Low risk Lymph node negative with all of the following characteristics: 1. pT ≤ 2 cm; 2. pathological grade 1; no invasion of peripheral vessels; 3. no HER-2/neu gene overexpression or amplification; 4. age ≥ 35 years. Intermediate risk Lymph node negative with one of the following: 1. PT > 2 cm; 2. Pathological grade 2-3; 3. Peritumor vascular invasion; 4. HER-2/neu gene overexpression or amplification; 5. Age < 35 years; 6. Positive lymph nodes (1 to 3 lymph nodes involved) and no HER-2/neu gene overexpression. -2/neu gene overexpression or amplification. High risk 1, positive lymph nodes (l-3 lymph nodes involved) and overexpression or amplification of HFR-2/neu gene; 2, positive lymph nodes (4 or more lymph nodes involved).