Causes of Breast Cancer

Breast cancer is caused by a mutation in the genetic code during cell replication.  These cellular “mistakes” happen more commonly as a person ages.  The cells grow abnormally and divide more rapidly than healthy cells do.  The accumulation of cells forms a tumor that grows in the breast and can spread to the lymph nodes or other parts of your body.

Breast cancer most commonly begins with cells in the milk-producing ducts (ductal carcinoma) but it may also begin in the lobules (lobular carcinoma).

Breast cancer is caused by a combination of your genetic makeup and your environment.  Certain risk factors have been identified that can increase a person’s risk of breast cancer.  About 5-10 percent of breast cancers are linked to a genetic mutation passed through generations of a family.  The most common are breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2), both of which increase a person’s risk of breast and ovarian cancer.