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.

a b s t r a c tTranscription factor NF-E2 p45-related factor 2 (Nrf2, also called Nfe2l2), a master regulator of redox homeostasis, and its dominant negative regulator, Kelch-like ECH-associated protein 1 (Keap1), together tightly control the expression of numerous detoxifying and antioxidant genes. Nrf2 and the 'antioxidant response element' (ARE)-driven genes it controls are frequently upregulated in pancreatic cancer and correlate with poor survival. Upregulation of Nrf2 is, at least in part, K-Ras oncogene-driven and contributes to pancreatic cancer proliferation and chemoresistance. In this review, we aim to provide an overview of Keap1-Nrf2 signalling as it relates to pancreatic cancer, discussing the effects of inhibiting Nrf2 or Nrf2/ARE effector proteins to increase chemosensitivity.

Inhibition of kynurenine 3-monooxygenase (KMO) protects against multiple organ dysfunction (MODS) in experimental acute pancreatitis (AP). We aimed to precisely define the kynurenine pathway activation in relation to AP and AP-MODS in humans, by carrying out a prospective observational study of all persons presenting with a potential diagnosis of AP for 90 days. We sampled peripheral venous blood at 0, 3, 6, 12, 24, 48, 72 and 168 hours post-recruitment. We measured tryptophan metabolite concentrations and analysed these in the context of clinical data and disease severity indices, cytokine profiles and C-reactive protein (CRP) concentrations. 79 individuals were recruited (median age: 59.6 years; 47 males, 59.5%). 57 met the revised Atlanta definition of AP: 25 had mild, 23 moderate, and 9 severe AP. Plasma 3-hydroxykynurenine concentrations correlated with contemporaneous APACHE II scores (R2 = 0.273; Spearman rho = 0.581; P < 0.001) and CRP (R2 = 0.132; Spearman rho = 0.455, P < 0.001). Temporal profiling showed early tryptophan depletion and contemporaneous 3-hydroxykynurenine elevation. Furthermore, plasma concentrations of 3-hydroxykynurenine paralleled systemic inflammation and AP severity. These findings support the rationale for investigating early intervention with a KMO inhibitor, with the aim of reducing the incidence and severity of AP-associated organ dysfunction.