Abstract
BACKGROUND: Lung cancer remains a leading cause of cancer-related deaths globally. Although evidence indicates rising early-onset cases and increasing incidence among females and never-smokers in Asia, these trends remain underexplored in Singapore. This study comprehensively examined historical incidence trends by age, sex, smoking status, and stage to inform targeted prevention and management strategies. METHODS: We analyzed lung cancer cases from administrative health records in Singapore (1968-2021) to calculate age-standardized and age-specific incidence by age (30-49 years, 50-64 years, ≥65 years), sex (male, female), smoking status (ever-, never-smokers), and stage (I-IV). Joinpoint regression identified significant trend changes, reporting annual percent change (APC), average annual percent change (AAPC), and 95% confidence intervals (CIs). AAPCs were evaluated for the full study period and the most recent five years, with Benjamini-Hochberg adjustment for multiple comparisons. FINDINGS: From 1968 to 2021, 53,308 lung cancer cases were recorded in Singapore, predominantly in males (67.7%) and Chinese (87.8%), with 81.6% at advanced stages (III-IV). Incidence rose significantly only in females aged 30-49 years (AAPC = 0.79%, 95% CI: 0.41-1.18) and declined in all male age groups, especially 50-64 years (AAPC = -1.34%, 95% CI: -1.53 to -1.12). Stage I diagnoses increased significantly in both sexes (females: AAPC = 7.19%, 95% CI: 5.24-9.22; males: AAPC = 3.79%, 95% CI: 1.94-5.46) and incidence among never-smokers rose significantly, particularly among females (AAPC = 4.06%, 95% CI: 2.99-5.11). INTERPRETATION: The narrowing male-female gap, rising early-onset cases among females, and increasing incidence in female never-smokers, particularly those ≥65 years, highlight a shifting lung cancer burden in Singapore. Despite improvements in early-stage detection, most cases remained advanced, emphasizing the need to strengthen lung cancer management and screening strategies in Singapore. FUNDING: This work is supported by the National Medical Research Council (Singapore) Health Promotion, Preventive Health, Population Health and Health Services Research (HPHSR) Clinician Scientist Award (HCSAINV24jul-0002).