THE QUESTION Therapies that suppress male hormones, or androgens, have long been used to treat prostate cancer. However, possible negative effects of these androgen-deprivation therapies include sexual problems, weakened bones, mood swings and a loss of muscle and strength. Should an increased risk for Alzheimer’s disease be on that list as well?

THIS STUDY analyzed data on 16,888 men who had prostate cancer, including 2,397 who were treated with androgen-deprivation therapy. Most of the participants were in their late 60s or early 70s, and none had a history of dementia or stroke. In about a three-year span, 125 of the men were diagnosed with Alzheimer’s disease. Those treated with androgen-deprivation therapy were nearly twice as likely as the others to have developed Alzheimer’s, and those who had been given the hormone treatment for at least a year had more than double the risk for Alzheimer’s, compared with men who did not have this treatment.

WHO MAY BE AFFECTED? Men with prostate cancer, the third most common cancer in the United States. About 221,000 men develop this cancer each year, nearly all of them older than 40. Some types of prostate cancer grow slowly and require minimal if any treatment; other types can spread rapidly and require more aggressive treatment. Treatment options, depending on the type and extent of the cancer, include close monitoring but no treatment unless the cancer progresses, radiation, chemotherapy, hormone therapy and surgery, or some combination.

CAVEATS Data on some risk factors for Alzheimer’s disease, such as family history, were not available. Some men may have been given hormone therapy because they had other health issues, such as cardiovascular disease, that made them poor candidates for surgical treatment but that also were risk factors for Alzheimer’s. The study did not determine whether the stage, or extent, of prostate cancer affected the likelihood of developing Alzheimer’s.

FIND THIS STUDY Dec. 14 online issue of the Journal of Clinical Oncology. (jco.org; click on “Early Release”).

LEARN MORE ABOUT prostate cancer at cancer.gov and cancer.org.

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.