Who Gets Breast Cancer? Anyone
Like most cancers, the risk of developing breast cancer increases as a woman get older. 95% of new cases and 97% of breast cancer deaths occurred in women 40 years of age and older.
Family History of Breast Cancer
Having a mother or sister diagnosed with breast cancer doubles the risk of breast cancer.
It is estimated that women:
- Aged between 30 and 39 have more than a one in 12 chance (8%) of developing breast cancer in the next 10 years.
- Aged between 40 and 49 have more than a one in5 chance (20%) of developing breast cancer in the next 10 years.
- Aged between 40 and 49 with mammogram results showing a dense breast pattern will have one in 8 chance (12%) of breast cancer in the next 10 years.
A family history of ovarian cancer is also associated with an increased risk of breast cancer. Women with breast cancer are also at risk for developing a second primary cancer. Women diagnosed with early onset of breast cancer (age < 40) have almost a 3 fold increased risk of any subsequent cancer, with a 4.5 fold increased risk of any subsequent breast cancer.
Breast Cancer Genes
Only about 5% to 10% of breast cancer cases are thought to be the result of gene defects (called mutations) inherited from a parent, namely BRCA1 and BRCA2. The risk of getting breast cancer by the age of 70 if you have either of these breast cancer gene faults is between 45% to 60%.
Most breast cancers are hereditary. You don’t need to worry if you don’t have a family history of breast cancer.
Most breast cancers happen by chance. Only about 20% to 30% of women with breast cancer have a family member with this disease. This means that most women (70% to 80%) who get breast cancer do not have a family history of this disease.