Trends in gastric cancer mortality by subsite (cardia vs. non-cardia) and racial disparities from 1999-2023.

298 Background: Gastric cancer is uncommon in the U.S. but has a poor prognosis. We compared mortality trends for cardia vs. non-cardia gastric cancer. Methods: Data from CDC WONDER for adults aged ≥25 years were analyzed. ICD-10 C16.0 (cardia) and C16.1-C16.6, C16.8, C16.9 (non-cardia) were used. AAMRs were calculated per 100,000 population stratified by sex and race. Average Annual Percentage Change (AAPC) and Annual Percentage Change (APC) were analyzed using joinpoint regression. Results: Cardia gastric cancer accounted for 23,871 deaths, while non-cardia subsites accounted for 288,451 deaths. The cardia AAMR changed from 0.48 in 1999 to 0.52 in 2023, reflecting a decline to 2013 (APC -1.08, p=0.03) followed by a significant rise between 2013 and 2023 (APC: 3.11, p=0.003; AAPC: 0.63, p=0.07). In contrast, non-cardia AAMR showed a sharp drop from 7.47 in 1999 to 3.92 in 2023, with steeper declines 1999-2008 (APC -3.42) and continued decreases 2008-2023 (APC -2.28; both p