6. Functional impact of neuropathy in patients receiving oxaliplatin chemotherapy

Abstract

The development of a generalised sensory neuropathy is the dose-limiting side-effect of the chemotherapeutic drug, oxaliplatin, the first line treatment in colorectal cancer. However, the functional impact of oxaliplatin-induced neuropathy has not been investigated. The present study was undertaken to investigate the potential relationship between neurophysiological parameters and functional outcomes in colorectal cancer patients treated with oxaliplatin chemotherapy. Nerve conduction studies and clinical examinations were conducted in 10 colorectal cancer patients receiving oxaliplatin chemotherapy (mean age 58.3 years; 7 male, 3 female). Symptoms of chemotherapy-induced peripheral neuropathy (CIPN) were assessed using the FACT-GOG NTX 13 questionnaire. The 9-hole peg test was undertaken by all patients as a measure of upper limb dexterity. All assessments were conducted at baseline, at the final cycle of treatment and 3 months following treatment completion. Three months following treatment completion there was a reduction in median and sural sensory amplitudes following oxaliplatin treatment (median; 67.8 ± 7.2%, sural; 62.4 ± 8%). This was accompanied by an increase in 9-hole peg test time (right hand; 4.9 ± 4.2%, left hand; 5.1 ± 3%). Assessment of neuropathy-related quality of life demonstrated an increase in neuropathic impairments which continued to progress following cessation of treatment, a phenomenon known as ‘coasting’ (FACT-GOG NXT-13 questionnaire; 27.4 ± 5.7%). Importantly, a significant correlation was noted between reductions in sural sensory amplitude, a marker of neuropathy severity, and prolongation in 9-hole peg test time (left hand r = 0.8, right hand r = 0.6). This study demonstrates prominent functional alterations in oxaliplatin treated patients that correlate with nerve conduction markers of neuropathy severity. This study emphasises the functional impact of oxaliplatin-induced neuropathy and underscores the importance of developing neuroprotective strategies for patients receiving oxaliplatin treatment.