The association of clinical and patient factors with chemotherapy-induced peripheral neuropathy (CIPN) in colorectal cancer: secondary analysis of the SCOT trial

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of oxaliplatin. CIPN can impair long-term quality of life and limit the dose of chemotherapy. We investigated the association of CIPN over time with age, sex, body mass index, baseline neuropathy, and chemotherapy regimen in people treated with adjuvant oxaliplatin-containing chemotherapy for colorectal cancer.

Patients and methods: We carried out secondary analysis of data from the SCOT randomised controlled trial. SCOT compared 3 months to 6 months of oxaliplatin-containing adjuvant chemotherapy in 6088 people with colorectal cancer recruited between March 2008 and November 2013. Two different chemotherapy regimens were used: capecitabine with oxaliplatin (CAPOX) or fluorouracil with oxaliplatin (FOLFOX). CIPN was recorded with the Functional Assessment of Cancer Therapy/Gynaecologic Oncology Group-Neurotoxicity 4 tool in 2871 participants from baseline (randomisation) for up to 8 years. Longitudinal trends in CIPN [averages with 95% confidence intervals (CIs)] were plotted stratified by the investigated factors. Analysis of covariance (ANCOVA) was used to analyse the association of factors with CIPN adjusting for the SCOT randomisation arm and oxaliplatin dose. P < 0.01 was adopted as cut-off for statistical significance to account for multiple testing.

Results: Patients receiving CAPOX had lower CIPN scores than those receiving FOLFOX. Chemotherapy regimen was associated with CIPN from 6 months (P < 0.001) to 2 years (P = 0.001). The adjusted ANCOVA coefficient for CAPOX at 6 months was -1.6 (95% CIs -2.2 to -0.9) and at 2 years it was -1.6 (95% CIs -2.5 to -0.7). People with baseline neuropathy scores ≥1 experienced higher CIPN than people with baseline neuropathy scores of 0 (P < 0.01 for all timepoints apart from 18 months). Age, sex, and body mass index did not link with CIPN.

Conclusions: A neuropathy assessment before treatment with oxaliplatin can help identify people with an increased risk of CIPN. More research is needed to understand the CIPN-inducing effect of different chemotherapy regimens.