Cancer mortality projections through 2026 among young adults in 15 upper-middle and high-income countries with focus on colorectal cancer.

[BACKGROUND] An increasing cancer incidence has been observed among recent generations over the last decade. However, apart from colorectal cancer, these increases were not associated with rises in mortality. This study aimed to project early-onset cancer mortality trends through 2026.

[METHODS] We extracted death counts for individuals aged 25-49 from the WHO Mortality Database and population data from the UN World Population Prospects. The analysis included the 15 most populous upper-middle and high-income countries with valid mortality data from 1990 to 2023, plus the EU-27. Projections of the number of deaths and age-standardized mortality rates (ASMRs) for 2026 were obtained using Poisson regression models fitted to death counts, with the logarithm of population as the offset term. The models were fitted on data from the most recent trend segment identified through joinpoint regression.

[RESULTS] In the EU-27, ASMRs from all cancers combined are projected to decrease by 2026 (males: -17.2% as compared to 2019-2021; females: -13.4%). Declines are expected in all countries for all cancers combined and lung cancer, and for 13/15 countries for breast cancer. Colorectal cancer mortality is projected to increase substantially in the UK (males: + 26.9%; females: + 21.2%), and to smaller extents in the USA, selected Latin American countries and Australian females. Pancreatic cancer mortality showed heterogeneous trends across countries and sexes.

[CONCLUSIONS] Overall, cancer mortality at age 25-49 years is projected to decline by 2026. Colorectal cancer mortality is expected to increase in the coming years in some countries, possibly reflecting the increased prevalence of overweight, obesity, and related metabolic conditions, including diabetes.