At present, the causes of breast cancer are unknown. However, there are some factors which may increase your risk of breast cancer.
One known risk factor is exposure to the drug Diethylstilbestrol (DES), also known in Australia as stilboestrol.
DES is a form of oestrogen that was commonly given to Australian women from the mid 1940s until the early 1970s to help prevent miscarriages and other pregnancy complications. It is no longer available for use in Australia.
In the early 1970s, DES was found to be linked to vaginal and cervical cancers in a small number of women who were exposed to DES in the womb.
Even though the majority of women exposed to DES won't experience any health issues, research shows that women who took DES while pregnant may have a small increased risk of breast cancer.
Research also shows that daughters of women who took DES during pregnancy may have a slightly increased risk of breast cancer after the age of 40 years.
If you used DES while you were pregnant, or are a daughter of a woman who took DES, and are 40 years or older you are encouraged to have an annual mammogram.
It's also important to be breast aware and to report any breast changes to your doctor, regardless of whether or not you have had a recent mammogram.
More information
If you want to know more about DES, you may like to read Cancer Australia's Risk of invasive breast cancer in women exposed to diethylstilbestrol in utero: A review of the evidence' position statement and Cancer Council NSW's Diethylstilbestrol (DES) and Cancer position statement.
