Drug treatment to reduce the risk of breast cancer
Drug treatment can reduce the risk of breast cancer in women who are at high or moderate risk because of breast or ovarian cancer in their family. Some of these drugs are not suitable for people who have osteoporosis (fragile bones that break easily) and some are not suitable for people who have had thrombosis (blood clots) or endometrial cancer. All options for reducing your risk should be discussed with you so that you can weigh up the possible benefits and risks and decide what to do.. If you have had both breasts removed (called a bilateral mastectomy) your risk will now be very low and drug treatment should not be necessary.
If you are at high risk and you haven't yet had the menopause, you should be offered a drug called tamoxifen if appropriate. If you're at high risk and have been through the menopause you should be offered a drug called anastrozole unless you have fragile bones that break easily (osteoporosis). Tamoxifen or another drug called raloxifene are other treatment options for women with osteoporosis.
If you are at moderate risk and you haven't yet had the menopause, you may be offered tamoxifen. If you're at moderate risk and have had the menopause, you may be offered anastrozole if you don't have osteoporosis. Or you may be offered tamoxifen or raloxifene depending on your circumstances. Again, healthcare professionals should discuss all treatment options with you before you make any decisions.
Anastrozole, tamoxifen or raloxifene should not be taken for more than 5 years. You should stop tamoxifen at least 2 months before trying for a baby and 6 weeks before planned surgery.
When this advice was updated (March 2017), anastrozole, tamoxifen and raloxifene did not have a licence in the UK for reducing the risk of breast cancer in people without breast cancer but with breast cancer in their family. Healthcare professionals should explain the possible benefits and harms of taking these drugs so that you can make a decision. They should record the details of these discussions. You can find more information about licensing medicines from NHS Choices.