A Systematic Review of Intra-pancreatic Fat Deposition and Pancreatic Carcinogenesis

Abstract

BackgroundExcess adiposity is considered causally related to pancreatic cancer. While most knowledge on the topic comes from studies on general and visceral adiposity, the role of intra-pancreatic fat deposition in pancreatic carcinogenesis just begins to be elucidated. The aim was to conduct a comprehensive systematic review of clinical studies on intra-pancreatic fat deposition in individuals with pancreatic cancer or pre-malignant lesions. MethodsA literature search was conducted independently by two reviewers using three electronic databases. Studies were included if they reported on intra-pancreatic fat deposition determined based on modern radiology or histology. Summary estimates were presented as pooled prevalence or relative risk and 95% confidence interval. ResultsA total of 13 studies (encompassing 2178 individuals) were included. The pooled prevalence of intra-pancreatic fat deposition in individuals with pancreatic cancer or pre-malignant lesions was 52% (95% confidence interval, 38–66%). The presence of pancreatic cancer or pre-malignant lesions was associated with a significantly increased risk of intra-pancreatic fat deposition (relative risk 2.78 (95% confidence interval, 1.56–4.94, p < 0.001). ConclusionIndividuals with pancreatic cancer or pre-malignant lesions are characterized by increased intra-pancreatic fat deposition. There are sound grounds for conceptually viewing intra-pancreatic fat deposition as a combination of fat accumulation in the pancreas (due to expansion of excess visceral fat) and fatty replacement of the pancreas (due to changes in cellular identity within the pancreas). Guidelines on reporting intra-pancreatic fat deposition need to be developed with a view to informing a comprehensive and standardized characterization of this clinical entity in future studies.