Breast cancer is the number one cause of female mortality. It affects 100 out of 100,000 women per year in developed countries. Each year, more than 1.3 million new cases are diagnosed, 53,000 of these in France. The risk factors of breast cancer are varied. They include genetic mutations, late first pregnancy, low parity or hormone therapy, but other causes of breast cancer such as way of life, environmental or professional causes have not yet been completely identified.