Endocrine Abstracts

Monitoring patients with NETs reveals a significant prevalence of gastrointestinal symptoms, often unrelated directly to the tumour¹. Exocrine pancreatic insufficiency exemplifies a common treatable cause of gastrointestinal symptoms in NET patients undergoing therapy with somatostatin analogues. There is a paucity of data regarding this important issue which affects quality of life in NETs. We explored the value of faecal elastase (FE) as a marker of exocrine pancreatic insufficiency in patients with NETs.

Methods: Thirty-nine patients with NETs (27 midgut, 5 pancreatic, 7 other) consecutively referred to a gastroenterology NET clinic, from oncology and endocrine clinics, completed standardised questionnaires regarding symptoms and quality of life (QoL) as part of clinical care: GSRS (gastrointestinal symptom rating scale) and NET QoL questionnaires (EORTC QLQ – G.I.NET21). FE was prospectively evaluated to investigate gastrointestinal symptoms. Data from questionnaires and medical records was analysed for an association between low FE (<200 ug/g) and steatorrhoea.

Results: Of 39 patients, 69% had well-differentiated low-grade (G1) tumours with the remainder intermediate (G2) or unknown grade. Median duration of disease was 69 months (range 9–265). 35/39 NETs (90%) had metastatic (stage IV) disease. 32/39 NETs had complete data, 78% (25/32) of which were established on long-acting somatostatin analogue therapy and 81% (26/32) complained of steatorrhoea. Only 6/32 patients had a low FE, four of whom complained of steatorrhoea (12.5%). 22/32 patients had steatorrhoea with a normal FE, 77% (17/22) of whom were taking regular somatostatin therapy. Sensitivity of FE in detecting steatorrhoea in NET patients was 15.4%. Less than one fifth of patients exhibiting signs of pancreatic insufficiency had an abnormal FE prior to commencing a trial of pancreatic enzyme replacement therapy.

Conclusions: There appears to be a lack of association between FE and steatorrhoea in patients with NETs. Many patients experienced steatorrhoea on somatostatin analogues despite normal FE; thus FE should not be used to evaluate pancreatic function in this group. Further studies are required to evaluate exocrine pancreatic insufficiency in patients with NETs undergoing treatment or surveillance.

¹Williams M et al, Exploring gastrointestinal symptoms in patients with neuroendocrine tumours ENETS 2016.