Global cancer mortality attributable to armed conflict: A GBD 1990–2021 analysis.

e23239 Background: Armed conflict disrupts cancer prevention, diagnosis, and treatment continuity, yet its contribution to global cancer mortality has not been systematically quantified using standardized population-level data. We leveraged Global Burden of Disease (GBD) estimates to evaluate the association between armed conflict exposure and cancer mortality across countries and over time. Methods: We conducted a longitudinal, country-level analysis using GBD 2021 estimates (1990–2021) for all-cancer mortality, age-standardized cancer death rates, years of life lost (YLLs), and disability-adjusted life years (DALYs). Armed conflict exposure was operationalized using GBD estimates for mortality due to conflict and terrorism, treated as a time-varying proxy for conflict intensity. Countries were categorized annually into conflict-intensity strata (none, low, moderate, high) based on conflict-related death rates. We assessed associations between conflict intensity and cancer outcomes using mixed-effects regression models with country-level random intercepts, adjusting for calendar year and sociodemographic index (SDI). Excess cancer mortality attributable to conflict was estimated by comparing observed cancer mortality in conflict-exposed country-years with model-predicted counterfactual mortality under a no-conflict reference stratum. Results: Across the 1990–2021 study period, increasing conflict intensity was consistently associated with higher age-standardized cancer death rates and greater cancer-related YLLs. The association demonstrated a dose–response pattern, with the largest excess cancer mortality observed in high-intensity conflict settings and in lower-SDI regions. Temporal analyses showed that sustained conflict exposure was associated with persistently elevated cancer mortality burden compared with non-conflict periods. Patterns were broadly consistent across sexes and major world regions. Conclusions: Using standardized GBD estimates, armed conflict intensity is associated with excess cancer mortality and premature cancer death at the population level. These findings support conceptualizing armed conflict as a structural determinant of cancer outcomes and underscore the need for resilient oncology care delivery, continuity-of-treatment strategies, and targeted cancer control interventions in conflict-affected settings.