cancer survivors is projected to increase in the coming years, there are currently no survivorship care models that address the specific and growing needs of this population. Current survivorship care models were evaluated to assess their suitability for GI cancer survivors. A survivorship care model based on foundational wellness principles is under development to address the specific needs of GI cancer survivors. This model delivers a cohesive and collaborative care continuum for survivors of different GI malignancies. Oncology providers in GI departments and internal medicine providers in survivorship programs are positioned to provide a comprehensive approach for the care of patients treated with curative intent. Survivorship care is introduced at the conclusion of active treatment in the form of an Onco-wellness consultation, an in-person or telemedicine comprehensive care plan creation and review by our Survivorship Program. Personalized care plan including long term and late effects of treatment, nutrition, physical activity and rehabilitation recommendations, prevention of secondary malignancies and psychosocial needs are reviewed. As patients transition from active treatment to survivorship within the GI Program, the GI Advance Practice Professionals (APPs) are well-positioned to deliver comprehensive survivorship care specific to the GI patient’s needs while integrating recommendations and principles from the Onco-wellness consultation. With projected shortages of both oncology and primary care physicians, such an APP-based model has the potential to bridge gaps in the survivorship care continuum and mutually benefit patients and physicians.

Pediatric Gastrointestinal Stromal Tumors and Neuroendocrine Tumors: Advances in Surgical Management

Gastrointestinal stromal tumors and neuroendocrine tumors in adult and pediatric populations differ immensely. Despite these established differences, the extreme rarity of gastrointestinal stromal tumors and neuroendocrine tumors in the pediatric population has resulted in the lack of consensus management guidelines, making optimal surgical approaches unclear. Comprehensive management principles to guide surgical approaches in adult literature are extensive. However, these are still lacking for pediatric patients. International cooperation to develop standardized pediatric-specific guidelines is urgently warranted in the future. This article highlights the vast differences between adult and pediatric parameters and provides recommendations on optimal and novel surgical approaches in children.

Recurrence Patterns After Surgical Resection of Gastroenteropancreatic Neuroendocrine Tumors: Analysis From the National Comprehensive Cancer Network Oncology Outcomes Database

OBJECTIVE

Current National Comprehensive Cancer Network guidelines for gastroenteropancreatic neuroendocrine tumors (GEPNETs) recommend complete (R0) surgical resection of the primary tumor and metastases, if feasible. However, large multicenter studies of recurrence patterns of GEPNETs after resection have not been performed.

METHODS

Patients 18 years or older who presented to 7 participating National Comprehensive Cancer Network institutions between 2004 and 2008 with a new diagnosis of a small bowel, pancreas, or colon/rectum neuroendocrine tumor (NET) and underwent R0 resection of the primary tumor, and synchronous metastases, if present, were included in this analysis. Descriptive statistics and Kaplan-Meier estimates were used to calculate recurrence rates and time-associated end points, respectively.

RESULTS

Of 294 patients with GEPNETs, 50% were male, 88% were White, and 99% had Eastern Cooperative Oncology Group performance status 0 to 1. The median age was 55 years (range, 20-90). The median follow-up time from R0 resection was 62.1 months. Recurrence rates were 18% in small bowel NETs (n = 110), 26% in pancreatic NETs (n = 141), and 10% in colon/rectum NETs (n = 50). The frequency of surveillance imaging was highly variable.

CONCLUSIONS

R0 resection was associated with variable risk of recurrence across subtypes. Further research to inform refinement of guidelines for the appropriate duration of surveillance after R0 resection is needed.

Diagnosis and Treatment of Primary Tumors of the Appendix: a Critical Review

INTRODUCTION

The aim of the current paper was to critically collect, select and summarize the evidence regarding diagnosis, treatment and follow up of primary tumors of the appendix.

METHODS

A literature review was performed by search and review of the scientific studies pertaining to the subject of our inquiry.

