Global burden of breast cancer and its association with red meat consumption: spatiotemporal trends, projections, and triangulation of evidence.

backgroundDespite being the leading cause of cancer-related deaths among women globally, a comprehensive understanding of breast cancer (BC) remains limited due to gaps in data quality, geographic coverage, burden metrics, and risk factor attribution. This study utilized a multi-model approach to assess the global burden of BC and its projected trends, complemented by Mendelian randomization (MR) analysis to explore the potential causal relationship between red meat consumption and BC risk.

methodsThis study utilized GBD data from 1990 to 2021 to assess the epidemiology of BC. Temporal trends and risk factor dynamics were examined using joinpoint regression and age-period-cohort (APC) analyses. Bayesian APC modeling was employed to project the disease burden through 2030. The analysis was stratified by socio-demographic index (SDI) and conducted by continent. Disease attribution factors were validated through MR.

resultsThe study identified significant geographical and gender disparities in global BC epidemiological patterns in 2021. Analysis of data from 1990 to 2021 revealed age-dependent variations in disease burden, particularly affecting populations aged 50 years and older. Although global disability-adjusted life years (DALYs) and mortality rates exhibited an overall decline, incidence rates continued to rise. Female DALYs consistently exceeded those of males, with male metrics showing post-peak declines and projected further reductions by 2030. Both genders demonstrated increasing trends in incidence and prevalence, with females exhibiting notably higher rates in high-income regions, including North America, Western Europe, Australia, and New Zealand. In contrast, males showed a relative predominance in certain African countries, parts of Western Europe, and China. The disease burden was inversely associated with the socio-demographic index (SDI), indicating limited improvements in regions with low SDI. By 2021, high red meat intake and elevated BMI were identified as the leading contributors to BC mortality in the GBD comparative risk assessment framework. Exploratory Mendelian randomization analysis provided suggestive evidence that genetically predicted beef consumption may be associated with increased BC risk, though these findings should be interpreted cautiously due to methodological limitations.

conclusionThe global burden of BC is increasing, particularly in low- and middle-SDI regions, highlighting the urgent need for coordinated international efforts to strengthen prevention and control strategies. Priority interventions should combine evidence-based screening practices from high-SDI settings with affordable, targeted therapies, while simultaneously expanding access to treatment, increasing healthcare capacity, and enhancing health education in resource-limited areas. Furthermore, addressing modifiable risk factors requires comprehensive dietary interventions, including promoting plant-based nutrition, launching community-based obesity prevention programs, and implementing public health strategies to reduce red meat consumption at the population level.