Introduction: Oxaliplatin-induced neurotoxicity is the single main dose-limiting factor in the treatment of colorectal cancer. The degree of neurotoxicity may be either acute and reversible or observed as cumulative and chronic peripheral nerve damage leading to peripheral neuropathy (PNP), walking difficulties, extremity hypersensitivity, tingling and numbness, and increased pain sensation.
Aim: The aim of this paper is to determine and compare the ratio of clinical versus subclinical PNP cases in colorectal patients who underwent oxaliplatin treatment.
Materials and methods: Thirty-two colorectal cancer patients were enrolled in the study. Patients received chemotherapy either as folinic acid and 5-fluorouracil and oxaliplatin or capecitabine and oxaliplatin regimen. Electroneurophysiological tests were performed before the treatment and after the 4th cycle when the risk of peripheral nerve damage increases. All patients were subject to a standard neurological examination and a semi-structured questionnaire interview.
Results and discussion: Following oxaliplatin treatment, 21 (66.6%) of all patients presented neurological symptoms and/or electrophysiologically measured signs of PNP; of those, 7 patients (33.4%) displayed only electrophysiological changes and the remaining 14 patients (66.6%) presented fully symptomatic PNP - 4 patients were new neuropathy cases while the other 10 patients were previously diagnosed with PNP and showed signs of further neuronal deterioration and progressing sensory and motor dysfunction.
Conclusion: Our study lays ground for further larger scale longitudinal studies on oxaliplatin neurotoxicity and its prevention. We believe that early diagnosis of oxaliplatin-induced neurotoxicity is essential in the prevention of irreversible nerve damage and should be prioritized when assessing and evaluating treatment so that adequate adjustment may be made.
Keywords: Colorectal cancer; nerve conduction velocity; neurotoxicity; oxaliplatin; peripheral neuropathy.