Women Prescribed High Dose Hormone Therapy, Despite Known Risks
A study from Stanford researchers shows many women are still receiving high dose hormone therapy, despite clinical evidence of higher risk of breast cancer and heart disease. The scientists say the findings are "disappointing", given the fact that low dose hormone replacement therapy is less risky and works to relieve menopausal symptoms.
A 2002 study compared heart disease risk in women given high dose hormone replacement therapy, but was stopped because estrogen and progestin therapy increased the chances of heart disease and breast cancer. The findings were contradictory to the widely held belief at the time that hormone replacement therapy protected menopausal women from cardiovascular disease.
Senior author Randall Stafford, MD, PhD, associate professor of medicine at the Stanford Prevention Research Center says, "Yes, there was an increase in the use of low-dose preparations”, following the halted trial, “but it was not sizeable."
Less than one-third of women given low dose hormone therapy in 2009
The study showed that in 2009, less than one-third of women were given low dose hormone therapy. After the 2002 study, menopausal use of high dose hormones dropped 47 percent.
Since the trial, evidence shows low dose hormones can relieve hot flashes and other menopausal symptoms that Sandra Tsai, MD, MPH, clinical instructor of medicine and lead author of the new study says, "may incur lower risks of breast cancer and cardiovascular disease."
Another option for menopausal treatment associated with declining estrogen is hormone patches that deliver small doses. The researchers expected their study would show wider use of transdermal therapy.
Stafford says, “We thought that over time there might be greater tailoring of therapy based on characteristics of the individual woman. The bottom line is that over time we didn't see the level of refinement in clinical practice that we expected." They also anticipated hormone prescribing during and just after menopause, but instead found older women, at high risk for complications, taking the drugs.
Dr. Tsai says the reason so many women – especially those that are older – are reluctant to stop hormone therapy replacement. They may not understand the risks of heart disease, breast cancer and blood clots from high dose estrogen and progestin. Another reason for the continued practice may be that physicians see the immediate benefits for menopause symptom relief and are reluctant to change the way they practice.
"It takes a huge event to change clinical practice," Stafford said. "We haven't had that big, well-controlled clinical trial hitting the front page of the newspapers, demonstrating that the risks of standard-dose estrogen and progestin therapies are potentially much higher than at lower doses."
Dr. Tsai says it will take a cooperative effort between research institutions, drug companies and professional societies to get the word out that high dose estrogen, progestin therapy for menopause treatment is dangerous. She says, "It takes too long to disseminate research into practice.”
The researchers obtained data for the study from the IMS National Disease and Therapeutic Index that provides information about prescriptions given by physicians at offices and outpatient clinics.
The findings show that older women especially are still taking high doses of hormones after menopause, despite clinical evidence that lower doses are effective and safer. The study authors aren’t sure why physicians haven’t changed the way they prescribe.