Trends in lung cancer mortality among adults younger than 55 years: A CDC WONDER analysis.

e20770 Background: Lung cancer remains the leading cause of cancer-related death in the United States, with risk increasing substantially with age. Most cases occur in adults aged 65 years or older, yet trends among younger patients are less well described. We evaluated long-term patterns in lung cancer mortality among individuals younger than 55 years. Methods: Mortality data were obtained from the CDC WONDER database using ICD-10 codes for lung cancer. Deaths among individuals younger than 55 years were analyzed from 1999 to 2020. Age-adjusted mortality rates (AAMRs) per 100,000 population were examined by sex and race. Results: From 1999 to 2020, a total of 269,823 lung cancer–related deaths occurred among individuals younger than 55 years. Over the study period, lung cancer mortality declined steadily in both sexes. Among females, AAMRs decreased from 9.85 in 1999 to 4.40 in 2020. A similar pattern was observed in males, with AAMRs falling from 14.53 to 4.92. Although mortality rates remained higher in males throughout the study period, the absolute decline was greater among males than females. Race-stratified analyses showed decreasing AAMRs across all racial groups. African American individuals experienced the highest mean AAMR but also the steepest decline, with rates decreasing from 19.4 to 5.1 over the study period. Conclusions: Despite lung cancer remaining a leading cause of cancer-related mortality, deaths among individuals younger than 55 years have declined substantially over the past two decades. This trend likely reflects reductions in smoking prevalence, increased use of low-dose CT screening, and advances in systemic therapies. Persistent sex- and race-based differences highlight the importance of continued efforts in prevention, early detection, and equitable access to care.