Abstract
<title>Abstract</title> <p> <bold>Background</bold> Lung cancer remains the leading cause of cancer-related mortality worldwide (1–3), while chronic kidney disease (CKD) is a major contributor to morbidity, mortality, and healthcare utilization. The coexistence of these conditions may complicate clinical management and adversely affect outcomes; however, long-term national mortality trends and demographic disparities among individuals with coexisting lung cancer and CKD remain incompletely characterized. We evaluated temporal trends in mortality involving coexisting lung cancer and CKD among U.S. adults aged ≥ 45 years between 1999 and 2024. <bold>Methods</bold> We conducted a retrospective, population-based serial cross-sectional analysis using the Centers for Disease Control and Prevention (CDC) WONDER Multiple Cause of Death database (4). Deaths involving coexisting lung cancer (ICD-10 code C34) and chronic kidney disease (ICD-10 code N18) were identified when both conditions were listed anywhere on the death certificate as underlying or contributing causes of death. Age-adjusted mortality rates (AAMRs) per 100,000 population were calculated using the 2000 U.S. standard population. Mortality trends were evaluated using Joinpoint Regression Program version 6.0.1. Annual percent changes (APCs) and average annual percent changes (AAPCs) with 95% confidence intervals (CIs) were estimated overall and according to age group, sex, race and ethnicity, census region, state, and metropolitan status. <bold>Results</bold> Between 1999 and 2024, 37,851 deaths involving coexisting lung cancer and chronic kidney disease were identified among U.S. adults aged ≥ 45 years. The overall AAMR increased from 0.70 to 1.50 per 100,000 population, corresponding to an AAPC of 1.29% (95% CI, 0.52–2.20). Mortality was consistently highest among older adults, men, and non-Hispanic Black individuals. Geographic disparities were evident, with the highest regional mortality observed in the Midwest and persistently higher mortality in non-metropolitan than metropolitan areas. Joinpoint analysis demonstrated a marked increase during 2008–2011, followed by a transient decline and renewed increase through 2024. <bold>Conclusions</bold> Mortality involving coexisting lung cancer and chronic kidney disease increased nationally over the study period, with substantial demographic and geographic disparities. These findings support continued surveillance, earlier recognition of high-risk populations, equitable access to multidisciplinary care, and targeted public health strategies to reduce the burden of coexisting lung cancer and CKD. </p>