Women whose close family members have had breast cancer, particularly at an early age, may benefit from medicines to reduce their risk of developing the disease.
New evidence demonstrated if 1,000 postmenopausal women at high risk of breast cancer took anastrozole for 5 years 35 cases of breast cancer would be prevented, compared to 21 if they took tamoxifen.
NICE recommends anastrozole is offered for 5 years to postmenopausal women at high or moderate risk of breast cancer unless they have severe osteoporosis. And clinicians should consider offering it to women at moderate risk of breast cancer.
Women at high risk who have not been through the menopause should continue to be offered tamoxifen, the guideline says.
The recommendations appear in the update of the Familial breast cancer guideline.
Professor Mark Baker, director of the centre for guidelines at NICE, said: "The evidence examined by the committee suggests anastrozole will not only reduce the number of breast cancer cases in postmenopausal women compared to tamoxifen, but it is also a more cost effective option. This is good news for women and for NHS budgets."
The current list price of an anastrozole is £1.19 for 28 tablets.