Introduction: Pancreatic ductal adenocarcinoma (PDAC) remains a lethal disease, characterized by late-stage diagnoses and low survival rates. Individuals who are considered high-risk for pancreatic cancer based on family history or genetic predisposition may benefit from surveillance for earlier detection of PDAC and subsequent improved survival rates. This study aimed to address a challenge in surveillance: the burden of pancreatic cysts detected and limited evidence regarding the risk of potential neoplastic progression.
Methods: We analyzed a prospective cohort of patients identified as high-risk for development of PDAC enrolled in a surveillance program at a tertiary academic medical center from 2003-2018. Patients underwent imaging surveillance with magnetic resonance imaging, computed tomography, and/or endoscopic ultrasound.
Results: Of 259 individuals at high-risk for pancreatic cancer, 53 (20.5%) had pancreatic cysts on baseline imaging, of whom 15 (5.8%) had cysts measuring ≥3 cm. Of patients with normal baseline pancreatic imaging, the majority did not develop cysts and did not experience progression. Of the remaining 197 individuals with normal pancreatic imaging at baseline, 77 (39.1%) were found to have pancreatic cysts while on surveillance. Upon follow-up in this subset, solid masses were detected in 5 patients (2.5%) and mural nodules in 1 (0.5%); incidence of cysts ≥3 cm was 0.5% over an average follow-up period of 5.5 years. There were no reported instances of cyst wall thickening or enhancement on follow-up. A dilated main pancreatic duct was observed in 11 of these 197 patients (5.6%), and cyst growth of ≥4 mm over a 12-month period occurred in 7 cases (3.6%). Neoplastic radiologic progression was noted in 32 (16.2%). Of patients who developed solid masses, none were associated with malignant transformation of pancreatic cysts.
Discussion: A sizeable proportion of patients at high-risk for PDAC have pancreas cysts at baseline evaluation and over a long-term surveillance period. Overall, there was low prevalence of worrisome features on baseline pancreatic imaging in these patients. Notably, of cases that developed adenocarcinomas, none were associated with malignant transformation of pancreatic cysts. However, neoplastic radiologic progression underscores the need for continuous and rigorous monitoring in this population.
Conclusion: There is a considerable prevalence of pancreatic cysts both at baseline and during long-term surveillance in the population at high-risk for development of PDAC. A low initial prevalence, but significant radiologic progression, in these patients emphasizes the need for continuous surveillance and the determination of optimal surveillance strategies.

Grace Gallagher

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