Epidemiologic patterns and mortality outcomes in young lung cancer non-smokers: A National Inpatient Sample analysis (2016–2021).

Abstract

11142 Background: While the incidence and mortality of smoking-related lung cancer have declined, cases among individuals who have never smoked (LCINS) are increasing, particularly among women and younger populations. LCINS often presents with distinct pathology features, unique genetic mutations, and a higher prevalence of early-onset disease. Despite these distinctions, limited evidence exists regarding the epidemiology and mortality outcomes of LCINS. This study aims to compare sociodemographic differences and mortality outcomes among early- and late-onset lung cancer, stratified by smoking status. Methods: We performed a pooled cross-sectional analysis using the National Inpatient Sample (NIS) from 2016 to 2021. Lung cancer patients, identified by ICD-10 codes (C34.x), were stratified by age (≤50 years and > 50 years) and smoking status (current, former, and non-smokers). Comorbidities were assessed using the Elixhauser Comorbidity Index. Descriptive statistics and multivariable logistic regression analyses were used to compare mortality outcomes, with statistical significance defined as p < 0.05. Analyses were performed using STATA MP 18. Results: A total of 199,798 lung cancer hospitalizations were identified, representing 998,990 weighted discharges across the U.S. Of these, 1.47% were young non-smokers (≤50 years), 1.33% young smokers, 26.63% older non-smokers ( > 50 years), and 25.8% older smokers. Young non-smokers were more likely to be female (60.8% vs 50.4% of the general population) and non-white (49.2% vs 23%), with a notably higher prevalence of Asian (11.4% vs 3.3%) and Hispanic (15.1% vs 4.8%) individuals. Young non-smokers had fewer health conditions compared to the general population, with a lower mean Elixhauser Comorbidity Index (19.38 vs 20.63) and lower prevalence of chronic pulmonary disease (16.5% vs 51.3%). However, they had a higher prevalence of metastatic disease (55.8% vs 40.8%). Inpatient mortality was higher in young non-smokers (7.2%) compared to young smokers (5.2%), and higher in older non-smokers (9.1%) than older smokers (5.0%). Multivariable logistic regression showed a statistically significantly increased mortality for young non-smokers compared to young current smokers (OR 1.58, 95% CI 1.26–1.99, p < 0.01), and similarly for older non-smokers (OR 1.72, 95% CI 1.42–2.08, p < 0.01), after adjusting for age, sex, race and other confounders. Conclusions: LCINS, particularly in early onset cases, represents a distinct subgroup with unique sociodemographic and clinical characteristics, including a higher prevalence of non-white individuals, fewer comorbidities, and an increased mortality rate. The higher mortality may reflect the advanced stage at presentation and poorer prognosis of LCINS, suggesting potential differences in disease mechanisms compared to smoking-related lung cancer. These findings highlight the need for tailored screening strategies and personalized treatment approaches for the LCINS population.