Breast cancer is a malignant tumor that occurs in the glandular epithelial tissue of the breast. The normal breast is made up of skin, fibrous tissue, mammary glands and fat. In terms of gender: 99% of breast cancers occur in women and only 1% in men. Breast is not an important organ to maintain the life activities of human body, and in situ breast cancer is not fatal; however, because breast cancer cells lose the characteristics of normal cells, the cells are loosely connected to each other and easily shed. Once the cancer cells are shed, the free cancer cells can spread throughout the body with blood or lymphatic fluid, forming metastasis and endangering life. Currently, breast cancer has become one of the common tumors that threaten women’s physical and mental health. The global incidence of breast cancer has been on the rise since the late 1970s. One out of eight women in the United States will develop breast cancer in their lifetime. China is not a country with high incidence of breast cancer, but it should not be optimistic. In recent years, the incidence rate of breast cancer in China has been increasing at a rate 1 to 2 percentage points higher than that of countries with high incidence. According to the 2009 breast cancer incidence data released by the National Cancer Center and the Bureau of Disease Prevention and Control of the Ministry of Health in 2012, the incidence of breast cancer in the national tumor registration area ranked 1st among female malignant tumors, and the incidence rate (crude rate) of female breast cancer was 42.55/100,000 nationwide combined, 51.91/100,000 in urban areas and 23.12/100,000 in rural areas. Breast cancer has become a major public health problem in the current society. The global breast cancer mortality rate has shown a decreasing trend since the 1990s; the reasons for this are, firstly, the screening of breast cancer, which has increased the proportion of early cases; and secondly, the development of comprehensive breast cancer treatment, which has improved the efficacy. Breast cancer has become one of the solid tumors with the best outcomes.