Menopause Hormone Therapy: 'Safe' Time?
New Studies Probe Timing of Hormone Replacement Therapy and Breast Cancer Risk
First Two Years: 'Safe' or Not? continued...
Asked about that, Calle says that "theoretically, it could be that screening is not as effective in picking up these tumors" because of increased breast density while women are taking hormones. "We can't directly study that," says Calle, explaining that her team didn't have the women's mammograms to review. Calle says that Stefanick and Chlebowski's hypothesis is "not unreasonable," but that "there's not really a way to test it or to refute it" with the data she used.
The breast density issue "is something they could look at in a future study," says breast cancer specialist Jennifer Litton, MD, an assistant professor of medicine at the University of Texas M.D. Anderson Cancer Center. Litton wasn't involved in either study.
Bigger Risk for Leaner Women?
Calle and colleagues noticed that in their study data, there was a small but significantly increased risk of breast cancer among lean women taking estrogen only.
"This is not something that's a surprise," says Calle.
Women with higher body mass index (BMI) tend to have higher estrogen levels because their fat cells make estrogen, so taking estrogen may make a bigger difference to thin women's risk, explains Litton, who says she found the BMI results to be "really interesting."
BMI wasn't a factor in the WHI study, Chlebowski notes. That may be because the women in the WHI study were "heavy," says Calle.
Weighing the Risks and Benefits
"Every woman is different," says Calle. "Some women don't really need [hormone replacement therapy] at all. Some women suffer greatly, and it may be that it would be more difficult for them to use it for a short period of time, but women are very different in this regard."
Chlebowski agrees and says that the breast cancer risk from hormone therapy is "almost certainly going to be small for short-term use, and many, many women probably need to take something" to cope with menopausal symptoms.
Chlebowski points out that continuing hormone therapy for five years roughly doubles breast cancer risk. So he suggests that after three to five years on hormone therapy, women and their doctors consider stopping hormone therapy to see if it's still needed. That time frame isn't set in stone; Calle's paper suggests that the time frame might be more like two to three years.
Litton doesn't rule out hormone therapy for women with severe symptoms who haven't had breast cancer, but she says she wouldn’t feel comfortable not trying to ease women off hormone therapy "as soon as possible and certainly in two years."
Litton points out that there are ways to treat hot flashes and vaginal dryness without hormones. For instance, some doctors use antidepressants to treat menopausal symptoms. "I think we need to look more into ... non-hormone ways to manage these pretty significant side effects" of menopause, says Litton.