Nearly half a million women in England and Wales with a family history of breast cancer should be offered drugs via the NHS to help lower their risk of developing the disease, according to updated guidance by the National Institute for Health and Care Excellence (NICE) released on Tuesday.

NICE is an independent watchdog that provides guidance and advice to the the NHS, local authorities, and other organizations responsible for commissioning or providing healthcare, public health or social care services.

While not mandatory, the updated clinical guideline is regarded as best practice and “the NHS is encouraged to follow the recommendations”, says NICE in a statement.

The updated guideline replaces one published in 2006 and focuses on the management of people who are at increased risk of developing breast cancer because of a family history of breast or ovarian cancer, or another familial cancer such as prostate or pancreatic cancer that can also raise the risk for breast cancer.

NICE says the NHS should give women in these groups tamoxifen or raloxifene because the drugs can help stop them getting breast cancer if they take the daily pills for five years.

Every year in the UK about 50,000 women and 400 men find out they have breast cancer, making it the most common cancer in the country.

The risk of developing breast cancer can depend on many factors, such as family history of the disease or a related cancer, the number of affected relatives who develop the disease, their age at onset, and the age of the patient in question.

About one in five patients with breast cancer has a family history of the disease and hundreds of thousands of otherwise healthy people are at higher risk of developing the disease than the population as a whole because the disease runs in their family.

Under the new guideline about 3% of women aged 35 and over in England and Wales are likely to be eligible to receive either tamoxifen or raloxifene as a preventive treatment for breast cancer. Thus out of nearly 16.3 million women in this age group, some 488,000 will be eligible.

Neither of these drugs is licensed in the UK for the prevention of breast cancer although they are approved for such use in the United States.

Currently in the UK women with breast cancer are given tamoxifen after surgery and chemotherapy to stop the cancer from returning, and raloxifene is licensed for the treatment of post-menopausal women with osteoporosis.

However, NICE has reviewed evidence that suggests both these drugs are equally effective in reducing the risk of developing breast cancer by about one third, or between 30% and 40%.

A study published recently in The Lancet showed that tamoxifen, raloxifene and other selective oestrogen receptor modulators (SERMs) significantly reduced the risk of developing the most common type of breast cancer among women at both high and average risk of the disease both during treatment, and for at least 5 years after stopping.

Because neither drug is approved for prevention of breast cancer in the UK, doctors prescribing tamoxifen or raloxifene for such “off-label” use should follow relevant professional guidance, and take full responsibility for their decision, says NICE.

It is also important to obtain and document informed consent from the patient says the NHS watchdog. Informed consent means doctors must check that patients understand not only the benefits (in this case the potential but not guaranteed reduction in breast cancer risk) and the risks (for example the side effects of the drugs) of undergoing a new treatment.

Professor Mark Baker, Director of the Centre for Clinical Practice at NICE says in a statement:

“Although neither drug is licensed as a preventative treatment in the UK, clinical evidence shows they are an effective option for many women and could be preferable to surgery.”

Currently in the UK, if someone has a family history of breast cancer they have two options. They can have a genetic test to verify a genetic reason for their family history and if that is positive, undergo annual screening so any tumours are found early.

The other option is to have their breasts removed by surgery, as actress Angelina Jolie did. Jolie says she carries a mutation in her BRCA1 gene.

Women who carry a BRCA1 or BRCA2 mutation have a significantly higher risk of developing breast and ovarian cancers.

Removal of the breasts by surgery is a major operation and can be very traumatic, says Baker, explaining that the new NICE guideline offers women more options in how they manage their risk of breast cancer:

“… those with a ‘moderate’ or ‘high’ risk of developing breast cancer because of their family history but who have not had the disease themselves can now be offered tamoxifen or raloxifene for five years to prevent it.”

The new NICE guideline calls for more men and women, including in some cases otherwise healthy people, to be tested for genetic mutations that cause cancers that run in families.

The guideline also includes the following recommendations:

  • Doctors should calculate a person’s risk of getting breast cancer by looking at their family history and using a proven method to work out if they are likely to be carrying a genetic fault such as a mutation in the BRCA1 or BRCA2 gene.

  • If such calculations don’t yield clear results, then doctors should use their clinical judgement to decide whether to offer genetic testing.

  • A relative who has or has had breast and/or ovarian cancer should be offered genetic testing if they have a 10% or more chance of having a mutation in either the BRCA1 or BRCA2 gene (in the previous guideline the threshold was 20%).

  • All women aged 30-49 who have, or have had breast cancer and remain at high risk for the disease, including those with a BRCA1 or BRCA2 mutation, should be offered an annual MRI screen.

Dr Caitlin Palframan, Assistant Head of Policy at Breakthrough Breast Cancer, and member of the group that developed the guideline for NICE, describes the new guidelines as a “game changer” for how we prevent breast cancer.

“Our strongest tool in the fight against breast cancer is prevention, and these new guidelines are a fantastic leap forward in the way we prevent breast cancer developing in those at highest risk,” she says.

Palframan says it is important that people have options to help them manage their own breast cancer risk, and for those at higher risk, it is important to have options that go beyond screening and surgery.

“From here the next challenge is ensuring the NHS is equipped to deliver on the promise of these recommendations; more screening, genetic testing and better preventative options for those few people at highest risk,” she adds.

Written by Catharine Paddock PhD