The indicator of breast cancer Ki67 <5% suggests that the possibility of recurrence and metastasis is low, and should be combined with tumor stage, grading, molecular typing and other comprehensive judgment. Whether breast cancer will recur and metastasize is related to a variety of factors and indicators, the current examination program can only initially assess the risk of metastasis and recurrence, but cannot accurately determine whether it will recur and metastasize. Ki67 is a tumor proliferation-related indicator, the higher the Ki67 positive rate, the more active the tumor proliferation, the higher the degree of malignancy, the higher the risk of recurrence and metastasis. 5% Ki67 positive rate is a low level, suggesting that the risk of recurrence and metastasis is low, but the risk of recurrence and metastasis is related to a variety of factors, and needs to be considered in conjunction with other indicators. The low-risk group of recurrent metastasis generally needs to meet the requirements of no regional lymph node metastasis, lesion ≤2cm, histologic grade I, hormone receptor positive, age >35 years old, and Ki67 ≤20%. It is recommended that the patient consult with a specialist in a timely manner and make a comprehensive judgment based on other clinical data, and if necessary, perform genetic testing and other auxiliary judgment.