The objective of the treatment of acute leukemia involves the
eradication of all neoplastic cells, including the last one. Ideally,
treatment should be controlled by monitoring cell kill. If the last
cells could be discovered and their biological properties be determined,
the qualitative and quantitative effects of treatment should be directly
evaluable. This should ultimately permit a calculated tumor cell
reduction thereby avoiding overtreatment and excessive toxicity and thus
providing a basis for individualized antileukemic treatment. In recent
years several new developments have contributed to the selective
discovery of minimal numbers of leukemic cells which are hidden among
the normal cells in the marrow cavities. These methods are the first
steps to the realization of the therapeutic goals indicated above. They
include the production and ap- plication of monoclonal antibodies
against differentiation antigens on the cell sur- face, the use of pulse
cytophotometry - and cell sorter techniques, the employment of
cytogenetics, the development of culture techniques for selective growth
of precursor cells and several others. These methodologies offer
prospects for refined diagnosis and, as far as the elimination of
leukemic cells is concerned, the further development of autologous bone
marrow transplantation. Eliminating tumor cells from autologous grafts
requires the detailed knowledge of the cellular inter- relationships
within the neoplasm so that the neoplastic cells responsible for tumor
propagation are specifically removed. Recognition and characterization
of the clonogenic cells of the neoplasm should then lead to determining
their sensitivity to the therapeutic agents which are clinically
applied.
