New study links combined hormone therapy with increased risk of breast cancer death.
A large study of the effects of hormone replacement therapy for post-menopausal women was stopped in 2002 when researchers found it increased the risk for health problems, including breast cancer.
Those hormone-related cancer cases were thought to be caught early, and survivable.
Now long-term follow-up research of those women on combined hormone therapy, estrogen plus progestin, finds the longer breast cancer patients had been on hormone therapy, the more advanced their cancer was at diagnosis.
"They develop worse breast cancers and they do worse with their breast cancer," says Dr. Jennifer Litton of the MD Anderson Cancer Center in Houston, Texas.
There was a small increase in hormone therapy-related breast cancer deaths.
"For every 10,000 women per year, 1-2 extra deaths from breast cancer that were noted," says Dr. JoAnn Manson.
Dr. Manson, of Brigham and Women's Hospital in Boston, is one of the researchers in the new study.
She says women who went off the hormone therapy greatly cut their chances of developing cancer.
"But a small amount of risk persists and we don't yet know how long that risk persists," she says.
Some women turn to hormone therapy when their hot flashes and other symptoms of menopause become too much to bear.
Experts generally say women with a low risk for breast cancer can use hormone therapy for a short time to get their symptoms under control if it's absolutely necessary but it should be a last resort.
The bottom line according to this new research: The risks of hormone therapy may be greater than any benefit.
Other drugs and lifestyle changes are available to help ease the symptoms of menopause.
Doctors say it's a complicated issue that should be personalized based on a patient's medical history.