Hormone Use Linked to Cancer Risks
Tuesday, March 4, 2008; 11:06 PM
CHICAGO -- 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.
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.
Those risks "were completely unanticipated," said Dr. Gerardo Heiss of the University of North Carolina in Chapel Hill, lead author of the follow-up analysis.
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 initial study of 16,608 postmenopausal women was designed to examine pros and cons of taking pills long thought to benefit women's health. It was halted in 2002 when more breast cancers, heart attacks and related problems were found in hormone users versus nonusers.
There were some health benefits _ decreased risks for hip fractures and colorectal cancer _ but the follow-up found those also faded after women stopped the pills.