Survival and Incidence of Gastric Neuroendocrine Tumors: A Surveillance, Epidemiology, and End Results (SEER)...

Gastric neuroendocrine tumors (GNETs) are slow-growing tumors derived from enterochromaffin-like cells whose prognosis depends on the type. Prior GNET studies have shown an increasing incidence, but survival analyses have been more limited. This study aims to investigate if the increasing incidence trend continues and better describe factors associated with survival for GNET patients.

In this retrospective population-based cohort study, patients diagnosed with GNET between 2000 and 2020 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Additional variables collected were age, sex, race, stage, presence of metastases, tumor size, treatment status for surgery, radiation, and chemotherapy, median household income, and population size. Descriptive statistics, population-based incidence, and Cox regression analyses were performed.

A total of 6512 patients were included. The one- and five-year survival rates were 90.4% and 83.8%, respectively. The population-adjusted incidence ranged from 0.272/100,000 in 2000 to 0.680/100,000 in 2020. The total percent change in incidence over the study range was 104.1% with an annual percent change of 4.27%, which met significance (p<0.05). Chi-square analyses demonstrated significantly higher 1- and 5-year cancer-specific survival among patients aged <50 years, males, Whites, those with localized stage, no metastases, tumor size 0.1-2.0 cm, and no receipt of surgery or chemotherapy (all p < 0.001). Cox regression results showed that age of 70+ years, regional and distant staging, any distant metastases, and tumor size >2.0cm and >5.0cm were associated with shorter survival (p<0.05). Additionally, females, Hispanic patients, and recipients of surgery were associated with longer survival (p<0.05).

The findings show GNET incidence has continued to increase over the past two decades. Additionally, clinical factors including stage, extent of metastasis, tumor size and socioeconomic factors like age, gender, and race were associated with changes in GNET survival. In the context of the increasing incidence of GNET, these findings describe factors associated with lower- and higher-risk tumors. Further assessment of these risk factors can benefit future research to better understand why GNET incidence is increasing, aid in risk stratification of GNET patients, and improve the prognosis of GNET.