Breast cancer causes are not clearly defined. Some doctors believe that 5 - 10 % of women who develop breast cancer inherit it. This is caused by a defect in breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2). There is also a theory that breast cancer can be caused by environment. No one really knows why breast cells become cancerous.
Breast Cancer CausesBreast Cancer Causes
In breast cancer, some of the cells in your breast begin growing abnormally. These cells divide more rapidly than healthy cells do and may spread (metastasize) through your bre
http://www.mayoclinic.com/health/breast-cancer/DS0...
Breast Cancer CausesBreast Cancer Causes
Many women who develop breast cancer have no risk factors other than age and sex.
Gender is the biggest risk because breast cancer occurs mostly in women.
Age is another
http://www.emedicinehealth.com/breast_cancer/page2...
What Causes Breast Cancer?What Causes Breast Cancer?
Certain changes in DNA can cause normal breast cells to become cancerous. DNA is the chemical in each of our cells that makes up our genes -- the instructions for how our
http://www.cancer.org/docroot/CRI/content/CRI_2_2_...
