Early oophorectomy may predict cognitive decline.(NEWS)

SAN DIEGO -- Women who underwent oophorectomy had an increased risk for developing dementia and cognitive impairment, especially if the surgery occurred before age 38, preliminary results from a large historical cohort study demonstrated.

Specifically, the risk for dementia and cognitive impairment increased 70% in women who underwent bilateral oophorectomy before age 46 and 260% in women who had unilateral oophorectomy before age 38, Dr. Walter A. Rocca reported in a poster session at the annual meeting of the American Academy of Neurology.

He cautioned that the findings are preliminary and noted that the data were obtained from telephone interviews and not from medical records or direct examinations. Still, he called the findings "important," especially for cases where women elect to undergo oophorectomy as a way to reduce the risk of ovarian cancer.

"It's a little bit counterintuitive that if you remove two ovaries you are almost better off than if you remove one," Dr. Rocca, a neurologist and epidemiologist at the Mayo Clinic, Rochester, Minn., said in an interview. "But there are two components here: the age at which the surgery is done, and also the possibility that the surgery itself may not be the full story. For example, we are looking at a genetic variant that may have to do with the synthesis of estrogen or the receptors for estrogen. We have been seeing that the genetic predisposition of women is very important, not just the surgery itself."

"Cancer of the ovaries is rare," he said. "On the other hand, if a woman faces low estrogen, she may get problems with osteoporosis, maybe myocardial infarction. So ... is it a good deal to do this preventive surgery or not? Before [this study] we didn't have the full picture. Now, the more pieces we put together, the more we can talk to women in an informed ...