Endoscopic ultrasonography-related diagnostic accuracy and clinical significance on small rectal neuroendocrine neoplasms

This research aimed to examine the diagnostic accuracy and clinical significance of endoscopic ultrasonography(EUS)in the context of small rectal neuroendocrine neoplasms(NENs).A total of 108 patients with rectal subepithelial lesions(SELs)with a diameter of<20 mm were included in the analysis.The diagnosis and depth assessment of EUS was compared to the histology findings.The prevalence of NENs in rectal SELs was 78.7%(85/108).The sensitivity of EUS in detecting rectal NENs was 98.9%(84/85),while the specificity was 52.2%(12/23).Overall,the diagnostic accuracy of EUS in identifying rectal NENs was 88.9%(96/108).The overall accuracy rate for EUS in assessing the depth of invasion in rectal NENs was 92.9%(78/84).Therefore,EUS demonstrates reasonable diagnostic accuracy in detecting small rectal NENs,with good sensitivity but inferior specificity.EUS may also assist physicians in assessing the depth of invasion in small rectal NENs before endoscopic excision.

Different lymph node staging systems for predicting the prognosis of colorectal neuroendocrine neoplasms

BACKGROUND Colorectal neuroendocrine neoplasms(NENs)are a rare malignancy that primarily arises from the diffuse distribution of neuroendocrine cells in the colon and rectum.Previous studies have pointed out that the status of lymph node may be used to predict the prognosis.AIM To investigate the predictive values of lymph node ratio(LNR),positive lymph node(PLN),and log odds of PLNs(LODDS)staging systems on the prognosis of colorectal NENs treated surgically,and compare their predictive values.METHODS This cohort study included 895 patients with colorectal NENs treated surgically from the Surveillance,Epidemiology,and End Results database.The endpoint was mortality of patients with colorectal NENs treated surgically.X-tile software was utilized to identify most suitable thresholds for categorizing the LNR,PLN,and LODDS.Participants were selected in a random manner to form training and testing sets.The prognosis of surgically treating colorectal NENs was examined using multivariate cox analysis to assess the associations of LNR,PLN,and LODDS with the prognosis of colorectal NENs.C-index was used for assessing the predictive effectiveness.We conducted a subgroup analysis to explore the different lymph node staging systems’predictive values.RESULTS After adjusting all confounding factors,PLN,LNR and LODDS staging systems were linked with mortality in patients with colorectal NENs treated surgically(P<0.05).We found that LODDS staging had a higher prognostic value for patients with colorectal NENs treated surgically than PLN and LNR staging systems.Similar results were obtained in the different G staging subgroup analyses.Furthermore,the area under the receiver operating characteristic curve values for LODDS staging system remained consistently higher than those of PLN or LNR,even at the 1-,2-,3-,4-,5-and 6-year follow-up periods.CONCLUSION LNR,PLN,and LODDS were found to significantly predict the prognosis of patients with colorectal NENs treated surgically.

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE compo-nent in at least 30%of each tumour.The non-NE component can include different histological combinations of glandular,squamous,mucinous and sarcomatoid phenotypes,and one or both of the components can be low-or high grade malignant.Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion,and the lack of specific clinical trials is the main reason why their management is difficult.The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data.It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that,due to their low incidence,will require long recruitment periods.

Progress in immunotherapy for neuroendocrine neoplasm of the digestive system

Neuroendocrine neoplasms(NENs)are rare heterogeneous tumors that can develop in almost any organ,with the digestive organs,including the gastrointestinal tract and pancreas being the most commonly affected sites.Despite the fact that advances in initial therapies have progressed,there is presently no recognized effective treatment for advanced NEN.Immune checkpoint inhibitors(ICIs)have shown superior efficacy in treating several types of solid tumors.Despite their successful role in the treatment of partial NENs,such as small cell lung cancer,and Merkel cell carcinoma,the role of ICIs in most of the NENs remains limited.Nevertheless,due to their specific anti-tumor mechanisms and acceptable safety profile,ICIs are a promising avenue for further study in NENs therapy.Recent clinical trials have illustrated that combination therapy with ICI is more efficient than monotherapy,and multiple clinical trials are constantly ongoing to evaluate the efficacy and safety of these combination therapies.Therefore,the purpose of this review is to provide a comprehensive summary of the clinical progress of immunotherapy in NENs affecting the digestive system,with a specific emphasis on the application of programmed cell death protein 1/programmed death receptor ligand 1 inhibitor.Furthermore,this review has an exploration of the potential beneficiary population and the inherent value of utilizing immunotherapy in the management of NENs.

