Question: what is the biggest risk factor for breast cancer?
Answer: Being a Woman. Just being a woman is the biggest risk factor for developing breast cancer. ... 
Genetics. ... 
Certain Breast Changes. ... 
Pregnancy History. ... 
Using HRT (Hormone Replacement Therapy) ... 
Light Exposure at Night. ... 
Exposure to Chemicals in Cosmetics. ... 
Exposure to Chemicals in Plastic.