New draft NICE guidance recommends giving tamoxifen or Evista (raloxifene) to women with a family history of breast cancer as a preventative drug.

The provisional guidance update makes new suggestions for genetic testing, screening and preventative treatment in women at high risk of breast cancer.

If confirmed by NICE, the recommendations would mean the first use of a drug by the NHS to prevent breast cancer.

Breast cancer is diagnosed in 50,000 women in the UK each year. Women with a sister and a mother or aunt who have developed breast cancer before the age of 50 are considered at high risk of developing the disease for genetic reasons.

Breast cancer is also likely to occur earlier, and to be harder to treat, in this patient class, who are fewer than 1% of women aged under 30.

Genetic testing can identify either of two mutant genes that are linked to increased risk of breast cancer, as well as ovarian cancer.

NICE emphasises the need to reduce the incidence of breast cancer in high-risk women. It estimates that for every 1000 women treated with tamoxifen or Evista for a five-year period, there would be 20 fewer cases of breast cancer.

However, the drugs have side-effects including increased risk of blood clots, so their preventative use would need to be carefully considered.

Tamoxifen was developed by AstraZeneca but has long been off patent. Lilly’s Evista came off patent more recently. Neither drug has UK marketing authorisation for prevention of breast cancer.

Chris Askew, Chief Executive of the charity Breakthrough Breast Cancer, said the draft guidance was “a historic step for the prevention of breast cancer”.

Breast cancer screening in the UK is under review following claims that it causes more harm than good.

The review will be led by Professor Mike Richards, National Cancer Director for England, who said he is taking the “current controversy very seriously”.

A recent review of clinical trials has said that for every 2,000 women screened in a 10-year period, one life would be saved, ten healthy women would undergo unnecessary treatment and at least 200 women would face psychological distress due to false positive results.

Susan Bewley, Professor of Complex Obstetrics at King's College London, who has turned down breast cancer screening, said: “The distress of overdiagnosis and decision making when finding lesions that might, or might not, be cancer that might, or might not, require mutilating surgery is increasingly being exposed.”

Screening programmes have helped doctors diagnose cancers earlier, but they also run the risk of false positives.

Breast cancer screening was introduced in the UK in 1988 and now offers tests to women over the age of 50 every three years.

The NHS says that 1,400 lives are saved every year through screening in England alone, and in 2002, the World Health Organization's International Agency for Research on Cancer estimated that screening reduced deaths from breast cancer by about 35%.

Chris Askew, Chief Executive at Breakthrough Breast Cancer, said: “The earlier breast cancer is picked up the better for the one in eight women who are diagnosed every year with this disease, as treatment options are more likely to be less aggressive and have successful outcomes.”

But Sara Hiom, Director of Health Information at Cancer Research UK, who is leading the review, said: “Women need more accurate, evidence-based and clear information to be able to make an informed choice about breast screening.”