Update of the metastatic mechanisms of malignant tumors / 医学研究生学报

ABSTRACT

Tumors are classified into two major categories,benign and malignant.One main difference between malignant and benign tumors is their tendency to metastasize and recur.The metastasis itself is an ominous sign for prognosis and responsible for most cancer deaths.The metastatic "cascade" comprises a lot of steps,including escape from the primary tumor site,penetration of local stroma,entry of local vascular or lymphatic vessels,aggregation with platelets,interaction with and adhesion to distant endothelia,extravasation,recolonization,and expansion,all the time avoiding effective immune clearance and being able to survive.It has now been shown to contain stem cell-like cells called cancer stem cells(CSC) in several solid tumors.Although generally rare,these cells appear to be highly tumorigenic and may drive tumor formation and mediate tumor metastasis.