P-P10 The survival benefit of pancreatic enzyme replacement therapy in adult patients undergoing treatment of pancreatic neuroendocrine tumours

Background Patients with pancreatic neuroendocrine tumours (pNETs), treated with somatostatin analogues (SSAs) or pancreaticoduodenectomy, are at risk of exocrine pancreatic insufficiency. This is frequently undiagnosed but can be treated with pancreatic enzyme replacement therapy (PERT). PERT improves survival and nutritional status in other exocrine pancreatic insufficiency-associated conditions such as pancreatic adenocarcinoma. This single-centre retrospective cohort study aimed to establish whether PERT increases survival or weight maintenance in SSA or pancreaticoduodenectomy-treated patients with pNETs. Methods Departmental databases identified patients (n = 82) diagnosed with pNETs between 2009 and 2019 and managed with SSAs and/or pancreaticoduodenectomy. Their baseline characteristics, treatments and outcomes were established from clinical records. Cases (n = 47) received PERT 3 months after either pancreaticoduodenectomy or commencement of SSAs, controls (n = 35) did not. Overall survival was analysed using the Kaplan-Meier method, the log-rank test and multivariable Cox regression. Percentage monthly weight changes were compared using the Mann-Witney U test. The cohort was investigated as a whole and stratified by intervention (pancreaticoduodenectomy or SSAs) as more cases having undergone pancreaticoduodenectomy was a potential confounder. Results Median survival was not reached in either group. Cases experienced significantly greater 5-year overall survival (81% vs 53%, p = 0.010), however, PERT was not independently associated with survival (Hazard ratio 0.47, 95% CI 0.17-1.30, p = 0.143). Cases showed superior median weight maintenance (+0.04% vs -0.10% per month, p = 0.013), but had lower mean baseline weights (70.0kg vs 81.9kg, p = 0.003). Considering SSA-treated patients (n = 55) only, cases (n = 27) showed greater median weight maintenance (+0.04% vs -0.21% per month, p = 0.025) and a trend towards improved median overall survival (55.5, 95% CI 10.3-100.7 vs 47.7, 95% CI 19.1-76.4 months, p = 0.054). Conclusions PERT may improve the maintenance of weight and therefore nutrition in patients with pNETs, treated with SSAs or pancreaticoduodenectomy. PERT may also convey a survival benefit in this same population, however, due to the numerous factors which affect survival, this study appears underpowered to reliably explore this outcome. Further studies are required to accurately define the use and benefits of PERT in this population.

Updated Principles of Surgical Management of Pancreatic Neuroendocrine Tumours (pNETs): What Every Surgeon Needs to Know

Pancreatic neuroendocrine tumours (pNETs) represent 1 to 2% of all pancreatic neoplasm with an increasing incidence. They have a varied clinical, biological and radiological presentation, depending on whether they are sporadic or genetic in origin, whether they are functional or non-functional, and whether there is a single or multiple lesions. These pNETs are often diagnosed at an advanced stage with locoregional lymph nodes invasion or distant metastases. In most cases, the gold standard curative treatment is surgical resection of the pancreatic tumour, but the postoperative complications and functional consequences are not negligible. Thus, these patients should be managed in specialised high-volume centres with multidisciplinary discussion involving surgeons, oncologists, radiologists and pathologists. Innovative managements such as “watch and wait” strategies, parenchymal sparing surgery and minimally invasive approach are emerging. The correct use of all these therapeutic options requires a good selection of patients but also a constant update of knowledge. The aim of this work is to update the surgical management of pNETs and to highlight key elements in view of the recent literature.

