Although many risk factors for breast cancer cannot be controlled -- such as genetic mutations, age, and family history -- others are associated with lifestyle choices.
The American Cancer Society offers this list of lifestyle factors that may increase a woman's risk of breast cancer:
* Having no children.
* Using oral contraceptives, depending on at what age and for how long they were taken.
* Using post-menopausal hormone replacement therapy (HRT).
* Abuse of alcohol.