Prevalence and natural course of MRI-diagnosed dilated main pancreatic duct: A longitudinal, population-based prospective cohort study with a ten-year follow-up.

BACKGROUND

Pancreatic main duct dilation (PMDD) may indicate an increased risk of developing pancreatic cancer. Little is known about the prevalence and natural course of PMDD in the general population. Therefore, this study aimed to analyse PMDD using magnet resonance imaging (MRI).

METHODS

Longitudinal MRI combined with magnetic resonance cholangiopancreatography was performed between 2008 and 2021 as part of the prospective population-based Study of Health in Pomerania (SHIP), with 2,2 ± 0,6 MRI per participant on average performed within an average of 10,8 ± 1,2 yrs. PMDD was defined as ≥ 5 mm, and was correlated with clinical and epidemiological data.

RESULTS

The prevalence of PMDD was 81/2985 individuals (2.7%). The mean age of these was 55.1 ± 13.2 yrs. Cumulative 5 yr-incidence of newly developed PMDD was 1.1% (22/1935) and 3.0% (15/496) after 10 yrs. Poisson regression analysis revealed strong associated factors of PMDD: active smoking (PR 2.93), diabetes (PR 2.58) and frequent alcohol abuse (PR 1.78) After a median follow-up period of 4.5 years, pancreatic cancer and chronic pancreatitis were diagnosed more frequently in the PMDD group: 2/81 (2.5%) vs. 24/2904 (0.8%) and 8/81 (9.9%) vs. 46/2904 (1.6%). Pancreatic cancer-specific survival was lower in cases of PMDD (HR = 4.96 (95% CI 1.31-18.84)).

CONCLUSION

A PMDD ≥5 mm is a frequent incidental MRI finding in the general population (2.7%). The risk of malignant transformation was higher with PMDD (2.5%) than without (0.8%). Chronic pancreatitis was diagnosed four times as often than pancreatic cancer in follow-up.