Hormone therapy and cancer: New study

Seven's On Call with Dr. Jay Adlersberg
March 3, 2008 9:00:00 PM PST
We heard years ago about the dangers of hormone replacement therapy. Now, disturbing new information about women who stopped taking it, but remain at risk for cancer.The first follow-up of a landmark study of hormone use after menopause shows heart problems linked with the pills seem to fade after women stop taking them, while surprising new cancer risks appear.

The conclusion that heart trouble associated with hormones may not be permanent is good news for millions of women who quit taking them after the government study was halted six years ago because of heart risks and breast cancer. But the new risks for other cancers, particularly lung tumors, in women who'd taken estrogen-progestin pills for about five years puzzled the researchers and outside experts.

Dr. Gerardo Heiss of the University of North Carolina in Chapel Hill was lead author of the follow-up analysis. He called the results "completely unanticipated."

The analysis focused on participants' health in the first two to three years after the study's end. During that time, those who'd taken hormones but stopped were 24 percent more likely to develop any kind of cancer than women who'd taken dummy pills during the study.

"There's still a lot of uncertainty about the cause of the increased cancer risk," said analysis co-author Dr. JoAnn Manson, chief of preventive medicine at Harvard's Brigham and Women's Hospital.

The cancers included breast tumors, which also occurred more frequently in hormone users during the study.

The researchers noted that the increased risks for all cancers amounted to only three extra cases per year for every 1,000 women on hormone pills, compared with nonusers. Still, Heiss said the results suggest that former hormone users need to be vigilant about getting cancer screening including mammograms.

"Vigilance is justified," he said. "No alarm, but vigilance."

The authors said the new results send the same message they've been advocating ever since the study ended: Health risks from estrogen-progestin pills outweigh their benefits, and they should only be used to relieve hot flashes and other menopause symptoms, in the lowest possible dose for the shortest possible duration.

The new analysis appears in Wednesday's Journal of the American Medical Association.

A spokesman for Wyeth Pharmaceuticals, maker of the Prempro estrogen-protestin pills used in the study, voiced a criticism frequently cited by scientists, too - that participants were in their 60s on average, at least 10 years old than typical hormone users. The latest results thus may not apply to typical users because older women have different health risks than younger ones, including more cancers in general, said Wyeth's Dr. Joseph Camardo.

Women who feel they need hormone therapy should talk to their doctors about the risks and benefits to determine what's best.