According to the CDC there are certain lifestyle and hereditary factors can increase your risk of developing breast cancer. By eliminating one or more of these factors, you may cut your cancer risk.
Risk Factors You Can't Change
Getting older - Risk increases with age; most breast cancers are diagnosed after age 50
Genetic mutations - These are inherited changes to certain genes, such as BRCA1 and BRCA2
Reproductive history - Beginning menstruation before age 12 and starting menopause after 55
Having dense breasts - More connective tissue in this type of breast can make it more difficult to find tumors with a mammogram
Personal history of breast cancer or certain non-cancerous breast diseases - Women who have already had breast cancer are more likely to get it again. Some non-cancerous breast diseases can also increase risk
Family history - A history of breast or ovarian cancer is higher with a close relative like a mother or sister. Also multiple members of either side of the family can also be an issue
Previous treatment using radiation therapy - Previous treatment using radiation therapy for another disease before age 30 can increase risk
Women who took the drug diethylstilbestrol (DES) - This was given to prevent miscarriage from 1940-1971. Women whose mother took this drug are also at higher risk
Risk Factors You Can Change
Inactivity - Not being physically active increases risk
Overweight and obesity after menopause - The risk is higher than for women at a normal weight
Reproduction - Having the first pregnancy after 30, not breastfeeding and not carrying to full term are all risks
Alcohol - Risk goes up with the more alcohol that is consumed
These risk factors are from the CDC