Age alone no longer should be considered a defining factor when determining whether an older patient with blood cancer is a candidate for stem cell
transplantation. That's the conclusion of the first study summarizing
long-term outcomes from a series of prospective clinical trials of
patients age 60 and over who were treated with the mini-transplant, a
"kinder, gentler" form of allogeneic (donor cell) stem cell
transplantation developed at Fred Hutchinson Cancer Research Center. The
findings are published Nov. 2 in JAMA, The Journal of the American
Medical Association.
"Age is no longer a barrier to allogeneic transplant," said Mohamed
Sorror, M.D., M.Sc., an assistant member of the Hutchinson Center's
Clinical Research Division and corresponding author of the paper.
Sorror and colleagues found that the five-year rates of overall and
disease-progression-free survival among mini-transplant patients were 35
percent and 32 percent, respectively. Patients in three age groups 60
to 64, 65 to 69 and 70 to 75 had comparable survival rates, which
suggested that age played a limited role in how patients tolerate the
mini-transplant. Increased medical problems unrelated to cancer
(comorbidities) and a higher degree of cancer aggressiveness were the
two factors that affected survival among those older patients. For
example, patients who had less-aggressive cancer and fewer comorbidities
had a five-year survival rate of 69 percent, while patients with more
aggressive cancer and a significant number of comorbidities had a
survival rate of 23 percent, regardless of age.
Although a long-term survival rate of one-third of patients may seem
low, these patients all would have died of their diseases within a
matter of months without a transplant. "The majority of patients were
referred for a transplant after they had exhausted all forms of
conventional therapy," said Sorror, who works in the research group led
by Rainer Storb, M.D., who developed the mini-transplant.
"While there is much room for improvement, particularly with regard to
relapse, these results are encouraging given the poor outcomes with
non-transplantation treatments, especially for patients with high-risk
AML (acute myeloid leukemia), fludarabine-refractory CLL (chronic lymphocytic leukemia) or progressive lymphoma," the authors wrote.
The mini-transplant, known in medical circles as nonmyeloablative
transplantation, was developed by researchers at the Hutchinson Center
for older and medically sicker patients who otherwise could not tolerate
the standard, more-toxic, high-dose regimens used to prepare patients
for transplantation.