Percutaneous transhepatic intraportal biopsy using gastroscope biopsy forceps for diagnosis of a pancreatic neuroendocrine neoplasm:A case report

BACKGROUND Pancreatic neuroendocrine neoplasms(PNENs)are a rare group of neoplasms originating from the islets of the Langerhans.Portal vein tumor thrombosis has been reported in 33%of patients with PNENs.While the histopathological diagnosis of PNENs is usually based on percutaneous biopsy or endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA),these approaches may be impeded by gastric varices,poor access windows,or anatomically contiguous critical structures.Obtaining a pathological diagnosis using a gastroscope biopsy forceps via percutaneous transhepatic intravascular pathway is an innovative method that has rarely been reported.CASE SUMMARY A 72-year-old man was referred to our hospital for abdominal pain and melena.Abdominal contrast-enhanced magnetic resonance imaging revealed a wellenhanced tumor(size:2.4 cm×1.2 cm×1.2 cm)in the pancreatic tail with portal vein invasion.Traditional pathological diagnosis via EUS-FNA was not possible because of diffuse gastric varices.We performed a percutaneous transportal biopsy of the portal vein tumor thrombus using a gastroscope biopsy forceps.Histopathologic examination revealed a pancreatic neuroendocrine neoplasm(G2)with somatostatin receptors 2(+),allowing systemic treatment.CONCLUSION Intravascular biopsy using gastroscope biopsy forceps appears to be a safe and effective method for obtaining a histopathological diagnosis.Although welldesigned clinic trials are required to obtain more definitive evidence,this procedure may help improve the diagnosis of portal vein thrombosis and related diseases.

Surgical management of pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex nature and pathophysiological behaviour,surgical management continues to evolve.Surgery remains the cornerstone of treatment for most non-functional and functional pancreatic neuroendocrine tumours,while lymphadenectomy remains a controversial subject.Different techniques,such as pancreas-preserving and minimally invasive approaches,continue to evolve and offer the same overall outcomes as open surgery.This comprehensive review describes in detail the current and most up-todate classification and staging of pancreatic neuroendocrine tumours,explores the rationale for nonsurgical and surgical management,and focuses on surgical treatment and more specifically,on minimally invasive approaches.

Mixed neuroendocrine-non-neuroendocrine neoplasms of the digestive system:A mini-review

Mixed neuroendocrine-non-neuroendocrine neoplasms(MiNENs)are rare mixed tumors containing both neuroendocrine(NE)and non-NE components.Each component must occupy at least 30%of the tumor volume by definition.Recent molecular evidence suggests MiNENs are clonal neoplasms and potentially harbor targetable mutations similar to conventional carcinomas.There have been multiple changes in the nomenclature and classification of MiNENs which has created some confusion among pathologists on how to integrate the contributions of each component in a MiNEN,an issue which in turn has resulted in confusion in communication with front-line treating oncologists.This mini review summarizes our current understanding of MiNENs and outline diagnosis,prognosis,and management of these neoplasms.The authors emphasize the importance of treating the most aggressive component of the tumor regardless of its percentage volume.

Clinicopathological features and survival analysis of gastroenteropancreatic neuroendocrine neoplasms: a retrospective study in a single center of China

Objective： To investigate the clinicopathological features, survival and prognostic factors for gastroenteropancreatic neuroendocrine neoplasms（GEP-NENs） in a Chinese population.Methods： We investigated 154 consecutive patients（88 males, 66 females; median age 56 years, age range 9-86 years） diagnosed with GEP-NENs between 2001 and 2013 at The Affiliated Hospital of Qingdao University. Demographic, clinical and pathological variables and survival data were retrieved.Results： The pancreas was the most common site of involvement（63/154, 40.9%）. Tumor size varied from 0.3 to 16.0 cm（median, 1.2 cm）. The patients were followed up for a median period of 22 months（range, 1-157 months）. The estimated 3- and 5-year overall survival（OS） rates for all patients were 84.0% and 81.9%, respectively. Multivariate analysis showed that larger tumor size, lymphatic metastases and distant metastases were significant predictors for poor survival outcome.Conclusions： Our data provide further information on the clinicopathological features of GEP-NENs in China. Additionally, we identified tumor size, lymphatic metastases and distant metastases as independent prognostic factors for long-term survival.

