Breast Cancer Survivors may have Lower Alzheimer's Risk, Linked to Radiation Therapy: JAMA

The reduced risk was particularly noticeable among survivors aged 65 years and older (SHR, 0.92; 95% CI, 0.85–0.99). However, a landmark analysis revealed that the lower risk of AD was no longer statistically significant after 5 years of survival, suggesting that the early survivorship period may uniquely influence cognitive outcomes.

Radiation therapy was linked to a notably lower risk of developing AD, with an adjusted hazard ratio (HR) of 0.77 (95% CI, 0.68–0.87). Meanwhile, anthracycline-based chemotherapy, often associated with cognitive complaints, did not significantly increase the risk of AD in this cohort. The findings showed that younger survivors had an overall lower incidence of AD when compared to older groups, and those who received radiation therapy experienced the lowest observed rates of AD.

Overall, this study contributes to the nuanced understanding of “chemo brain” and cognitive aging in cancer survivors. While treatment-related cognitive impairment remains a valid concern, this research suggests that some treatments may offer neuroprotective benefits, possibly through mechanisms related to inflammation, immune modulation, or vascular changes.

Reference:

Jeong, S.-M., Jung, W., Cho, H., Choi, H. L., Jeon, K. H., Nam, K.-W., Lee, Y.-G., Kim, B., Han, K., & Shin, D. W. (2025). Alzheimer disease in breast cancer survivors. JAMA Network Open, 8(6), e2516468. https://doi.org/10.1001/jamanetworkopen.2025.16468