Prostate cancer treatment and Alzheimer’s

Once again the treatment for a cancer can have cruel results. This will not be good news for a lot of people.
From the NY Times:

Hormone therapy, a common treatment for prostate cancer, is associated with an increased risk for Alzheimer’s disease, a new study has found.

The goal of hormone therapy, also known as androgen deprivation therapy, is to lower the level of male sex hormones, or androgens, that stimulate the growth of prostate cancer cells.

Researchers used records of 16,888 people with prostate cancer, of whom 2,397 were treated with hormone therapy. Over a median follow-up of 2.7 years, there were 125 new diagnoses of Alzheimer’s disease.

Over all, those treated with hormone therapy had an 88 percent increased risk of Alzheimer’s compared with other patients. The longer the hormone treatment, the more the risk increased, and patients with at least 12 months of treatment had more than double the risk. The study is in The Journal of Clinical Oncology.

The finding persisted after adjusting for race, smoking, cardiovascular disease, diabetes, prior cancers and other factors.

“It would not be appropriate to change the way we treat patients now,” said the lead author, Dr. Kevin T. Nead, a resident in radiation oncology at the University of Pennsylvania. “Androgen treatment is life-extending treatment, and very important. We found an association, but there is no evidence that hormone therapy causes Alzheimer’s.”

Androgens have been shown to affect the accumulation of amyloid plaques, one of the features of Alzheimer’s disease, and this may be one mechanism that could explain the finding.