Does in vitro bone marrow purging improve the outcome after autologous bone marrow transplantation?

High-dose therapy with bone marrow rescue is now regarded as an effective treatment for a variety of malignancies. In an attempt to circumvent the scarcity of HLA-matched donors, autologous marrow has been successfully used as the source of cells for hematopoietic reconstitution. There has been considerable controversy as to whether any malignant cells present in the graft could contribute to relapse of disease post-transplant. In this paper we review clinical results obtained by using autologous transplantation and present evidence on how ex vivo tumor purging may contribute to the outcome.