Role of traditional Chinese medicine and its chemical components in anti-tumor metastasis.

Tumor incidence has become higher and higher in recent years, and it has also become the first killer jeopardizing human health. Tumor metastasis is the major barrier for tumor treatment. Some metastases occur in 5 or 10 years and some even in 20 years after tumor is controlled, but the metastases are impossible to defend effectively till now. Therefore, controlling tumor metastasis is critical in determining tumor patients' outcomes. In consideration of the limitations, toxicity and side effects of chemotherapeutic drugs for antitumor metastasis at present stage, seeking for drugs among traditional Chinese medicines (TCM) that share high safety and can effectively prevent and control metastasis is being paid more and more attention. This article is to expound the mechanisms of tumor metastasis and summarize the researches on antitumor metastasis with TCM.