As far as cancers go, acute myeloid leukemia (AML) is
one of the most aggressive and deadly. Unfortunately,
aggressive cancers often go hand in hand with aggressive
treatments — and AML is no exception. As it stands,
only half of kids with acute myeloid leukemia (AML) are
cured. The other half are stuck with the disease and an
unfortunate 5 to 15% die of treatment-related complications.
What isn't clear, however, is whether a patient's weight
can tip the scales to worsen or improve survival odds
in AML. Extra weight has already been linked to an increased
risk of death in older women with this disease. A paper
in the January 12 issue of the Journal of the American
Medical Association now brings children and young
adults into the picture as well.
WEIGHING
IN ON AML
Dr Beverly Lange and colleagues from the Children's
Hospital of Philadelphia retrospectively compared the
survival rates in AML patients ranging in age from one
to 20 who varied in weight at the time of their diagnoses.
Their results confirm that surviving AML is indeed a
weighty issue, literally.
Of the 768 children and young adults,
the body mass indices (BMIs) of 84 fell in the bottom
10% of the population, while 114 were overweight with
a BMI in the upper fifth percentile. The remaining 570
subjects, who had BMIs somewhere in between these extremes,
were classed as middleweight.
STAY
IN THE MIDDLE
The odds of surviving AML, expressed as a hazard ratio,
were significantly less for the underweight and overweight
crowd than for the middleweight kids. This may have
been because they were more likely to suffer treatment-related
deaths caused mainly by infections that cropped up during
the first two rounds of chemotherapy.
A decreased rate of survival for
the underweight children did not surprise Dr Lange.
"They may be underweight because they have a worse disease,"
she says. "Also, some patients may be malnourished because
of poverty and lack of proper nutrition. Undernourished
patients in general have immunodeficiency and in some
cases may have other infections."
HEAVY
NEWS
The bad news for those at the other end of the weight
scale does not appear to be a sign "that [the patient's]
doses of chemotherapy calculated according to height
and weight were too high," according to Dr Lange. Rather,
she says that "a possible reason for their deaths are
the comorbidities that go along with being overweight
such as a pre-diabetic state with poor glucose tolerance
and tension, relative immobility, and difficulties encountered
or perceived by staff in performing."
The bottom line is that the over
and underweight AML patients are at risk of treatment-related
complications, which reduces their chances of survival.
Dr Lange and colleagues emphasized the finding's significance,
writing that, "the reduced survival in underweight and
overweight patients is roughly equal to the improved
survival accomplished by 10 years of progress in pediatric
AML."
JAMA Jan 12, 2005;293:203-11
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