For many years, clinicians have thought that older teens with
acute myeloid leukemia (AML) would tolerate therapies better than
the youngest patients.
"Clinicians have assumed that because they were bigger and
stronger, they might be able to tolerate treatment better," says
Alan Gamis, MD, Chief of the Section of Oncology at Children's
Mercy Hospitals and Clinics. Dr. Gamis, along with other leading
AML researchers, reviewed outcomes on several Children's Oncology
Group (COG) clinical trials for AML to verify this assumption.
"What our study tells us is that those patients are at the
highest risk of death due to complications, not the lowest," says
The trials were conducted by the COG and their research included
data on AML patients from 200 institutions from 1995 to 2005.
Children's Mercy, one of the larger childhood cancer centers in the
country, also is one of the larger members of COG. Dr. Gamis chairs
COG's national AML committee.
Prior studies have shown that patients aged 16 to 21 years, who
might be cared for by either medical or pediatric oncologists, have
higher cure rates on the more intensive pediatric AML
regimens. But this also carries greater risk during
treatment. And, AML treatment is considered the most intense
of all cancer therapies. As such, "the norm in pediatrics
over the past 10 years has been to keep children in the hospital
until their blood counts have recovered. However, because
older patients can tell us how they feel, many clinicians around
the world, rather than keep those patients in the hospital, have
allowed them to go home before they recovered their blood counts,"
Dr. Gamis says.
However, the study, for which lead author Jason Canner presented
preliminary results at the American Society of Clinical Oncology
Annual Meeting in 2011, "tells us that we must be much more
cautious with these patients' care as far as not allowing them to
be discharged too early," says Dr. Gamis. Further, the study
identified how to improve survival and cure by improving supportive
COG is entering more detailed analyses of patients enrolled in
current trials to better identify causes of complications and
mortality. "We've also added a couple of additional trials to see
if we can prevent those deaths by use of prophylactic antibiotics
and antifungals," says Dr. Gamis. The new trials will be offered to
patients of all ages. "But we certainly have a heightened interest
of what's going to happen for our teens."