ABSTRACT
The development of tumor treatment with immunotherapy involves several research areas, such as antibody- or cell-mediated therapy through stimulation of the patients own immune system. Antibodies carrying toxins have a large potential for use in passive antibody-mediated immunotherapy. Immunotherapy will probably be most useful when the treatment of metastatic disease is considered. Metastatic cells from a certain tumor have to be treated with agents that can reach all the particular sites in which metastatic growth can take place. Several types of molecules can be classified as specific tumor markers, and some of them are retained in the tumor cell membranes, while others are excreted into the systemic circulation. Studies on multicellular spheroids have shown heterogeneity in the binding of monoclonal antibodies, and the heterogeneity was dependent both on the types of cells and on the types of antibodies or antibody fragments applied.
