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.
"As is, in its current presentation, this abstract could only create confusion for providers and patients as a national news story," said Dr. Tim Byers, professor of preventive medicine and biometrics at the University of Colorado in Denver.
"The results are really four years old and have already been incorporated in current concepts regarding menopausal hormone therapy," said Dr. Rowan Chlebowski, principal investigator at the Los Angeles Biomedical Research Institute. Chlebowski was part of the group who published some of the initial WHI results. "They are certainly free to come to somewhat different conclusions regarding the WHI estrogen-alone trial, but perhaps they should be clear regarding what 're-analyzed' means."
"The women who took estrogen alone all had a hysterectomy," said Dr. Susan Love, president of the Dr. Susan Love Research Foundation. "The application of this study would not be as broad as the authors suggest because it would apply only to women who have had their uterus removed and are low risk for breast cancer."
Despite the conflicting messages, some women say they are willing to accept whatever cancer risk is associated with HRT in order to get relief from their menopausal symptoms.
Barbara Dehn, a San Francisco-based nurse practitioner in obstetrics and gynecology, has been on HRT for the past three years. Because she's a medical expert, she knows all the risks associated with her therapy.
"It helps, and it's made it so I can sleep reasonably," said Dehn, who is 52. "I get maybe one night sweat three or four nights a week, but that's much better than the 11 I used to get."
But the associated breast cancer risk is never far from her mind.
"Because my mammograms have been fine, I have no regrets about being on HRT, but I worry every time I have my mammogram."
Other women, like Ann Middleman of Long Island, N.Y., decided the risk -- whatever it is -- isn't worth it. She was on HRT for eight years, but when she learned from the 2002 WHI study that HRT is associated with increased breast cancer and also didn't protect against heart disease, she stopped the medication.
"In 2008, I found a small tumor in my breast that turned out to be malignant. Is there a connection? Who knows? But I won't be going back on HRT any time soon," said Middleman.
Dehn and other experts say while Ragaz's findings aren't new, the potential benefits of estrogen-alone therapy were overshadowed by the focus on the risks associated with combination therapy.
"It got ignored because we were focusing on the increased risk of estrogen plus progesterone," said Dehn.
"The publicity on hormone therapy has been so sensationalized and the risks so exaggerated that the view that any benefit can emerge from all of this has been lost to the public and mainstream medical profession," said Dr. Michelle Warren, professor of medicine at NY Presbyterian Hospital.
"This is interesting and provocative research that should lead to additional studies of the effects of E (estrogen) alone on the breast, and on breast cancer risk," said Dr. Seema Khan, co-leader of the breast cancer program at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University in Chicago, in an e-mail.
"The abstract being presented today provides more information on the WHI study and should be given attention by the media in order to let women know that the argument against post-menopausal estrogen use remains undecided," said Dr. Howard Zacur, director of the division of reproductive endocrinology at the Johns Hopkins Fertility Center in Lutherville, Md.
For women who may be wondering, in light of the latest findings, whether to go on HRT, Dehn shares some advice as a medical expert and a patient.
"It's a toss-up, a conundrum. There are lots of other women who don't get cancer. They should take the time to talk to their own personal healthcare provider and weigh the risks versus the benefits."