Many factors may influence the development of breast cancer, including:
- Age: Most cases occur in women 50 or older; it is less common in women 35 or younger. Age is the most influential risk factor.
- Personal or Family History: Your risk is higher with a personal or family history (especially mother, sister, daughter) of breast or ovarian cancer.
- Hormones/Childbirth: Your risk is higher if you had your first period before age 12, began menopause after age 55, never had children or had your first child after age 30. Postmenopausal use of hormone therapy increases your risk of developing breast cancer.
- Weight: Obesity and weight gain afer menopause are risk factors.
Other risk factors include:
- Alcohol consumption
- Family history of breast, colon, uterine or ovarian cancer
- Previous breast cancer, whether or not it spread to surrounding tissues.
- Number of biopsies even though they have been benign
- BRCA-I and BRCA-II gene mutation.
- Ethnicity - if you are a Jewish woman of Ashkenazi heritage.
- Atypical hyperplasia (an excessive formation of cells) confirmed by biopsy.
- Breast feeding and exercise help to reduce the risk of breast cancer.