Hormones Do Not Worsen Breast Cancer Prognosis, Study Shows
Feb. 4, 2000 (Los Angeles) -- Breast tumors in women using
hormone-replacement therapy (HRT) do not differ in severity from those in women
who did not use HRT and have a similar projected outcome, researchers in
Scotland have found. Their study appears in the current issue of the British
These findings come on the heels of two recent studies showing that HRT may
interfere with mammography results, and that combination HRT may increase a
woman's risk of breast cancer. The fact that the prognosis is no worse in women
who were using HRT "is reassuring to doctors prescribing
hormone-replacement therapy," the authors write.
"It is gratifying to know that this study did not show increased
aggressiveness in terms of tumor size and type in women who are on
estrogen," says Glen R. Justice, MD, medical director of the Orange County
Regional Cancer Center at the Fountain Valley Regional Medical Center in
Fountain Valley, Calif. Some investigators have even suggested that HRT might
make breast tumors more responsive to therapy, but Justice tells WebMD, "I
never did assume that people on hormones had a better prognosis, and I'm glad
this study debunks that myth."
To conduct their study, lead author Sheila Stallard and her colleagues at
the North Glasgow Hospitals University NHS Trust studied over 1,100 women who
were diagnosed with breast cancer between May 1988 and December 1993. A total
of 166 (14.9%) of the women were using HRT at the time they developed breast
cancer. When the authors analyzed each case for tumor type, grade, and size,
they found no difference between women who were taking HRT at the time of
diagnosis and those who were not.
"These findings are consistent with our general thinking of the way
estrogen is believed to act on breast tissue," says Anne Blackwood, MD,
assistant professor of medicine and epidemiology at the University of
Pennsylvania. She tells WebMD that in the U.S., women are more likely to be
screened for breast cancer when they receive HRT, which may promote earlier
diagnosis and a better long-term outcome. But "there are no long-term
follow-up data and no information on survival in this study, so we don't know
the impact on the prognostic factors of women who go off HRT and are treated
for their breast cancer." Neither she nor Justice was involved in the
HRT is still a valuable therapy, Justice tells WebMD. It can lengthen life
by as much as one year through a decrease in the risk of heart disease and
fractures from osteoporosis. However, women with a family history of breast
cancer or a biopsy showing any abnormalities should not take HRT and are
probably good candidates for the drug tamoxifen, which can decrease the risk of
breast cancer by 50% in high-risk women. According to Blackwood, "The key
issue is for each woman to have a clear discussion with her doctor, who will
have a better idea of her risk of breast cancer. For the average woman with no
breast-cancer risk factors, HRT remains a safe and viable option."
- Researchers analyzed a group of patients diagnosed with breast cancer and
found that those taking HRT had a similar tumor characteristics and prognoses
to those not taking the therapy.
- HRT can decrease the risks of heart disease and osteoporosis, but may
increase the risk of breast cancer.
- Women should discuss their individual risk profiles with their doctor when
deciding whether or not to take HRT or an alternative, such as tamoxifen.