'Tamoxifen should be offered in the same way as statins to all women at risk of breast cancer,' Dr Rebekah Law, a leading breast cancer surgeon and research fellow at the Royal Marsden, said at the most recent breast cancer conference, causing quite the stir.
The drug, which costs just 45p per pill, is routinely used to treat breast cancer patients but it has long been recommended that women at moderate to high risk of breast cancer should be offered preventive treatments like tamoxifen.
Shockingly, only 2 per cent of women at the highest risk of the disease know it exists.
For years, women who are at an increased risk of breast cancer - which is now around one in three - have been denied proper access to endocrine therapy because of the entrenched views that suggest it is better for a woman to be able to conceive and stave off the symptoms of the menopause for as long as possible than reduce her risk of cancer.
But Dr Law says these blanket views are outdated and do not keep up with the current reality: more and more young women are being diagnosed with breast cancer.
This could be about to change.
Speaking at the 15th European Breast Cancer Conference, in Barcelona, Dr Law said: 'If you give women who are at an increased risk of developing breast cancer an endocrine prevention agent, so something like tamoxifen, then you can significantly reduce their risk of developing the disease by up to 50 per cent.'
Research shows that the protective effect can last for decades.
Tamoxifen is a type of selective oestrogen receptor modulator (SERM) which works by blocking the effects of the hormone oestrogen.
It is typically used to treat women with early stage breast cancer by stopping oestrogen from attaching to cancer cells - blocking signals to grow and multiply.
And whilst post-menopausal women who are considered at very high risk of the disease - due to genetic and familial risk factors - are more routinely prescribed this class of drugs, Dr Law says this doesn't go far enough, and all women should be offered the preventive treatment.
Historically, healthcare professionals have been reluctant to push endocrine therapy due to a barrage of side-effects including hot flushes, increased risk of endometrial cancers and deep vein thrombosis.
The drug typically needs to be taken for five years and women cannot conceive during this time. They will then have to wait a further three months before trying to get pregnant.
Dr Law acknowledged that whilst there are side-effects at higher doses, new research has shown that if you give women a smaller dose - dubbed baby tam - these side-effects disappear, with the exception of one hot flush a day.
'The main crux of this argument is that if you get the dose right then we don't give women the side-effects which were impeding them from continuing with the treatment.
'My argument - that we need to talk across the age spectrum - borrows from the cardiovascular world.
'We have all heard of statins. Our grandparents take them; our parents take them; so there is collective understanding that this is normal - so when we come to be offered it we are more likely to say yes.'
Current data suggested only 2 per cent of women within high-risk breast cancer screening services have heard of risk reducing tamoxifen, despite it being approved for use more than a decade ago.
'We shouldn't be force-feeding women preventative medication, but we need to get to the same level of normalising endocrine prevention,' Dr Law said.
It has long been recommended that women at moderate to high risk of breast cancer should be offered preventive treatments such as tamoxifen
'We are seeing more affected women than healthy women so we need to think about a new system to increase prevention uptake,' says Dr Pascal Pujol, head of oncogenetics at the University Hospital of Montpellier
'There are huge similarities between the two drugs - but you don't have to take endocrine prevention for as long - and yet because we haven't normalised it in society, women aren't aware of its potentially life-saving effects.
'We need to inform people early so that when it's the right time for them, whenever that may be, they can make that choice.'
Dr Pascal Pujol, head of oncogenetics at the University Hospital of Montpellier, is one of the many doctors who are hesitant to prescribe the drug too soon.
He says: 'We don't want to impact an otherwise healthy woman's quality of life and sexual wellness just because there is a slight risk she might develop the disease further down the line.'
'If you want to target this woman with a familiar risk you have to target it young, from the age of 40, but then you pay more side-effects.'
But even Dr Pujol is now coming round to the idea that prevention should always be a choice, especially for women at very high risk.
He cited a UK-based study that found women who had a first-degree relative with breast cancer were able to reduce their risk of the disease by half with endocrine therapy.
'This is a huge target,' he said. 'So, maybe I am switching actually from against to for.
'I think we all agree that we don't have time. We are seeing more affected women than healthy women so we need to think about a new system to increase prevention uptake.'
The goal, both sides of the debate agree, is for women to receive individualised care, taking into account their medical history, life stage, and end goals.
The American Society of Clinical Oncology (ASCO) recommends use of the drug for women over the age of 35 but Dr Law says this may not be young enough and it's not just about prescribing age.
'It's more about when do we inform women,' she said. 'Give women the information and say "if you take tamoxifen this is how much you will reduce your risk by".'
Screening has been highlighted as a good time to do this, with women invited for their first breast screening between the ages of 50 and 53. But experts from both sides of the debate are concerned that we are leaving screening too late.
They added that once a woman has cancer, their risk of recurrence is much higher and that prevention will always be better than a cure.
Reading of risk is crucial here. There are several different types of breast cancer - with some, such as triple negative breast cancer, more serious than others.
'All of this needs to be in the context of lifestyle changes as well. It can't just be a single thing but the bigger picture,' Dr Law says.
'But the bottom line is preventive treatment should always be a choice.'
Breast cancer is the most common cancer in women in the UK, with more than 56,000 new cases each year. Recent figures suggest that 8 per cent of breast cancers are caused by alcohol. Being overweight or obese also significantly increases a woman's risk of developing the disease.
Globally, cases are predicted to rise by a third to more than 3.5 million a year by 2050, according to the Global Burden of Disease Study Breast Cancer Collaborators.