Risk of All-Cause Dementia, Alzheimer Disease, and Vascular Dementia in Breast Cancer Survivors
Alexandra Wennberg, Mozhu Ding, Maria Feychting, Karin Modig
Abstract
Background and Objectives: Now more than two-thirds of cancer survivors are aged 65 years or older, but evidence about their long-term health is thin. Cancer and its treatments have been linked to accelerated aging, so there is a concern that aging cancer survivors have an increased risk of age-related diseases, including dementia. Methods: codes. Survival analyses were conducted using age-adjusted subdistribution hazard models accounting for competing risk of death. Results: We did not observe an association between breast cancer survivorship and risk of all-cause dementia, AD, or VaD. However, in models stratified by age at cancer diagnosis, women diagnosed with cancer after age 65 years had a higher risk of all-cause dementia (subdistribution hazard ratio [SHR] = 1.30, 95% CI 1.07-1.58), AD (SHR = 1.35, 95% CI 1.05-1.75), and VaD (SHR = 1.64, 95% CI 1.11-2.43) in models adjusted for age, education, and country of origin. Discussion: Older breast cancer survivors who survive cancer have a higher risk for dementia than their peers without a cancer diagnosis, in contrast to earlier studies showing that prevalent or incident cancer is associated with a lower risk of dementia. With the older adult population growing rapidly and because cancer and dementia are 2 of the most common and debilitating diseases among older adults, it is critical that we understand the link between the 2.