Estrogen Discouraged for Disease Prevention
New Findings continued...
Among the other findings reported in the newly released analysis:
- Long-term use of Premarin was associated with a 39% reduction in the risk of hip fracture. In earlier studies, combination estrogen/progestin treatment also had this effect.
- Premarin use was not associated with an increased risk of breast cancer. Previous studies have linked estrogen/progestin combination treatment to an increase in breast cancer.
- Treatment with estrogen alone was linked to an increase in deep vein blood clots in the legs but did not appear to increase the risk for blood clots in the lungs.
- The use of Premarin was not found to affect colorectal cancer risk. Combination estrogen/progestin treatment decreased the risk.
The WHI is also evaluating the use of estrogen for the prevention of age-related dementia and memory loss, and these findings should be published in about two months, Alving said.
Risk Appears Low for Younger Women
Although the reduced hip fracture findings from the WHI study are encouraging, the experts agreed that most women are better off taking other drugs approved for the prevention and treatment of osteoporosis, a common contributor to hip fractures.
"There are also intriguing findings starting to emerge suggesting that the dose of estrogen needed (to protect bones) is much lower than what is currently being given for osteoporosis prevention," WHI project officer Jacques Rossouw, MD, said during the news conference.
Studies have suggested that the increase in heart disease and stroke risk associated with menopausal hormone therapy may be confined to older women who are well past menopause before starting hormone therapy. Rossouw said that the risk of short-term use among younger women "is likely to be very low."
In a prepared statement, Premarin's manufacturer, Wyeth, points out that the average age of the women in the current study was 63 and says that in preliminary analysis of the study results, "it appears that the risks monitored in WHI were lower for women aged 50-59 and increased with age.
"While these results should be interpreted with caution, they appear to suggest that [Premarin] may have a more favorable risk profile for younger versus older women," says Wyeth.