INTRODUCTION
The five-year relative survival rate for childhood cancer has improved from 70% to 80 %, therefore QoL in this vulnerable population is of interest to ongoing research. Currently, two systematic reviews show that most of the published research evaluates the QoL of survivorship rather than the QoL during treatment. The QoL of children with acute lymphoblastic leukemia (ALL) would also change throughout the different phases of the treatment regimen as well as after ceasing treatment. The present study aims to evaluate the dynamic changes in QoL in pediatric patients with ALL after diagnosis.

METHODS
A repeated cross-sectional study was conducted with applying a mixed effect model to controlling all potential confounders. Pediatric patients with ALL were followed up by repeated measurements since diagnosis by using the PedsQL Generic Core Scales and the PedsQL Cancer Module. The Kernel smoothing method was used to capture dynamic change in QoL in children with ALL since diagnosis.

RESULTS

A total of 302 participants were classified to four age group as follow: 33.04% toddler aged 2-4 (3.31 ± 0.73), 26.09% young child aged 5-7(5.83 ± 0.74), 29.13% children aged 8-12 (10.03 ± 1.29), 11.74% adolescent aged 13-18(14.16 ± 1.17), with 59.60 percent of children are boys. Most of the proxy in this study are female (85.09%), married (94.70%), lives in rural (67.54%) and only finished high school (70.19%).
For toddlers (aged 2-4), generic QoL domain scores of QoL of children with ALL aged 2-4 were good until three years after initial diagnosis, except frequently appeared procedural anxiety for constantly for two years and worried treatment during initial six months after diagnosis. Proxy data showed children (5-18 yrs) generic QoL domains were good, except physical (schooler in 1st year, adolescent in 2nd and 3rd years), emotional (adolescent in 3rd years), pain and nausea (in 2nd and 3rd years), procedural anxiety (young children and adolescent in 2nd and 3rd years). Proxy reported the young children and schoolers often concern appearance first two to three years after diagnosis. Children data showed impaired QoL domains, i.e, physical and nausea (schoolers in 6 initial months), pain for all three groups (from from 2nd to 3rd year).
Analysis from data of proxy report for toddler aged 2-4 years, time after diagnosis was positively correlated with emotional, treatment anxiety domains. Physical in toddler was poor in unemployed proxy group. Toddlers had more procedural anxiety in unemployed proxy group. Treatment anxiety improves over time but worse in proxy group whose education below college level.
Analysis from data of proxy report for children aged 5-18 years, young children (5-7 years) were better in cognition but worse in procedural anxiety compared with two elder groups (aged 8-12 years and aged 13-18 years). We found a positive correlation between time after diagnosis and seven QoL domains including: physical, emotional, pain, nausea, procedural anxiety, treatment anxiety, and worry domains. Proxy group whose education lower college level (<12 years of education) positively associated with pain, but negatively associated with cognition and perceived physical appearance anxiety domain.
Analysis from data of children self-report for children aged 5-18 years, compared with two elder groups (aged 8-12 years and aged 13-18 years), young children (5-7 years) had better in physical but worse in procedural anxiety, treatment anxiety. We found the positive correlation between time after diagnosis and six QoL domains including: physical, pain, nausea, procedural anxiety, treatment anxiety, and worry domain. T-cell acute lymphoblastic leukemia had a positive correlation with perceived physical appearance anxiety. Proxy group whose education below college (<12 years of education) positively correlated to physical, pain, and cognition.

CONCLUSION

Proxy data revealed QoL in aged 2-4 years generally were good until three years after initial diagnosis, except frequently appeared procedural anxiety. Both proxy and children reported several similar deteriorated QoL domains (physical, emotional) as well distinct those (procedural anxiety, social, pain, nausea) for the initial three years after diagnosis. Time after diagnosis has profound effects on QoL in this population. Proxy’s characteristics (i.e., education, employment), child age, and immuno type as T-cell acute lymphoblastic leukemia have significant correlation with various QoL domains in divergent aged groups. The agreement level of self-reports and proxy reports is differently distributed by child age and PedsQL domains.

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