Hormones' Role In Cancer Gets Worse
Replacement therapy not only fuels the growth of breast cancer, it makes tumors harder to detect, research saysJun 25, 2003 | St. Petersburg Times
Millions of women stopped taking hormone therapy last summer after a landmark study showed it increased the risk of breast cancer, heart disease and stroke.
Now, the latest research from the same study is sounding more alarms about a drug once billed as a risk-free elixir against aging.
Women taking the hormones estrogen and progestin not only were more likely to get breast cancer, but their tumors also were more likely to have spread beyond the breast and to be slightly larger when diagnosed, the study said.
They also were more likely to have abnormal mammogram results, prompting more tests to rule out cancer, says the study, published today in the Journal of the American Medical Association.
The new data "provides further compelling evidence against" using hormones, says a Journal editorial, which adds that taking them long-term is "fraught with hazard."
"It may be that there are women who have terrible menopausal symptoms, for whom short-term therapy may be okay," said Peter Gann, professor at Northwestern University's Feinberg School of Medicine and co-author of the editorial.
Some earlier studies had suggested that tumors linked to hormone therapy might be more localized and more easily treated. But the new study, from the Women's Health Initiative, said the opposite.
"That's the shocker in this study," said Anna Parsons, associate professor of obstetrics and gynecology at the University of South Florida's College of Medicine. "When you have advanced stage (cancer), that automatically makes the prognosis worse."
Doctors stressed that the risk of getting breast cancer after taking hormones is small, eight more invasive breast cancers in 10,000 women taking hormones for one year.
But for decades, doctors prescribed a combination of the hormones estrogen and progestin to millions of women going through menopause, even those not suffering symptoms.
The hormones came to be seen as a fountain of youth, one that not only would get rid of the hot flashes and night sweats that can accompany menopause, but also protect against heart disease, stroke and bone loss.
"Everyone was taking (hormones) because of the advertisements: "You look younger, you feel younger,' " said breast oncologist Pamela Munster of the H. Lee Moffitt Cancer Center & Research Institute in Tampa. "But just for the rejuvenation of youth, that's not a good idea anymore."
Now, scientists say the early studies that promised so much were flawed. They observed only women who chose to take hormone therapy, pointed out Rowan T. Chlebowski, lead author of today's article.
"They were generally healthier," Chlebowski said. They weighed less, smoked less and were better educated than other women.
By contrast, the Women's Health Initiative assigned women at random to take either the estrogen-progestin drug Prempro or a placebo pill.
In the year since the health initiative was published, the number of women taking hormones has plummeted from about 6-million to 3-million, the Journal says. Doctors said hormone use is likely to drop even further now.
"Those women on the fence may get off the fence and say, "That's it, I'm coming off,' " said gynecologist Wulf Utian, executive director of the North American Menopause Society.
The study followed 16,608 women ages 50 to 79 who had gone through menopause and had not had a hysterectomy.
The study found that 245 women taking hormones developed breast cancer, compared to 185 women taking placebo pills. It also found 199 women on hormones with invasive cancer, compared to 150 without. Tumors were slightly larger, more likely to have spread to the woman's lymph nodes and more likely to be diagnosed at an advanced stage.
After the first year, 9.4 percent of the women receiving hormones had an abnormal mammogram, compared to 5.4 percent of the others. Across the nation, that would mean about 120,000 extra mammograms each year, the study's authors said.
Some doctors were cautious about the study. Utian said the news is significant, but disagreed with the "pretty scathing" editorial.
"I absolutely would not go that far," he said.
For women with severe symptoms, Utian said, the small increase in health risk may be worth it. Utian pointed out that the studied women averaged 63 years old and took hormones for years. That leaves some question about the risk level for younger women who take hormones for a shorter time.
Gilbert Shamas, a St. Petersburg ob/gyn, said he still prescribes hormones after discussing the risks and benefits with each patient.
"A lot of our patients stopped cold turkey" last summer, Shamas said. Many "came back kind of sheepishly and said "I'd rather be dead' " than not return to hormones.
Parsons said she's already finding other ways to treat patients.
"The trend is to find nonhormonal treatments because hormones just do too much," she said. "They're like having a key that opens every lock."
Parsons still prescribes hormones, but generally at lower doses or in different forms. Antidepressants can ease hot flashes, and drugs designed to treat osteoporosis can prevent bone loss, she said. Some patients turn to natural sources of estrogen, such as soybeans and black cohosh.
"We don't really know how to measure the effects of these, but in small amounts, they're low-potency," she said.
Hormones still are a valid choice for some, Parsons said.
"But what we've learned is it's not a tonic," she said. "You don't just give it to people thinking it's going to make them live longer. There's no reason to give it to women who don't need it."