According to the risk of recurrence, breast cancer can be divided into low risk group, moderate risk group and high risk group. Patients in low risk group are: 1) T less than or equal to 2 cm; 2) negative lymph nodes; 3) pathological grade I; 4) ER and or PR expression; 5) no amplification or strong positive HER2; 6) no involvement of lymphatic vessels; 7) age greater than or equal to 35 years. The above 7 points need to be satisfied simultaneously. High risk of recurrence group is defined as: 1) those with more than or equal to 4 positive lymph nodes; 2) those with 1-3 positive lymph nodes and HER2 positivity; 3) those with 1-3 positive lymph nodes and triple negative breast cancer pathology. Any one of the above can be judged as high risk group. All others are considered as moderate risk group for recurrence. It is worth noting that HER2-positive breast cancer with T less than 1 cm, HER2 does not affect the prognosis if ER positive, and HER2 affects the prognosis if ER negative.