Comparative outcomes of pancreatic neuroendocrine neoplasms: A population-based analysis of the SEER database

Background: A paucity of data exists regarding the natural history and survival outcomes of pancreatic neuroendocrine neoplasms (PanNENs), a rare histological subtype which can be classified as functional (F-PanNENs) and non-functional (NF-PanNENs). The purpose of this study is to characterize their clinicopathological features and survival outcomes in a large cohort of patients from United States. Methods: All patients diagnosed with F-PanNENs or NF-PanNENs between 1998 and 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Patient demographic, clinicopathological features and survival outcomes were analyzed. Logistic regression analysis was used to identify factors associated with NF-PanNENs diagnosis over F-PanNENs. Cox regression analysis was utilized to determine the prognostic variables for overall survival (OS) in all PanNENs patients. Results: A total of 2347 patients were identified: 1181 in the F-PanNENs group and 1206 in the NFPanNENs group. NF-PanNENs were larger in size, poorly differentiated, more commonly found in a head pancreas location, and had increased lymph node positivity and liver involvement compared to FPanNENs. Patients with F-PanNENs were associated better survival outcomes than those with NFPanNENs. Diagnosis at early year, poorer differentiation, and larger tumor size were independently correlated with NF-PanNENs diagnosis. In addition, multivariable analysis determined that age, gender, year of diagnosis, marital status, tumor grade, size, stage, number, and surgical treatment were independent prognostic factors for OS of all PanNENs patients. Conclusion: The clinicopathological characteristics and survival outcomes were significantly different between NF-PanNENs and F-PanNENs. Furthermore, we identified the clinical features correlated with NF-PanNENs diagnosis over F-PanNENs.