RESULTS

Recommendations regarding pimary tumors of the appendix were formulated on the basis of the collected evidence. CONCLUSION : Primary tumors of the appendix are rare and a high index of suspicion is required not to miss a potentially life threatening medical condition.

Tumour grade and primary site predict patterns of recurrence and survival in patients with resected gastroenteropancreatic neuroendocrine tumors

BACKGROUND

Patterns of recurrence help to inform surveillance of patients with resected gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

Patients with GEP-NETs in British Columbia, Canada (2004-2015) were reviewed. Associations between tumor characteristics, recurrence and survival were analyzed.

RESULTS

Among 759 patients, 41%, 25%, and 17% had grade 1, 2, and 3 disease, respectively. 387 patients had R0/R1 resections, of which 30% recurred (median 25 months). 5-year incidence of recurrence was 22% (grade 1), 46% (grade 2), and 59% (grade 3) (p < 0.001). Grade predicted distant recurrence (Grade 2 HR 1.89, 95% CI 1.16-3.07; p = 0.011; Grade 3 HR 3.29, 95% CI 1.81-5.99; p < 0.001). Compared to small bowel NETs, pancreas NETs had less peritoneal recurrence (OR 0.15, 95% CI 0.03-0.68, p = 0.014). No patients had isolated pulmonary recurrences.

CONCLUSION

Higher grade tumors and pancreatic NETs require more frequent surveillance. Evidence is limited for pulmonary surveillance.

VIPoma: a rare cause of diarrhea. A case report

Introduction: Vasoactive intestinal peptide-secreting tumor (VIPoma) is a rare functional pancreatic neuroendocrine tumor (F-PNET) characterized by secretory diarrhea, hypokalemia, and hypochlorhydria. Its low incidence and high risk of malignancy pose a clinical challenge that requires a high degree of clinical suspicion. Case presentation: A 61-year-old woman visited the emergency department of a tertiary care hospital in Medellín, Colombia, due to chronic diarrhea (7 months) that led to dehydration, renal failure, metabolic acidosis, and hypokalemia. As a result, a treatment based on loperamide, intravenous fluids and broad-spectrum antibiotics was started. In addition, chromogranin A levels of 477 ug/L (<100) were reported, while an abdominal MRI showed a 33x30mm mass in the head and uncinate process of the pancreas, so outpatient surgical management was decided. However, three days after discharge, and due to the persistence of clinical signs, the patient was admitted to another hospital (also a tertiary care hospital), where, given the high suspicion of VIPoma, and once the diarrhea was solved, the mass was removed (Whipple procedure) without any complication. Finally, the diagnosis was confirmed based on serum vasoactive intestinal peptide levels (930 pg/mL (RV<75)) and the pathology report (PNET tumor grade 2). Two years after the surgery, the patient was asymptomatic, and no residual lesions or metastases were evident in a control MRI. Conclusion: Late diagnosis of VIPoma is associated with worsened quality of life, severe complications, and high prevalence of metastasis. Therefore, it should be suspected in patients with chronic secretory diarrhea that is not caused by an infection, since early diagnosis and timely treatment can contribute to achieving better survival rates in these patients.

Incidence, survival and stage at diagnosis of small intestinal neuroendocrine tumours in Queensland, Australia, 2001-2015

AIM

Multiple studies have observed increasing incidence of small intestinal (SI) neuroendocrine tumours (NETs). The aim of this study was to describe incidence, mortality and survival of SI NETs by sub-site and stage at diagnosis.

METHODS

Data on patients diagnosed with SI NETs between 2001 and 2015 were sourced from the Queensland Oncology Repository. Staging algorithms utilising several data sources were used to calculate stage at diagnosis (localised, regional or metastatic disease).

