Projecting the future burden of lung cancer in Aotearoa New Zealand: informing screening implementation through regional and ethnic projections to 2045

AIM: Lung cancer is the leading cause of cancer-related death in Aotearoa New Zealand and a major contributor to health inequities, particularly among Māori and Pacific peoples. Despite declines in smoking prevalence, lung cancer incidence remains high. Detailed projections are needed to inform future cancer service planning and support cancer control strategies. METHODS: An age-period-cohort Poisson regression model was fitted to national cancer registry data (2001-2022), stratified by sex, prioritised ethnicity, age group and Health New Zealand - Te Whatu Ora region. Time-based weighting and non-parametric bootstrapping were used to derive projections and uncertainty intervals to 2045. RESULTS: Annual lung cancer cases are projected to increase by 38.3%, from 2,544 in 2020-2022 to 3,519 in 2045 (95% uncertainty interval [UI] 3,275-3,771), despite a decline in the age-standardised rate from 28.2 to 23.6 per 100,000 (95% UI 21.6-25.7). Substantial ethnic inequities persist. Māori cases are projected to rise from 570 to 1,063 (an 86.5% increase), and Pacific cases from 129 to 245 (an 89.9% increase). Although rates are projected to fall across all groups, Māori are expected to continue to experience the highest rates. Regional variation is also evident, with the Northern Region projected to experience the largest increase in case numbers, from 872 to 1,280 by 2045. CONCLUSION: Although age-standardised incidence rates are expected to decline, rising case numbers indicate growing demand for diagnostic and treatment services. These projections support the need for equitable implementation of lung cancer screening and sustained investment in culturally responsive prevention and cessation support.