Longitudinal neuropsychological outcomes after pediatric non-CNS cancer diagnosis and the role of neurological complications

Background Long-term survivors of non-central nervous system (CNS) pediatric cancers may experience neuropsychological deficits, but little is known about earlier post-diagnosis functioning. Risk factors for poorer neuropsychological outcomes may include CNS complications and peripheral neuropathy. This study describes neuropsychological functioning over time after non-CNS cancer diagnosis and explores the role of CNS complications and peripheral neuropathy on neuropsychological outcomes. Methods This prospective longitudinal study included 117 patients with non-CNS cancer aged 6-18 years. They underwent neuropsychological testing 3-6 months after diagnosis and approximately 2 years later. Neuropsychological performance at the final timepoint was compared to the normal population and to patients' own estimated IQ using t-tests. Linear mixed models and logistic regression were performed to study change or decline over time, and associations with CNS complications and peripheral neuropathy. Results Attention, verbal fluency and reading fluency scores were below participants' estimated IQ (p<0.05). Performance over time was stable on most outcomes, although variability was high. Patients who experienced a CNS complication had lower memory scores at 3-6 months, but scores normalized 2 years later (p=0.020). Patients treated with high-risk chemotherapy remained stable on impulsivity/inattentiveness, while patients treated without high-risk chemotherapy improved over time (p=0.010). Younger age at diagnosis was associated with declining neuropsychological scores (p=0.011). Conclusion On average, neuropsychological performance remains stable within the first 2-3 years after non-CNS cancer diagnosis. CNS complications, high-risk chemotherapy, and younger age at diagnosis may be risk factors for poorer outcome. High variability among patients stresses the importance of individual follow-up.