GLP-1 receptor expression in pancreatic neuroendocrine tumours: implications for the use of GLP-1 receptor agonists — ASN Events
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  3. GLP-1 receptor expression in pancreatic neuroendocrine tumours: implications for the use of GLP-1 receptor agonists

GLP-1 receptor expression in pancreatic neuroendocrine tumours: implications for the use of GLP-1 receptor agonists (#315)

Monica Majumder 1 2 , Mervyn Kyi 3 4 5 , Spiros Fourlanos 3 4 5 , Angeline JJ Shen 3 4 6 , Cherie Chiang 3 4 6 , Michael Michael 7 , Nirupa Sachithanandan 1 4 6 , Emma Boehm 8 9
  1. Department of Diabetes and Endocrinology, St Vincent’s Hospital, Melbourne , Victoria, Australia
  2. Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
  3. Department of Diabetes and Endocrinology, Royal Melbourne Hospital , Melbourne, Victoria, Australia
  4. Department of Medicine, The University of Melbourne, Melbourne , Victoria, Australia
  5. Australian Centre for Accelerating Diabetes Innovations, The University of Melbourne, Melbourne, Victoria, Australia
  6. Department of Internal Medicine, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
  7. Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
  8. Department of Molecular Imaging and Therapeutic Nuclear Medicine, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  9. Department of Clinical Pathology, Collaborative Centre for Genomic Cancer Medicine, University of Melbourne, Melbourne, Victoria, Australia

Objective: Glucagon-like peptide 1 receptors (GLP-1R) are expressed in a wide variety of neuroendocrine tumours (NETs) including insulinoma. The use of GLP-1 receptor agonists (GLP-1RA) is becoming ubiquitous for management of diabetes and obesity. We describe a series of patients in whom GLP-1RAs unmasked hypoglycaemia leading to insulinoma diagnosis.

Methods and Results: We report on three cases where GLP-1RA use precipitated new hypoglycaemia leading to the diagnosis of NET.  All three cases had evidence of a GLP-1R expressing pancreatic NET on a 68Gallium Exendin-4 positron emission tomography/computed tomography (PET/CT) scan including two patients with tissue-proven insulinoma (figure 1). We also report a fourth case of GLP-1RA use in a patient with known metastatic pancreatic NET who experienced improvement of post-prandial dumping syndrome symptoms however notably there was no localised expression of GLP-1R on 68Gallium Exendin-4 PET/CT.

Conclusions: Expression of GLP-1R in NET is well established. However, the impact of GLP-1RAs on NET growth and hormone secretory function in this group is not well characterised. Based on these case reports and literature review, we hypothesise that GLP-1RAs may potentiate clinical features associated with insulinoma pathophysiology. The potential impact of GLP-1RA on tumour behaviour should be considered when prescribing GLP-1RAs in patients with NET.