Late Breaking Abstract - Late pulmonary adverse effects in childhood survivors of acute lymphoblastic leukemia; A national cross-sectional study

Enhanced survival rates in childhood acute lymphoblastic leukemia (ALL), attributed to improved treatment protocols, unfortunately entails significant cost. Pulmonary toxicities are common during ALL treatment. Thus, long-term risk of late pulmonary adverse effects (LPAE), including pulmonary function (PF) deficit and pulmonary symptomatology (PS), persists as significant concerns. Previous studies lack control matching and exclusion of obsolete radiation therapy. Addressing these gaps, we aim to uncover LPAE in a childhood ALL survivor cohort treated with the NOPHO ALL2008 protocol. This Danish national cross-sectional study conducted at Aarhus and Copenhagen University Hospital (Feb 2019 - May 2024) included 206 ALL survivors and 219 age- and gender-matched controls, aged 5-17.9. Participants underwent anthropometric examinations, PS questionnaires, and PF testing. The primary and secondary outcomes were the mean differences in PS and PF between groups. Exertional dyspnea were more frequent and severe in ALL survivors compared to controls (26/185 vs. 7/209, p <. 001) and survivors had significantly reduced z-score for forced expiratory volume during the first second (−0.07 vs. 0.28, p =. 003) and reduced diffusing capacity for monoxide (−0.30 vs. 0.12, p <. 001) compared to controls. These pulmonary function deficits were especially pronounced in ALL survivors treated with high risk chemotherapy and high risk stem cell transplantation. These significant findings with clinical relevance underscore the need for long-term pulmonary monitoring and follow-up recommendations to enhance diagnostics, treatment and prophylaxis of LPAE by clinicians in these patients.