The risk of dementia in breast cancer survivors: a meta-analysis of observational studies

Cognitive problems are among the most common post-treatment symptoms experienced by breast cancer patients, raising concerns about their long-term cognitive health. This meta-analysis aims to clarify the relationship between cognitive decline in breast cancer survivors and the risk of developing dementia. PubMed, Embase, and Cochrane Library were searched for cohort studies published from database inception to August 27, 2024, using medical subject headings (MeSH) and keywords. All statistical analyses were performed using Stata statistical software version 14.0. If p > 0.1 and I2 ≤50%, a fixed-effects model was adopted. If I2 > 50%, a random-effects model was adopted. The funnel plot and Egger's test were used to evaluate publication bias. The meta-analysis, comprising 9 studies and involving 887,678 individuals, revealed that breast cancer survivors did not exhibit an increased risk of all-cause dementia [RR = 0.997, 95%CI (0.965, 1.029); I2=0.0%, p = 0.386], Intriguingly, endocrine therapy [RR = 0.904, 95%CI (0.865, 0.946); I2 = 41.7%, p = 0.161] and chemotherapy [RR = 0.754, 95%CI (0.604, 0.940); I2 = 0.0%, p = 0.592] may even serve as potential protective factors against dementia in breast cancer survivors. This meta-analysis indicates that breast cancer survivors do not face an elevated risk of all-cause dementia. Furthermore, treatments such as endocrine therapy and chemotherapy may have a protective effect against dementia. Further research is needed to explore the underlying mechanisms and confirm these findings.