The pathogenesis of cancer metastasis: Relevance to therapy

Abstract

Metastasis, the spread of malignant tumor cells from a primary neoplasm to distant parts of the body where they multiply to form new growths, is a major cause of death from cancer. The treatment of cancer poses a major problem to clinical oncologists, because by the time many cancers are diagnosed, metastasis may already have occurred, and the presence of multiple metastases makes complete eradication by surgery, radiation, drugs, or biotherapy nearly impossible. Metastases can be located in different organs and in different locations within the same organ. These aspects significantly influence the response of tumor cells to therapy and the efficiency of anticancer drugs, which must be delivered to tumor lesions to destroy cells without leading to undesirable side effects. Similarly, immune effector cells of current biotherapeu-tic regimens may not reach or localize in metastases with different organs. © Springer Science+Business Media B.V. 2009.