Retrospective study on mixed neuroendocrine non-neuroendocrine neoplasms from five European centres

BACKGROUND Mixed neuroendocrine non-neuroendocrine neoplasm(MiNEN)is a rare diagnosis,mainly encountered in the gastro-entero-pancreatic tract.There is limited knowledge of its epidemiology,prognosis and biology,and the best management for affected patients is still to be defined.AIM To investigate clinical-pathological characteristics,treatment modalities and survival outcomes of a retrospective cohort of patients with a diagnosis of MiNEN.METHODS Consecutive patients with a histologically proven diagnosis of MiNEN were identified at 5 European centres.Patient data were retrospectively collected from medical records.Pathological samples were reviewed to ascertain compliance with the 2017 World Health Organisation definition of MiNEN.Tumour responses to systemic treatment were assessed according to the Response Evaluation Criteria in Solid Tumours 1.1.Kaplan-Meier analysis was applied to estimate survival outcomes.Associations between clinical-pathological characteristics and survival outcomes were explored using Log-rank test for equality of survivors functions(univariate)and Cox-regression analysis(multivariable).RESULTS Sixty-nine consecutive patients identified;Median age at diagnosis:64 years.Males:63.8%.Localised disease(curable):53.6%.Commonest sites of origin:colon-rectum(43.5%)and oesophagus/oesophagogastric junction(15.9%).The neuroendocrine component was;predominant in 58.6%,poorly differentiated in 86.3%,and large cell in 81.25%,of cases analysed.Most distant metastases analysed(73.4%)were occupied only by a poorly differentiated neuroendocrine component.Ninety-four percent of patients with localised disease underwent curative surgery;53%also received perioperative treatment,most often in line with protocols for adenocarcinomas from the same sites of origin.Chemotherapy was offered to most patients(68.1%)with advanced disease,and followed protocols for pure neuroendocrine carcinomas or adenocarcinomas in equal proportion.In localised cases,median recurrence free survival(RFS);14.0 months(95%CI:9.2-24.4),and median overall survival(OS):28.6 months(95%CI:18.3-41.1).On univariate analysis,receipt of perioperative treatment(vs surgery alone)did not improve RFS(P=0.375),or OS(P=0.240).In advanced cases,median progression free survival(PFS);5.6 months(95%CI:4.4-7.4),and median OS;9.0 months(95%CI:5.2-13.4).On univariate analysis,receipt of palliative active treatment(vs best supportive care)prolonged PFS and OS(both,P<0.001).CONCLUSION MiNEN is most commonly driven by a poorly differentiated neuroendocrine component,and has poor prognosis.Advances in its biological understanding are needed to identify effective treatments and improve patient outcomes.

Recent trends in the treatment of well-differentiated endocrine carcinoma of the small bowel

Well-differentiated endocrine carcinomas of the small bowel are fairly rare neoplasms that present many clinical challenges. They secrete peptides and neuroamines that may cause carcinoid syndrome. However, many are clinically silent until late presentation with major effects. Initial treatment aims to control carcinoid syndrome with somatostatin analogs. Even if there is metastatic spread, surgical resection of the primitive tumor should be discussed in cases of retractile mesenteritis, small bowel ischemia or subocclusive syndrome in order to avoid any acute complication, in particular at the beginning of somatostatin analog treatment. The choice of treatment depends on the symptoms, general health of the patient, tumor burden, degree of uptake of radionuclide, histological features of the tumor, and tumor growth. Management strategies include surgery for cure (which is rarely achieved) or for cytoreduction, radiological interventions (transarterial embolization or radiofrequency ablation), and chemotherapy (interferon and somatostatin analogs). New biological agent and radionuclide targeted therapies are under investigation. Diffuse and non-evolving lesions should also be simplymonitored. Finally, it has to be emphasized that it is of the utmost importance to enroll these patients with a rare disease in prospective clinical trials assessing new therapeutic strategies.

Differential diagnosis of diarrhoea in patients with neuroendocrine tumours: A systematic review

BACKGROUND Approximately 20%of patients with neuroendocrine tumours(NETs)develop carcinoid syndrome(CS),characterised by flushing and diarrhoea.Somatostatin analogues or telotristat can be used to control symptoms of CS through inhibition of serotonin secretion.Although CS is often the cause of diarrhoea among patients with gastroenteropancreatic NETs(GEP-NETs),other causes to consider include pancreatic enzyme insufficiency(PEI),bile acid malabsorption and small intestinal bacterial overgrowth.If other causes of diarrhoea unrelated to serotonin secretion are mistaken for CS diarrhoea,these treatments may be ineffective against the diarrhoea,risking detrimental effects to patient quality of life.AIM To identify and synthesise qualitative and quantitative evidence relating to the differential diagnosis of diarrhoea in patients with GEP-NETs.METHODS Electronic databases(MEDLINE,Embase and the Cochrane Library)were searched from inception to September 12,2018 using terms for NETs and diarrhoea.Congresses,systematic literature review bibliographies and included articles were also hand-searched.Any study designs and publication types were eligible for inclusion if relevant data on a cause(s)of diarrhoea in patients with GEP-NETs were reported.Studies were screened by two independent reviewers at abstract and full-text stages.Framework synthesis was adapted to synthesise quantitative and qualitative data.The definition of qualitative data was expanded to include all textual data in any section of relevant publications.RESULTS Forty-seven publications(44 studies)were included,comprising a variety of publication types,including observational studies,reviews,guidelines,case reports,interventional studies,and opinion pieces.Most reported on PEI on/after treatment with somatostatin analogs;9.5%-84%of patients with GEP-NETs had experienced steatorrhoea or confirmed PEI.Where reported,14.3%–50.7%of patients received pancreatic enzyme replacement therapy.Other causes of diarrhoea reported in patients with GEP-NETs included bile acid malabsorption(80%),small intestinal bacterial overgrowth(23.6%-62%),colitis(20%)and infection(7.1%).Diagnostic approaches included faecal elastase,breath tests,tauroselcholic(selenium-75)acid(SeHCAT)scan and stool culture,although evidence on the effectiveness or diagnostic accuracy of these approaches was limited.Assessment of patient history or diarrhoea characteristics was also reported as initial approaches for investigation.From the identified evidence,if diarrhoea is assumed to be CS diarrhoea,consequences include uncontrolled diarrhoea,malnutrition,and perceived ineffectiveness of CS treatment.Approaches for facilitating differential diagnosis of diarrhoea include improving patient and clinician awareness of non-CS causes and involvement of a multidisciplinary clinical team,including gastroenterologists.CONCLUSION Diarrhoea in GEP-NETs can be multifactorial with misdiagnosis leading to delayed patient recovery and inefficient resource use.This systematic literature review highlights gaps for further research on prevalence of non-CS diarrhoea and suitability of diagnostic approaches,to determine an effective algorithm for differential diagnosis of GEP-NET diarrhoea.