Causes of Breast Cancer

Certain genes control the life cycle—the growth, function, division, and death—of a cell. When these genes are damaged, the balance between normal cell growth and death is lost. Normal breast cells become cancerous because of changes in DNA structure. Breast cancer is caused by cellular DNA damage that leads to out-of-control cell growth.

Causes of Breast Cancer: Genetics & Mutations

Inherited genes can increase the likelihood of breast cancer. For example, mutations of genes BRCA1 and BRCA2 (linked to an increased risk of breast and ovarian cancers) can inhibit the body’s ability to safe-guard and repair DNA. Copies of these mutated genes can be passed on genetically to future generations, leading to a genetically-inherited increased risk of cancer.

Causes of Breast Cancer: Environment

Breast cancer may be caused by environmental exposure. Sunlight can cause DNA damage that leads to breast cancer through ultraviolet radiation. So can air pollutants like soot, wood dust, asbestos, and arsenic, to name just a few.

Causes of Breast Cancer: Lifestyle

Lifestyle choices can lead to breast cancer as well. Eating a poor diet, inactivity, obesity, heavy alcohol use, tobacco use including smoking, and exposure to chemicals and toxins are all associated with a greater breast cancer risk.

Causes of Breast Cancer: Medical Treatment

Medical treatment with chemotherapy, radiation, or immunosuppressive drugs used to decrease the spread of cancer throughout the body can also cause damage to healthy cells. Some “second cancers”, completely separate from the initial cancer, have been known to occur following aggressive cancer treatments.