Estrogen HRT: No Breast Cancer Risk
No Added Breast Cancer Risk With Estrogen-Only Hormone Replacement Therapy After Hysterectomy
"Women have been on a roller coaster ride. That ride is over," Taylor says. "For women with hysterectomy, the evidence is clear: Estrogen is safe for them. There is no breast cancer risk for estrogen alone. This has been the No. 1 fear keeping women from using estrogen for their menopausal symptoms."
While the study did not consistently find an overall reduction in breast cancer, the women on estrogen-only therapy did have significantly fewer cases of the most common kind of breast cancer -- ductal cancer.
"What was significantly decreased was ductal cancer, the most common form, a real reduction by almost 30% in the most common kind of breast cancer," Taylor says.
What about women who have not had a hysterectomy?
"As we see more detailed results from the WHI, we see there are some reassuring findings for women without hysterectomy," Taylor says. "In terms of heart disease, in younger women there is no increased risk. Ongoing studies with newly menopausal women are suggesting a benefit even with combined estrogen/progestin treatment. There was increased risk of breast cancer, but this number was very small. ... On balance, the risks of estrogen plus progestin are very low."
That's a controversial opinion. Boston University epidemiologist Lynn Rosenberg, ScD, recently analyzed data from a study of more than 23,000 black women. Reporting in the April 10 issue of the Archives of Internal Medicine, she finds that women who used hormone therapy -- even estrogen alone -- had a higher risk of breast cancer than women who never used hormone therapy.
"In my view, the weight of evidence would make me very suspicious of estrogen alone," Rosenberg tells WebMD. "It seems absolutely certain that estrogen plus progestin increases the risk of breast cancer, particularly if you take if for a long time."
Doctors currently prescribe hormone therapy for women who need help with the symptoms of menopause. Taylor says every woman with these symptoms is a candidate for this treatment, unless they have a high risk of breast cancer or a clotting disorder.
"The paradigm of treating menopause symptoms with the lowest effective dose of hormone therapy, for the shortest period necessary, is very sensible," Taylor says.