Genome analysis identifies differences in the transcriptional targets of duodenal versus pancreatic neuroendocrine tumours

ObjectiveGastroenteropancreatic neuroendocrine tumours (GEP-NETs) encompass a diverse group of neoplasms that vary in their secretory products and in their location within the gastrointestinal tract. Their prevalence in the USA is increasing among all adult age groups.AimTo identify the possible derivation of GEP-NETs using genome-wide analyses to distinguish small intestinal neuroendocrine tumours, specifically duodenal gastrinomas (DGASTs), from pancreatic neuroendocrine tumours.DesignWhole exome sequencing and RNA-sequencing were performed on surgically resected GEP-NETs (discovery cohort). RNA transcript profiles available in the Gene Expression Omnibus were analysed using R integrated software (validation cohort). Digital spatial profiling (DSP) was used to analyse paraffin-embedded GEP-NETs. Human duodenal organoids were treated with 5 or 10 ng/mL of tumor necrosis factor alpha (TNFα) prior to qPCR and western blot analysis of neuroendocrine cell specification genes.ResultsBoth the discovery and validation cohorts of small intestinal neuroendocrine tumours induced expression of mesenchymal and calcium signalling pathways coincident with a decrease in intestine-specific genes. In particular, calcium-related, smooth muscle and cytoskeletal genes increased in DGASTs, but did not correlate with MEN1 mutation status. Interleukin 17 (IL-17) and tumor necrosis factor alpha (TNFα) signalling pathways were elevated in the DGAST RNA-sequencing. However, DSP analysis confirmed a paucity of immune cells in DGASTs compared with the adjacent tumour-associated Brunner’s glands. Immunofluorescent analysis showed production of these proinflammatory cytokines and phosphorylated signal transducer and activator of transcription 3 (pSTAT3) by the tumours and stroma. Human duodenal organoids treated with TNFα induced neuroendocrine tumour genes, SYP, CHGA and NKX6.3.ConclusionsStromal–epithelial interactions induce proinflammatory cytokines that promote Brunner’s gland reprogramming.

Mesenteric Variceal Haemorrhage and Ectopic Cushing’s Syndrome as Presenting Features of a Pancreatic Neuroendocrine Tumour Recurrence

Pancreatic neuroendocrine tumours can have varied and complex presentations. Whilst hormone hypersecretion often induces characteristic clinical syndromes, non-specific symptoms may arise due to localized tumour effects. Malignant invasion of local vasculature is an increasingly recognized complication of these neoplasms and can be associated with significant morbidity. Herein, we present the case of a 47-year-old male with a recurrence of a pancreatic neuroendocrine tumour who presented with unusual upper gastrointestinal bleeding. The tumour had recurred within the superior mesenteric vein, replacing the vessel and invading its branches. This resulted in porto-mesenteric hypertension and the formation of bleeding mesenteric varices. The patient subsequently developed progressive metabolic disturbances and was diagnosed with ectopic Cushing’s syndrome, despite his primary tumour having been non-functional. This case demonstrates not only a rare pattern of tumour recurrence but also the potential for pancreatic neuroendocrine tumours to de-differentiate and change from non-functional to hormone secreting, a phenomenon which may complicate diagnosis and management.

Streptozocin/5-fluorouracil chemotherapy of pancreatic neuroendocrine tumours in the era of targeted therapy

Purpose The role of streptozocin-based chemotherapy (STZ CTx) in advanced, well-differentiated pancreatic neuroendocrine tumours (PanNET) and the best sequence of treatments in advanced PanNET are unclear. We examined the outcomes after STZ CTx in patients who had been selected according to the current therapeutic guidelines. Methods Data from 50 PanNET patients consecutively treated with STZ CTx between 2010 and 2018 were analysed. The endpoints of the study were the objective-response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results STZ CTx was the first-line treatment in 54% of patients. The PanNET grades were as follows: 6% G1, 88% G2, and 6% well-differentiated G3. The ORR was 38%. Stable disease was the best response in 38% of patients and 24% showed progressive disease. Treatment was discontinued because of toxicity in one patient. Median PFS and OS were 12 (95% confidence interval (CI), 8.5–15.5) and 38 months (95% CI, 20.4–55.6), respectively. In the Kaplan-Meier analysis, the median OS was 89 months (95% CI, 34.9–143.1) for STZ CTx as first-line therapy compared with 22 months (95% CI, 19.3–24.7; p = 0.001, log-rank test) for subsequent lines. Bone metastases negatively impacted survival (HR, 2.71, p = 0.009, univariate analysis, HR, 2.64, p = 0.015, multivariate analysis, and Cox regression). Conclusions In patients selected according to current guidelines, PFS, and OS after STZ CTx were lower than previously reported, whereas ORR was unchanged. First-line treatment was positively associated with OS and the presence of bone metastases was negatively associated with OS. Pre-treatment with targeted or peptide-receptor radionuclide therapy did not alter ORR, PFS, or OS.