RESULTS

We identified 778 SI NETs and of those 716 (92%) had either a documented or derived stage. Incidence doubled from 0.68 per 100 000 to 1.42 per 100 000 over the 15-year period. Most common site was ileum (49.1%) and 84.2% were of carcinoid morphology type. Stage at diagnosis was calculated for 91.7% of patients with 28.3% presenting with regional involvement and 23.9% with distant metastasis. Risk factors associated with metastatic disease were jejunal and SI site not otherwise specified, neuroendocrine carcinoma histology and residing in a rural area. Increasing incidence of localised disease and a corresponding reduction in metastatic disease was observed over time. Five-year cause-specific survival for patients diagnosed between 2001 and 2005 was 82.5%, increasing to 93.8% from 2011 to 2015. Survival was lowest for those with metastatic disease (74.2%). Survival increased between 2001 to 2005 and 2011 to 2015 for each disease stage.

CONCLUSIONS

SI NET incidence in Queensland doubled between 2001 and 2015. Survival was high and improved over time.

The clinical characteristics and survival associations of pancreatic neuroendocrine tumors: does age matter?

Background

Pancreatic neuroendocrine tumor (pNET) is the second most common epithelial neoplasm of the pancreas. As in pancreatic adenocarcinoma (PDAC), patients with different onset ages display different clinical features and prognosis. We grouped pNET patients into the early-onset pNET (EOpNET) and typical age-at-onset pNET (TOpNET) to investigate the effect of onset age on their clinical characteristics and prognosis.

Methods

Data were collected retrospectively from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2015; cohort 1) and the Fudan University Shanghai Cancer Center (FUSCC) (2005-2018; cohort 2). The clinical characteristics were compared using chi-squared tests. Cox proportional hazards regression was used to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs), and overall survival was formulated by Kaplan-Meier curves.

Results

In total, data from 5,368 and 330 patients were included from the SEER database and the FUSCC, respectively. Gender did not affect survival in the EOpNET group. Tumors located in the tail (HR: 0.721, 95% CI: 0.63-0.83, P<0.001) and body (HR: 0.712, 95% CI: 0.60-0.85, P=0.001) had a lower risk of death compared to tumors in the head of the pancreas in the TOpNET group. The overall survival of the EOpNET group {136 [3-143] months} was better than the TOpNET group {85 [3-143] months} (P<0.001) in the SEER database. Results from the FUSCC group were similar to the SEER cohort.

Conclusions

The EOpNET group had significantly better overall survival than the TOpNET group, and early surgical resection is encouraged for all pNET patients. In any future personalized treatment of pNET, the patient's onset age should be considered as an important factor in guiding treatment and prognosis.

Practical recommendations for the management of patients with gastroenteropancreatic and thoracic (carcinoid) neuroendocrine neoplasms in the COVID-19 era

Neuroendocrine neoplasms (NENs) are a heterogeneous family of uncommon tumours with challenging diagnosis, clinical management and unique needs that almost always requires a multidisciplinary approach. In the absence of guidance from the scientific literature, along with the rapidly changing data available on the effect of COVID-19, we report how 12 high-volume NEN centres of expertise in 10 countries at different stages of the evolving COVID-19 global pandemic along with members of international neuroendocrine cancer patient societies have suggested to preserve high standards of care for patients with NENs. We review the multidisciplinary management of neuroendocrine neoplasms during the COVID-19 pandemic, and we suggest potential strategies to reduce risk and aid multidisciplinary treatment decision-making. By sharing our joint experiences, we aim to generate recommendations for proceeding to other institutions facing the same challenges.

Metastatic insulinoma presenting 14 years after benign tumour resection: a rare case and management dilemma

SUMMARY

We present a 60-year-old woman who underwent successful surgical resection (partial pancreatectomy) for a low grade non-functioning pancreatic neuroendocrine tumour (pNET), with no biochemical or radiological features of recurrence on follow-up visits for 5 years. Fourteen years after the initial surgery, she developed spontaneous severe hypoglycaemic episodes which required hospitalisation, with subsequent investigations confirming the diagnosis of a metastatic insulin-secreting pNET (insulinoma). Medical management of her severe spontaneous hypoglycaemic episodes remained challenging, despite optimum use of diazoxide and somatostatin analogue therapy. Based on a discussion at the regional neuroendocrine tumour multidisciplinary team meeting, she underwent an elective hepatic trans-arterial embolization which was unfortunately unsuccessful. She ended up requiring an emergency right hemihepatectomy and left retroperitoneal mass resection which finally stabilised her clinical condition.

