Introduction Non‐central nervous system cancer in childhood (non‐CNS CC) and its treatments pose a major threat to brain development, with implications for functional networks. Structural and functional alterations might underlie the cognitive late‐effects identified in survivors of non‐CNS CC. The present study evaluated resting‐state functional networks and their associations with cognition in a mixed sample of non‐CNS CC survivors (i.e., leukemia, lymphoma, and other non‐CNS solid tumors). Methods Forty‐three patients (off‐therapy for at least 1 year and aged 7–16 years) were compared with 43 healthy controls matched for age and sex. High‐resolution T1‐weighted structural magnetic resonance and resting‐state functional magnetic resonance imaging were acquired. Executive functions, attention, processing speed, and memory were assessed outside the scanner. Results Cognitive performance was within the normal range for both groups; however, patients after CNS‐directed therapy showed lower executive functions than controls. Seed‐based connectivity analyses revealed that patients exhibited stronger functional connectivity between fronto‐ and temporo‐parietal pathways and weaker connectivity between parietal‐cerebellar and temporal‐occipital pathways in the right hemisphere than controls. Functional hyperconnectivity was related to weaker memory performance in the patients' group. Conclusion These data suggest that even in the absence of brain tumors, non‐CNS CC and its treatment can lead to persistent cerebral alterations in resting‐state network connectivity.
Non‐CNS childhood cancer is associated with alterations in functional connectivity. In patients, we observed both hyper‐ and hypoconnectivity when compared with healthy controls, however, altered functional connectivity was found only in the right hemisphere. Fronto‐parietal long‐range connections are more likely to be altered than short‐range connections. Stronger functional connectivity is associated with weaker verbal memory performance in survivors of childhood cancer.