Owais, Muhammad

e16157 Background: Liver cancer mortality remains a major public health burden in the United States despite advances in prevention and treatment. Psychoactive substance use disorder (PSUD) is an increasingly prevalent comorbidity; however, national trends and disparities in liver cancer mortality among adults with PSUD remain poorly characterized. Methods: We conducted a retrospective analysis of liver cancer-related deaths among U.S. adults aged 25 years and older with PSUD from 1999 to 2023 using Centers of Disease Control (CDC) Wide Ranging Online Data for Epidemiological Research (WONDER) mortality database. Age-adjusted mortality rates (AAMRs) were calculated per 100,000 population and stratified by census region, state, urban–rural status, sex, and race/ethnicity. Temporal trends were assessed using Joinpoint regression to estimate average annual percent change (AAPC). Statistical significance was determined using p-value (<0.05). Results: Overall liver cancer related AAMR per 100,000 among adults with PSUD significantly increased from 0.15 in 1999 to 1.02 in 2023 (AAPC: 7.47; 95% CI: 6.33 to 8.61; p < 0.000001). The overall mortality burden was higher in males. However, females experienced larger rises in mortality (AAPC: 10.03; 95% CI: 8.85 to 11.24; p < 0.000001) as compared to males (AAPC: 7.30; 95% CI: 5.78 to 8.84; p < 0.000001). Marked racial disparities were observed, with non-Hispanic Black and non-Hispanic White individuals experiencing the highest mortality rates with persistent increases over time, while Hispanic/Latino populations exhibited modest and variable trends. A substantial geographic variability was observed, with the greatest increases in the Midwest and the South. State-level analysis revealed higher mortality rate in Oregon (1.27) followed by Washington (1.12) and Texas (1.06) respectively. Both rural and urban areas experienced a sharp rise in mortality with AAPC being slightly higher in rural areas (AAPC: 10.34) as compared to urban areas (AAPC: 9.67). Conclusions: Liver cancer mortality among U.S. adults with PSUD has risen markedly over the past two decades, with substantial demographic and geographic disparities. These findings highlight the need for integrated liver cancer screening and substance use disorder interventions targeting high-risk populations. Variables AAMR (95% CI) in 2023 AAPC (95% CI) Overall 1.02 (0.98 –1.05) 1999-2023: 7.47* (6.33 – 8.61) Female 0.42 (0.39 – 0.46) 1999-2023: 10.03* (8.85 – 11.24) Men 1.69 (1.62 –1.76) 1999-2023: 7.30* (5.78 – 8.84) White 1.05 (1.0 –1.09) 1999-2023: 9.52* (8.08 – 10.98) Black / African Americans 1.22 (1.09 – 1.35) 1999-2023: 6.59* (5.50 – 7.68) Hispanics / Latinos 0.75 (0.65 – 0.84) 1999-2023: 1.26 (-1.01 – 3.60) AAMR (95% CI) in 2020 AAPC (95% CI) Rural 1.51 (1.39 – 1.62) 1999-2020: 10.34* (5.05 – 15.90) Urban 0.92 (0.82 – 0.95) 1999-2020: 9.67* (7.32 – 12.06)

e16023 Background: Stroke is an underrecognized cause of death among patients with gastric cancer. While overall cancer mortality has improved, less is known about long-term trends and disparities in stroke-related deaths. We examined national patterns in stroke mortality among gastric cancer patients from 1999 to 2023. Methods: U.S. national mortality data were used to calculate age-adjusted mortality rates (AAMR) per 100,000. Joinpoint regression identified temporal changes and estimated annual percent change (APC) and average annual percent change (AAPC). Analyses were stratified by age, sex, race and ethnicity, census region, and urbanization. Results: Between 1999 and 2023, an overall decline in stroke-related mortality was noted with AAMR falling from 167.29 to 111.35 per 100,000 people (AAPC −1.70%, 95% CI −1.9 to −1.5). The decline was greatest between 2002 and 2009 (−5.28% per year) after which it began to plateau until it rose significantly between 2018 and 2021 (APC 6.56%) followed by a decline after 2021 (−3.63%). Older adults had the highest level of stroke related mortality, and therefore the greatest reduction over time (from 756.36 to 479.63) with a total reduction of −36.6% yet they saw a significant increase in mortality between 2018 and 2021. Middle aged patients had little overall improvement and demonstrated the steepest recent increase (APC 8.46%). Younger patients concluded the study period at rates similar to those seen in 1999. Men demonstrated a greater incidence of stroke related mortality compared to women (118.67 vs 104.15 in 2023) with similar trends over time. Racial disparities were present with Black patients showing the highest stroke related mortality in all years (from 242.47 to 156.26) and the largest recent increase (APC 7.37%). Regionally, the South and rural areas carried the highest mortality burden; however, all geographic areas demonstrated an identical increase between 2018 and 2021. Conclusions: Although stroke-related mortality among gastric cancer patients has declined over two decades, recent nationwide increases highlight ongoing vulnerability and persistent disparities. Targeted integration of cardiovascular risk assessment and stroke prevention into gastric cancer care may help sustain progress and reduce inequities. Group (Category A / Category B) AAMR 1999 (A / B) AAMR 2023 (A / B) Recent Surge Trend 2018–2021 (APC) Overall 167.3 111.4 +6.6%* Sex (Male / Female) 181.5 / 156.2 118.7 / 104.2 +6.8%* / +6.2%* Race (NH White / NH Black) 160.4 / 242.5 108.2 / 158.4 +6.3%* / +7.4%* Race (Hispanic / Asian) 140.3 / 153.6 97.7 / 80.0 +6.9%* / +5.2%* Age (Young / Middle) 6.7 / 47.7 6.7 / 42.3 +7.8%* / +8.5%* Age (Old 65+) 756.4 479.6 +6.2%* Region (Northeast / Midwest) 141.5 / 172.0 82.7 / 115.3 +4.4%* / +6.7%* Region (South / West) 177.5 / 171.4 125.7 / 107.2 +6.9%* / +6.2%* An asterisk (*) indicates that the APC is statistically significant (p < 0.05).