Effects of the intensity and timing of asbestos exposure on lung cancer risk at two mining areas in Quebec

BACKGROUND: Bone marrow transplantation (BMT) has been limited in the past by the availability of matched donors for patients. Over the past decade, the use of umbilical cord blood (UCB) as a source of hematopoietic stem cells has revolutionized the field of BMT, providing a source of hematopoietic stem cells for an increasing number of patients in need of a transplant. RESULTS: Umbilical cord blood transplantation (UCBT) appears to result in sustained engraftment of donor hematopoiesis similar to results achieved with marrow and peripheral blood hematopoietic stem cells. Early results indicate that UCBT is associated with a lower incidence and less severity of graft-versus-host disease than other sources of stem cells, potentially decreasing the morbidity and mortality of BMT. As the potential of UCBT has been realized, cord blood storage facilities have been established to provide UCB. The rapid emergence of UCBT has transformed a waste product of birth into a life-saving resource. Its use, however; has raised numerous ethical and medical concerns unique to this alternative source of stem cells. CONCLUSIONS: Umbilical cord blood transplantation represents a major advance in providing another stem cell source to patients in need of allogeneic hematopoietic stem cell transplantation. As with all new technologies, UCBT will have to be carefully studied over the next several years to determine its safety, efficacy, and precise indications in comparison with other sources of hematopoietic stem cells. The ethics of UCBT must properly respect the rights and needs of both donors and recipients.