Global Burden, Quality of Care, and Attributable Risk Factors of Young-Onset Breast Cancer (YOBC) by WHO Regions: A Systematic Analysis for the Global Burden of Disease Study 2019.

[BACKGROUND] Young-onset breast cancer (YOBC) in females is often associated with aggressive features, but the current burden of YOBC remains poorly estimated. We aim to estimate the global and subregional estimate of YOBC and their attributable risk factors while evaluating the quality of care.

[METHODS] We retrieved data of YOBC from the Global Burden of Disease (GBD) 1990-2019 database. Incidence, mortality, and disability-adjusted life-years (DALYs) of YOBC and attribution to each risk factor were evaluated, stratified by WHO region. Trends were estimated from 1990 to 2019. A principal component analysis was conducted to produce the quality-of-care index (QCI).

[RESULT] In 2019, there were 168,775 new cases of YOBC in females, 42,742 deaths driven by YOBC and 2,468,523 DALYs due to YOBC globally (2010: 89,174 cases, 29,759 deaths, and 1,692,549 DALYs). The age-standardized incidence, mortality, and DALYs rate in 2019 were 11.5 per 100,000 women, 2.9 per 100,000 women, and 168.5 per 100,000 women, respectively. The growth predominantly occurs in African and Eastern Mediterranean regions. The burden of YOBC is shifting from Europe to the Asia-Pacific region, paralleling a concurrent shift in YOBC burden attributable to smoking and alcohol consumption. Global QCI value was 77, while the African region had the lowest QCI (31).

[CONCLUSION] This shift in the YOBC burden from Europe to the Asia-Pacific region mirrors the concurrent shift in burden attributable to smoking and alcohol consumption, further highlighting the necessity for targeted public health interventions in these regions.