Pancreatic cysts: What imaging characteristics are associated with development of pancreatic ductal adenocarcinoma?

Purpose To assess relationship between pancreatic cysts (PC) and pancreatic ductal adenocarcinoma (PDAC) and to compare imaging features of PC in subjects who develop PDAC and those who do not. Material and methods This case-control IRB-approved HIPAA-compliant study included patients with PDAC (cases) and lung cancer (controls), diagnosed between 1/1/05–1/1/14. The most recent abdominal CT/MR of each patient done >6 months prior to cancer diagnosis date was reviewed by radiologist blinded to case/control status. Presence of PC, number and size of largest PC, presence of main pancreatic duct (MPD) dilatation (MPD >3 mm) were recorded. Simple PC was defined as lack of calcifications, septations and enhancement. Logistic regression models with binary outcome of PDAC were constructed. Results There were 88 cases and 273 controls with mean ages of 69.6 years (±10.3) and 69.8 years (±12.0), respectively (p = 0.864). PC were present in 21.6% (19/88) cases and in 9.2% (25/273) controls (p = 0.002). The OR of PC for development of PDAC was 2.83, adjusting for age, sex and race (p = 0.001). Mean PC size was 14.8 mm (±8.7) in cases and 7.6 mm (±8.0) in controls (p = 0.007). PC were solitary in 6 (31.6%) of 19 cases and 21 (84.0%) of 25 controls (p = 0.001). There was no significant difference in proportions of simple cysts or MPD dilatation between cases and controls. Multiple PC had 8.2 times increased odds of PDAC compared with solitary PC, adjusting for cyst size (p = 0.007). Conclusion Multiple PC are associated with 8.2 times higher odds of PDAC compared with solitary PC.