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 9265). 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.
05 Dec 2016
UK and Ireland Neuroendocrine Tumour Society