The use of hormone replacement therapy by post-menopausal women is associated with an increased risk of ovarian cancer, according to a new Danish study.
Compared with women who never took HRT, current users had a 38 percent increased risk of ovarian cancer, according to the study published last week in the journal of the American Medical Association. That risk increased to 44 percent when restricting the analyses to cells covering the ovaries, the most common and most lethal of the ovarian cancers in postmenopausal women.
Although earlier studies also have suggested a link between HRT and ovarian cancer, this study was designed specifically to assess the risk. The study found an association regardless of duration of HRT use, dosage or how it was administered.
On a positive note, the risk of developing ovarian cancer declined with the number of years since a woman had used HRT, according to the study conducted by Lina Steinrud Morch of Rigshospitalet, Copenhagen University in Denmark, and colleagues.
The safety of using HRT in postmenopausal women has been debated for years, particularly after a major U.S. study by the Women's Health Initiative found in 2002 that those taking hormone replacement had greater risk for heart disease, stroke, blood clots and breast cancer. The announcement prompted doctors to severely cut back on prescribing hormone replacement that some people had lauded as a fountain of youth for older women.
Since then, new studies have found other risks of HRT.
Local gynecologic oncologists noted that the study showed an association, but not a causal link, between HRT use and ovarian cancer.
"There's been some suggestions on some other studies that looked at other issues giving an inkling there might be an association," said Dr. Jan Seski, director of gynecologic oncology at Allegheny General Hospital.
"It's interesting because it does reinforce that there may be an association between use of hormone replacement therapy and the development of cancer of the ovary, but the risk is very small, and it's not cause and effect. It's an association: People who take HRT seem to have a larger incidence of ovarian cancer. It's not a very large risk, but it's there.
"What it doesn't answer is: Does it cause ovarian cancer? Is it a causative? ... Or is it just something associated with a group of patients asking for hormone replacement therapy?"
Dr. John Comerci, director of gynecologic oncology at Western Pennsylvania Hospital, said the study was well-constructed but also noted that it proved association rather than cause.
"I think that you need several of these large cohort studies to confirm there really is an effect," Dr. Comerci said. "Also this study was done overseas and may not be reflective of American women. That said, it's such a large study and so well done that you have to sit up and take notice."
The Danish study concluded that risk of ovarian cancer is one of several factors to take into account when assessing the risks and benefits of hormone use.
Pohla Smith can be reached at firstname.lastname@example.org or 412-263-1228.