Economic factors and screening practices in global lung cancer staging disparities: A systematic review.

e22500 Background: To assess the global distribution of lung cancer staging at diagnosis and explore the impact of economic disparities and screening practices on staging outcomes. Methods: The MEDLINE and Embase databases were systematically searched, supplemented by a review of gray literature and published cancer reports. Population- or hospital-based cancer registry reports on lung cancer staging at diagnosis were also included. The percentage of lung cancer stages in different countries was extracted and the distribution of stages, changes in stage incidence over time, and the impact of screening programs were examined Correlations between the Human Development Index (HDI), Social Development Index (SDI), and proportion of distant metastatic lung cancer were assessed. Subgroup analyses were conducted based on sex, age, tumor histology. Results: Among the 35 countries in the main analysis, the proportion of distant metastatic lung cancer ranged from 30.4% in Hungary to 81.2% in Brunei Darussalam, with a median of 50.8% (interquartile range: 44.8–59.2%). Higher HDI and SDI were not significantly associated with lower proportions of distant metastatic lung cancer (HDI: ρ = −0.19, 95% confidence level (CI): −0.50 to 0.15; SDI: ρ = −0.22, 95% CI: −0.51 to 0.13). In countries with lung cancer screening programs, the proportion of metastatic cases decreased in the United States (from 56.5% in 2004 to 48.5% in 2021) and England (from 54.7% in 2013 to 48.7% in 2021). Additionally, the United States and the Republic of Korea experienced an increase in early-stage incidence, while the United States saw a significant decline in late-stage incidence. Higher metastasis rates were observed in males, younger patients, and patients with small cell lung cancer. Conclusions: Significant global variations in lung cancer staging at diagnosis highlight the need for targeted strategies to enhance early detection and improve treatment outcomes, particularly in regions with a high incidence of metastatic disease.