Decline in HRT linked to reduced risk of breast cancer
By Sophie Borland
The safety of hormone replacement therapy has been thrown into doubt after research showed that withdrawing it from women reduced the risk of breast cancer.
Scientists found that a fall in the numbers of menopausal women taking HRT has coincided with a ten per cent decrease in cancer rates.
Fears over the treatment’s safety were first raised in 2002 when a major US study linked it to breast cancer, heart disease and strokes.
The study suggested women who did not have HRT had postponed breast cancer by two or three years
It led to thousands of British women abandoning the pills, and within three years the numbers using it had halved to one million.
But its link to breast cancer has since been disputed and in 2007 another study found that the risks only applied to those in their seventies and eighties - much older than women who usually take HRT.
Now Canadian researchers have found that the decline in use of HRT prompted by the health scares coincided with a ten per cent fall in breast cancer rates in their country.
They found the biggest decline in use of HRT was between 2002 and 2004, when the proportion of women taking it fell from 12.7 per cent to just 4.9 per cent.
Over the same time period the number of breast cancer diagnoses fell by 9.6 per cent.
But the researchers also said that they did not think HRT actually caused breast cancer, it merely encouraged it to develop several years earlier.
So women who developed tumours whilst taking the treatment may well have got them anyway.
The study found that the cancer rates began to rise again in 2005, suggesting that women who did not have HRT had postponed breast cancer by two or three years
Dr Pritwash De, from the Cancer Control Policy, at the Canadian Cancer Society said: 'The nearly 10 per cent drop in invasive breast cancer incidence rate coincided with the decline in the use of hormone replacement therapy reported among Canadian women aged 50–69 years.
'The tandem drop in breast cancer incidence and use of hormone replacement therapy is a phenomenon that has been reported internationally.
'The results support the hypothesised link between the use of hormone replacement therapy and invasive breast cancer incidence and indicate that the sharp decline in
breast cancer incidence in 2002 is likely explained by the concurrent decline in the use of hormone replacement therapy among Canadian women.
'To our knowledge, this is the first Canadian study to examine the link between population-level declines in the use of hormone replacement therapy and breast cancer incidence among postmenopausal women.'
HRT usually prescribed to women in their 50s to treat the symptoms of menopause such as hot flushes, night sweats and mood changes, and it can also protect the bones.
Around 2.6 million women in Britain are currently prescribed the treatment, which can be taken via a range of methods, including tablets, implants, skin gels and patches.
This number has fallen from 6.2 million in 2001, before the breast cancer study was published.