LEARNING POINTS

Ours is only the seventh case report of a previously benign pNET presenting as a functional insulin secreting metastatic tumour. However, it is the first case report, in which the metastatic functional pNET presented after such a long hiatus (14 years). There is currently no clear consensus regarding the length of follow-up of non-functional pNET which are deemed cured post-surgical resection, with most guidelines advocating a median follow up of 5 years (1). The delayed presentation in our case suggests additional considerations should be made regarding optimal post-operative surveillance duration based on the age of the patient, location of the tumour, lymph node spread and Ki-67 index. Hepatic artery embolization and/or partial hepatectomy remains a treatment option for pNET patients with significant hepatic metastasis.

Clinical and Molecular Risk Factors for Recurrence Following Radical Surgery of Well-Differentiated Pancreatic Neuroendocrine Tumors

Well-differentiated pancreatic neuroendocrine tumors are increasingly diagnosed neoplasms. For localized disease, surgery is the first-line therapy and is curative in most cases. However, although recurrence is a rare event, it can still occur up to 10 years from surgery, worsening the prognosis. Many clinical and pathological factors have been associated with recurrence; however, it is currently unclear how to accurately discern patients at risk for relapse of disease from those that should be considered cured. In this review, we focus on clinical, pathological, and molecular factors associated with recurrence and discuss available prediction tools to assess the risk of recurrence following surgery.

Routine Early 68Ga-DOTATATE Positron Emission Tomography Has Low Yield After Resection of Appendiceal Neuroendocrine Neoplasms

OBJECTIVES

Appendiceal neuroendocrine neoplasms (appNEN) generally carry a low recurrence risk. Ga-DOTATATE positron emission tomography (DOTA PET) is increasingly used as it is more sensitive than cross-sectional imaging. We hypothesize that early DOTA PET is unlikely to detect recurrent disease in patients with low-risk resected appNEN because of the delayed pattern of recurrence.

METHODS

Retrospective study (dual review) of patients undergoing DOTA PET 0 to 18 months after resected appNEN. The primary outcome was the proportion of scans demonstrating residual disease.

RESULTS

Forty-one patients were included (median age, 29 years; 63% female), most with small, low-grade appNEN. No scans (0%) showed residual/distant disease. Eight (20%) of 41 scans showed indeterminate findings requiring follow-up. Five (12%) scans were recommended for follow-up with modalities other than DOTA PET (vertebra, 3; thyroid; bone, 1 each). Three (7%) were recommended for follow-up with DOTA PET (all with indeterminate abdominal uptake). These 3 patients had no recurrent disease on follow-up.

CONCLUSIONS

The Ga-DOTATATE PET is of no value when performed in the first 18 months after resected appNEN. Although 20% of scans showed indeterminate findings, more than half did not require repeat DOTA PET. Despite advantages over cross-sectional imaging, DOTA PET is not recommended in staging after completely resected appNEN.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Medical Management of Pancreatic Neuroendocrine Tumors

This article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Extent of Lymph Node Dissection for Small Bowel Neuroendocrine Tumors

