S1386 Diverging Patterns of Cardia and Non-Cardia Gastric Adenocarcinoma Incidence by Race and Age in the United States From 2000-2018

Abstract

Introduction: Gastric adenocarcinoma is the fifth-leading cause of cancer incidence and fourth-leading cause of cancer mortality worldwide. In the United States (US), racial groups differ in their incidence of cardia (CGA) and non-cardia (NCGA) gastric adenocarcinomas. There have been few studies published observing secular trends in incidence of both CGA and NCGA stratified by race in the US. Methods: Age-adjusted incidence rates and trends of CGA and NCGA in adults aged ≥ 25 years were calculated using data form 18 registries reporting to the Surveillance, Epidemiology, and End Results (SEER) Program from years 2000-2018. Race/ethnicity was classified as non-Hispanic White, non-Hispanic Black, American Indian/Alaskan Native, Asians/Pacific Islanders, and Hispanic. Analysis was also stratified by age (25-49 and ≥50). We used joinpoint regression to assess annual percent change (APC), average annual percent change (AAPC), and corresponding 95% confidence intervals (CIs). Results: The incidence of NCGA decreased in all racial groups, regardless of age, across the study period. The incidence of CGA also decreased in all racial groups among individuals ≥50 (Table 1). However, among individuals 25-49, the incidence of CGA is increasing among non-Hispanic Whites (AAPC = 1.0, 95% CI; 0.3, 1.7), Asian/Pacific Islanders (AAPC = 2.5, 95% CI; -0.3, 5.4), and Hispanics (AAPC = 2.3, 95% CI; 0.9, 3.8) (Figure 1). Conclusion: NCGA incidence is decreasing in all racial and age groups. By contrast, CGA incidence in increasing in the young among certain racial/ethnic groups. Clinicians and policy makers must be cognizant of these recent and worrisome trends. Moreover, appropriate cancer prevention programs are needed to target these at-risk populations.Table 1.: Average annual percent change in cardia and non-cardia gastric cancer incidence rates by race and age: SEER 2000-2018 SEER, Surveillance, Epidemiology and End Results; AAPC, average annual percent change. † Lack of data to analyze AAPC.Figure 1.: Age- and race-specific cardia gastric cancer incidence trends in the SEER data, 2000-2018 A. Non-Hispanic Whites aged 25-49 B. Non-Hispanic Asian/Pacific Islanders aged 25-49 C. Hispanics aged 25-49 D. Non-Hispanic Whites aged ≥50 E. Non-Hispanic Asian/Pacific Islanders aged ≥50 F. Hispanics aged ≥50