Endoscopic surveillance alone is feasible and safe in type I gastric neuroendocrine neoplasms less than 10 mm in diameter.

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.

New Developments in Gastric Neuroendocrine Neoplasms.

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.

Incidence of post-ERCP pancreatitis from direct pancreatic juice collection in hereditary pancreatitis and familial pancreatic cancer before and after the introduction of prophylactic pancreatic stents and rectal diclofenac.

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.

Trypsinogen mutations in pancreatic disorders.

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.