As the causes of breast cancer are not fully understood, it's not known if it can be prevented altogether.
Some treatments are available to reduce the risk in women who have a higher risk of developing the condition than the general population.
Studies have looked at the link between breast cancer and diet, and although there are no definite conclusions, there are benefits for women who:
Use our body mass index (BMI) calculator to check if you're a healthy weight.
It's also been suggested that regular exercise can reduce your risk of developing breast cancer by almost as much as a third.
If you've been through the menopause, it's particularly important that you're not overweight or obese. This is because being overweight causes more oestrogen to be produced by your body, which can increase your risk of some types of breast cancer.
Studies have shown women who breastfeed are statistically less likely to develop breast cancer than those who do not.
The reasons are not fully understood, but it could be because women do not ovulate as regularly while they're breastfeeding and oestrogen levels remain stable.
Your level of risk is determined by factors such as your age, your family's medical history, and the results of genetic tests.
If you have an increased risk of developing breast cancer, treatment is available to reduce your risk.
You'll usually be referred for specialist genetic testing if it's thought you have an increased risk of breast cancer. Healthcare professionals at these services should discuss treatment options with you.
The 2 main treatments are surgery to remove the breasts (mastectomy) or medicine.
A mastectomy is surgery to remove the breasts. It can be used to treat breast cancer and can also reduce the chances of developing the condition in the small number of women who have a high risk.
By removing as much breast tissue as possible, a mastectomy can reduce your risk of breast cancer by up to 90%.
However, like all operations, there's a risk of complications, and having your breasts removed can have a significant effect on your body image and sexual relationships.
If you want to, you can usually choose to have a breast reconstruction either during the mastectomy operation, or at a later date.
During breast reconstruction surgery, your original breast shape is recreated using either breast implants or tissue from elsewhere in your body.
An alternative is to use breast prostheses. These are artificial breasts that can be worn inside your bra.
An alternative to mastectomy is a nipple-sparing mastectomy, where the whole mammary gland is removed, but the skin of the breast is preserved. This is not widely available at the moment, but it's being used more often and can achieve excellent results.
Find out more about your body and your breasts after treatment.
There are 3 medicines available on the NHS for women who have an increased risk of breast cancer:
These medicines are usually taken once a day for 5 years. They can reduce your risk of breast cancer while you're taking them and possibly for several years afterwards.
Side effects of these medicines can include:
If your doctor suggests taking medicine to reduce your risk of breast cancer, ask them about the benefits and risks of each medicine.