Why hormone therapy for breast cancer may be associated with a lower risk of developing dementia

They found that the use of hormone therapy for breast cancer treatment was associated with a 7% lower risk of developing Alzheimer’s disease and other dementias later in life. (Getty)

Some types of breast cancer They are affected by hormones, such as estrogen and progesterone. Tumor cells have proteins that act as receptors that attach to these hormones, helping them grow. Treatments that prevent these hormones from attaching are called hormonal therapies.

Now, scientists in the United States have discovered that the use of hormone-modulating therapy for the treatment of breast cancer was associated with a 7% lower risk of developing Alzheimer’s disease and other dementias in later life. studywhich was published in the magazine JAMA Network Open, It also revealed that although this treatment was associated with protection against the development of dementia in general, the association decreased with age and varied by ethnicity.

“Our findings underscore the importance of taking into account individual patient factors when prescribing medications or developing treatment plans for breast cancer,” said lead author, Francesmary Modugnodoctor in Medicine and Public Health, professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh and a member of the Magee-Womens Research Institute and the UPMC Hillman Cancer Center.

“It is not a one-size-fits-all approach. We have to think about each individual patient to optimize outcomes and minimize risks,” he said.

It was also found that, although hormone therapy was associated with protection against the development of dementia in general, the association decreased with age and varied by ethnicity/Archive

About two-thirds of breast cancer patients have hormone receptor-positive tumors, meaning they grow in response to estrogen or progesterone. In these patients, hormone therapy can prevent tumor growth by preventing hormones from binding to these receptors.

Although use of the therapy is linked to increased survival, there was conflicting data about whether it increases or decreases the risk of developing dementias characterized by memory loss, changes in mood or behavior, and difficulties with thinking, problem-solving and reasoning.

To better understand the risk of dementia following the use of hormone therapies in breast cancer patients, Modugno teamed up with senior author Dr. Chao Cai, an assistant professor at the University of South Carolina School of Pharmacy.

They used a federal database of people aged 65 and older to identify women who were diagnosed with breast cancer between 2007 and 2009, and who did not have a prior diagnosis of dementia or history of hormone therapy use prior to their breast cancer diagnosis.

Two-thirds of breast cancer patients are known to have hormone receptor-positive tumors, meaning they grow in response to estrogen or progesterone. (Getty Images)

Of the 18,808 patients who met the criteria, 66% had received the therapy within three years of their diagnosis, and 34% had not. Over a median of 12 years of follow-up, 24% of the treatment users and 28% of the non-users developed dementia. They found that the protective effect of hormone therapy was most pronounced in patients aged 65 to 69 years and decreased with age. In particular, when patients were over 80 years of age, there was an increased risk of dementia in the treatment users.

“Our study suggests that younger women may benefit more from hormone therapy in terms of reducing the risk of developing Alzheimer’s disease and other types of dementia,” Cai said. She added: “The benefits of therapy were diminished in women aged 75 years or older, particularly those who identified as ‘white.’ This suggests that the timing of initiation of HMT is crucial and that treatment plans should be tailored to the patient’s age.”

Black women aged 65 to 74 who used the therapy had a 24% reduction in relative risk of developing dementia, which dropped to 19% after age 75. White women aged 65 to 74 had an 11% reduction in dementia risk with the treatment, but this beneficial association disappeared after age 75.

Francesmary Modugno was the leader of the investigation / Courtesy of Francesmary Modugno

“Black women have higher rates of breast cancer and tend to experience greater stress throughout their lives due to structural racism and other societal factors, which are associated with worse outcomes,” Modugno said. “We don’t know the mechanisms underlying the racial disparities we see with therapy and dementia risk, but it’s possible that these factors may contribute. This merits further investigation.”

The doctor Coronado Rainforestprofessor of Obstetrics and Gynecology at the Complutense University of Madrid and head of the Section of the San Carlos Clinical Hospital in Madrid and president of the Spanish Association for the Study of Menopausesaid: “I agree with what the authors say: treatment of women should always be individualized and, although with biases, it is the most relevant study published to date that reports that hormonal therapy for breast cancer has no adverse effect on the risk of dementia, and that depending on age and ethnicity it can be a beneficial factor (in addition to increasing breast cancer survival).”

For clinical practice, the results of the study will not have much impact, “since the indication of whether or not to use hormone therapy is established by protocol and improved survival has been seen; if it also does not affect memory, even better. In women over 75 years of age, where it does not seem beneficial, I do not think that treatment should be avoided if necessary due to this data. So more studies are needed,” Coronado told SMC Spain.