The growing cancer burden: Age-period-cohort projections in Aotearoa New Zealand 2020-2044

Background: Cancer is a major cause of premature death and inequity, and global case numbers are rapidly expanding. This study projects future cancer numbers and incidence rates in Aotearoa New Zealand. Methods: Age -period -cohort modelling was applied to 25 -years of national data to project cancer cases and incidence trends from 2020 to 2044. Nationally mandated cancer registry data and official historical and projected population estimates were used, with sub -groups by age, sex, and ethnicity. Results: Cancer diagnoses were projected to increase from 25,700 per year in 2015-2019 to 45,100 a year by 2040-44, a 76% increase (2.3% per annum). Across the same period, age -standardised cancer incidence increased by 9% (0.3% per annum) from 348 to 378 cancers per 100,000 person years, with greater increases for males (11%) than females (6%). Projected incidence trends varied substantially by cancer type, with several projected to change faster or in the opposite direction compared to projections from other countries. Conclusions: Increasing cancer numbers reinforces the critical need for both cancer prevention and treatment service planning activities. Investment in developing new ways of working and increasing the workforce are required for the health system to be able to afford and manage the future burden of cancer.