There are many risk factors for breast cancer. Some are things you can't change and some you can.
Being female is the biggest risk factor for breast cancer. Only 1% of breast cancers occur in men.
Age is the second biggest risk factor for breast cancer. Most breast cancers (about 80%) occur in women over 50.
Family history of breast cancer
Most breast cancers (95%) occur in women with no family history of breast cancer.
Even when women have a family history of breast cancer, most are not at an increased risk of breast cancer. Their family history is due to chance alone.
Only a very small number of women with a family history of breast cancer are at an increased risk of breast cancer. Factors that increase risk include the gender of the family member diagnosed with breast cancer and how old they were at diagnosis.
Of 100 women:
Family history vs very strong family history
We define family history of breast cancer as having either:
- a female first degree relative (mother, sister or daughter) diagnosed with breast cancer before the age of 50
- a male first degree relative (father, brother or son) diagnosed with breast cancer at any age.
Only 4 out of 100 women are at a moderately increased risk of developing breast cancer based on their family history.
If you meet our criteria for family history of breast cancer, you’ll be offered screening every year instead of every 2 years. If no signs of breast cancer have been found by the time you turn 60, you’ll start to have breast screens every 2 years. This is because your risk is considered to have reduced.
We define a very strong family history of breast cancer as being aged 30 to 49 and meeting the Cancer Australia High Risk criteria.
Only one out of 100 women is at a high risk of developing breast cancer based on her family history.
There is a Breast Cancer Family Clinic for women with a very strong family history of breast cancer. The clinic offers advice, counselling and a personal management plan. You'll need a referral from your doctor to attend this clinic. You should talk to your doctor if you think you might have a very strong family history of breast cancer. Your doctor will be able to assess your breast cancer risk and decide if a referral to the Breast Cancer Family Clinic is appropriate.
Previous diagnosis of breast cancer
If you’ve had breast cancer before, you’re at an increased risk of developing breast cancer again. You should talk to your treating doctor to see if screening with us is right for you.
Women with higher breast density are at increased risk of breast cancer. The reasons for this are not well understood.
Breasts tend to become less dense as women get older but about 30% of women over 50 have dense breasts. Breast cancers are harder to find in x-rays of dense breasts. This is because dense breast tissue and breast cancers both appear white on x-rays. Despite this, breast screening is still the best way of finding breast cancers in women with dense breasts who are aged 50 to 74.
Read more about breast density and breast screening (PDF, 124kB) on the BreastScreen Australia website.
Can I reduce my risk of breast cancer?
There are some things that you can do to reduce your risk of breast cancer.
Maintain a healthy body weight
Eat a wide variety of food from all food groups. Increase your fruit and vegetable intake. Limit foods that are high in added fat, sugar and salt.
Be active every day
Aim for at least 30 minutes of moderate intensity physical activity each day. Doing any physical activity is better than doing none.
Limit alcohol consumption
Research has found that drinking alcohol increases your risk of breast cancer. The more you drink, the more your risk increases. If you choose to drink, have no more than one standard drink a day.
Last updated: October 2021