Breast Cancer Survival and Its Link to Reduced Alzheimer's Risk: The Role of Radiation Therapy

Recent research from Samsung Medical Center has revealed that women who survive breast cancer tend to have an 8% lower risk of developing Alzheimer’s dementia compared to women without cancer. Remarkably, this protective effect appears to be influenced by specific cancer treatments, particularly radiation therapy.

Breast cancer remains the most common cancer among women worldwide, with over 2.3 million diagnoses reported in 2022. Thanks to advances in detection and treatment, survival rates have improved significantly, surpassing 93% for early-stage disease. As a result, managing long-term health effects of treatment has become increasingly important. Among these concerns are cognitive issues, often described as 'chemobrain,' which involve memory lapses and concentration difficulties experienced during and after treatment.

There have been mixed findings regarding whether cancer survivors are at higher or lower risk of dementia. Some studies suggest a decreased incidence, while others note increased risk, especially in older women. To clarify this, a large study published in JAMA Network Open examined national insurance data, comparing Alzheimer’s disease (AD) development in breast cancer survivors and matched individuals without cancer.

The study analyzed data from 70,701 women treated for breast cancer between 2010 and 2016, alongside 180,360 control participants. Participants were monitored for an average of 7.3 years. AD diagnosis was confirmed through clinical diagnoses and prescribed dementia medications. Results showed that survivors had a slightly lower incidence rate of AD—2.45 per 1,000 person-years—compared to 2.63 per 1,000 in controls. Notably, women aged 65 and older experienced a more pronounced reduction in risk.

Interestingly, the decreased risk was most evident within the first five years following treatment, suggesting a window of short-term protection. After this period, the risk levels of survivors and controls converged. Further analysis indicated that radiation therapy was significantly associated with the reduced AD risk (adjusted hazard ratio of 0.77). In contrast, other treatments such as chemotherapy with anthracyclines and hormonal therapies like tamoxifen or aromatase inhibitors did not show a significant impact.

These findings suggest that breast cancer survivors, particularly those receiving radiation therapy, may experience a temporary reduction in Alzheimer’s disease risk. This insight opens avenues for improving cognitive health monitoring and developing targeted prevention strategies for cancer survivors as survivorship rates continue to grow.

Understanding the mechanisms behind this protective effect remains an area of ongoing research. It could involve immune response modulation, hormonal changes, or other treatment-related factors. Nevertheless, these results highlight the importance of personalized long-term care plans for breast cancer survivors, integrating cognitive health assessments into routine follow-up.

Source: https://medicalxpress.com/news/2025-06-surviving-breast-cancer-alzheimer-therapy.html