Leukaemia cells can hide in fat tissue to evade chemotherapy, which may explain why obese children with leukaemia are more likely to develop chemotherapy resistance and have higher relapse rates, researchers say.
A previous study found that obese children with leukaemia are 50% more likely to relapse than lean children.
Higher relapse after treatment
In this new study, researchers observed that obese mice with leukaemia had higher relapse rates than lean mice after they were treated with the first-line chemotherapy drug vincristine. In the mice that relapsed, leukaemia cells were found to be hiding in fat tissue during chemotherapy.
"We were surprised to find leukaemia cells in the fat tissue," lead researcher Dr. Steven D. Mittelman, the fellowship research director with the Division of Endocrinology at Children's Hospital Los Angeles, and assistant professor of paediatrics, physiology and biophysics at the Keck School of Medicine, University of Southern California, said in a news release from the American Association for Cancer Research.
He and his colleagues also found that four chemotherapy drugs used in children -- vincristine, nilotinib, daunorubicin and dexamethasone -- all worked less effectively in culture when fat cells were nearby.
The study appears online September 22 in the journal Cancer Research.
Mittelman said further research is needed to determine how body fat affects chemotherapy.
The study findings offer "striking experimental support for the clinical observations that obesity is associated with poor prognosis in multiple cancers," Dr. David Hockenbery, a member of the Fred Hutchinson Cancer Research Center and a professor of internal medicine at the University of Washington, said in the news release. – (HealthDay News, September 2009)
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