Predictors Based on the Radiologic Characteristics for Aggressiveness of Small (< 20 mm) Nonfunctioning Pancreatic Neuroendocrine Tumors.

Background and objectives: To find the association between preoperative computed tomography (CT) features combined with tumor marker and known high-risk factors of small nonfunctioning pancreatic neuroendocrine tumors (NF-PNETS), thereby selecting appropriate treatment strategy for these patients.

Method: One hundred fourteen patients with NF-PNETs< 20 mm who underwent surgical operation were retrospectively analyzed from 2009 to 2023. Univariate and multivariable logistic regression analyses were performed to find the relationship between preoperative clinical psychological and CT features and high-risk factors. The overall survival (OS) rates with and without high-risk factors were compared.

Results: Of 114 patients, 29(25%) had at least one of these high-risk factors. Main pancreatic duct dilation (OR, 3.315; 95% CI, 1.079-10.184; p = 0.036), irregular tumor margin (OR, 2.955; 95% CI, 1.021-8.551; p = 0.046), positive tumor marker (OR, 6.047; 95% CI, 1.408-25.963; p = 0.015) were associated with increased odds of having any of these high-risk factors. The time to death differed significantly between patients with and without high-risk factors. Patients combining with high-risk factors were associated with lower 3- and 5-year OS (100% vs. 81.8%, 93.1% vs. 81.8%, respectively; p = 0.035 for both).

Conclusion: Main pancreatic duct dilation, irregular tumor margin and positive tumor marker could screen a subset of patients recommended for surgery.