Breast cancer is a severe malignancy and remains the leading cause of death among women globally (Siegel et al., 2020, Torre et al., 2015). According to data from the World Health Organization Cancer Research Institute, approximately 2.3 million new cases of breast cancer are diagnosed worldwide each year, with this number steadily increasing (Sung et al., 2021). The growing incidence of breast cancer not only exerts substantial pressure on healthcare resources and impacts survival rates but also profoundly affects patients’ quality of life (Arnold et al., 2022, Lin et al., 2020), leading to enduring psychological stress and social challenges that place a considerable burden on both personal and public health systems (Feiten et al., 2014, Milovic et al., 2023). WHO's global breast cancer initiative aims to reduce the global mortality rate of breast cancer by 2.5 % annually, thereby reducing breast cancer deaths by 2.5 million worldwide between 2020 and 2040, meanwhile a 25 % reduction in breast cancer deaths by 2030 and a 40 % reduction in breast cancer mortality among women under the age of 70 by 2040 are targeted (WHO, 2024). To achieve these goals, the importance of early detection and timely diagnosis is undeniable.

Currently, alcohol consumption is considered the main factor contributing to cancer-related deaths and Disability-Adjusted Life Years (DALYs) (Tran et al., 2022). In 2020, approximately 741,300 new cancer cases globally (4.1 % of the total) were attributable to alcohol consumption (Rumgay et al., 2021). Previous studies have consistently shown a strong correlation between breast cancer and alcohol consumption, with a consensus that even low levels of alcohol intake can increase the risk of developing breast cancer (Chen et al., 2011). A review study from Canada suggests that alcohol may increase the incidence of breast cancer through the mediating factor of phosphate toxicity (Brown et al., 2023). Another research indicates that the amount of alcohol consumed is related to breast cancer mortality (Escala-Garcia et al., 2020, Kwan et al., 2023). Participants who consumed four or more drinks per drinking occasion experienced an increased breast cancer-specific mortality, while those who drank less had a reduced mortality rate (Weaver et al., 2013). As for continued drinking behavior after diagnosis, a study found that alcohol consumption increased the risk of breast cancer recurrence only among pre-menopausal women (Kwan et al., 2010). Alcohol can promotes the development and metastasis of breast cancer by activating pathways such as Vascular Endothelial Growth Factor (VEGF) and Epithelial-Mesenchymal Transition (EMT) (Starek-Świechowicz et al., 2022). The previous studies have demonstrated, from a mechanistic perspective, the significant association between alcohol consumption and breast cancer incidence, mortality, and treatment. However, a macro-level quantitative assessment of alcohol's impact on breast cancer could provide a comprehensive reference for breast cancer prevention and control strategies.

Breast cancer is having an increasingly significant impact on population health, and therefore, many studies have analyzed the epidemiological trends of its disease burden and associated risk factors (Xu et al., 2023, Yuan et al., 2024). The Global Burden of Disease (GBD) study provides a comprehensive, multidimensional framework for assessing disease impact, utilizing DALYs and mortality rates as key indicators of disease burden, and spans a broad range of countries, time periods, age groups, and genders (Ferrari et al., 2024). By employing this framework, the GBD study calculated the disease burden of 88 risk factors in 204 countries and territories, revealing a substantial disease burden of breast cancer attributable to alcohol consumption (Brauer et al., 2024). Another global study evaluated the disease burden of cancer attributable to alcohol consumption, showing that approximately 13.3 % of all alcohol-attributable cancer cases were breast cancer (Rumgay et al., 2021). Although some studies have analyzed the impact of alcohol consumption on the disease burden of breast cancer, a comprehensive assessment stratified by region, age and sex is still lacking.

In this study, we employ the GBD statistical model to conduct a comprehensive evaluation of the disease burden of breast cancer related to alcohol consumption across different regions and countries. We quantitatively assess alcohol's impact on both mortality and disability-adjusted life years (DALYs) of breast cancer, with particular emphasis on examining how socioeconomic development, as measured by the Socio-demographic Index (SDI), modifies this disease burden. This systematic analysis offers valuable insights for evidence-based policymaking and supports the development of targeted interventions to reduce the global burden of breast cancer associated with alcohol consumption.