Treatment of lymphoid malignancies with non-myeloablative stem cell transplantation.

The traditional approach to allogeneic hematopoietic stem cell transplantation involves the administration of myeloablative preparative regimens. This form of conditioning is associated with a relatively high incidence of regimen-related toxicity. As a result, candidates for allogeneic stem cell transplantation may be excluded owing to advanced age or co-morbid medical illness. Recently, so-called "non-myeloablative" regimens have been introduced, where less intense conditioning therapy is used in an attempt to reduce regimen-related toxicity. In addition, non-myeloablative transplantation takes advantage of the graft-versus-tumour effect that is characteristic of allogeneic stem cell transplantation. We review the background, available clinical data, and future directions in non-myeloablative stem cell transplantation, and focus on its potential use in the treatment of lymphoid malignancies.