Disparities in the Diagnosis and Treatment of Breast Cancer Among People With Disabilities.

Importance: Breast cancer is the most common cancer among women worldwide, yet individuals with disabilities may face substantial barriers affecting their diagnosis and treatment outcomes. Objective: To examine disparities in the diagnosis, treatment, and survival outcomes of patients with breast cancer and disability compared with those without disabilities. Design, Setting, and Participants: This retrospective cohort study linked the January 1, 2012, to December 31, 2019, Cancer Public Library Database records with the Korean National Disability Registration System, with follow-up through December 2020. The participants were women age 30 years or older with a diagnosis of breast cancer. Exposure: Presence and severity of medically verified disabilities, including physical, brain, sensory, and additional impairments. Main Outcomes and Measures: The primary outcomes were cancer stage at diagnosis, receipt of standard treatments (surgery, chemotherapy, or radiotherapy), and overall mortality. Multivariate logistic and Cox regression models adjusted for demographic, clinical, and socioeconomic factors. Statistical analyses were conducted in April 2025. Results: Among 150 412 women with breast cancer, 7443 (4.9%) had disabilities and 142 969 (95.1%) did not. Patients with disabilities were more likely to be aged 65 years or older (3068 patients with disabilities [41.2%] vs 20 182 patients without disabilities [14.1%]). In particular, those with severe disabilities were more likely than patients without disabilities to receive a diagnosis at distant (505 patients with disabilities [6.8%] vs 6601 patients without disabilities [4.6%]) or unknown (308 patients with disabilities [4.1%] vs 3518 patients without disabilities [2.5%]) stage. They were also less likely to undergo surgery (adjusted odds ratio [aOR] 0.91; 95% CI, 0.85-0.98), receive chemotherapy (aOR, 0.77; 95% CI, 0.73-0.81), or receive radiotherapy (aOR, 0.85; 95% CI, 0.79-0.90). The disparity was most pronounced for patients with severe brain impairments. Overall mortality was significantly higher among patients with disabilities (adjusted hazard ratio [aHR], 1.59; 95% CI, 1.50-1.69), particularly among those with severe disabilities (aHR, 2.15; 95% CI, 1.98-2.33). Conclusions and Relevance: In this cohort study of women with breast cancer, those with disabilities experienced significant disparities in stage at diagnosis, treatment access, and survival outcomes compared with those without disabilities. These findings highlight the critical need for targeted interventions to address disability-related barriers and ensure equitable health care.