Women younger than 45 years who have both ovaries removed surgically and do not receive adequate hormone replacement therapy are more likely to die from several causes, according to an Article in the October issue of The Lancet Oncology. Deaths from hormone-related cancers and diseases of the brain or cardiovascular system increased by 1•6–6•0 times for women in this age-group compared with those in the reference population who had not had their ovaries removed. The increased risk was seen mainly in women who were not given oestrogen after surgery until at least the age of 45 years (within 5 years of the median age of normal menopause). The increased risk became evident only 10 or more years after the procedure.
Dr Walter Rocca, a neurologist and epidemiologist at the Mayo Clinic, Rochester, MN, USA, made this discovery serendipitously while investigating links between ovary removal and brain diseases such as Parkinson's disease and dementia. The researchers showed that, overall, the risk of death was not increased in women who had both ovaries removed. However, in those that were aged 45 years and younger, the risk was 1•6 times higher than in the referent women, and this risk increased to 6•3 times when considering deaths from neurological causes. Dr Rocca explains that if a woman younger than 45 years has cancer of the ovaries or a benign disease in the ovaries that requires removal, however, there is still compelling reason to remove the ovaries for treatment. Removal should also be considered in older women and in women with a very high risk of ovarian cancer, he says.
In their study, Dr Rocca and colleagues followed up 1293 women who had undergone removal of one ovary and 1097 who had had both ovaries removed, and compared their results with those for 2390 women who had not undergone ovariectomy. All the operations were done before menopause and for reasons other than cancer. The women were all followed up until their deaths or until the end of the study, which was staggered between 2001 and 2006, via a combination of interviews with the women or a surviving relative, medical records, and death certificates.
The findings from this study also have general research implications for the role of oestrogen, according to Dr Rocca. "Our results confirm that oestrogen is probably protective of the brain and cardiovascular system," he says. "They also further establish that the effects of oestrogen are age-dependent: oestrogen may be clearly useful and protective at younger ages, but it may become less important after menopause and then have no effect or it may cause a disadvantage if given as treatment in later years."
Contact: Lisa Lucier T) 507-284-5005 (days); 507-284-2511 (evenings) newsbureau@mayo.edu
Journal
The Lancet Oncology