Malignant tumor cells are metastatic, but not all malignant tumors metastasize. In addition to the tumor itself, the factors that determine whether a tumor metastasizes include the overall host factors and other external factors. In addition to the tumor itself, there are also host factors and other external factors to determine whether the tumor metastasizes. 2.Faster growth rate is more likely to metastasize than slower growth rate. 3.Degree of differentiation: The worse the differentiation, the higher the malignancy and the earlier the metastasis. 4.Tumor classification: sarcoma is more likely to metastasize earlier than cancer, and more likely to metastasize through blood channels, while cancer is more likely to metastasize through lymphatic channels. Body systemic factors 1. Immune status: Those with low immune function or immune defects are more likely to have tumors and metastasize easily and early. 2.Endocrine status: The occurrence of certain tumors is related to the change of hormone level, and some hormones such as steroid hormone, ACTH and growth hormone have a promoting effect on the metastasis of certain tumors. 3.Disorder of higher nerve activity can promote the growth and metastasis of tumor. 4.Tissue damage: tumor metastasis easily occurs in tissue damage. 5.Coagulation factor: In recent years, anticoagulation therapy has been tried to reduce the chance of tumor metastasis and decrease its metastasis rate. External factors 1. abnormal physical examination: tumor is overly squeezed and metastasis occurs due to blind physical examination for many times and roughly. 2.Physiotherapy and manual massage: it can promote the shedding, growth and metastasis of tumor cells. 3.Inappropriate surgical operation: rough surgery, excessive pulling, squeezing, blind enlarged exploration, inappropriate puncture and cutting biopsy (small incision), etc. may promote tumor metastasis.