RECENT findings indicate the potential cognitive benefits of hormone-modulating therapy (HMT) for older women undergoing breast cancer treatment. Breast cancer is the most common cancer diagnosis among women in the US, with age representing a significant risk factor. Although incidence has been increasing, mortality rates for breast cancer have declined, with over 2.5 million breast cancer survivors over 65. HMT is the standard treatment regimen for breast cancer, and recent clinical trials and observational studies have indicated that HMT may modulate the risk of mild cognitive impairment and Alzheimer’s disease and related dementia (ADRD). Researchers conducted a cohort study to explore whether HMT affects the risk of developing ADRD.
The study utilised the Surveillance, Epidemiology, and End Results (SEER)–Medicare-linked database, analysing data from 18,808 women aged 65 and older diagnosed with breast cancer between 2007 and 2009. These women, who did not have a prior diagnosis of ADRD, were monitored to assess the impact of HMT on their cognitive health. The cohort was divided based on whether they received HMT within three years of their initial breast cancer diagnosis, with 12,356 women receiving HMT and 6,452 not receiving the therapy.
Over an average follow-up period of 12 years, the findings revealed a 7% relative reduction in the risk of developing ADRD among those who received HMT. Notably, this protective effect varied significantly by age and race. Women aged 65 to 74 who self-identified as Black experienced a 24% relative risk reduction, the most pronounced benefit observed in the study. In comparison, White women in the same age group saw an 11% reduction in ADRD risk. However, the protective association diminished with age. For White women aged 75 and older, the reduction in ADRD risk associated with HMT was not statistically significant. In contrast, Black women continued to experience a reduced risk even in the older age group, though the degree of protection decreased.
The study suggests that HMT might offer cognitive protection, particularly for younger older adults and those of Black ethnicity, but the benefits may wane as patients age. The authors call for further research to understand the mechanisms behind these age and racial differences and to refine guidelines for HMT use in older breast cancer patients.
Laith Gergi, EMJ
Reference
Cai C et al. Alzheimer disease and related dementia following hormone-modulating therapy in patients with breast cancer. JAMA Netw Open. 2024;7(7):e2422493.
