Effect of age and body weight on toxicity and survival in pediatric acute myeloid leukemia: results from NOPHO-AML 2004.

Abstract

Treatment for pediatric acute myeloid leukemia is very toxic and the association between outcome and age and body mass index is unclear. We investigated effect of age and body mass index on toxicity and survival in pediatric acute myeloid leukemia. We studied all patients who completed first induction course of NOPHO-AML 2004 (n=318). Toxicity following induction and consolidation courses (n=6) was analyzed. The probabilities of toxicity and death were determined using time-to-event analyses with Cox multivariate proportional hazard regression for comparative analyses. Age 10-17 years was associated with sepsis with hypotension (hazard ratio 2.3 (95% confidence interval 1.1-4.6)). Overweight (>1 standard deviation) was associated with requiring supplemental oxygen (1.9 (1.0-3.5)). The 5-year event-free and overall survival were 47 % and 71%. Children aged 10-17 years showed a trend for inferior 5-year overall survival compared to children aged 2-9 (64% versus 76%, p=0.07). Infants showed a trend for superior 5-year event-free survival (66% versus 43%, p=0.06). Overweight children aged 10-17 showed a trend for superior survival (5-year event-free survival 59% versus 40%, p=0.09 and 5-year overall survival 78% versus 56%, p=0.06) compared to healthy weight children aged 10-17. In conclusion children aged 10-17 and overweight children had a higher risk of grade 3-4 toxicity. Children aged 10-17 showed inferior survival, but, unexpectedly, in this age group overweight children tended to have increased survival. This suggests different pharmacokinetics of chemotherapeutic drugs in adolescents and warrants further studies.