How long it takes for breast cancer to start metastasis cannot be generalized, and it is related to the stage of disease, physical fitness, treatment, etc. It may metastasize in a few months or a few years or even longer. If it is early breast cancer and the patient’s physical quality is relatively good, radical surgical resection should be taken as early as possible, together with chemotherapy, endocrine therapy, targeted therapy and other comprehensive treatments. Generally the possibility of recurrence and metastasis is relatively small, or it may recur and metastasize only after many years. In case of intermediate or advanced breast cancer, radical surgical excision is often not possible due to the spreading as well as metastasis of the lesion itself, especially when the patient’s physical condition is relatively poor, and metastasis may occur in a very short period of time, e.g. metastasis usually occurs in a few months for advanced breast cancer. Once breast cancer is diagnosed, it is necessary to actively cooperate with doctors to take treatment and have regular checkups.