Kate Johnson

November 02, 2015

BALTIMORE — Cancer Research UK says it is "deeply concerned for women's health" after research presented here at the American Society for Reproductive Medicine 2015 Annual Meeting caused "extremely misleading" headlines in the United Kingdom about hormone replacement therapy (HRT) and the risk for cancer.

"Using HRT is safe," according to the headline in the Guardian, and the front page of the Mirror declared: "It's official: HRT is NOT a danger to women as experts conclusively dismiss worries over safety."

But the researchers behind the small, Pfizer-funded, American study are bewildered by the reaction, which they say has misrepresented their work.

"They're certainly over-reading it," said investigator Frederick Naftolin, MD, DPhil, professor and director of reproductive biology research at the New York University School of Medicine in New York City. "This little tiny study is massively underpowered and of course wasn't designed to look at ovarian cancer, or any cancer for that matter," he told Medscape Medical News.

"The real thing we were looking at is body fat composition," said investigator Lila Nachtigall, MD, a professor at NYU Langone Medical Center in New York City. "We could never prove safety."

The retrospective cohort study involved 136 postmenopausal women: 56 had taken no HRT and 80 had been taking HRT for an average of 14 years.

All patients underwent dual-energy x-ray absorptiometry to assess the percentage of total body fat and total body lean mass — the primary outcomes. Secondary outcomes were body mass index and relevant comorbidities — such as osteoporosis, diabetes, hypertension, hyperlipidemia, and breast and gynecologic pathologies (including breast, endometrial, and ovarian cancers).

"We wanted to find out if HRT causes weight gain because that is a concern for many women," Dr Nachtigall explained.

In a nutshell, there was no difference in body composition between the women who had taken no HRT and those who had, and there was a "lack of difference in medical comorbidities," according to the investigators.

Yet without seeing the study details, Cancer Research UK swiftly cited poor science.

"It's wrong to claim definitive evidence based on one small study," Harpal Kumar, chief executive officer of Cancer Research UK, said in a press release.

"The first thing to say, even without having seen the finer details of the research, is this is far too small a study to base health advice on," according to a Cancer Research UK science blog.

Dame Valerie Beral, from the University of Oxford in the United Kingdom, and from Cancer Research UK, where she headed the Million Women Study on HRT, took to the airwaves. "There are over 50 studies worldwide that in total have studied several million women, and to base advice on the results of 80 women, even over 10 years, is quite meaningless," she said on BBC radio.

But when Medscape Medical News asked Cancer Research UK how the study findings could have been interpreted to reflect cancer risk, the group backtracked.

"As the research presented at the conference in Baltimore has not been peer reviewed or published, we cannot comment on the specifics of the study," said Fiona Dennehy, press officer at Cancer Research UK, despite previous comments from the organization.

There are some serious questions about the funding and the comments that rubbished previous studies.

There is a deeper issue, hinted Greg Jones, who is senior press officer at Cancer Research UK. "There are some serious questions about the funding and the comments that rubbished previous studies," he told Medscape Medical News.

Dr Naftolin said he is not surprised. "This is not the kind of response that is going to resolve anything. They have an axe to grind and they're grinding it," he said.

Both he and Dr Nachtigall do not claim to be neutral on the subject of cancer risk and HRT, and it is likely that their outspokenness has led to them being accused of "rubbishing" other studies.

The pair was involved in a recent letter (Lancet. 2015;12;386:1037) that criticized an affiliate of Cancer Research UK for its meta-analysis linking HRT to an increased risk for ovarian cancer (Lancet. 2015;385:1835-1842).

The meta-analysis by the Collaborative Group on Epidemiological Studies of Ovarian Cancer — which is funded by Cancer Research UK — "is a faulty paper and we pointed it out in our letter," said Dr Naftolin.

"It's uncalled for to say from this paper that women should be concerned for ovarian cancer if they take HRT. They have no evidence for that. We have serious concerns about the way the study was done. It's a meta-analysis of studies showing increased risk, and they left out the studies showing no increased risk," he said, adding that Dr Nachtigall was involved in one such study showing no increased risk (Obstet Gynecol. 1979;54:74-79).

Unlike Cancer Research UK, North American cancer groups are much less vocal about the issue of HRT.

The American Association for Cancer Research, the American Society of Clinical Oncology, and the American Cancer Society all told Medscape Medical News that they have no official position or recommendations about HRT.

The study was funded by Pfizer.

American Society for Reproductive Medicine (ASRM) 2015 Annual Meeting: Abstract O-12. October 19, 2015.


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