(HealthDay News) — For women with breast cancer, hormone-modulating therapy (HMT) is associated with reduced risk of Alzheimer disease and related dementias (ADRD), according to a study published online July 16 in JAMA Network Open.

Chao Cai, PhD, from the University of South Carolina in Columbia, and colleagues examined the association between HMT for breast cancer treatment and the risk of developing ADRD among women aged 65 years or older in a cohort study.

Of 18,808 women aged 65 years and older diagnosed with breast cancer between 2007 and 2009, 65.7 and 34.3% received and did not receive HMT, respectively, within three years after diagnosis. The researchers found that during an average of 12 years of follow-up, 23.7 and 27.9% of HMT users and non-HMT users developed ADRD. Overall, HMT was associated with a reduced relative risk of ADRD (hazard ratio [HR], 0.93). The association varied by race and decreased with age. The greatest reduction in ADRD risk associated with HMT was seen for women aged 65 to 74 years who self-identified as Black (HR, 0.76); among women aged 75 years or older, the association was attenuated (HR, 0.81). The relative risk reduction was lower for women aged 65 to 74 years who self-identified as White (HR, 0.89) and was no longer significant for those aged 75 years or older. No significant association was seen for HMT and ADRD for other races.

“Further research is warranted to validate the observed associations in diverse populations and to elucidate the mechanisms underlying our observations,” the authors write.

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