IMPE Abstracts

Background: Sarcopenia is a common disorder among elderly people defined by the loss of skeletal muscle mass accompanied by a physical function disorder. In recent years, it has been reported that the loss of skeletal muscle mass is a poor prognostic factor in pediatric cancer patients as well as adult cancer patients. In the elderly, a decrease in IGF-1 was suggested to be one of the responsible factors in the development of sarcopenia, but there have been no reports addressing the relationship between skeletal muscle mass and endocrine parameters or growth in children.

Objective: To investigate skeletal muscle mass in pediatric patients with acute leukemia (AL) and to clarify the relationship between skeletal muscle mass and endocrine indices.

Methods: Among first-episode pediatric AL patients aged 1-15 years who began treatment between April 2002 and March 2021, 33 patients (28; lymphoid, 5; myeloid) with abdominal CT imaging before treatment initiation were included. Pre-treatment body height, weight, total psoas muscle area (tPMA) at two intervertebral lumbar levels, L3-4 on abdominal CT, and IGF-1 SDS were investigated to assess the percentage of sarcopenia, which was defined as tPMA Z score < -2.0, in pediatric AL patients. We also examined the correlation between pre-treatment tPMA Z scores and IGF-1 SDS (12 patients) and the correlation between the rate of change in tPMA and IGF-1 scores before treatment and after remission induction therapy (13 patients).

Results: At pre-treatment, BMI ranged from 3.9 to 96.5%ile, tPMA Z scores was -3.24 to +0.02 (tPMA<-2.0 in 14/33 patients), IGF-1 SDS ranged from -4.04 to +0.15 SD. After induction treatment, tPMA significantly decreased and the tPMA Z scores ranged from -4.36 to -1.76. Although pre-treatment IGF-1 did not significantly correlate with pre-treatment tPMA, smaller tPMA Z scores tended to be associated with lower IGF-1 SDS.

Discussion: Significant skeletal muscle mass loss was observed by AL treatment, which was equivalent to previous reports. IGF-1 might be a predictive marker of sarcopenia because patients with lower pretreatment IGF-1 SDS tended to preserve skeletal muscle mass. Limitations of this study include small numbers of IGF-1 measurements and the lack of confirmation of the changes over time. Future prospective study evaluating endocrine indices including IGF-1 over time is needed to confirm the present study.

Conclusion: Skeletal muscle mass was generally low in pediatric AL patients at the onset. Most of them revealed additional loss of muscle mass after induction treatment.