Breast cancer-menopause hormone link gets stronger

ATLANTA -- Research on two continents signaled more bad news for menopause hormones, offering the strongest evidence yet that they can raise the risk of breast cancer and are tied to a slightly higher risk of ovarian cancer.

New U.S. government numbers showed that breast cancer rates leveled off in 2004 after plunging in 2003 -- the year after millions of women stopped taking hormones because a big study tied them to higher heart, stroke and breast cancer risks. Experts said the leveling off shows that the 2003 drop in the cancer rate was real and not a fluke.

From 2001 to 2004, breast cancer rates fell almost 9 percent -- a dramatic decline, researchers report in today's edition of the New England Journal of Medicine.

The trend was even stronger for the most common form of the disease -- tumors whose growth is fueled by hormones.

Those rates fell almost 15 percent among women ages 50 to 69, the group most likely to have been on hormone pills.

At the same time, a study of nearly 1 million women in the United Kingdom showed that those who took hormones after menopause were 20 percent more likely to develop ovarian cancer or die from it than women who never took the pills. That study was published online by the London-based journal The Lancet.

For consumers, the new research doesn't change the advice to use the lowest dose for the shortest time possible for hot flashes and other menopause symptoms that can't otherwise be controlled.

For cautious scientists, the new breast cancer numbers were more evidence of the hormone-breast cancer link.

"The story has gotten stronger," said Peter Ravdin, a biostatistician at the University of Texas M.D. Anderson Cancer Center in Houston who led the research.

Some were skeptical several months ago when Ravdin and National Cancer Institute researchers first reported the 2003 drop in the breast cancer rate. The new numbers, which add 2004, prove it was no fluke, said Julie Gralow, a spokeswoman for the American Society of Clinical Oncology and cancer expert at the University of Washington.

"Because it didn't bump back up again," it supports the idea that the rate has stabilized at a new lower level, said Gralow, who had no role in the study.

Brenda Edwards, one of the journal authors who is a National Cancer Institute researcher, agreed.

"Now we have a statistically significant decline" over three years and clear proof of a trend, she said.

Although some recent analyses suggest heart risks from menopause hormones are not as great as had been believed for younger, newly menopausal women, the statistics out this week add to the worries about cancer.