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Researchers say they have discovered a way to predict which children with acute myeloid leukemia (AML) are at the highest risk of delayed neutrophil recovery.
The team examined the role of telomeres in neutrophil recovery and found that the length of a patient’s telomeres can indicate the rate of recovery following chemotherapy.
The group reported their findings in the Journal of Clinical Oncology.
“We were interested in telomere length as a marker of blood count recovery because defects in telomere maintenance are known risks for bone marrow failure and aplastic anemia,” said study author Maria Monica Gramatges, MD, PhD, of Baylor College of Medicine in Houston, Texas.
“We know that up to 15% to 20% of children can take 2 months or longer to recover their blood counts after a course of AML chemotherapy. Our goal was to understand if these children had an underlying genetic predisposition associated with an impaired capacity for recovery.”
Dr Gramatges and her colleagues hypothesized that short telomere length could be associated with a delay in neutrophil recovery.
So they obtained bone marrow samples from AML patients who recovered as expected (within 30 days) after each chemotherapy course (n=62), and from AML patients who experienced significant delays in recovery after chemotherapy (n=53).
The team then measured telomere length on each subject and categorized the group by quartile, from shortest to longest.
Subjects in the quartile with the shortest telomere lengths took the longest to recover, especially during the last 2 courses of chemotherapy. In an adjusted analysis, lower telomere content was significantly associated with prolonged neutropenia after the fourth (P=0.002) and fifth courses of chemotherapy (P=0.009).
The researchers said these results support the hypothesis that telomeres are an indicator of capacity for neutrophil recovery following chemotherapy.
Dr Gramatges hopes the results of this study will be helpful in further understanding which children are at a higher risk for prolonged myelosuppression and how to target those children with modified treatments, improved supportive care, and closer monitoring in order to prevent potential complications such as severe infections.
“A significant proportion of children with AML suffer from treatment-related toxicities, with some succumbing to complications of the therapies we give, rather than from the actual cancer itself,” Dr Gramatges said.
“We hope this research will help us identify those who are at a higher risk for delayed recovery and use this knowledge to reduce the morbidity and mortality associated with AML treatment.”
