13. Hormonal Birth Control
In some circumstances, hormones in certain types of birth control methods, including oral contraceptives, birth control shots, and IUDs, can increase the risk of breast cancer.
12. Hormone Therapy After Menopause
While hormone therapy with estrogen and progesterone can help relieve symptoms of menopause and help prevent osteoporosis, it can also increase the risk of breast cancer. Not to mention, it can also increase the likelihood that the cancer is found at a more advanced stage and ups the risk of heart disease, blood clots, and strokes. According to the American Cancer Society, the risks may, unfortunately, outweigh the benefits.
11. Being a Woman
Due to breast cancer relying on estrogen to grow, being a woman is an automatic risk factor for developing breast cancer, says Jennifer Specht, MD, oncologist at Seattle Cancer Care Alliance and an associate member of the clinical research division at Fred Hutchinson Cancer Research Center.Related: 9 Symptoms That Could Be Warning Women of Cancer