What is risk factor?
A risk factor is anything that may increase a person's chance of developing a disease. It may be an activity, such as smoking, diet, family history, or many other things. Different diseases, including cancers, have different risk factors.
Knowing your risk factors for any disease can help guide you into the appropriate actions, including changing behaviors and being clinically monitored for the disease.
What are the risk factors for breast cancer?
Any woman may develop breast cancer. However, the following risk factors may increase the likelihood of developing the disease.
Risk factors that cannot be changed
- Gender - Breast cancer occurs nearly 100 times more often in women than in men.
- Aging - Two out of 3 women with invasive cancer are diagnosed after age 55.
- Personal history of breast cancer - If you have had breast cancer before, you are more likely to have breast cancer again in that breast or in the other breast.
- Radiation to the chest wall - Radiation, as treatment for other forms of cancer, especially after age 30
- Family history and genetic factors - Having a close relative, such as a mother or sister, with breast cancer increases the risk, as does history of early breast cancer in the family and family history of male breast cancer. This includes changes in certain genes, such as BRCA1, BRCA2 and others.
- Benign breast disease - Women with certain benign breast conditions, such as atypical hyperplasia, have an increased risk of breast cancer.
- Early menstrual periods - Women whose periods began early in life (before age 12) have a slightly higher risk of breast cancer.
- Late menopause - Women are at a slightly higher risk if they began menopause later in life (after age 55).
Commonly cited lifestyle-related risk factors
- Not having children, or having your first child after age 30
- More than 10 years use of oral contraceptives
- Physical inactivity
- Alcohol use (more than 2 drink per day)
- Long-term, postmenopausal use of combined estrogen and progestin (HRT) for more than five years
- Weight gain and obesity, especially after menopause