Hormone Therapy in Breast Cancer Treatment: A Double-edged Sword Against Dementia

Introduction

A recent study has shed light on the potential neuroprotective effects of hormone-modulating therapy, commonly used in the treatment of breast cancer. This research suggests that such therapy may not only combat breast cancer but also provide a shield against Alzheimer's disease and related dementias, particularly among older women. The findings, which indicate a more pronounced benefit for younger Black women, open up new avenues for personalized treatment strategies in oncology and neurology.

The Cognitive Impact of Hormone-Modulating Therapy

Hormone-modulating therapy has been a staple in the treatment of hormone receptor–positive breast cancer. However, its cognitive effects and any potential links to dementia have remained largely unexplored. This study aimed to fillthis gap by examining the relationship between hormone -modulating therapy and the risk of Alzheimer's disease and related dementias in women aged 65 and above.

Methodology

The researchers delved into the SEER-Medicare database, a rich source of information on cancer patients linked with Medicare claims. They identified a cohort of women diagnosed with breast cancer and compared the incidence of Alzheimer's disease and related dementias between those who received hormone-modulating therapy within three years following their diagnosis and those who did not. To control for confounding factors, the study excluded women with a prior diagnosis of dementia or those who had received hormone-modulating therapy prior to their breast cancer diagnosis.

Key Findings

The study included 18,808 women, of whom 66% had received hormone-modulating therapy. Over a 12-year follow-up period, the incidence of Alzheimer's disease and dementia was 24% among those who received therapy, compared to 28% among non-recipients. This translates to a 7% reduced risk of Alzheimer's disease and dementia for those who underwent hormone -modulating therapy (hazard ratio [HR], 0.93; P=0.05). The benefits weremost significant among Black women aged 65-74, with a 24% lower risk (HR, 0.76), while the effect was less pronounced in those 75 and older (HR, 0.81). White women aged 65-74 who received hormone-modulating therapy also showed an 11% lower risk (HR, 0.89), but this association disappeared in older age groups. The use of aromatase inhibitors and selective estrogen receptor modulators was associated with a significant reduction in dementia risk.

Implications for Personalized Treatment

These findings underscore the importance of tailoring breast cancer treatment plans to the individual characteristics of each patient. The higher risk of Alzheimer's disease and dementia among Black women, in particular, highlights the need for a personalized approach. The study suggests that hormone therapy may offer additional cognitive benefits, protecting against cognitive decline beyond its established role in cancer treatment.

Study Details and Publication

The research, led by Dr. Chao Cai from the Department of Clinical Pharmacy and Outcomes Sciences at the University of South Carolina, was published in JAMA Network Open on July 16. The study was supported by the National Institutes of Health, the Carolina Center on Alzheimer's Disease and Minority Research pilot project, and the Dean's Faculty Advancement Fund at the University of Pittsburgh.

Limitations and Future Research

The study's scope was limited to women aged 65 and above, which may affect its applicability to younger women. The dataset lacked genetic information and detailed laboratory data related to dementia, which could be crucial for understanding the underlyingmechanisms. The study did not assess the duration of hormone-modulating therapy beyond three years or the specific formulations used, which could influence the results. Additionally, potential confounders such as variations in chemotherapy, radiation, and surgical treatments were not fully addressed. Future research shouldaim to expand the study's scope to younger populations, includegenetic and laboratory data, and account for a broader range oftreatment variables.

Conclusion

The study's findings provide a compelling argument for the consideration of hormone-modulating therapy in breast cancer treatment, not only for its established oncological benefits but also for its potential neuroprotective effects. As we continue to unravel thecomplex interplay between cancer treatment and cognitive health,studies like these pave the way for more personalized and holistic treatment approaches.

Disclosures

The study was funded by the National Institutes of Health, the Carolina Center on Alzheimer's Disease and Minority Research pilotproject, and the Dean's Faculty Advancement Fund at the University of Pittsburgh. The authors have reported no relevant financial disclosures.

The Way Forward

As we move forward, the implications of this study are far-reaching. It calls for a reevaluation of hormone-modulating therapy in the context of breast cancer treatment and opens up new avenues for research into the prevention of Alzheimer's disease and related dementias. The potential for hormone therapy to protect against cognitive decline adds a new dimension to the ongoing dialogue on cancer treatment and survivorship. With further research, we may be able to offer patients not only a chance at overcoming cancer but also at preserving their cognitive health in the longterm.