Myelodysplasia syndrome (MDS) killed my mother. Therefore, this paper caught my eye.
This paper describes a multicenter study from Argentina that examined children with MDS. MDS affects the blood cell-producing stem cells in the bone marrow so that these cells make immature red blood cells that do not properly carry oxygen to tissues. The rogue stem cells produce droves and droves of these immature cells that overpopulate the bone marrow and crowd out the normal bone marrow stem cells. Patients with MDS suffer shortness of breath, weakness and fatigue, mental lapses, and other symptoms of anemia. They also must rely on blood transfusions in order to keep them alive. Bone marrow transplants or umbilical cord transplants can cure MDS patients.
In this study, Ana Basquiera, from the Hospital Privado Centro Médico de Córdoba, Argentina, and her colleagues evaluated the overall survival, disease-free survival (DFS), non-relapse mortality (NRM) and relapse incidence in MDS children who underwent bone marrow and umbilical cord transplants. These children received these transplants in six different clinical throughout Argentina. All in all, 54 transplants were conducted in 52 patients. The mean age of these patients was 9 years old (range: 2–19), and 35 of the patients were males.
Several different types of MDS were seen in these patients, but all of them were not treatable by other means. Because MDS often precedes leukemia, seven (13%) patients at the time of the transplant transformed to acute myeloid leukemia (AML) and the diagnosis of two other patients also worsened.
All patients had their own bone marrow wiped out by means of a “conditioning regimen.” These are drugs that destroy the bone marrow stem cells of the patient and leave them without the means of make their own red blood cells or immune cells. Patients must then receive high doses of antibiotics and anti-fungal drugs while their bone marrow is repopulated. As you can guess, this is a nasty, dangerous procedure.
Of these patients, 63% received bone marrow stem cells, 26% stem cells from peripheral blood, and 11% umbilical cord blood. Five-year disease-free survival and overall survival were 50% and 55% respectively; and for patients with juvenile myelomonocytic leukemia, 57% and 67% respectively.
Cumulative incidence of non-relapse mortality and relapse were 27% and 21% respectively. Statistical analyses of the data from these treatments showed that patients who had received umbilical cord blood (HR 4.07; P = 0.025) and were younger than nine years old tended to have a lower overall survival rate. Also, younger patients who experienced graft-versus-host disease (GVHD), in which the engrafted immune cells begin to attack the tissues of the patient, had a higher rate of non-relapse mortality (no real surprise there).
Thus, more than half of the patients achieved long-term overall survival. The mortality and relapse rates were rather high, however, and it is possible that less toxic conditioning regimens or more intensive prevention of GVHD could lead to better results in some children. Until such procedures are make available, such mortality rates will probably remain high, even though the procedure does potentially cure the patients of MDS. Thus this remains a “high risk, big pay-off” procedure.
This was published in Pediatric Blood and Cancer.