For years, doctors have warned women that taking hormone replacement therapy, or HRT, may be linked with an increased risk of breast cancer. Now, a controversial new paper suggesting that a particular form of HRT may actually lower the risk of breast cancer in some women is coming under attack from medical experts who say it could send the wrong message.
The research, presented at the annual San Antonio Breast Cancer Symposium, uses previously collected data to suggest that menopausal women with no strong family history of breast cancer who are on estrogen replacement therapy may be at a 30 percent to 40 percent lower risk of developing breast cancer.
But the findings are drawing fire from many doctors and researchers. ABC News Chief Medical Editor Dr. Richard Besser says the study suffers from a number of inherent weaknesses. Among them, he said, is the fact that the findings are being presented at a meeting and not in a peer-reviewed medical journal. This means that the study has not been analyzed by other researchers who could point out problems with study design or data interpretation.
Dr. Leslie Ford, associate director of the Division of Cancer Prevention at the National Cancer Institute also questioned the findings, saying there's no evidence that the researchers used the original data set to arrive at their conclusions.
Despite the criticism, the study's lead author stands by his research. Dr. Joseph Ragaz, medical oncologist and clinical professor at the School of Population and Public Health at The University of British Columbia in Vancouver, Canada, acknowledged the study results fly in the face of conventional thinking about finding contradicts a widely held belief about HRT.
"Our analysis suggests that, contrary to previous thinking, there is substantial value in bringing HRT with estrogen alone to [treatment] guidelines," said Ragaz in a press release. "The data show that for selected women it is not only safe, but potentially beneficial for breast cancer, as well as for many other aspects of women's health."
Ragaz and his colleagues re-analyzed data from hormone replacement therapy trials of the Women's Health Initiative (WHI), a national health study aimed at developing strategies for preventing heart disease, breast cancer, colorectal cancer and bone fractures in postmenopausal women.
Back in 2002, results from the WHI showed that HRT in the form of an estrogen and progesterone combination was associated with an increased risk of breast cancer. The WHI also looked at the effects of estrogen alone on breast cancer risk, but the results were not conclusive.
Ragaz said his findings are statistically significant, and should lead to a more intensive look at the use of estrogen-only therapy.
"The results show indisputably a reduction of breast cancer events," said Ragaz. Since the use of estrogen-only HRT is known to increase the risk of uterine cancer, his study only analyzed women who underwent hysterectomies.
While some medical experts say the findings aren't new and found fault with the analysis, others expressed concern that these findings could send conflicting messages to women who are either on HRT or are considering it.