Gastric Neuroendocrine Tumors (G-Nets): Incidence, Prognosis and Recent Trend Toward Improved Survival

Background/Aims: Gastric neuroendocrine tumors (G-NETs) are uncommon neoplasms that can present with or without clinical symptoms. In this study, we evaluated the incidence, prognosis, and temporal trends of G-NETs. Methods: We analyzed all cases of G-NETs registered in the Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2014. Incidence was estimated by age and joinpoint analyses. Survival rates were calculated and survival trends over time were evaluated. Results: A total of 3740 eligible patients were enrolled in the study. G-NETs incidence increased from 0.31 per 1 000 000 patients in 1975 to 4.85 in 2014, with an annual percentage changes (APCs) of 8.9% (95% confidence interval [CI] = 7.7% to 10.21%, P < 0.001, t test (29) from 1975 to 2001 and 3.6% from 2002 to 2014 (95% CI= 2.3% to 4.9%, P < 0.001). For cases diagnosed between 1973 and 1982, five-year survival was 62.8% ± 7.0% (Standard error, SE) and increased to 86.7% ± 0.7% for cases diagnosed between 2003 and 2012 (P < 0.001). Years of diagnosis, gender, age at diagnosis, marital status, grade, tumor size, tumor stage, and surgery performed or not were the strongest predictors of worse survival in both univariate and multivariate analysis (P