The management of nodal disease remains controversial for small bowel neuroendocrine tumors (SB-NETs). Debates remain regarding the therapeutic role and extent of routine lymph node dissection (LND) for localized SB-NETs, as well as the need for aggressive resection of advanced loco-regional SB-NETs with mesenteric nodal masses. This review will address these questions regarding lymph node dissection for well-differentiated WHO grade 1 and 2 SB-NETs. In general, the aggressiveness and radicality of resection should be balanced against the length of bowel resected and post-operative functional outcomes. In localized SB-NETs with clinically negative lymph nodes, a nodal harvest of ≥ 8 lymph nodes provides accurate staging, but has not been shown to confer survival benefit. For loco-regional SB-NETs with clinically positive lymph nodes identified on imaging, 4 stages of nodal extent have been described: stage 1 nodes are located near to the intestinal border, stage 2 on arterial branches close to the origin of the SMA, stage 3 along the SMA itself, and stage 4 extend in the retroperitoneum under the pancreatic neck. In SB-NETs, every attempt should be made at resection of the primary tumor and the nodal mesenteric mass for curative-intent management and to prevent debilitating complications from mesenteric fibrosis. A mesenteric-sparing approach is favored to allow for resection for complex proximal nodal masses while preserving intestinal length and function. All patients with SB-NETs with nodal mesenteric mass should be assessed by a surgeon for resection; if deemed unresectable, consideration should be given to assessment in high-volume NETs centres to confirm proximal mesenteric-sparing resection is not feasible.

Commonwealth Neuroendocrine Tumour Research Collaboration and the North American Neuroendocrine Tumor Society Guidelines for the Diagnosis and Management of Patients With Lung Neuroendocrine Tumors: An International Collaborative Endorsement and Update of the 2015 European Neuroendocrine Tumor Society Expert Consensus Guidelines

Lung neuroendocrine tumors (LNETs) are uncommon cancers, and there is a paucity of randomized evidence to guide practice. As a result, current guidelines from different neuroendocrine tumor societies vary considerably. There is a need to update and harmonize global consensus guidelines. This article reports the best practice guidelines produced by a collaboration between the Commonwealth Neuroendocrine Tumour Research Collaboration and the North American Neuroendocrine Tumor Society. We performed a formal endorsement and updating process of the 2015 European Neuroendocrine Tumor Society expert consensus article on LNET. A systematic review from January 2013 to October 2017 was conducted to procure the most recent evidence. The stepwise endorsement process involved experts from all major subspecialties, patients, and advocates. Guided by discussion of the most recent evidence, each statement from the European Neuroendocrine Tumor Society was either endorsed, modified, or removed. New consensus statements were added if appropriate. The search yielded 1109 new publications, of which 230 met the inclusion criteria. A total of 12 statements were endorsed, 22 statements were modified or updated, one was removed, and two were added. Critical answered questions for each topic in LNET were identified. Through the consensus process, guidelines for the management of patients with local and metastatic neuroendocrine tumors have been updated to include both recent evidence and practice changes relating to technological and definitional advances. The guidelines provide clear, evidence-based statements aimed at harmonizing the global approach to patients with LNETs, on the basis of the principles of person-centered and LNET-specific care. The importance of LNET-directed research and person-centered care throughout the diagnosis, treatment, and follow-up journey is emphasized along with directions for future collaborative research.

Pancreatic neuroendocrine tumors: A review of serum biomarkers, staging, and management

Pancreatic neuroendocrine tumors (pNETs) are a heterogeneous group of tumors with complicated treatment options that depend on pathological grading, clinical staging, and presence of symptoms related to hormonal secretion. With regard to diagnosis, remarkable advances have been made: Chromogranin A is recommended as a general marker for pNETs. But other new biomarker modalities, like circulating tumor cells, multiple transcript analysis, microRNA profile, and cytokines, should be clarified in future investigations before clinical application. Therefore, the currently available serum biomarkers are insufficient for diagnosis, but reasonably acceptable in evaluating the prognosis of and response to treatments during follow-up of pNETs. Surgical resection is still the only curative therapeutic option for localized pNETs. However, a debulking operation has also been proven to be effective for controlling the disease. As for drug therapy, steroids and somatostatin analogues are the first-line therapy for those with positive expression of somatostatin receptor, while everolimus and sunitinib represent important progress for the treatment of patients with advanced pNETs. Great progress has been achieved in the combination of systematic therapy with local control treatments. The optimal timing of local control intervention, planning of sequential therapies, and implementation of multidisciplinary care remain pending.