Cancer Treatment Today

The history of stem cell research includes work with both animal and human stem cells. Stem cells can be classified into three broad categories, based on their ability to differentiate. Totipotent stem cells are found only in early embryos. Each cell can form a complete organism (e.g., identical twins). Pluripotent stem cells exist in the undifferentiated inner cell mass of the blastocyst and can form any of the over 200 different cell types found in the body. Multipotent stem cells are derived from fetal tissue, cord blood, and adult stem cells.

A prominent application of stem cell research has been bone marrow transplants using adult stem cells. Among early attempts to do this were several transplants carried out in France following a radiation accident in the late 1950′s. Since physicans could not isolate stem cells at that time, they transfused bone marrow with stem cells in it. Autologous marrow means from the same individual while allogeneic marrow is provided by another individual. A bone marrow transplant between identical twins guarantees complete HLA compatibility between donor and recipient. These were the first kinds of transplants in humans, followed by autologous transplants. It was not until the 1960′s that physicians knew enough about HLA compatibility to perform transplants between siblings who were not identical twins. In 1973 a team of physicians performed the first unrelated bone marrow transplant. In 1984 Congress passed the National Organ Transplant Act, which among other things, included language to evaluate unrelated marrow transplantation and the feasibility of establishing a national donor registry. This led ultimately to National Marrow Donor Program (NDWP) a separate non-profit organization that took over the administration of the database needed for donors in 1990. The 1990′s saw rapid expansion and success of the bone marrow program with more than 16,000 transplants to date for the treatment of immunodeficiencies and leukemia.

Now that stem cells can be harvested from the blood, stem cell transpalntation has largely replaced bone marrow transplantation, although recent trials have revived an interest in bone marrow trnasplantation and its possible advantages over stem cell transplants. Adult stem cells also have shown great promise in other areas. Stem cell transplant for acute myelogenous leukemia. Philadelphia (PA): Intracorp; 2005. Various p. [50 references]

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Buckner CD: Autologous bone marrow transplants to hematopoietic stem cell support with peripheral blood stem cells: a historical perspective. J Hematother 1999 Jun; 8(3): 233-6