Bone health monitoring should be mandated in women with deleterious BRCA mutations who undergo prophylactic bilateral salpingo-oophorectomy, researchers say.
A Canadian study of 95 women who underwent the preventive surgery at a mean age of 48 years, found bone density dropped significantly between pre-surgery DEXA scans and scans performed about one year later.
Among women who were premenopausal at surgery, there was a decrease in the BMD across the lumbar spine, femoral neck and total hip after oophorectomy.
In women who were postmenopausal at surgery, there was a smaller decrease in BMD across the lumbar spine and femoral neck but not the total hip.
Women who were pre-menopausal before surgery and received hormonal treatment had significantly less bone loss than other women.
“These findings strongly support including routine monitoring of BMD in this high-risk population and recommending adequate calcium intake, weight-bearing exercise, and the use of exogenous hormones among those without a history of breast cancer,” the researchers said.
About 45% of the women had a history of breast cancer and 34% had previously received chemotherapy.
The study found calcium and vitamin D use increased significantly from about 45% before surgery to 78% afterwards while selective estrogen receptor modulator use increased from 16% to 22%.
Commenting on the study for the limbic, Professor Mathis Grossmann said the effects of oophorectomy in pre-menopausal women were not surprising.
“There is no reason to believe that women with BRCA mutations should behave any different in terms of their bone responsiveness to oestrogens than women who don’t,” he said.
“I think what is a little bit surprising, but this might be because of the lack of a control group, is that the postmenopausal women also had bone loss with an oophorectomy.”
He said that lack of a control group meant there was no correction for the effect of age alone. The postmenopausal women were also relatively young and therefore early after menopause. And there were also possible confounding effects of other treatments including chemotherapy and bone loss due to immobility during cancer treatment, weight loss or glucocorticoid use.
“This really tells us that bone loss in these women is not just a matter of oestrogen deficiency but also all those other factors that are involved in their cancer treatment,” he said.
“I thinks it’s important to be aware that what they found in their retrospective single centre study is that really BMD testing wasn’t done consistently even in their institution.”
Professor Grossman, a consultant endocrinologist at Austin Health, Melbourne, said the study highlighted the fact that women who often have a good prognosis after breast cancer need to be evaluated for any negative effects of their cancer treatment on bone.
“The good news is that, if indicated, it looks like anti-resorptive treatment will prevent bone loss and probably reduce fracture risk -so that treatment is not only effective for bone health but there is also some evidence that it might also, in high risk women, reduce breast cancer-related outcomes e.g. skeletal events and bone metastases.”