Trends, differences, and future projections of lung cancer attributable to secondhand smoke across 204 countries and...

Secondhand smoke (SHS) has long been identified as a significant risk factor for lung cancer, yet the precise magnitude of its contribution to the global lung cancer burden remains unclear. Our study aims to elucidate the harms associated with lung cancer caused by secondhand smoke while emphasizing the importance of avoiding SHS.

The annual deaths and disability-adjusted life years (DALYs) data were obtained from the Global Burden of Disease Study (GBD) 2021 for this secondary dataset analysis. Trends in mortality and DALYs were evaluated, along with correlations with the sociodemographic index (SDI). Projections from 2021 to 2036 utilized a Bayesian age-period-cohort model.

In 1990, SHS-related lung cancer was responsible for approximately 0.058 million deaths and 1.599 million DALYs, globally. By 2021, these numbers had increased to approximately 0.098 million deaths and 2.356 million DALYs worldwide. Between 1990 and 2021, SHS-related lung cumulatively caused 2.428 million deaths and 62.785 million DALYs. From 1990 to 2021, deaths and DALYs increased significantly, while age-standardized mortality rates (ASMR) and age-standardized DALY rates (ASDR) decreased. Specifically, ASMR decreased from 1.45 to 1.14, and ASDR dropped from 38.40 to 26.93. The high-middle SDI region bore the largest burden, accounting for nearly 40% of global deaths and DALYs. East Asia held the highest burden of lung cancer attributable to secondhand smoke in 2021, while Oceania had the lowest burden. Projections suggest that male ASMR will decline to 1.18 by 2036, while female ASMR is expected to rise to 0.91 by 2029 before decreasing to 0.89 by 2036.

The considerable burden of lung cancer attributable to secondhand smoke underscores the urgent need for targeted public health interventions, particularly in high-risk demographics and regions. To mitigate disparities and enhance global health outcomes, it is crucial to prioritize the avoidance of SHS and the establishment of smoke-free environments.