Hormone therapy (HMT) for breast cancer has been linked to a 7% lower risk of developing Alzheimer’s disease and related dementias (ADRD), according to a large study published in JAMA Network Open. This study, led by Francesmary Modugno and Chao Caiemphasizes the need for personalized treatment plans for breast cancer patients to optimize outcomes and minimize risks.
HMT blocks hormones from attaching to receptors
Approximately two-thirds of breast cancer patients have hormone receptor-positive tumors, which grow in response to estrogen or progesterone. HMT helps these patients by blocking the hormones from attaching to the receptors, thus impeding tumor growth. While HMT increases survival rates, its impact on the risk of developing ADRD has been debated.
The study analyzed data from women aged 65 and older diagnosed with breast cancer with no previous ADRD diagnosis or history of using HMT before their cancer diagnosis. Out of 18,808 patients, 66% received HMT within three years of their diagnosis. Over an average of 12 years of follow-up, 24% of HMT users and 28% of non-users developed ADRD.
The researchers accounted for age-related death risk and HMT exposure duration, finding that HMT use generally decreased the relative risk of ADRD. The protective effect was most significant in patients aged 65-69 and decreased with age, with an increased ADRD risk in HMT users over 80.
HMT may reduce ADRD risk in younger women
Cai noted that younger women might benefit more from HMT in reducing ADRD risk, while benefits decrease for women aged 75 and older, especially among white women. Black women aged 65-74 who used HMT had a 24% reduction in ADRD risk, which dropped to 19% after age 75. White women in the same age range had an 11% reduction, with no benefit observed after age 75.
Modugno highlighted the need for further investigation into racial disparities, considering Black women have higher breast cancer rates and stress due to structural racism, possibly affecting outcomes.
Cai concluded that the relationship between HMT for breast cancer and dementia risk is complex and multifactorial, necessitating ongoing research to understand the mechanisms and provide clearer guidance on HMT use.
