The injection of stem cells collected from umbilical cords into the pelvic bone of patients with leukemia appears promising; however, longer follow-up is necessary to determine outcomes for these patients. These results were recently published in an early online publication of the Lancet Oncology.
Leukemia is a type of cancer that originates in the blood cells. There are several types of leukemia, some of which are much more aggressive than others and require more aggressive types of therapy. One therapeutic option for patients with acute types of leukemia is 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 the following sources: umbilical cord blood immediately following the birth of a child (cells are then frozen and stored in a central facility), peripheral (circulating) blood, or 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.
Recent research has indicated that umbilical cord stem cells may reduce the rate of GVHD while providing similar outcomes among patients with leukemia; further assessment evaluating umbilical cord stem cells is ongoing.
Researchers from Italy recently conducted a clinical trial to evaluate the effectiveness of using umbilical cord stem cells that are injected directly into the bone marrow of patients with leukemia. This trial included 32 patients with acute myeloid leukemia (AML) and 12 with acute lymphoblastic leukemia (ALL) with a median age of 36 years. Overall, 14 patients had advanced-stage disease that did not respond to standard therapies, and no patient had a suitable donor for the stem cell transplant.
- No complications occurred during the infusion of stem cells into the bone marrow.
- No patients developed acute, severe GVHD.
- At 13 months 16 patients were alive and in complete remission (no detectable cancer cells).
- Five patients died from treatment-related complications of the transplant, seven died from infection, and four patients died from a relapse of their disease.
The researchers concluded that these results ?[lead] to the possibility of use of this technique in a large number of adult patients.?? Although this technique is still under investigation, it provides promise for the future of patients with leukemia.
Reference: Frassoni F, Gualandi F, Podesta M, et al. Direct intrabone transplant of unrelated cord-blood cells in acute leukaemia: a Phase I/II study. Lancet Oncology [early online publication]. August 9, 2008. DOI:10.1016/S1470-2045(08)70180-3.