What are the highest risk factors for breast cancer?
With regards to breast cancer prevention, one of the main risk factors for developing breast cancer is exposure to estrogen. For women who start their periods younger than 12, and for woman who go into menopause older than 55, they have an increased risk of developing breast cancer because the breast tissue has been exposed to estrogen over this long period of time. In addition, women who after menopause take hormone replacement therapy have been shown to be at an increased risk for developing breast cancer. There's been some controversy because in the US study, the estrogen and progestin increase the risk of developing breast cancer while the estrogen alone did not increase the risk of developing breast cancer. However, there are European studies which show that estrogen alone does increase the risk of breast cancer. Biologically and intuitively it makes sense that estrogen would increase a woman's risk because we do know that long term estrogen exposure does increase the risk of developing breast cancer. In addition, women who have not had children are at a greater risk of developing breast cancer. Whereas women who have had children after the age of 30 are at a greater risk of developing breast cancer, as well as if they have a family history. Then it starts to get into some of the genetics of breast cancer, women can be born with genetic predispositions to having breast cancer. For instance, BRCA1, BRCA 2 mutations or simply having a relative with breast cancer can increase your risk for having breast cancer. Toxic exposures like alcohol, smoking, radiation to the chest and to the breasts can also increase a woman's risk of developing breast cancer.
