What causes breast cancer?
Breast cancer is triggered by molecular alterations in breast tissue cells, usually epithelial cells in the breast ducts. These alterations have their origin in DNA changes and mutations that override cells’ natural function to divide only when needed and die if they detect alterations. This turns cancer cells into immortal cells that keep on dividing aggressively without restraint.
Several mutations have been found to trigger breast cancer, including mutations in the CDH1, MLH1, MLH2, STK11, TP53, and PTEN gene. Thus, a family history of cancer is particularly important because some patients carry more predispositions than others to display abnormalities in these genes.
Another cause of breast cancer has to do with hormones because breast cells respond and start growing in response to female sex hormones. Thus, women with a higher level of estradiol are more likely to have breast cancer. It may also be triggered by the use of hormone replacement therapy and exogenous hormones.