Small and Stable Pancreatic Cysts Are Reassuring During Surveillance: Results From the PACYFIC Trial

Pancreatic cysts are increasingly discovered on imaging studies performed for unrelated conditions. Currently, surveillance of these lesions poses a substantial burden on patients, and health care recourses. We hypothesized that individuals with small and stable cysts have a diminutive risk of progressing to high-grade dysplasia (HGD) or pancreatic cancer (PC) that is similar to that in the general population.

This nested PACYFIC-study is a collaboration among 44 centers in Europe and Northern-America, and investigates the risk of HGD and PC for different cyst sizes and growth rates in participants without baseline worrisome features (WF) or high-risk stigmata (HRS).

Of the 2369 PACYFIC participants, 975 met the inclusion criteria, with a mean age of 67 years (SD 13) and 65% being female. Of these, 438 individuals (45%) had a baseline small cyst size (< 15 mm), and 885 (91%) individuals had a slow growth rate (< 2.5 mm/year). During a median follow-up of 45 months (IQR 27), 20 individuals (2.1%) developed HGD, or PC. Individuals with small cysts had a 1.5-fold lower risk of developing WF or HRS (hazard ratio [HR] 0.7 [0.5-1.0], p = 0.03) than those with larger cysts but a similar risk of developing HGD or PC (p > 0.05). Slow growth was protective against the development of WF or HRS (HR 0.4 [0.2-0.6], p < 0.001) and HGD or PC (HR 0.04 [95% CI 0.02-0.12], p < 0.001). Individuals with small, stable sized cysts without baseline WF or HRS did not have a higher risk of HGD or PC than the general population (standardized incidence ratio [SIR] 1.13 [95% CI 0.01-6.30]).

Cyst size < 15 mm and growth rate < 2.5 mm/year appear to be "reassuring" features associated with a negligible risk of developing WF or HRS and HGD or PC. For cysts with these characteristics-and without baseline WF or HRS-less intensive surveillance (than currently recommended) or even cessation may be appropriate.