1231 Racial and Ethnic Differences in Mortality in Gastric Cancer and Esophageal Adenocarcinoma in the United States

Abstract

INTRODUCTION: Studies have shown that the incidence of non-cardia gastric cancer (GC) has been declining in recent years, while the rate of cardia GC has been increasing, paralleling the trends of esophageal adenocarcinoma (EAC). Mortality trends in these malignancies have not been well studied, particularly for non-cardia GC. The aim of our study was to examine differences in incidence-based mortality in cardia and non-cardia GC, as well as EAC for comparison, in a representative cohort of the US population. METHODS: A total of 19,025 individuals with non-cardia GC, 14,268 with cardia GC, and 18,015 with EAC were identified in the Surveillance, Epidemiology, and End Results database. Age-adjusted incidence-based mortality rates and corresponding annual percent change (APC) were calculated between 2004-2016 to assess trends. Mortality analyses were stratified by race/ethnicity, age, and stage of disease at diagnosis. RESULTS: The age-adjusted incidence-based mortality rate (per 100,000 population) for non-cardia GC was 2.50, for cardia GC was 1.85, and for EAC was 2.31. Mortality in non-cardia GC was higher in blacks, Hispanics, and Asians/Pacific Islanders than non-Hispanic whites (P-value < 0.01 for each group). These differences remained statistically significant across all age groups and stages of disease (P-value < 0.01). From 2004-2016, mortality rates have not changed significantly over time for any racial/ethnic group. Interestingly, incidence-based mortality in EAC and cardia GC was higher in non-Hispanic whites than blacks, Hispanics, and Asians/Pacific Islanders (P-value < 0.01 for each group). These differences remained statistically significant across all age groups and stages of disease (P-value < 0.05). From 2004-2016 mortality has been rising in whites for EAC (APC = 3.86, P-value < 0.05) and cardia GC (APC = 3.90, P-value < 0.05), and in Hispanics for cardia GC (APC = 2.23, P-value < 0.05). CONCLUSION: Incidence-based mortality is higher in blacks, Hispanics, and Asians/Pacific Islanders in non-cardia GC, and higher in non-Hispanic whites in EAC and cardia GC. These differences persist when adjusting for age and stage of disease at diagnosis. Further research is needed to better understand the underlying causes of these differences in order to improve outcomes.