Younger, premenopausal women with a much-higher-than average breast cancer risk -- such as women with an abnormal BRCA1 or BRCA2 gene -- have several options to significantly reduce that risk. One option is surgery to remove both ovaries -- called preventive bilateral oophorectomy. A study suggests that premenopausal women who have preventive oophorectomy to reduce breast cancer risk may be more likely to have low bone mineral density and arthritis.
The results were presented at the 2011 San Antonio Breast Cancer Symposium.
The ovaries are the main source of estrogen in premenopausal women. And because most breast cancers are hormone-receptor-positive, meaning they need estrogen to grow and develop, removing the ovaries can reduce breast cancer risk in high-risk premenopausal women by dramatically lowering their estrogen levels.
Still, there are side effects with oophorectomy. One is the abrupt onset of menopause at an early age, which can include menopausal side effects such as hot flashes, night sweats, and mood swings. Also, because estrogen also helps keep bones strong, lower estrogen levels can cause bone loss, which makes bones weak.
Researchers looked at the bone health, arthritis, and oophorectomy history of 3,660 women who had a bone mineral density test as part of the very large National Health and Nutrition Examination Survey (NHANES). Some of the women had osteoporosis (weakened bones) based on their bone mineral density levels. The researchers also looked at the records of 4,039 women who had answered a question about being diagnosed with osteoarthritis (the most common form of arthritis). Some of the women said they had been diagnosed with osteoarthritis. Some women in each group also had had bilateral oophorectomy.
The researchers looked for links between having had bilateral oophorectomy before age 45 and being diagnosed with osteoporosis and/or osteoarthritis.
Compared to women who didn't have bilateral oophorectomy, women who did were:
- more likely to have low bone mineral density scores
- 78% more likely to have osteoporosis
- 78% more likely to have been diagnosed with osteoarthritis
The higher risk of osteoporosis in women who had bilateral oophorectomy when they were younger isn't surprising since bone health is so dependent on estrogen. But the reasons for the higher osteoarthritis risk aren't so clear. Cartilage is a major part of a joint. Cartilage health somewhat depends on estrogen. Some experts think that the link between estrogen and cartilage health explains why women who had bilateral oophorectomy had nearly double the risk of being diagnosed with osteoarthritis.
If you're a premenopausal woman with a much higher-than-average risk of breast cancer and are considering bilateral oophorectomy to reduce your risk, it's a good idea to talk to your doctor about ALL your risk reduction options (including medicines and prophylactic mastectomy). You also may want to ask about the impact oophorectomy could have on your overall health and the steps you can take to minimize any unintended consequences of oophorectomy.
If you do have bilateral oophorectomy to reduce your breast cancer risk, be sure to talk to your doctor about your options for minimizing the effects of sudden menopause after the surgery and monitoring and managing your long term bone health.
The Breastcancer.org Bone Health pages have detailed information on how bone health is measured, how certain treatments can affect bone health, and tips to keep your bones as strong as they can be.