What are the risk factors for breast cancer?

Breast cancer causes and risk factors

There are several genetic and environmental risk factors for breast cancer. Only about 30% of breast cancer patients have an identifiable risk factor.

Genetics and familial history - accounts for 5-10% of all breast cancers. Several genes have been identified for 50% increased breast cancer risk (BRCA1, BRCA2, P53). Women with familial history of breast or ovarian cancer should be tested regularly.

Age – 90% of breast cancers occur in women over 45. Rarely (2%) forms in women under age 35.

Early menarche – girls that begin their menstrual cycle before 12.

Late menopause – women who experience menopause after 55.

Estrogen hormones – estrogen can stimulate the growth of breast tissue, including tumor cells. Hormone replacement therapy can increase the risk of breast cancer. Oral contraceptives slightly increase breast cancer risk.

Alcohol consumption –drinking alcoholic beverages daily can double the risk of breast cancer.

Diet – some studies suggest that diets rich in processed meats can increase breast cancer risk.

Overweight or obesity – a higher body mass index is associated with breast cancer. However, women with higher BMI also have increased estrogen hormone levels, which may account for the breast cancer link in overweight women.