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| Epidemiologist Dame Valerie Beral, who headed the UK Million Women Study (Photo source: http://www.theage.com.au/national/breast-cancer-pioneer-now-honoured-at-home-20100613-y5yo.html) |
It’s been more than a decade since the risks of Hormone Replacement Therapy was first brought to the world’s notice. The startling findings were reported by the Women’s Health Initiative (WHI) trials conducted in the US. These were then confirmed by the UK Million Women Study, the largest study of its kind in the world.
While the WHI Postmenopausal Therapy Trials were part of an effort to address the high risk of cardiovascular disease in older women, the Million Women Study looked at how various reproductive and lifestyle factors affect women’s health - in particular, hormone replacement therapy.
Boon to bane
Within no time, what was till then considered a boon to womankind began to be looked askance at. The trade-off between weight gain, hot flushes, dryness of the vagina (though, granted, these are the least of the problems) and breast cancer was ridiculously skewed.
And of course, the risks didn’t stop with breast cancer. Women taking HRT over an extended period of time also had an increased risk of cardio-vascular disease, increased risk of stroke, blood clots and pulmonary embolism. There was also no effect on the weight gain that is often a part of menopause as well.
Was it all bad?
No. What was good was it definitely reduced the frequency of hot flushes and that of fractures.
The findings of the risks changed health policy in many places around the world and HRT began to be viewed not as a panacea for women but as a therapy that should be advised for specific problems, and more often than not, in low doses and over short periods of time.
Did Cochrane have a role to play?
Yes, it did. There was no way Cochrane could have or would have avoided looking at a health-care issue of such magnitude – affecting women across the world.
Over the years, there have been many Cochrane reviews that looked at the risks and benefits of Hormone Replacement Therapy, both with oestrogen alone and with a combination of oestrogen and progesterone. And through its Evidence, Cochrane was able to bring to light many more risks like increased risk for cancer of the gall bladder and for dementia in older women who have taken it for over five years. The evidence provided by Cochrane went on to further change health policy.
The Cochrane review
The summary of the review on long-term hormone therapy for peri-menopausal and post-menopausal women which involved 41,904 women aged 26 to 91 years says:
In healthy women (11 studies), combined continuous HT significantly increased the risk of obstruction of a vein by a blood clot (venous thrombo-embolism), fatal or nonfatal heart attack (after one year’s use), stroke (after three years), breast cancer, gallbladder disease and (in women over 65 years) dementia. Long-term oestrogen alone significantly increased the risk of venous thromboembolism, stroke and gallbladder disease. Among women with cardiovascular disease (six studies) long-term use of combined HT significantly increased the risk of venous thromboembolism, particularly in the first two years of use, and gallbladder disease. HT offered the benefit of a significant reduction in the risk of fracture (no greater in women at high risk of fractures) or colorectal cancer but only after four or five years’ treatment with HT, while the highest risk of cardiovascular events with combined HT occurred in the first year of use.
All this may not be anything new to a lot of you but unfortunately, there are many women who are still in the dark about the risks of Hormone Replacement Therapy and go into treatment uninformed.
This post, a day after the 10th anniversary of the release of the results of the Women's Health Initiative (WHI), was intended to once again bring this issue into focus and throw light on areas that are half-lit in many a woman’s and man’s mind.
www.cochrane-sacn.org
