Temporal trends and future projections of six major cancers among women of childbearing age in northeast Asia: analysis of data from the global burden of disease study 2021.

Background: Cancer among women of childbearing age (WCBA) imposes major health and socioeconomic burdens, yet integrated assessments of temporal trends and future projections in Northeast Asia (NEA) are limited. Methods: Using Global Burden of Disease 2021 estimates, we quantified incidence, mortality, and disability-adjusted life years (DALYs) for breast, cervical, uterine, ovarian, colorectal (CRC), and tracheal, bronchus, and lung (TBL) cancers among women of childbearing age (WCBA; 15-49 years) in six Northeast Asia countries from 1990-2021. We calculated age-standardized incidence, mortality and DALY rates, temporal odds ratios for the proportion of WCBA among all female cases, estimated annual percentage changes (EAPCs), and mortality-to-incidence ratios (MIRs), referencing a 46.6% threshold. Age-standardized incidence and mortality rates to 2050 were projected using Bayesian age-period-cohort models fitted with integrated nested Laplace approximation. Findings: Between 1990 and 2021, the proportion of cancer incidence, deaths, and DALYs among WCBA relative to all females declined across all cancer types. The steepest proportional declines were for TBL incidence ( Interpretation: Although mortality and DALYs among WCBA in NEA have improved, rising breast and uterine cancer incidence, persistently high lung cancer MIRs remain major concerns. Strengthened tobacco control and air-quality policies, expanded HPV vaccination and cervical screening, promotion of healthy lifestyles, and equitable access to early diagnosis and treatment are essential to reduce cross-country disparities in cancer outcomes among WCBA.