Clinicopathological features and prognostic factors associated with gastroenteropancreatic mixed neuroendocrine non-neuroendocrine neoplasms in Chinese patients

BACKGROUND The incidence of mixed neuroendocrine-non-neuroendocrine neoplasms(MiNEN)is low.To improve our understanding of this rare tumor type and optimally guide clinical treatment,associated risk factors,clinical manifestations,and prognosis must be explored.AIM To identify risk factors that influence the prognosis of patients with gastroenteropancreatic MiNEN(GEP-MiNEN).METHODS We retrospectively analyzed the clinical data of 46 patients who were diagnosed with GEP-MiNEN at the First Affiliated Hospital of Bengbu Medical College(Anhui,China)between January 2013 and December 2017.Risk factors influencing the prognosis of the patients were assessed using Kaplan-Meier curves and cox regression models.We compared the results with 55 randomly selected patients with gastroenteropancreatic GEP neuroendocrine tumors,47 with neuroendocrine carcinomas(NEC),and 58 with poorly differentiated adenocarcinoma.RESULTS Among the 46 patients with GEP-MiNEN,thirty-five had gastric tumors,nine had intestinal tumors(four in the small intestine and five in the colon and rectum),and two had pancreatic tumors.The median age of the patients was 66(41-84)years,and the male-to-female ratio was 2.83.Thirty-three(71.7%)patients had clinical stage III and IV cancers.Distant metastasis occurred in 14 patients,of which 13 had metastasis to the liver.The follow-up period was 11-72 mo,and the median overall survival was 30 mo.Ki-67 index≥50%,high proportion of NEC,lymph node involvement,distant metastasis,and higher clinical stage were independent risk factors affecting the prognosis of patients with GEP-MiNEN.The median overall survival was shorter for patients with NEC than for those with MiNEN(14 mo vs 30 mo,P=0.001),but did not significantly differ from those with poorly differentiated adenocarcinoma and MiNEN(30 mo vs 18 mo,P=0.453).CONCLUSION A poor prognosis is associated with rare,aggressive GEP-MiNEN.Ki-67 index,tumor composition,lymph node involvement,distant metastasis,and clinical stage are important factors for patient prognosis.

Clinicopathological characteristics and prognosis of 232 patients with poorly differentiated gastric neuroendocrine neoplasms

BACKGROUND Poorly differentiated gastric neuroendocrine neoplasms(PDGNENs)include gastric neuroendocrine carcinoma(NEC)and mixed adenoneuroendocrine carcinoma,which are highly malignant and rare tumors,and their incidence has increased over the past few decades.However,the clinicopathological features and outcomes of patients with PDGNENs have not been completely elucidated.AIM To investigate the clinicopathological characteristics and prognostic factors of patients with PDGNENs.METHODS The data from seven centers in China from March 2007 to November 2019 were analyzed retrospectively.RESULTS Among the 232 patients with PDGNENs,191(82.3%)were male,with an average age of 62.83±9.11 years.One hundred and thirteen(49.34%)of 229 patients had a stage III disease and 86(37.55%)had stage IV disease.Three(1.58%)of 190 patients had no clinical symptoms,while 187(98.42%)patients presented clinical symptoms.The tumors were mainly(89.17%)solitary and located in the upper third of the stomach(cardia and fundus of stomach:115/215,53.49%).Most lesions were ulcers(157/232,67.67%),with an average diameter of 4.66±2.77 cm.In terms of tumor invasion,the majority of tumors invaded the serosa(116/198,58.58%).The median survival time of the 232 patients was 13.50 mo(7,31 mo),and the overall 1-year,3-year,and 5-year survival rates were 49%,19%,and 5%,respectively.According to univariate analysis,tumor number,tumor diameter,gastric invasion status,American Joint Committee on Cancer(AJCC)stage,and distant metastasis status were prognostic factors for patients with PDGNENs.Multivariate analysis showed that tumor number,tumor diameter,AJCC stage,and distant metastasis status were independent prognostic factors for patients with PDGNENs.CONCLUSION The overall prognosis of patients with PDGNENs is poor.The outcomes of patients with a tumor diameter>5 cm,multiple tumors,and stage IV tumors are worse than those of other patients.

