4. Menstruating Early
If you got your first period before the age of 12, that means you have had more menstrual cycles in your lifetime and have therefore been exposed to more estrogen and progesterone, which as previously mentioned, increases your risk of breast cancer.
3. Menopause After 55
Going through menopause after the age of 55 signifies you’ve had more menstrual cycles, which as mentioned, further exposes you to estrogen and progesterone. Again, ultimately increasing your risk of breast cancer.
2. Radiation to the Chest During Childhood
“Being treated for a childhood cancer with radiation to the chest significantly increases the risk of developing breast cancer later in life,” says Dr. Specht. The risk is considered higher if you had radiation as a teen or young adult, since this is the stage when breasts are developing.
1. Exposure to DES
Women who consumed diethylstilbestrol (DES), which is an estrogen-like drug that was administered from the 1940s through the early 1970s to lower the risk of miscarriages, have bad side effects and a slightly increased risk of developing breast cancer. Women whose mothers took DES while pregnant may also have a slightly higher risk of getting breast cancer, according to the American Cancer Society.Related: 10 Foods That Are Linked to Cancer