Important issues of cancer metastasis

The 5 year survival rates of small liver cancer resection were no longer improved in the past 40 years, indicating the importance of studies on cancer metastasis. Several important issues of cancer metastasis will be delineated: (1) Changing concepts of cancer metastasis: Cancer metastasis is a systemic issue, metastatic potential of cancer originated from primary tumor, cancer stem cell is the key component of cancer metastasis, metastatic potential also influenced by immune inflammatory microenvironment, metastatic potential is an alterable event. (2) The pro metastatic effect of cancer eradication: In Liver Cancer Institute of Fudan University, experimental studies using human hepatocellular carcinoma nude mice model with high metastatic potential indicated that palliative resection, radiotherapy, chemotherapy, hepatic artery ligation and molecular targeted therapies that target to VEGF (eg. Sorafenib) promoted the metastatic potential of residual cancer, mainly via hypoxia, inflammation and immuno suppression with different molecular alterations. Interestingly, effective intervention that inhibits metastasis and prolongs survival has been found using clinical available drugs in experimental studies. Such as cytokine (interferon), anti inflammatories (aspirin and zoledronic acid), herbal medicine (Songyou Yin) and Tanshinone ⅡA, a novel tripeptide tyroserleutide, etc. (3) Systemic intervention, including nervous system, immunotherapy, endocrinal intervention, as well as metabolic intervention, etc. were briefly discussed.