New insights in diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms(GEP-NENs)are rare epithelial neoplasms derived from pluripotent endocrine cells along the gastrointestinal tract and pancreas.GEP-NENs are classified into well-differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas.Despite overlapping morphological features,GEP-NENs vary in molecular biology,epigenetic,clinical behavior,treatment response,and prognosis features and remain an unmet clinical challenge.In this review,we introduce recent updates on the histopathologic classification,including the tumor grading and staging system,molecular genetics,and systemic evaluation of the diagnosis and treatment of GEP-NENs at different anatomic sites,together with some insights into the diagnosis of challenging and unusual cases.We also discuss the application of novel therapeutic approaches for GEP-NENs,including peptide receptor radionuclide therapy,targeted therapy,and immunotherapy with immune checkpoint inhibitors.These findings will help improve patient care with precise diagnosis and individualized treatment of patients with GEP-NENs.

Advances in medical treatment for pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms(PanNENs)are rare neoplasms with strong heterogeneity that have experienced an increasing incidence rate in recent years.For patients with locally advanced or distant metastatic PanNENs,systemic treatment options vary due to the different differentiations,grades and stages.The available options for systemic therapy include somatostatin analogs,molecularly targeted agents,cytotoxic chemotherapeutic agents,immune checkpoint inhibitors,and peptide receptor radionuclide therapy.In addition,the development of novel molecularly targeted agents is currently in progress.The sequence of selection between different chemotherapy regimens has been of great interest,and resistance to chemotherapeutic agents is the major limitation in their clinical application.Novel agents and high-level clinical evidence continue to emerge in the field of antiangiogenic agents.Peptide receptor radionuclide therapy is increasingly employed for the treatment of advanced neuroendocrine tumors,and greater therapeutic efficacy may be achieved by emerging radiolabeled peptides.Since immune checkpoint inhibitor monotherapies for PanNENs appear to have limited antitumor activity,dual immune checkpoint inhibitor therapies or combinations of antiangiogenic therapies and immune checkpoint inhibitors have been applied in the clinic to improve clinical efficacy.Combining the use of a variety of agents with different mechanisms of action provides new possibilities for clinical treatments.In the future,the study of systemic therapies will continue to focus on the screening of the optimal benefit population and the selection of the best treatment sequence strategy with the aim of truly achieving individualized precise treatment of PanNENs.

Correlation between radiologic features on contrastenhanced CT and pathological tumor grades in pancreatic neuroendocrine neoplasms

Contrast-enhanced computed tomography(CT)contributes to the increasing detection of pancreatic neuroendocrine neoplasms(PNENs).Nevertheless,its value for differentiating pathological tumor grades is not well recognized.In this report,we have conducted a retrospective study on the relationship between the 2017 World Health Organization(WHO)classification and CT imaging features in 94 patients.Most of the investigated features eventually provided statistically significant indicators for discerning PNENs G3 from PNENs G1/G2,including tumor size,shape,margin,heterogeneity,intratumoral blood vessels,vascular invasion,enhancement pattern in both contrast phases,enhancement degree in both phases,tumor-to-pancreas contrast ratio in both phases,common bile duct dilatation,lymph node metastases,and liver metastases.Ill-defined tumor margin was an independent predictor for PNENs G3 with the highest area under the curve(AUC)of 0.906 in the multivariable logistic regression and receiver operating characteristic curve analysis.The portal enhancement ratio(PER)was shown the highest AUC of 0.855 in terms of quantitative features.Our data suggest that the traditional contrastenhanced CT still plays a vital role in differentiation of tumor grades and heterogeneity analysis prior to treatment.

