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.