There are other factors that can slightly increase or decrease the risk of developing breast cancer. Some of these are listed below.
Factors which may increase risk include:
- having previously had breast cancer
- periods starting before the age of 12
- menopause later than average age (52)
- not having children
- first pregnancy at the age of 30 or older
- taking hormone replacement therapy (HRT) – the type you take and how long you take it for is relevant (the risk reduces over time once you stop)
- taking the oral contraceptive pill for a number of years (the risk reduces over time once you stop)
- a few types of benign (not cancer) breast problems
- dense breasts (seen on mammogram)
- being overweight, especially after the menopause
- drinking more alcohol than the recommended amount (14 units a week)
- exposure to high levels of radiation
- previously treated with chest radiation for other cancers as a child or young adult
- smoking (the evidence is inconsistent but suggests this may only be significant for post-menopausal women who start smoking at a young age and continue to smoke for many years).
Factors which may decrease risk include:
- periods starting after the age of 12
- menopause before the age of 45
- having children (especially having the first before the age of 20)
- breastfeeding (the longer the time period, the greater the benefit; this could be one baby or more)
- doing regular exercise
- eating a well-balanced diet and limiting your intake of saturated fats
- maintaining a healthy weight.
Having one or more risk factors might mean that the likelihood of you developing breast cancer is only slightly greater than if you don’t have these risk factors. It doesn’t mean that you will develop breast cancer and importantly your overall individual risk may still be small. Remember one person may have many risk factors and not develop breast cancer, while another may have very few risk factors and be diagnosed with the disease.