Author(s): PELI, L., VILLA, E.T., MORIGGI, T.1, POLLASTRI, L.1, CORTI, E.1, RADAELLI, G.1, CORTI, M.1, PAOLETTI, F.1, INSELVINI, E.1, JANKOVIC, M.1, BALDUZZI, A.2,3, LANFRANCONI, F.1, Institution: FONDAZIONE MONZA BRIANZA PER IL BAMBINO E LA SUA MAMMA, Country: ITALY, Abstract-ID: 2377

INTRODUCTION:
Children and adolescents with cancer (CAYA-c) who have completed intensive treatment for hematologic malignancies experience a marked decline in exercise capacity due to treatment toxicity, disease effects, and prolonged physical inactivity. Initiating personalized exercise programs (PEx) at diagnosis as preventive strategy may mitigate these persistent effects into survivorship. Accurate assessment of residual exercise tolerance through integrated CPET-NIRS is essential for tailoring interventions.

METHODS:
Thirty-nine patients (mean age 14.6±3.0 years, 56% male) who had completed intensive treatment for blood cancers (mean 13.1±4.6 months off-therapy) underwent maximal cardiopulmonary exercise testing (CPET, n=39) with simultaneous near-infrared spectroscopy (NIRS, n=35). Key variables analyzed were peak oxygen consumption (VO₂peak %predicted) and muscle oxygen extraction using NIRS (%HHb peak/%ischemia). Statistical analyses included Pearson correlations and linear regression (α=0.05).

RESULTS:
Thirty-nine participants (mean age 14.6 years, 56% male) completed CPET assessments. Compared to healthy peers, participants exhibited reduced VO₂peak (70.3±13.4% predicted). VO₂peak %predicted positively correlated with %HHb peak (r=0.45, p<0.0001, R²=0.45), indicating impaired muscle oxygen extraction. Borg RPE was independent of VO₂peak (p=0.21), confirming maximal test attainment.

CONCLUSION:
Exercise intolerance persists following intensive hematologic cancer treatment in CAYA-c, with integrated CPET-NIRS revealing muscle oxygen extraction impairment as the predominant mechanism. Introduction of structured PEx programs at diagnosis as preventive intervention throughout the entire treatment continuum may facilitate exercise capacity preservation and successful reintegration into daily life and sports participation.