Initiating pancreatic neuroendocrine tumour (pNET) screening in young MEN1 patients: results from the DutchMEN Study Group

Context Non-functioning pancreatic neuroendocrine tumours (NF-pNETs) are highly prevalent and constitute an important cause of mortality in patients with multiple endocrine neoplasia type 1 (MEN1). Still, the optimal age to initiate screening for pNETs is under debate. Objective To assess the age of occurrence of clinically relevant NF-pNETs in young MEN1 patients. Patients and setting Pancreatic imaging data of MEN1 patients were retrieved from the DutchMEN Study Group database. Design Interval-censored survival methods were used to describe age-related penetrance, compare survival curves, and develop a parametric model for estimating the risk of having clinically relevant NF-pNET at various ages. Intervention(s) Not applicable. Main outcome measure(s) The primary objective was to assess age at occurrence of clinically relevant NF-pNET (size ≥20 mm or rapid growth); secondary objectives were the age at occurrence of NF-pNET of any size and pNET-associated metastasized disease. Results Five of 350 patients developed clinically relevant NF-pNETs before age 18, two of which subsequently developed lymph node metastases. No differences in clinically relevant NF-pNET-free survival were found for sex, timeframe, and type of MEN1 diagnosis or genotype. The estimated ages (median, 95% CI) at a 1%, 2.5% and 5% risk of having developed a clinically relevant tumour are 9.5 (6.5 – 12.7), 13.5 (10.2 – 16.9) and 17.8 years (14.3 – 21.4) respectively. Conclusion Analyses from this population-based cohort indicate that start of surveillance for NF-pNETs with pancreatic imaging at age 13–14 is justified. The psychological and medical burden of screening at a young age should be considered.

Long-term morbidity and mortality in patients diagnosed with an insulinoma

Objective: Insulinomas are rare functional pancreatic neuroendocrine tumours. As previous data on the long-term prognosis of insulinoma patients are scarce, we studied the morbidity and mortality in the Finnish insulinoma cohort. Design: Retrospective cohort study Methods: Incidence of endocrine, cardiovascular, gastrointestinal and psychiatric disorders, and cancers was compared in all the patients diagnosed with an insulinoma in Finland during 1980–2010 (n=79, including two patients with multiple endocrine neoplasia type 1 syndrome), vs. 316 matched controls, using the Mantel-Haenszel method. Overall survival was analysed with Kaplan-Meier and Cox regression analyses. Results: The median length of follow-up was 10.7 years for the patients and 12.2 years for the controls. The long-term incidence of atrial fibrillation [rate ratio, RR 2.07 (95% CI 1.02–4.22)], intestinal obstruction [18.65 (2.09–166.86)], and possibly breast [4.46 (1.29–15.39)] and kidney cancers (RR not applicable) was increased among insulinoma patients vs. controls, p<0.05 for all comparisons. Endocrine disorders and pancreatic diseases were more frequent in the patients during the first year after insulinoma diagnosis, but not later on. The survival of patients with a non-metastatic insulinoma (n=70) was similar to that of controls, but for patients with distant metastases (n=9), the survival was significantly impaired (median 3.4 years). Conclusions: The long-term prognosis of patients with a non-metastatic insulinoma is similar to the general population, except for an increased incidence of atrial fibrillation, intestinal obstruction, and possibly breast and kidney cancers. These results need to be confirmed in future studies. Metastatic insulinomas entail a markedly decreased survival.