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Purpose: Type I gastric neuroendocrine neoplasms (g-NENs) have a low risk of metastasis and a generally favourable prognosis. Patients with small type I g-NENs (≤10 mm) frequently require no treatment, whereas those with larger polyps usually undergo resection. We evaluated the safety and outcomes of endoscopic surveillance after no initial treatment in selected patients with type I g-NENs., Methods: Retrospective analysis of type I g-NEN patients across two European Neuroendocrine Tumour Society Centers of Excellence 2003-2019., Results: Following initial assessment, 87 of 115 patients with type I g-NEN (75 with polyps ≤10 mm) received no initial treatment and underwent endoscopic surveillance. 79/87 (91%) demonstrated no clinically meaningful change in tumour size or grade over a median 62 month follow up. Only two patients developed NEN progression that required a change in management and two other patients developed gastric adenocarcinoma/high grade dysplasia; all four initially had ≥11 mm g-NENs., Conclusions: Patients with ≤10 mm type I g-NENs were unlikely to develop clinically significant tumour progression and in most cases, resection was not needed. The endoscopic surveillance interval could therefore potentially be safely increased to every 2-3 years in such patients. However, lifelong surveillance is still advocated due to the additional risk of developing gastric adenocarcinoma., (© 2022. The Author(s).)

Purpose of Review: Gastric neuroendocrine neoplasms (g-NENs) are a rare type of stomach cancer. The three main subtypes have different pathogeneses, biological behaviours and clinical characteristics, so they require different management strategies. This article will provide an overview of g-NENs and highlight recent advances in the field., Recent Findings: Molecular profiling has revealed differences between indolent and aggressive g-NENs, as well as a new somatic mutation responsible for some familial type I g-NENs. Novel biomarkers have been developed which will hopefully improve diagnosis, treatment, risk stratification and follow-up. Patient treatment is also changing, as evidence supports the use of less aggressive options (e.g. endoscopic surveillance or resection) in some patients with more indolent tumours. g-NEN heterogeneity poses challenges in understanding and managing this rare disease. More basic science research is needed to investigate molecular pathogenesis, and future larger clinical studies will hopefully also further improve treatment and patient outcomes., (© 2022. The Author(s).)

Objectives: Individuals from hereditary pancreatitis (HP) and familial pancreatic cancer (FPC) kindreds are at increased risk of developing pancreatic cancer. Premalignant molecular changes may be detected in pancreatic juice collected by endoscopic retrograde cholangiopancreatography (ERCP). The objective was to determine the risk of post-ERCP pancreatitis (PEP)., Methods: A prospective study (1999-2013) was undertaken of 80 ERCPs (24 in HP and 56 in FPC) from 60 individuals and the impact of PEP prophylaxis using a self-expelling pancreatic stent and 50 mg diclofenac per rectum from 2008., Results: There was no PEP in the HP cohort and 13 (23.2%) PEP from 56 procedures in the FPC cohort (P = 0.0077). Up to 2008 PEP had occurred in 7 (43.8%) of 16 procedures in FPC individuals versus none of 18 procedures in HP individuals (P = 0.0021). After the introduction of prophylaxis, the incidence of PEP fell to 6 (15.0%) of 40 procedures in FPC individuals (P = 0.0347).The odds ratio (95% confidence interval) was 0.23 (0.06-0.84) in favor of prophylaxis (0.035)., Conclusions: Individuals with HP are at minimal risk for PEP. Although the risk of PEP in individuals with FPC can be reduced by using prophylactic self-expelling stents and diclofenac, it remains too high for routine screening.

There are multiple PRSS1 mutations described in hereditary pancreatitis but only a minority of these are clinically relevant. The two most frequent point mutations are in exon 2 (N29I) and exon3 (R122H), found in diverse racial populations. Both mutations result in early onset pancreatitis but the mechanism underlying this phenotype is unclear. The frequency of these mutations in such diverse populations suggests they have spontaneously occurred many times. The origin of the major mutations may be explained by gene conversions, accounting for multiple founders. The implications are discussed in terms of mechanism of action of the mutations and clinical presentation.

Hereditary pancreatitis is an autosomal dominant disease with incomplete penetrance (80%), accounting for approximately 1% of all cases of pancreatitis. It is characterized by the onset of recurrent attacks of acute pancreatitis in childhood and frequent progression to chronic pancreatitis. Whitcomb et al. identified the cationic trypsinogen gene (PRSS1) on chromosome 7q35 as the site of the mutation that causes hereditary pancreatitis. The European registry of hereditary pancreatitis and familial pancreatic cancer (EUROPAC) aims to identify and make provisions for those affected by hereditary pancreatitis and familial pancreatic cancer. The most common mutations in hereditary pancreatitis are R122H, N29I and A16V but many families have been described with clinically defined hereditary pancreatitis where there is no PRSS1 mutation. It is known that the cumulative lifetime risk (to age 70 years) of pancreatic cancer is 40% in individuals with hereditary pancreatitis. This subset of individuals form an ideal group for the development of a screening programme aimed at detecting pancreatic cancer at an early stage in an attempt to improve the presently poor long-term survival. Current screening strategies involve multimodality imaging (computed tomography, endoluminal ultrasound) and endoscopic retrograde cholangiopancreatography for pancreatic juice collection followed by molecular analysis of the DNA extracted from the juice. The potential benefit of screening (curative resection) must be balanced against the associated morbidity and mortality of surgery. Philosophically, the individual's best interest must be sought in light of the latest advances in medicine and science following discussions with a multidisciplinary team in specialist pancreatic centres.