Background
People with disabilities experience higher morbidity and mortality, not only due to underlying conditions but also because of structural barriers, poorer healthcare access, and lower quality of care. Evidence shows persistent health inequalities, including in cancer outcomes. In breast cancer, women with disabilities face major barriers to screening, leading to later-stage diagnosis and worse prognosis. However, research on disability and breast cancer survival remains limited. Existing studies rarely differentiate disability types or fully account for socioeconomic status, psychosocial factors, and multimorbidity, all of which influence survival and are more prevalent among women with disabilities. The contribution of these factors and timing of inequalities remain underexplored.
Objectives
To estimate the excess mortality risk among women with disabilities diagnosed with breast cancer compared with women without disabilities. We also aim to examine how these inequalities evolve over time since diagnosis and to assess the contribution of stage at diagnosis, socioeconomic and psychosocial factors, and multimorbidity.
Methods
A population-based study using national registers for women living in Sweden anytime between 2008-2020 and diagnosed with breast cancer (stage I-IV) during this period, identified in the Breast Cancer Quality Register. Women with disability were compared to women without disability. Disability status and type were determined by register-based information up until the year preceding breast cancer diagnosis. All-cause and breast cancer-specific mortality was assessed through the Causes of Death Register. Follow-up started at diagnosis and ended at death, emigration or December 31, 2020, whichever occurred first. Cox models were used to estimate hazard ratios (HRs) and 95% CIs to estimate the associations between disability and mortality, after accounting for stage, calendar year and age at diagnosis, education, income, depression, civil status, and Charlson comorbidity index. Time-varying HRs were estimated when the proportional hazard assumptions was not satisfied. Differences in standardized survival probabilities were used to assess the contribution of different factors in explaining inequalities.
Results
The study included 4,242 women with disability and 26,299 women without. The risk for all-cause death (HR, 1.86; 95% CI: 1.70-2.04) and breast cancer-specific death (HR 1.52; 95% CI: 1.36-1.70) was higher for women with disabilities than without. When stratifying for stage at diagnosis, the increased risk for women with disability remained significant among those diagnosed at earlier stages. Stage at diagnosis accounted for 27% and 38% of the excess all-cause mortality and breast cancer–specific mortality, exceeding the combined contribution of socioeconomic, psychosocial, and multimorbidity factors. Inequalities were more pronounced in proximity of diagnosis for women diagnosed at stage I.
Conclusions
Even in countries with universal healthcare and disability-inclusive policies, women with disabilities are more likely to experience unequal breast-cancer consequences. Policy makers and the healthcare system should coordinate efforts to reduce disparities in stage at diagnosis and to identify potential barriers along the cancer treatment path.