How does hormone help cancer?
Hormonal exposure increases the number of potential target cells by stimulating breast growth during puberty, menstrual cycles, and pregnancy. Exposure also drives cycles of proliferation that place cells at risk for DNA damage. Once premalignant or malignant cells are present, hormones can stimulate their growth, as well as the growth of normal epithelial and stromal cells that may aid and abet tumor development.Estrogen may also play a more direct role in carcinogenesis. Metabolites of estrogen can cause mutations or generate DNA-damaging free radicals.