The impact of diabetes on neuropathic symptoms and receipt of chemotherapy among colorectal cancer patients: results from the PROFILES registry

This study assessed differences in neuropathic symptoms between colorectal cancer (CRC) patients with and without diabetes. Moreover, we aimed to explore whether neuropathic symptoms could be explained by the receipt of chemotherapy as it was previously shown that cancer patients with diabetes less often receive chemotherapy. Data from a cross-sectional study among CRC patients (2-11 years after diagnosis) was used. Data were collected by the Patient Reported Outcomes Following Initial treatment and Long term Evaluation of Survivorship (PROFILES) registry which is linked to clinical data from the population-based Eindhoven Cancer Registry. Diabetes status was self-reported and neuropathic symptoms were measured with the European Organization for Research and Treatment of Cancer quality of life questionnaire-chemotherapy-induced peripheral neuropathy 20 (EORTC QLQ-CIPN20). Two hundred eighteen CRC patients with diabetes were matched on age and sex to 975 CRC patients without diabetes. After adjustments for cancer treatment including chemotherapy and other covariates, logistic regression models showed that CRC patients with diabetes experienced more mild to severe neuropathic symptoms, including tingling fingers or hands (odds ratio (OR) = 1.40; 95 % confidence interval (CI) 1.00-1.94), tingling toes or feet (OR = 1.47; 95 % CI 1.04-2.07), numbness in toes or feet (OR = 1.83; 95 % CI 1.28-2.62), and erection problems among men (OR = 1.83; 95 % CI 1.11-3.03) as compared to CRC patients without diabetes. No differences in cancer treatment were found between CRC patients with and without diabetes. CRC patients with diabetes experienced more neuropathic symptoms, regardless of cancer treatment, suggesting that diabetes itself rather than treatment with chemotherapy results in more neuropathic symptoms among cancer patients with diabetes compared to those without. Up to 39 % of cancer survivors might expect mainly mild, neuropathic symptoms, with more symptoms among patients with co-occurring diabetes.