A recent study, published in JAMA has found an association between hormone-modulating therapies (HMT) used in breast cancer treatments and neurodegenerative diseases (NDD), like Alzheimer’s disease (AD) and dementia. It was observed that breast cancer patients treated with tamoxifen and steroidal aromatase inhibitors have very low chances of catching these neurodegenerative diseases.
Cohort study finds that for women undergoing breast cancer treatments, tamoxifen, examestane and anastrozole are associated with decreased risk of AD and other dementias later in life. @UAZCIBS https://t.co/M36fEbYkyr
— JAMA Network Open (@JAMANetworkOpen) March 25, 2020
The study was conducted by Gregory L. Branigan, B.S. and a Ph.D. candidate in medical pharmacology at the University of Arizona Health Sciences and his co-workers. They say:
As there is an increased life expectancy after the treatment, so before selection of the options available for breast cancer therapy, they must be evaluated for their potential risks and benefits associated with lower risk of developing NDD.
It was a retrospective cohort study that involved Humana dataset claims from January 2007 till March 2017. The Humana dataset is a collection of claims from a private payer and Medicare Insurance from all over the U.S. Out of 326,485 patient records, 57,843 were selected for the study. These breast cancer suffering women were aged between 45 years or older and diagnosed with NDD after one year of cancer therapy. Out of these, the patients on HMT were identified and were analyzed for the link between HMT exposure and NDD development. It was noted that tamoxifen and steroidal aromatase inhibitors exposure was associated with a decrease in the number of women who were diagnosed with NDD particularly for Alzheimer’s disease and dementia. The researchers concluded that HMT therapy can be useful in preventing AD and dementia in breast cancer patients prophylactically.
The hormone modulating therapy (HMT) for this study included raloxifene, tamoxifen and aromatase inhibitor. Other NDD studied were multiple sclerosis, Parkinson’s disease and the results were not significantly different in those with HMT exposure.
After skin cancer, breast cancer is the second most prevalent type of cancer in women. Almost 12.8% of all the women worldwide are diagnosed with breast cancer during their lifespan. In 2019, as many as 268,000 new cases of breast cancer were diagnosed. In the US alone, it is estimated that 3,477,866 women were living with breast cancer in 2016 and the tally continues to rise.
Due to early diagnosis and therapy, the mean 5-year survival rate (89.9%) has increased and the death rate has decreased considerably. So, the risk of acquiring other diseases increases as the survival rates in breast cancer improve. Aging breast cancer population has increased risk of developing NDD like Alzheimer’s disease, multiple sclerosis and dementia. Women are at two to three fold higher risk for developing these than men.
Breast cancer therapies include radiotherapy, chemotherapy, surgery, biologics and hormone modulation therapies which include selective estrogen receptor modulators, like tamoxifen, and aromatase inhibitors, like exemestane and anastrozole. These drugs are good treatment options for pre- and post-menopausal women with estrogen positive type of breast cancers.