Hematopoietic stem cell transplantation: a glimpse of the past and a view of the future.

Hematopoietic stem cell transplantation (HSCT) is still the only definitive treatment for some malignant and nonmalignant diseases. The amount of knowledge that has been gained regarding this treatment is enormous. Research and development has been focused on minimizing transplant-related toxicity and disease recurrence. Early experiences of bone marrow administration to patients include marrow given by mouth, by intramuscular injection, intramedullary, and by intravenous route. Radiation injury in humans was a major stimulus for research in bone marrow transplantation. Early research was done on animals and then logically applied to humans. Over the last four decades, there was key progress made in the development of conditioning regimens, the selection of patients, the selection of donors, and prevention and treatment of complications associated with the HSCT procedure. It is believed that the recent and future advances of HSCT will make the transplant process less complex and more successful. In the 21st century, there will be marked improvements scientifically, technologically, and clinically in the HSCT procedure. If the current rate of research, clinical development, and dedication continues, HSCT should be even more rewarding and exciting for all clinicians who care for these patients and families.