Keypoint: Cancer survival rates are worse in adults with female breast, colorectal, or lung cancer who also have an intellectual or developmental disability.
Patients with vs patients without intellectual or developmental disabilities have worse cancer survival rates, according to study findings published in the Canadian Journal of Public Health.
Researchers conducted a population-based retrospective cohort study to explore the association between intellectual and developmental disabilities and cancer survival in adults with female breast, colorectal (CRC), or lung cancer. Outcomes of interest included death attributable to any cause and death attributable to cancer. Statistical analyses included Cox proportional hazards models and competing events analyses.
The researchers sourced data from multiple linked databases in Ontario, Canada. Adult patients diagnosed with malignant breast (n=123,695), colorectal (n=98,809), or lung (n=116,232) cancer between 2007 and 2019 were evaluated for mortality on the basis of intellectual and developmental disability status. Requirements for intellectual and developmental disability status included the individual to have at least:
1 hospital admission,
1 complex continuing care admission,
1 emergency department visit,
1 home care visit, or
2 physician visits with an eligible diagnoses code in addition to a health encounter before cancer diagnosis.
Overall, 486 (0.39%) patients with breast cancer (28.4% aged 50-59; 100% women), 506 (0.51%) patients with CRC (24.1% aged 60-69; 56.3% men), and 385 (0.33%) patients with lung cancer (30.4% aged 60-69; 54.0% men) met the criteria for intellectual or developmental disability.
Among all cohorts, survival differed significantly on the basis of intellectual or developmental disability (P <.001). Compared with the patients with breast cancer, CRC, and lung cancer without intellectual or developmental disabilities, patients with these disabilities had lower 5-year overall survival rates across all cohorts (breast cancer: 81.7% vs 61.5%; CRC: 56.6% vs 34.2%; lung cancer: 19.7% vs 11.9%).
After adjusting for cofounders, intellectual or developmental disability was associated with worse overall survival among patients with breast cancer (adjusted hazard ratio [aHR], 2.74; 95% CI, 2.41-3.12; P <.001), CRC (aHR, 2.42; 95% CI, 2.18-2.68; P <.001), or lung cancer (aHR, 1.49; 95% CI, 1.34-1.66; P <.001).
Similarly, intellectual or developmental disability was associated with worse cancer-specific survival among patients with breast cancer (aHR, 2.28; 95% CI, 1.86-2.78; P <.001), CRC (aHR, 2.57; 95% CI, 2.26-2.92; P <.001), or lung cancer (aHR, 1.38; 95% CI, 1.21-1.57; P <.001).
After stratifying cancer-specific survival by patient characteristics, intellectual or developmental disability was determined to be a significant predictor for mortality among all subgroups with breast cancer except for those with tumor, node, metastasis (TNM) stage 0 or I (aHR, 0.86; 95% CI, 0.32-2.30); among all subgroups with CRC; and among all subgroups with lung cancer except for those aged 49 and younger (aHR, 0.89; 95% CI, 0.48-1.66).
Study limitations included documented prevalence of intellectual or developmental disabilities among patients with breast cancer, CRC, or lung cancer that were lower than estimated the prevalence of the same in Canada; potential misclassification of intellectual or developmental disability; the inability to differentiate types of intellectual or developmental disability; and loss to follow-up.
“High-quality knowledge to inform patient-centered, evidence-based care gaps for people with IDD [intellectual or developmental disabilities] and cancer is urgently needed,” the researchers concluded.
This article originally appeared on Neurology Advisor
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