Late effects of oxaliplatin-induced peripheral neuropathy (LEON)--cross-sectional cohort study of patients with colorectal cancer surviving at least 2 years.

ABSTRACT

OBJECTIVES: Oxaliplatin accumulates in dorsal root ganglia, causing an axonal neuronopathy. Symptoms include numbness, pain and gait disturbance which may persist and impact on quality of life (QOL). Despite widespread use of this drug, its late effects and patient satisfaction outcomes have not been widely reported. Furthermore, there has been limited qualitative research published in this area. The objectives of this study were to establish the incidence and clinical impact of chronic peripheral neuropathy. METHODS: We conducted a cross-sectional observational study of patients who started oxaliplatin treatment at least 2 years prior to study commencement. Patients were assessed in three ways clinical assessment encompassing neurological examination and nerve conduction studies to calculate a total neuropathy score (TNS); self-reported assessment via validated questionnaires; and assessment by recorded interview. The clinical and questionnaire-based assessments were analysed quantitatively and the interview data used for qualitative assessment. RESULTS: Twenty-five patients consented to participate. The mean starting dose of oxaliplatin given was 92 mg/m(2). The cumulative dose received ranged from 375 to 2,400 mg, with a mean cumulative dose of 1,515 mg. Oxaliplatin was ceased due to neuropathy in six patients (24 %), after a mean of 9 cycles of treatment. Modified TNS ranged from 1 to 15 with a mean of 9.5. There was a statistically significant correlation between cumulative oxaliplatin dose and TNS. Quality of life and functional impact questionnaires showed mildly lower physical quality of life, higher pain scores and functional impairment secondary to sensory deficit. Qualitative analysis demonstrated variable bio-psycho-social effects of chronic neuropathy but, importantly, highlighted that many patients felt they had been insufficiently warned of the risk of neuropathy. Despite this, the majority was satisfied with their decision to receive the drug. CONCLUSION: Many patients objectively demonstrated mild to moderate oxaliplatin neuropathy >2 years post-treatment. The majority of patients did not recall being warned of the risks of chronic peripheral neuropathy. Many of those who recall being warned did not feel sufficient emphasis was placed on the issue. Despite a varying burden of neuropathic symptoms, the majority of patients were highly satisfied with their decision to receive oxaliplatin.