It seems like we're constantly getting new and sometimes conflicting information about the safety of using estrogen to control menopausal symptoms, particularly hot flashes. The latest in study on the topic, released yesterday, links the long-term use of estrogen plus progesterone and estrogen-only hormone therapy with an increased risk of breast cancer.
Women who still have their uteruses take the combined therapy because the progesterone prevents a potentially cancerous build-up of the uterine lining. Women who've had their uteruses removed take estrogen alone.
Earlier studies have shown a link between the combined therapy and breast cancer risk, especially when women take hormones for more than a few years. But this study indicates that women who are taking estrogen alone are also at risk if they are on hormone therapy for more than 10 years.
The data comes from the Nurses' Health Study, which followed the health of about 60,000 nurses who were 30 to 55 years old in 1976. The researchers found that there was an 88 percent higher risk of breast cancer in women who had taken the combined therapy for 10 to 15 years compared to women who had not taken hormone therapy at all. The risk increased the longer the women took hormone therapy.
In women who were taking only estrogen for 10 to 15 years, researchers found a 22 percent increased risk compared to women who had not taken hormone therapy. With these women as well, the risk increased the longer they were on hormone therapy.
Does this mean that you should completely avoid hormone therapy? There's no simple answer to that question. The current thinking is that you should only take estrogen to relieve specific symptoms, particularly hot flashes, and you should first try lifestyle changes that could help (like losing weight or quitting smoking).
If lifestyle changes don't provide adequate relief, then talk to your doctor about how your individual medical history might affect your risk.