Umbilical Cord Transplants Provide Same Outcomes as Related Allogeneic Stem Cell Transplants
Daily Cancer News
CancerConsultants.com
Feb 7 2007
According to an article recently published in Blood, using umbilical cord blood for stem cell transplants provides results that are similar to or better than results of an allogeneic stem cell transplant utilizing stem cells from a related donor.
Hematologic malignancies are cancers that originate in the cells of the blood. There are several different types of hematologic malignancies, many of which are treated with a stem cell transplant.
One type of stem cell transplant, an allogeneic stem cell transplant, involves the use of high-dose therapy to kill more cancer cells than standard doses. Unfortunately, the higher doses tend to destroy important hematopoietic stem cells (immature blood cells). These stem cells mature into red blood cells, which transport oxygen and nutrients to tissues in the body; white blood cells, which help the body fight infection; and platelets, which aid the blood in clotting.
Low levels of hematopoietic stem cells caused by high-dose treatment can result in life-threatening conditions. In an effort to prevent this condition, hematopoietic stem cells from a donor are infused into the patient following therapy. Hematopoietic stem cells may be obtained from umbilical cord blood immediately following the birth of a child (cells are then frozen and stored in a central facility), from peripheral (circulating) blood, or in the bone marrow (spongy material inside large bones).
In addition to restoring low levels of a patient’s stem cells following therapy, donor stem cells also attack the patient’s cancer cells. Unfortunately, they may also attack a patient’s healthy tissues, a condition referred to as graft-versus-host-disease (GVHD). Due to the potential severity of GVHD, researchers try to use stem cell donors who are related to the patient and have “matched” proteins, a practice that reduces the risk of GVHD. Unfortunately, many patients will die from their disease while waiting for a matched donor. Researchers continue to investigate ways to reduce GVHD without compromising the effectiveness of donor stem cells.
Researchers from Japan recently conducted a clinical trial including patients with leukemia or lymphoma who underwent umbilical cord blood transplants or peripheral or bone marrow allogeneic stem cell transplants.
- At three years mortality related to treatment was 9% for those treated with umbilical cord transplants and 13% for those treated with bone marrow or peripheral blood transplants.
- At three years relapses occurred in 17% for those treated with umbilical cord transplants and 26% for those treated with bone marrow or peripheral blood transplants.
- At three years cancer-free survival was 70% for those treated with umbilical cord transplants and 60% for those treated with bone marrow or peripheral blood transplants.
- For patients who were at a standard risk of developing a recurrence, cancer-free survival at three years was 93% for those treated with umbilical cord transplants and 85% for those treated with bone marrow or peripheral blood transplants.
- For patients who were at a high risk of developing a recurrence, cancer-free survival at three years was 56% for those treated with umbilical cord transplants, compared with 45% for those treated with bone marrow or peripheral blood transplants.
- GVHD was less frequent after umbilical cord transplants compared with bone marrow or peripheral blood transplants.
The researchers concluded that umbilical cord transplants provide results that are comparable to or better than those achieved with standard allogeneic stem cell transplants utilizing peripheral blood or bone marrow stem cells from a related donor. These results provide additional evidence that the use of umbilical cord stem cells may be an effective alternative to an allogeneic stem cell transplant from an unrelated donor.
Reference: Takahashi S, Ooi J, Tomonari A, et al. Comparative single-institute analysis of cord blood transplantation from unrelated donors with bone marrow or peripheral blood stem-cell transplants from related donors in adult patients with hematologic malignancies after myeloablative conditioning regimen. Blood. 2007;109:1322-1330.
