NEW ORLEANS, (Reuters Health) -- Preliminary results from a 3-year
study of 168 patients with high-risk blood and immune system cancers show that
those who received stem cell transplants had a survival advantage over those who
received standard treatment with bone marrow transplantation.
The 2-year survival rate for stem cell transplant recipients was 70%
compared with a survival rate of 45% for bone marrow transplant recipients.
These results were presented by researchers at the Fred Hutchinson Cancer
Research Center during the 41st American Society of Hematology meeting, held
this week in New Orleans.
Patients in the study included those with advanced-stage acute myelogenous
leukemia (CML) or acute lymphocytic leukemia (ALL) who had one or more relapses,
those with lymphomas that had not responded to treatment and those with
myelodysplasias. The patients in the study were randomly assigned to receive
either a bone marrow transplant or stem cells, which were collected from the
blood of a matched donor and infused intravenously.
"The evidence is convincing enough that we've already made a change in
treating our high-risk patients," researcher and lead author of the study, Dr.
William Bensinger of Fred Hutchinson Cancer Research Center in Seattle,
Washington, said.
The study also showed that stem cell transplant patients engrafted more
quickly and recovered platelet activity more rapidly than those who received
bone marrow transplants.
"These results are exciting because most strategies aimed at reducing
relapse are associated with higher toxicities, more complications and higher
mortality," Bensinger noted. "This data suggests that stem cell transplants may
offer the best of both worlds -- fewer relapses and fewer complications."
Bensinger thinks that stem cells may offer an advantage for patients with
lower-risk leukemias and lymphomas, but it remains less clear because enough
data has not yet been gathered.
Bensinger cautioned that these results are still preliminary. Early
results show a slightly higher risk among stem cell transplant recipients of
chronic graft-versus-host disease, a serious condition in which donor immune
cells attack the patient's skin, liver eyes, mouth, esophagus and joints. The
disorder is treated with immune suppressant drugs to control it. Significantly,
other studies also point to stem cell recipients experiencing higher rates of
this condition, which may not occur until 3 to 5 years after a transplant,
Bensinger pointed out.
Physicians must follow patients in the current study for another year or
two before it is clear whether chronic graft-versus-host disease occurs at
higher rates in this patient population, cautioned Bensinger.
