In a historic move, National Health Service cost regulators are considering giving women with a strong family history of breast cancer treatment to prevent the disease from developing.
A proposed update to the National Institute for Health and Clinical Excellence's familial breast cancer clinical guideline is exploring whether hormone therapy could be given to at-risk women for up to five years to help cut their risk of getting the disease.
According to the Institute, for those for whom surgery is unsuitable, so-called 'chemoprevention' through drugs such as tamoxifen and raloxifene "may represent a more acceptable means of risk reduction", even though they are not licensed specifically for this use in the UK.
"High quality evidence" from randomised trials suggests the incidence of breast cancer is lower in patients given tamoxifen than in those given a placebo, and that raloxifene has a similar effectiveness when used as prophylaxis for the disease, it said.
However, the documents also stress that while both drugs reduce the risk they do come with side effects, and these carry a different weight when being considered in a preventative strategy.
In the adjuvant setting, tamoxifen can cause blood clots and cancer of the lining of the womb, while raloxifene can increase the risk of osteoporosis and bone fracture and can sometime cause intolerable muscle and joint aches and pains.
Writing in the Lancet Oncology in 2011, a panel of experts estimated that 10% of women in the higher risk category could benefit from taking drugs as a preventative strategy, just as millions of people at risk from heart disease take statins.
But they recommended that only women who have a 4% or higher risk of developing breast cancer within 10 years are offered it for disease prevention.
The 'chemoprevention' strategy has been looked at before in previous guidance, but no recommendations were made at the time. However, since then, more data on the longer-term use of hormone therapy has become available, prompting NICE to take another look at the issue.
Breakthrough Breast Cancer has welcomed the "exciting" move.
"An update to this guideline is long overdue and we’re especially pleased it has been extended to include both women who have had breast cancer, and men, for the first time," said Chris Askew, the charity's chief executive.
But he also stressed that "once finalised, this guideline will pose new challenges for the NHS as it will need to deliver on its recommendations, including a potentially large increase in genetic testing".
NICE's decision is expected in June this year.