Physical functioning report and pulmonary function deficit in childhood acute lymphoblastic leukaemia survivors: A national cross-sectional ALL-STAR Lungs study

Survivors of childhood acute lymphoblastic leukaemia (ALL) are at increased risk of pulmonary function deficit (PFD), which may impair physical functioning. This study aimed to evaluate parent proxy- and self-reported physical functioning and its association with PFD and abnormal bronchodilator response (+BDR) among ALL survivors compared to controls. This cross-sectional study recruited 5-17.9-year-old ALL survivors from a national cohort (N=295) treated according to the NOPHO ALL2008 protocol (≥ 1 year post-treatment) and controls. Physical functioning was assessed using the Paediatric Quality of Life Inventory questionnaire. Pulmonary function tests (PFTs) identified PFD (abnormal PFT) and +BDR according to ERS/ATS criteria. T-tests and ordinal logistic regression compared groups. Among 184 ALL survivors and 207 controls included, survivors treated with high-risk chemotherapy (15-17.9 y, proxy: mean difference (MD) -19.9 [-29.0; -10.7], p < .001) and stem cell transplanted (5-15 y, proxy: -24.7 [-30.1; -19.4], p < .001 and 15-17.9 y, self: -14.5 [-24.1; -4.8], p = .004) reported significantly poorer physical functioning than controls, comparable to those of chronically ill children, particular in endurance and strength activities. In 5-15-year-olds with PFD/+BDR, survivor proxy reports were significantly poorer than controls (MD -14.4 [-20.8; -8.0], p < .001 / -14.3 [-24.9; -3.8], p = .01). PFD/+BDR had no significant impact on survivor reports. PFD/+BDR exacerbates physical functioning deficits in ALL survivors compared to peers, emphasising the need to mitigate treatment-related declines and monitor pulmonary function.