Distributions and trends in the global burden of young-onset tracheal, bronchus, and lung cancer by region, age, and sex from 1990 to 2021: An age-period-cohort analysis.

BACKGROUND

The young onset Tracheal, Bronchus, and Lung Cancer (TBLC) exhibits distinct gene mutations and clinical characteristics. With worsening air pollution, the incidence of young onset TBLC is increasing, resulting in significant economic burdens. The specific epidemiology of the disease burden remains elusive.

METHODS

The updated Global Burden of Disease (GBD) 2021 study was employed. This study reports on the disease burden trends of young TBLC (≤54 years) and its risk factors. Data is presented as counts and age-standardized rates (ASRs) per 100,000 people across different age groups, years, sexes, sociodemographic levels (SDI), and geographic locations (global, regional, and national). An age-period-cohort (APC) model was used to analyze longitudinal curves on age, period, and cohort effects for young TBLC. Decomposition analysis broke down temporal changes into three factors: population aging, population growth, and epidemiological change, to quantify the changes and identify their causes. An inequality index was applied to examine the inequality of disease burden of young TBLC by sex across different SDI levels between 1990 and 2021.

RESULTS

From 1990-2021, the global number of individuals under 55 diagnosed with TBLC increased from 320,715 to 489,080, representing a 52 % rise. However, the age-standardized rates of prevalence (Average annual percentage changes (AAPC) -0.05 %), incidence (AAPC -0.59 %), mortality (AAPC -0.88 %), and disability-adjusted life-years (DALYs) (AAPC -0.92 %) all showed a notable decline tendency. In 2021, there were 258,360 new diagnoses and 207,000 deaths from young TBLC, with ASRs of incidence and mortality at 6.43 and 5.49 per 100,000, respectively. Regionally, East Asia bore the highest burden, with about 117,730 new young TBLC cases and an ASR of 12.01 per 100,000 people. Decomposition analysis indicated that population growth was the primary driver for the increased prevalence of young TBLC. While tobacco-related DALYs for young TBLC decreased globally, tobacco remains the leading risk factor. In contrast, air pollution-related DALYs have significantly increased in middle and lower SDI regions. Over the past two decades, the burden of young TBLC among females has grown substantially, with increased inequality observed in 2021. Tobacco was the largest contributor to the PAF of young female DALYs in high SDI regions, whereas air pollution was the leading contributor in other SDI regions.

CONCLUSION

While the total number of young TBLC cases has been on the rise trend, primarily due to population changes, the ASRs of young TBLC burdens have decreased over the past two decades. In 2021, East Asia recorded the highest ASRs for young TBLC in terms of prevalence, incidence, and mortality. Tobacco remains the primary risk factor for young TBLC, and the DALYs burden from tobacco use has significantly decreased. However, the incidence of TBLC among non-smoking young females has grown rapidly over the past two decades, mainly due to air pollution, leading to increased inequality.