Lung cancer burden in AYAs: Global and U.S. trends.

Abstract

8603 Background: Lung cancer remains a leading cause of cancer-related mortality and is increasingly observed among adolescents and young adults (AYA), with shifting tobacco use and rising air pollution implicated as potential risk factors. This study examines global and U.S. epidemiological and risk factor trends of tracheal, bronchial, and lung cancer (TBLC) in AYA population (20-54 years). Methods: We utilized Global Burden of Disease database (1990-2023) for TBLC, to extract Age Specific incidence (ASIR) and mortality rates (ASMR), as well as proportional and absolute ASMRs associated with all risk factors, tobacco use and ambient particulate matter (PM2.5). Joinpoint analysis assessed changes in trends and calculated EAPC (Estimated Annual Percentage Changes). All rates are reported per 100,000 population. Results: In 2023, the global ASIR of TBLC among AYAs was 8.69 (n = 167,524) in males and 4.70 (n = 88,569) in females, with absolute incidence increasing by 13% in males and 50% in females. Absolute mortality similarly increased by 9% in males and 39% in females, with ASMRs of 6.99 and 3.52, respectively in 2023. In US, while overall incidence and mortality declined, ASIR in 2023 for females (0.62) was found to be almost similar to males (0.64), whereas ASMR remained higher in males (0.49) than females (0.43). At global level, tobacco remained the leading ASMR contributor in 2023, with higher burden in males (males 4.8, 68.2%; females 1.1, 31%), followed by PM2.5 (males 1.1, 20.5%, females 0.5, 20.8%). No TBLC-related mortality was attributed to household air pollution in 2023. The most significant decline in tobacco- and PM2.5–associated TBLC mortality in males occurred from 2003 to 2020 (tobacco: EAPC −2.66; PM2.5: 2006-2017: EAPC −0.76), and in females between 2008 to 2021 (tobacco: EAPC −3.5, PM2.5: 2017-2020: EAPC -4.8). By 2023, 18.8% of male and 43.1% of female TBLC deaths had no identified risk factors. In the US, ASMR declined continuously across all risk factors in both sexes, and by 2023, 25.4% of male and 32.0% of female TBLC deaths had no identified associated risk factors. Despite overall reductions in ASIR and ASMR globally and in USA, Mortality to Incidence ratio remained largely stable, with only minimal decreases observed globally (males −3.6%, females −7.5%) and in the US (males −2.3%, females −5.8%). Conclusions: Our analysis demonstrated an absolute increase in TBLC incidence and mortality globally in both sexes, with males continuing to experience higher mortality. In the USA, the sex-based gap in ASIR has nearly disappeared. Although tobacco-related mortality declined, it remained the leading risk factor. By 2023, 20–25% of AYA males and 30–43% of AYA females TBLC deaths were attributable to non-modifiable risk factors, highlighting the need for screening guidelines that better address AYAs, particularly those without traditional risk factors.