Background: Chemotherapy induced peripheral neuropathy (CIPN) may be an important cause of morbidity in childhood cancer survivors (CCS), contributing to reduced physical function and restricted participation in day-to-day activities. This study aimed to evaluate the prevalence and impact of CIPN in long term CCS.
Methods: Comprehensive neurotoxicity assessments were undertaken in CCS who completed platinum or vinca alkaloid based chemotherapy >5 years ago, comprising of clinical, functional, quality of life and neurophysiological parameters including conventional nerve conduction studies and novel nerve excitability studies.
Results: Neurotoxicity assessments were performed on 110 participants aged 7-47 years, who received chemotherapy at a mean age of 5.8±0.4yrs and completed treatment 11.2±0.7yrs ago. 33% of patients demonstrated clinical and/or neurophysiological evidence of peripheral neuropathy. Overall, CCS demonstrated reduction in sensory amplitudes compared to age-matched controls (Mean difference -6.3μV; 95%CI -9.6, -3.0µV; p=0.0003), suggesting an impact on axonal reserve. Participants treated with platinum agents (p=0.008) or dual neurotoxic chemotherapy were most affected (p=0.01). There were persistent abnormalities in functional excitability properties of sensory nerves in participants with prior cisplatin treatment (p<0.05). Clinical functional parameters of manual dexterity (44.5th percentile, 95%CI 36.1, 52.9%), balance (49th percentile, 95%CI 38.9, 59%) and co-ordination (55.9th percentile, 95%CI 46.9,65%) were relatively preserved compared to the normal population.
Conclusion: CIPN produces significant long term morbidity in CCS. Clinical and neurophysiological abnormalities in CCS are consistent with global axonal loss, which may predispose to further age-related degenerative change. Exposure to platinum or dual neurotoxic chemotherapy are risk factors for long term neuropathy. Relative preservation of clinical function suggests a window of opportunity for physical therapy which may preserve long term function.