Thousands of women at high risk of breast cancer could benefit from a daily pill that halves their risk of developing the disease, claim scientists
Taking the drug anastrozole for five years cuts the risk by 53 per cent compared with women taking a dummy pill.
Results from a new trial could transform the options for postmenopausal women with a family history of breast cancer or other risk factors.
A breast cancer prevention drug offers a new option to women at high risk of the disease. It means that, unlike Angelina Jolie and Sharon Osbourne, they might not feel they need to have their breasts removed
Earlier this year new NHS guidelines took the historic step of recommending for the first time the use of the drugs tamoxifen and raloxifene as a preventative measure for such women.
But latest research shows anastrozole is more effective, has fewer side effects and is just as cheap – costing around £120 in total for a preventive course of pills.
Tamoxifen cuts the risk of breast cancer by a third, with protection lasting up to 20 years, but it has menopause-like side effects such as hot flushes and more serious, rarer problems including an increased risk of cancer of the womb lining.
The guidance meant almost half a million healthy women at higher risk had a less drastic alternative to having their breasts removed, as chosen by celebrities including Angelina Jolie and Sharon Osbourne.
The new study looked at almost 4,000 postmenopausal women at high risk of breast cancer with an average age of 59. Half were given 1mg of anastrozole daily and half had a placebo.
In the five years of follow up 40 women in the anastrozole group developed breast cancer compared to 85 women in the placebo group – a cut of 53 per cent.
The results of the IBIS II trial, funded by Cancer Research UK charity, were published in The Lancet medical journal.
Professor Jack Cuzick, lead researcher and head of Queen Mary University of London’s Centre for Cancer Prevention, said: ‘This research is an exciting development in breast cancer prevention.
Taking the drug anastrozole for five years cuts the risk by 53 per cent compared with women taking a dummy pill. Image shows a molecular model of anastrozole
‘We now know anastrozole should be the drug of choice when it comes to reducing the risk of breast cancer in postmenopausal women with a family history or other risk factors for the disease.
‘This class of drugs is more effective than previous drugs such as tamoxifen and crucially, it has fewer side effects.
‘Unpleasant side effects such as acute aches and pains have often been associated with oestrogen depriving drugs.
‘However, in this study, the reported side effects were only slightly higher than in the placebo arm. This means most symptoms were not drug related, and the concern about side effects for this type of drug may have been overstated in the past.’
Research shows some women taking tamoxifen long-term are deterred by the side effects.
Professor Cuzick said the National Institute for Health and Care Excellence (Nice) should urgently re-visit its guidance to consider adding anastrozole to their recommended drugs for women predisposed to developing breast cancer.
Compared to tamoxifen, anastrozole is more effective, has fewer side effects and is just as cheap - costing around £120 in total for a preventive course of pills
‘By including this drug in their clinical guidelines, more women will benefit from this important advancement in preventive medicine’ he added.
Many breast tumours are fuelled by the hormone oestrogen. Anastrozole works by preventing the body from making oestrogen and, like tamoxifen, has for many years been used to prevent recurrence after surgery in women after the menopause.
Women were judged to be at high risk of breast cancer if they fulfilled one of the following criteria: having two or more blood relatives with breast cancer, having a mother or sister who developed breast cancer before the age of 50, and having a mother or sister who had breast cancer in both breasts, or having certain high risk types of benign breast disease.
Experts fear there may be a significant delay in reviewing the Nice guidelines because it has only just produced them.
The guideline development group also looked at drugs like anastrozole, but there wasn't enough evidence at the time to support them.
Professor Tony Howell, scientific director of the Genesis Breast Cancer prevention charity and one of the trial investigators, said: ‘This is a remarkable study as it has found that women get greater preventive benefit on anastrozole than either tamoxifen or raloxifene, which are currently prescribed by Nice.
‘It has also shown that the side effects from anastrozole are relatively modest, with fewer serious side effects than those encountered by women taking tamoxifen.
‘I saw over 200 women in Manchester after they completed five years on the study and found it difficult to tell whether they were on the active drug or placebo, because the anastrozole was so relatively well tolerated.
‘This provides us with another preventative treatment option, which has the potential to save and prolong the lives of thousands of women.’
Many breast tumours are fuelled by the hormone oestrogen. Anastrozole works by preventing the body from making oestrogen and, like tamoxifen, has for many years been used to prevent recurrence after surgery
Dr Caitlin Palframan, Head of Policy at Breakthrough Breast Cancer, said: ‘The challenge will be ensuring drugs like these are actually offered on the NHS, as many eligible women still don't have access to the risk reducing treatments already recommended in national guidelines.
‘We're working closely with the NHS to ensure important drugs are made available to women when it's appropriate, with the support to help them make an informed choice about their options.’
Trial investigator Winthrop Professor Christobel Saunders, from The University of Western Australia’s School of Surgery, said: ‘The findings from this research may provide a new approach to prevent breast cancer, not only for women today, but also for their daughters and granddaughters in the future.’
Kate Law, director of clinical research at Cancer Research UK, said ‘This landmark study shows that anastrozole could be valuable in helping to prevent breast cancer in women at higher than average risk of disease. We now need accurate tests that will predict which women will most benefit from anastrozole and those who will have the fewest side-effects.’
Anastrozole was originally developed by British company Zeneca Pharmaceuticals, now AstraZeneca, and goes under the brand name Arimidex.
Read more: http://www.dailymail.co.uk/health/article-2522550/anastrozole-HALVE-risk-breast-cancer-women-high-risk.html#ixzz2nIJC2Cvf
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