Friday, December 10, 2010

Another reversal of medical advice?

Doctors to re-think benefits of HRT after study shows oestrogen may protect women against breast cancer

Using HRT could protect some women against breast cancer rather than trigger the disease, according to controversial new research. It suggests a certain form of Hormone Replacement Therapy lowers the risk of the disease by at least a third.

The findings from researchers at a U.S. conference have been criticised for causing potential confusion among women who have been warned for several years that HRT causes a slight rise in the chances of developing breast cancer.

The latest research investigated the effect of using oestrogen only HRT, which is prescribed to women who have had their womb surgically removed. A new analysis of previously collected data shows that women with no strong family history of breast cancer who are taking oestrogen only HRT may be at a 30 to 40 per cent lower risk of cancer.

The findings were presented at the San Antonio Breast Cancer Symposium. Lead researcher Joseph Ragaz, medical oncologist and clinical professor in the faculty of medicine, School of Population and Public Health at The University of British Columbia, Vancouver, BC, Canada, said: 'Our analysis suggests that, contrary to previous thinking, there is substantial value in bringing HRT with oestrogen alone to the guidelines.

'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. 'These findings should intensify new research into its role as a protective agent against breast cancer.'

Prof Ragaz and colleagues reanalysed data from the Women's Health Initiative (WHI) hormone replacement therapy trials. The WHI study was launched in 1991 and included more than 161,000 U.S. women aged 50 to 79 years.

Prof Ragaz said many women had been deterred by WHI results showing more heart disease, stroke and cancer among HRT users, even though later analysis changed some of them. 'The WHI results as originally interpreted led to a major pendulum swing against HRT' he said.

About one million British women currently use HRT to combat symptoms of the menopause, down from the peak of three million women a decade ago.

The re-analysis found that sub-groups of women with no strong family history of breast cancer who received oestrogen alone had a significantly reduced risk of getting breast cancer. In addition, the 75 per cent of women without benign disease prior to the trial enrolment also had a lower risk.

Prof Ragaz said 'Reduction of rates of breast cancer in the majority of women who are candidates for oestrogen-based HRT is a new finding because oestrogen was always linked with a higher incidence of breast cancer.'

The paradox was caused by the fact that oestrogen helped drive the development of breast cancer when the hormone was produced by the body, yet did not do so when administered through HRT. Oestrogen given in this way 'is actually protective for most women' he said.

'The recommendations based on prior analyses of the results of the WHI HRT studies was not to use HRT, but we are optimistic this will change' he said. 'Our conclusion, based on the data presented, should enhance considerations for an early approval of HRT based on oestrogen-alone for the majority of selected women suffering with menopausal symptoms and galvanise new research on HRT for individual women.'

More than half of women taking HRT need to use another hormone called progestogen at the same time because it protects the womb against cancer. But these women appear to lose any breast cancer protection from HRT and may even run a higher risk of the disease.

Dr Tim Byers, professor of preventive medicine and biometrics at the University of Colorado in Denver, said the findings could create 'confusion' for patients and doctors.

Dr Susan Love, president of the California-based Susan Love Research Foundation, said: '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 womb removed and are low risk for breast cancer.'

Dr Sarah Rawlings, Head of Policy at Breakthrough Breast Cancer said: 'We’ve known for some time that HRT can affect breast cancer risk and this effect is different depending on the type of HRT used. 'Although further research is needed, these findings are interesting as they suggest that oestrogen only HRT may reduce breast cancer risk in some women.

'We’d encourage women to talk to their doctors about the risks and benefits of taking HRT and make a decision that is suitable for them.'


Peanut allergy treatment breakthrough

AUSTRALIAN scientists have identified "fragments" of a peanut's make-up that could underpin the world's first treatment for the often lethal food allergy. The research identified peanut proteins that lab tests showed were able to interact with immune cells from an allergic person, and so build tolerance, but they showed no sign of triggering anaphylaxis.

"These dominant fragments are the best candidates for a peanut allergy vaccine," said Professor Robyn O'Hehir who led the research at Melbourne's The Alfred hospital and Monash University.

"Immunotherapy is commonly used to treat people who are allergic to wasp and bee stings (where) protein extracts from the venom are given in increasing doses to desensitise the individual. "Until now, peanuts have been regarded as too dangerous an allergy-provoker to try immunotherapy, however the latest discovery overcomes this problem."

Professor O'Hehir said the peanut proteins could be translated into a therapy able to be go into clinical trials within three years and, if proven safe and effective, a world-first treatment could follow "within five to seven years". It would not be a once-off jab but instead people with the potentially lethal allergy would have a series of injections, over weeks or months, to gradually increase their tolerance.

The same research team has also made recent headway with grass pollen, with a desensitising therapy now in a clinical trial in the US.

Peanut allergy is the most common cause of life-threatening food reactions, including anaphylaxis. Professor O'Hehir said about one in every hundred in the population have peanut allergy and, of these, about one in four can have a life-threatening reaction. "We also know this is a growing problem but we don't know why peanut allergy is becoming more common," she said.

"It is a huge burden on the community - I think everybody knows somebody with a peanut allergy - and there are certainly more foods with hidden peanuts. "So this would be a huge benefit to patients, to have an effective and safe vaccine to treat peanut allergy."

The only approach now available to these people was to avoid all food containing peanuts and to carry an emergency dose of adrenaline should they accidentally eat the wrong thing.

The research was supported by the Ilhan Food Allergy Foundation, and is published in the Journal of Allergy and Clinical Immunology.


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