Gastric neuroendocrine neoplasms: A review

Gastric neuroendocrine neoplasms(g-NENs)or neuroendocrine tumors are generally slow-growing tumors with increasing incidence.They arise from enterochromaffin like cells and are divided into four types according to clinical characteristic features.Type 1 and 2 are gastrin dependent,whereas type 3 and 4 are sporadic.The reason for hypergastrinemia is atrophic gastritis in type 1,and gastrin releasing tumor(gastrinoma)in type 2 g-NEN.The diagnosis of g-NENs needs histopathological investigation taken by upper gastrointestinal endoscopy.g-NENs are positively stained with chomogranin A and synaptophysin.Grading is made with mitotic index and ki-67 proliferation index on histopathological analysis.It is crucial to discriminate between types of g-NENs,because the management,treatment and prognosis differ significantly between subtypes.Treatment options for g-NENs include endoscopic resection,surgical resection with or without antrectomy,medical treatment with somatostatin analogues,netazepide or chemotherapy regimens.Follow-up without excision is another option in appropriate cases.The prognosis of type 1 and 2 g-NENs are good,whereas the prognosis of type 3 and 4 g-NENs are close to the prognosis of gastric adenocancer.

Mixed neuroendocrine–nonneuroendocrine neoplasms of the gastrointestinal system:An update

Mixed neuroendocrine-nonneuroendocrine neoplasms(Mi NENs)of the digestive tract are a rare heterogeneous group of tumors that present many challenges in terms of diagnosis and treatment.Over the years,the diagnostic criteria,classification,and clinical behavior of these tumors have been the subjects of ongoing debate,and the various changes in their nomenclature have strengthened the challenges associated with Mi NENs.This review is performed to provide an understanding of the key factors involved in the evolution of the designation of these tumors as Mi NEN,highlight the current diagnostic criteria,summarize the latest data on pathogenesis and provide information on available treatments.Moreover,this work seeks to increase the awareness about these rare neoplasms by presenting the clinicopathological features and prognostic factors that play important roles in their behavior and discussing their different regions of origin in the gastrointestinal system(GIS).Currently,the Mi NEN category also includes tumors in the GIS with a nonneuroendocrine component and epithelial tumors other than adenocarcinoma,depending on the organ of origin.Diagnosis is based on the presence of both morphological components in more than 30%of the tumor.However,this value needs to be reconfirmed with further studies and may be a limiting factor in the diagnosis of Mi NEN by biopsy.Furthermore,available clinicopathological data suggest that the inclusion of amphicrine tumors in the definition of Mi NEN is not supportive and warrants further investigation.The diagnosis of these tumors is not solely based on immunohistochemical findings.They are not hybrid tumors and both components can act independently;thus,careful grading of each component separately is required.In addition to parameters such as the metastatic state of the tumor at the time of diagnosis and the feasibility of surgical resection,the aggressive potential of both components has paramount importance in the choice of treatment.Regardless of the organ of origin within the GIS,almost Mi NENs are tumors with poor prognosis and are frequently encountered in the elderly and men.They are most frequently reported in the colorectum,where data from molecular studies indicate a monoclonal origin;however,further studies are required to provide additional support for this origin.

Endoscopic techniques for diagnosis and treatment of gastroentero-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-enteropancreatic 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-enteropancreatic 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.

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.

Liver-directed therapies for liver metastases from neuroendocrine neoplasms:Can laser ablation play any role?

Aggressive cytoreduction can prolong survival in patients with unresectable liver metastases(LM)from neuroendocrine neoplasms(NEN),and minimally invasive,liver-directed therapies are gaining increasing interest.Catheter-based treatments are used in disseminated disease,whereas ablation techniques are usually indicated when the number of LM is limited.Although radiofrequency ablation(RFA)is by far the most used ablative technique,the goal of this opinion review is to explore the potential role of laser ablation(LA)in the treatment of LM from NEN.LA uses thinner needles than RFA,and this is an advantage when the tumors are in at-risk locations.Moreover,the multi-fiber technique enables the use of one to four laser fibers at once,and each fiber provides an almost spherical thermal lesion of 12-15 mm in diameter.Such a characteristic enables to tailor the size of each thermal lesion to the size of each tumor,sparing the liver parenchyma more than any other liver-directed therapy,and allowing for repeated treatments with low risk of liver failure.A recent retrospective study reporting the largest series of LM treated with LA documents both safety and effectiveness of LA,that can play a useful role in the multimodality approach to LM from NEN.

