Breast Cancer Risks

Family history of breast cancer

It is estimated that between 5% and 10% of breast cancer have a genetic component. The genes involved are BRCA1 and BRCA2. Abnormal changes (mutations) in the BRCA1 and BRCA2 genes are present in about 70% of all inherited breast cancers. It is not clear how much these gene changes increase a woman's risk of breast cancer. However, it has been estimated that these women have between a 40% and 85% chance of developing breast cancer during their lifetime. The lifetime risk of women without genetic mutations is about 13%.

Risk Factors of breast cancer

Different cancers have different risk factors. However, having a cancer risk factor, or several of them, does not necessarily mean that a person will get cancer. Some women with one or more breast cancer risk factors never develop it. In fact, 70% of all women with breast cancer have no known risk factors. Known risk factors are as follows:

• History of previous cancer in one breast increases the risk of developing cancer in the other breast.
• Age: The risk of getting breast cancer increases as one gets older. Thus, mammogram screening should be done regularly even after menopause.
• Age at childbirth: Having first child after age 30 or never having children puts the woman at higher risk.
• Family history: If the first degree relative (mother, sister or daughter) has breast cancer, the risk of getting breast cancer is higher. The risk is even greater if the relative developed breast cancer before menopause and had cancer in both breasts.
• Other cancer in the family: A family history of cancer of the ovaries, cervix, uterus or colon increases the risk of breast cancer.
• Breast conditions such as large cysts in the breast with atypical ductal hyperplasia, (abnormal cells changes after breast lump removal) increases risk of breast cancer by 4 to 5 times.
• Early menstruation: The risk increases if menstruation starts before 12 years old.
• Late menopause: The risk increases if menopause occurs after 50 years old.
• Overweight: Excessive weight gain, especially after menopause increases the risk.
• Excessive radiation: This is especially in women given radiation for example in the management of tuberculosis (T.B.) or for treatment for cancers such as lymphoma.
• Alcohol: Use of alcohol is linked to increased risk of developing breast cancer.