Trends and disparities in diffuse non-Hodgkin lymphoma-related mortality among u.S. elderly adults: A nationwide analysis (1999-2020) with projections to 2030

Abstract Abstract Background: Diffuse Non-Hodgkin Lymphoma (DNHL) remains a significant contributor to cancer-related mortality among the elderly in the United States (U.S.). Objectives: In this study, we aim to analyze the temporal trends and demographic-geographic disparities in DNHL-related deaths among U.S. adults aged ≥55 years from 1999 to 2020, with projections 2030. Methods: Mortality data were extracted from the CDC WONDER database, identifying decedents aged ≥55 years with DNHL (ICD-10 codes C83.0–C83.9) as the underlying cause of death. Crude mortality rates (CMRs) and age-adjusted mortality rates (AAMRs) per 100,000 population were calculated. Temporal trends were analyzed using Joinpoint regression to estimate annual percent change (APC) and average annual percent change (AAPC) along with 95% confidence intervals (CIs). Stratified analyses were conducted by sex, race/ethnicity, census region, state, and urbanization status. Mortality trends were projected through 2030 using an autoregressive integrated moving average (ARIMA) model in R Studio (4.4.3). Model fit was evaluated using AIC and residuals. Results: A total of 66,991 deaths were recorded due to DNHL among elderly individuals between 1999 and 2020, with a significant overall AAPC of 2.82 (95% CI: 0.99 to 4.68, p = 0.002). The AAMR initially declined from 3.72 (1999) to 2.6 (2008) with an APC of -4.20, then rose substantially to 6.44 by 2020 (APC: 5.27). Males exhibited a higher AAMR (5.89) than females (2.97), with significant AAPCs of 2.80 (95% CI: 1.4 to 4.2). By race/ethnicity, Whites had the highest AAMR (4.45), followed by Hispanics (3.46) and Blacks (2.33), with rising trends observed across all groups post-2006. Urbanization analysis revealed the highest AAMRs in Micropolitan and Small Metro areas, with consistently rising trends since 2008. Regionally, the Midwest exhibited the highest AAMR (5.00), followed by the West (4.41), South (3.85), and Northeast (3.70). State-level AAMRs ranged from 2.62 (Nevada) to 8.00 (Iowa). The highest crude death rates were among those aged ≥85, increasing from 7.44 to 18.41 (AAPC: 4.35; 95% CI: 2.68, 6.05). ARIMA models projected the AAMR to reach 9.18 by 2030 (6.71 in females and 11.71 in males). Conclusion: After an initial decline, age-adjusted mortality from DNHL among the elderly has significantly increased since 2008 across nearly all demographic and geographic subgroups. These findings underscore the need for renewed public health focus on targeted cancer control strategies, especially among males, rural populations, and specific racial/ethnic groups.Keywords: Diffuse Non-Hodgkin Lymphoma; Mortality Trends; Elderly Population; Forecasting Analysis