Gastroenteropancreatic neuroendocrine neoplasms:A clinical snapshot

Our understanding about the epidemiological aspects,pathogenesis,molecular diagnosis,and targeted therapies of neuroendocrine neoplasms(NENs)have drastically advanced in the past decade.Gastroenteropancreatic(GEP)NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors.Most NENs are welldifferentiated,and slow growing.Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin,glucagon,vasoactive intestinal polypeptide,gastrin,somatostatin,adrenocorticotropin,growth hormone releasing hormone,parathyroid hormone-related peptide,serotonin,histamine,and 5-hydroxy indole acetic acid(5-HIAA).Biomarkers such as pancreatic polypeptide,human chorionic gonadotrophin subunits,neurotensin,ghrelin,and calcitonin are used in the diagnosis of non-functional NENs.5-HIAA levels correlate with tumour burden,prognosis and development of carcinoid heart disease and mesenteric fibrosis,however several diseases,medications and edible products can falsely elevate the 5-HIAA levels.Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs.Emerging novel biomarkers include circulating tumour cells,circulating tumour DNA,circulating micro-RNAs,and neuroendocrine neoplasms test(NETest)(simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood).NETest has high sensitivity(85%-98%)and specificity(93%-97%)for the detection of gastrointestinal NENs,and is useful for monitoring treatment response,recurrence,and prognosis.In terms of management,surgery,radiofrequency ablation,symptom control with medications,chemotherapy and molecular targeted therapies are all considered as options.Surgery is the mainstay of treatment,but depends on factors including age of the individual,location,stage,grade,functional status,and the heredity of the tumour(sporadic vs inherited).Medical management is helpful to alleviate the symptoms,manage inoperable lesions,suppress postoperative tumour growth,and manage recurrences.Several molecular-targeted therapies are considered second line to somatostatin analogues.This review is a clinical update on the pathophysiological aspects,diagnostic algorithm,and management of GEP NENs.

Utility of CT in differentiating liver metastases of well-differentiated gastroenteropancreatic neuroendocrine neoplasms from poorly-differentiated neuroendocrine neoplasms

Objective： To determine the capability of dynamic enhanced computed tomography（CT） to differentiate liver metastases（LMs） of well-differentiated from poorly-differentiated gastroenteropancreatic neuroendocrine neoplasms（GEP-NENs）.Methods： Patients with LMs of GEP-NENs who underwent dynamic enhanced CT examination in Peking University Cancer Hospital from January 2009 to October 2015 were included and data were retrospectively analyzed. We assessed the qualitative and quantitative CT features to identify the significant differentiating CT features of LMs of poorly-differentiated GEP-NENs from those of well-differentiated GEP-NENs using univariate analysis and a multivariate logistic regression model.Results： The study included 22 patients with LMs of well-differentiated GEP-NENs and 32 patients with LMs of poorly-differentiated GEP-NENs. Univariate analysis revealed statistically significant differences between the LMs of well-and poorly-differentiated GEP-NENs in terms of feeding arteries（36.4% vs. 75.0%, χ2=8.061,P=0.005）, intratumoral neovascularity（18.2% vs. 59.4%, χ2=9.047, P=0.003）, lymphadenopathy（27.3% vs. 81.2%,χ2=15.733, P〈0.001）, tumor-to-aortic ratio in the hepatic arterial and portal venous phase（T-A/AP： 0.297±0.080 vs.0.251±0.059, t=2.437, P=0.018; T-A/PVP： 0.639±0.138 vs. 0.529±0.117, t=3.163, P=0.003） and tumor-to-liver ratio in the hepatic arterial phase（T-L/AP： 1.108±0.267 vs. 0.907±0.240, t=2.882, P=0.006）. The LMs of poorlydifferentiated GEP-NENs showed more feeding arteries, more intratumoral neovascularity, more lymphadenopathy and a lower tumor-to-aortic ratio. Multivariate analysis suggested that intratumoral neovascularity [P=0.015, OR=0.108, 95% confidence interval（95% CI）, 0.018–0.646], lymphadenopathy（P=0.001,OR=0.055, 95% CI, 0.009–0.323） and T-A/PVP（P=0.004, OR=5.3 E–5, 95% CI, 0.000–0.044） were independent factors for differentiating LMs of poorly-differentiated from well-differentiated GEP-NENs.Conclusions： Dynamic enhanced CT features（intratumoral neovascularity, lymphadenopathy and T-A/PVP）are useful in the pathological classification of LMs of GEP-NENs.