Background and Aims: Risk factors for pancreatic neuroendocrine tumors (PNETs) are not well understood. The aim of this systematic review was to assess if diabetes mellitus, smoking, alcohol use, and family history of cancer are risk factors for PNETs. Methods: MEDLINE and abstracts from the European and North American Neuroendocrine Tumor Societies (ENETS and NANETS) were searched for studies published until October 2013. Eligible studies were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results: Five studies evaluating 4 individual populations were included (study accrual period 2000-2011) into the meta-analysis, involving 827 cases (range 160-309 per study) and 2,407 controls (range 233-924 per study). All studies had a case-control design and described regional series. The pooled adjusted odds ratio was 2.74 (95% CI: 1.63-4.62; p < 0.01; I² = 60.4%) for history of diabetes, 1.21 (95% CI: 0.92-1.58; p = 0.18; I² = 45.8%) for ever smoking, 1.37 (95% CI: 0.99-1.91; p = 0.06; I² = 0.0%) for heavy smoking, 1.09 (95% CI: 0.64-1.85; p = 0.75; I² = 85.2%) for ever alcohol use, 2.72 (95% CI: 1.25-5.91; p = 0.01; I² = 57.8%) for heavy alcohol use, and 2.16 (95% CI: 1.64-2.85; p < 0.01; I² = 0.0%) for first-degree family history of cancer. Conclusions: Diabetes mellitus and first-degree family history of cancer are associated with an increased risk of sporadic PNET. There was also a trend for diagnosis of sporadic PNET associated with heavy smoking. Alcohol use may be a risk factor for PNET, but there was considerable heterogeneity in the meta-analysis. These results suggest the need for a larger, homogeneous, international study for the clarification of risk factors for the occurrence of PNET.

Background In a tertiary center setting we aimed to study the diagnostic accuracy and clinical impact of EUS-guided biopsy sampling (EUS-FNB) with a reverse bevel needle compared with that of fine needle aspiration (EUS-FNA) in the work-up of subepithelial lesions (SEL). Methods All patients presenting with SELs referred for EUS-guided sampling were prospectively included in 2012-2015. After randomization of the first pass modality, dual sampling with both EUS-FNB and EUS-FNA was performed in each lesion. Outcome measures in an intention-to-diagnose analysis were the diagnostic accuracy, technical failures, and adverse events. The clinical impact was measured as the performance of additional diagnostic procedures post-EUS and the rate of unwarranted resections compared with a reference cohort of SELs sampled in the same institution 2006-2011.Results In 70 dual sampling procedures of unique lesions (size: 6-220 mm) the diagnostic sensitivity for malignancy and the overall accuracy of EUS-FNB was superior to EUS-FNA compared head-to-head (90 vs 52%, and 83 vs 49%, both p \ 0.001). The adverse event rate of EUS-FNB was low (1.

Pancreatic neuroendocrine neoplasms (PNENs) represent 10% of all pancreatic tumors by prevalence. Their incidence has reportedly increased over recent decades in parallel with that of pancreatic adenocarcinoma. PNENs are relatively rare, and of the few institutions that have published potential risk factors, findings have been heterogeneous. Our objective was to investigate the association between potential risk and protective factors for the occurrence of sporadic PNENs across a European population from several institutions. A multinational European case-control study was conducted to examine the association of selected environmental, family and medical exposure factors using a standardized questionnaire in face-to-face interviews. A ratio of 1:3 cases to controls were sex and age matched at each study site. Adjusted univariate and multivariate logistic regression analysis were performed for statistically significant factors. The following results were obtained: In 201 cases and 603 controls, non-recent onset diabetes (OR 2.09, CI 1.27-3.46) was associated with an increased occurrence of PNENs. The prevalence of non-recent onset diabetes was higher both in cases with metastatic disease (TNM stage III-IV) or advanced grade (G3) at the time of diagnosis. The use of metformin in combination with insulin was also associated with a more aggressive phenotype. Drinking coffee was more frequent in cases with localized disease at diagnosis. Our study concluded that non-recent onset diabetes was associated with an increased occurrence of PNENs and the combination of metformin and insulin was consistent with a more aggressive PNEN phenotype. In contrast to previous studies, smoking, alcohol and first-degree family history of cancer were not associated with PNEN occurrence.

Endoscopic ultrasound-guided tissue acquisition performed with a 22 gauge reverse bevel biopsy needle is safe but not superior to conventional fine-needle aspiration performed with a 25 gauge open tip needle in diagnosing solid pancreatic lesions. However, the performance of both these modalities may facilitate the diagnostic work-up in selected patients, such as cases suspicious for pancreatic neuroendocrine tumors and metastases. NCT02360839.