Changing Disparity of Gastric Cancer Incidence by Histological Types in US Race-Specific Populations

BACKGROUND: The incidence pattern of gastric cancer by histological types across major race/ethnic groups is unknown. METHODS: Age-standardized rates from 1992-2016 by race/ethnicity were calculated using data from Surveillance, Epidemiology, and End Results Program (SEER). Annual percent changes (APCs) in rates and corresponding 95% confidence intervals (CIs) were calculated and pairwise comparison of rates between race/ethnic groups was performed using the Joinpoint Regression Program. Calendar periods of incidence rates of gastric cardia and non-cardia cancer by histological types across race/ethnicity groups were shown by figures. RESULTS: The White population has the highest incidence of gastric cardia adenocarcinoma and the incidence is keeping constant from 1992 through 2016 except the decreasing in the Asian population (AAPC = −1.4, 95%CI (−2.1, −0.8)). Although the incidence of non-cardia adenocarcinoma is decreasing in each group, the descending trend in the Asian population is the quickest (AAPC = −3.8, 95%CI (−4.0, −3.5)). Gastric carcinoids were observed to have statistically significant increasing trends in all race/ethnicity groups, especially in Hispanic women from 0.4 per 100,000 to 1.6 per 100,000 persons. The incidence of gastrointestinal stromal tumors (GISTs) is rising, with Non-Hispanic blacks having the highest incidence. CONCLUSION: This study demonstrated disparities in the incidence of gastric cancer by histological types among different race/ethnic groups. Further investigations are warranted to understand the changing incidence patterns by race/ethnicity.