Trends and disparities in appendiceal cancer mortality in the United States from 1999 to 2023

Appendiceal cancer (AC), once rare, is now recognized as a complex disease with rising mortality. At diagnosis, 74% of AC cases are already metastatic. No standardized chemotherapy exists for advanced cases, despite an alarming 232% increase in incidence in the United States, predominantly in individuals under 50 years. We analyzed U.S. mortality patterns by demographics and geography to identify high-risk groups. A retrospective analysis was performed using the CDC WONDER database. Deidentified death certificate data was extracted through ICD-10 code C18.1 to identify Appendiceal cancer–related deaths from 1999 to 2023. We analyzed mortality disparities by gender, race/ethnicity, states, and urban/rural classification. Age-adjusted mortality rates (AAMR) per 100,000 with 95% CI were reported. Trends and annual percent change (APC) were assessed using Joinpoint regression. Between 1999 and 2023, 15,928 appendiceal cancer–related deaths occurred in the U.S. AAMRs increased from 0.08 in 1999 to 0.24 in 2017 (APC: 5.61; 95% CI 5.14,6.07), then plateaued till 2023. Females consistently had higher AAMRs than males. NH-Whites had the highest racial AAMR (3.95), followed by NH-Blacks (3.73), with Hispanics/Latinos lowest (1.43). Rural areas had the highest 2020 AAMR (0.27), increasing sharply after 2004 (APC: 7.72). State-level AAMRs ranged from 0.08 (Nevada) to 0.30 (Delaware), with top-percentile states having nearly triple the rates of those in the lowest percentile. Appendiceal cancer deaths are increasing in the United States, highlighting the need for targeted efforts to address this trend and reduce the risk of a growing health burden.