Pulmonary Function Deficit and Clinical Associations in Childhood Acute Lymphoblastic Leukaemia Survivors: A National Retrospective ALL-STAR Lungs Cohort Study.

BACKGROUND

Although survival for childhood acute lymphoblastic leukaemia (ALL) has improved, long-term pulmonary function deficit remains a concern. We aimed to explore the prevalence of pulmonary function deficit and abnormal pulmonary function tests in childhood ALL survivors and clinical associations.

METHODS

This national, retrospective cohort study (February 2019-May 2024) included eligible 5-17.9 year-old survivors (N = 295) who performed a valid pulmonary function test ≥ 1 year after treatment (N = 185). Clinical associations included treatment characteristics, pulmonary diagnosis, and radiological findings from medical charts.

RESULTS

Among 185 survivors, 37% (95% confidence interval (CI): [30, 45]) had pulmonary function deficit, with the highest prevalence (56%) among 15-17.9-year-olds. Abnormal test prevalence was 37% [27, 48] for diffusing capacity (carbon monoxide and/or nitric oxide), 29% [22, 38] for lung clearance index, 12% [8,18] for forced expiratory volume in the first second, and 11% [7, 17] for broncho-dilator response. Bronchiolitis obliterans, stem cell transplantation and CT-verified bronchiectasis were significant clinical associations of pulmonary function deficit (100%, 97.5% CI: [40, 100], 89% [76, 103], 73% [51, 96]) and abnormal diffusing capacity (100% (97.5% CI [29, 100]), 82% [59, 105], 75% [45, 105]), respectively. Bronchiectasis (88% [65, 110]) and transplantation (64% [39, 89]) were associated with a higher prevalence of abnormal lung clearance index. Bronchiolitis obliterans (75% [19, 99]) and transplantation (61% [39, 84]) were associated with a higher prevalence of abnormal forced expiratory volume in the first second.

CONCLUSIONS

Pulmonary function deficit was frequent in childhood ALL survivors, especially after stem cell transplantation or pulmonary disease. Tailored long-term pulmonary monitoring, including small airway function and diffusing capacity, may aid in timely detection and intervention.