AUTHOR=Luo Shuaiwu , Wang Jiakun , Wu Linquan , Wang Cong , Yang Jun , Li Min , Zhang Ligan , Ge Jin , Sun Chi , Li Enliang , Lei Jun , Liao Yuting , Zhou Fan , Liao Wenjun 

TITLE=Epidemiological trends for functional pancreatic neuroendocrine tumors: A study combining multiple imputation with age adjustment

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1123642

DOI=10.3389/fendo.2023.1123642

ISSN=1664-2392

ABSTRACT=Purpose: The purpose of this study was to examine trends in the incidence and incidence-based (IB) mortality of functional pancreatic neuroendocrine tumors(F-PNETs), and to identify factors associated with survival times.
Methods: Data were obtained from the Surveillance, Epidemiology, and End Results database from 2000 to 2017. Trends in the age-adjusted incidence of F-PNETs and IB mortality were examined using the Joinpoint Regression Program. Statistical analyses were run using chi-square tests, Kaplan–Meier curves, and the Cox proportional hazards model. Multiple imputation was used to deal with missing data.
Results: A total of 142 patients with F-PNETs met the study inclusion criteria. It was found that the incidence of F-PNETs decreased over the study period, with an annual percent change (APC) of -2.5% (95% CI [-4.3, -0.5], P<0.05). This decrease was found to be significant for women, and also when limited to cases with distant disease or rare F-PNETs, with APCs of -4.2% (95% CI [-7.4, -0.9], P<0.05), -6.7% (95% CI [-10.4, -2.8], P<0.05), and -9.1% (95% CI [-13.5, -4.4], P<0.05), respectively. The Cox regression analysis revealed that the tumor size, tumor stage, tumor type, and surgical resection were associated with F-PNETs mortality. 
Conclusions: This was the first population-based epidemiological study of F-PNETs and we found a continual decrease in the incidence of F-PNETs from 2000 to 2017. The prognosis and survival times were closely related to the calendar year at diagnosis, tumor stage, and tumor size.