Marked Expansion of Exocrine and Endocrine Pancreas With Incretin Therapy in Humans With Increased Exocrine Pancreas Dysplasia and the Potential for Glucagon-Producing Neuroendocrine Tumors

TLDR

Incretin therapy’s effects on the pancreas are debated, with potential β‑cell regeneration versus proliferative harm. In patients with type 2 diabetes receiving incretin therapy, pancreatic mass rose by ~40 %, accompanied by heightened exocrine proliferation and dysplasia, α‑cell hyperplasia, glucagon‑producing microadenomas, and a neuroendocrine tumor, while β‑cell mass was reduced overall but increased sixfold in treated subjects, indicating marked expansion of both exocrine and endocrine compartments with tumorigenic potential.

Abstract

Controversy exists regarding the potential regenerative influences of incretin therapy on pancreatic β-cells versus possible adverse pancreatic proliferative effects. Examination of pancreata from age-matched organ donors with type 2 diabetes mellitus (DM) treated by incretin therapy (n = 8) or other therapy (n = 12) and nondiabetic control subjects (n = 14) reveals an ∼40% increased pancreatic mass in DM treated with incretin therapy, with both increased exocrine cell proliferation (P < 0.0001) and dysplasia (increased pancreatic intraepithelial neoplasia, P < 0.01). Pancreata in DM treated with incretin therapy were notable for α-cell hyperplasia and glucagon-expressing microadenomas (3 of 8) and a neuroendocrine tumor. β-Cell mass was reduced by ∼60% in those with DM, yet a sixfold increase was observed in incretin-treated subjects, although DM persisted. Endocrine cells costaining for insulin and glucagon were increased in DM compared with non-DM control subjects (P < 0.05) and markedly further increased by incretin therapy (P < 0.05). In conclusion, incretin therapy in humans resulted in a marked expansion of the exocrine and endocrine pancreatic compartments, the former being accompanied by increased proliferation and dysplasia and the latter by α-cell hyperplasia with the potential for evolution into neuroendocrine tumors.