Global inequality in burden of breast cancer from 1990 to 2019: a cross-national study

Background Breast cancer been the most commonly diagnosed cancer worldwide and contributes to great global disease burden. Exploring global inequality in breast cancer burden can help global collaboration to improve availability and equitable distribution of resources for BCa across countries Method We extracted data on age-standardized disability-adjusted life years rates (ASDRs) for breast cancer from 1990 to 2019 reported in the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. To assess global inequality, slope index of inequality (SII) and concentration index were calculated as absolute and relative metrics, corresponding with 95% confidence interval (CI). Results Varied ASDRs were observed across 204 countries and territories in both 1990 and 2019. The SII changed from 160.4 (95% CI, 128.6, 183.9) in 1990 to -125.1 (95% CI, -176.4, -86.3), highlighting that countries with the lower socio-demographic index were disproportionately burdened with higher disease burdens. The concentration index changed from 18.0(95% CI, 17.4, 18.3) in 1990 to 5.3 (95% CI, 4.4, 5.6) in 2019, indicting reduced relative health inequality from 1990 to 2019. Meanwhile, females reported higher ASDRs and exhibited greater global inequality in burden than males. Conclusion Countries with lower sociodemographic development would shoulder disproportionately higher burden of breast cancer. The shift in the disproportionate burden suggested the need of reasonable allocation of global resources, with a particular priority for low-income countries.