Significance of descriptive symptoms and signs and clinical parameters as predictors of neuropathic cancer pain

Purpose Evaluation of symptoms and signs for the management of neuropathic cancer pain (NCP) is challenging. This study aimed to identify clinical predictors of NCP and symptoms and signs most relevant of those in Korean patients. Methods This nationwide, descriptive, cross-sectional, multicenter, observational study included 2,003 cancer patients aged ≥20 years who reported a visual analog scale (VAS) score ≥1 for pain and provided informed consent for participation. The Douleur Neuropathic (DN4) questionnaire (score ≥4) was used to determine symptoms and signs as well as the presence of NCP. Results The prevalence of NCP was associated with age <65 years [OR, 1.57; 95% CI, 1.270- 1.934], disease duration >6 months (OR, 1.57; 95% CI, 1.232-2.012), stage IV cancer (OR, 0.75; 95% CI, 0.593-0.955), history of chemotherapy (OR, 1.74; 95% CI, 1.225-2.472), and moderate-to-severe cancer pain (OR, 2.05; 95% CI, 1.671-2.524) after multivariate analysis. The most common descriptive symptoms of NCP were tingling, electric shock, and pins and needles. For NCP patients in the presence or absence of the clinical predictors, pins and needles (p = 0.001) and painful cold (p<0.001) symptoms were significantly frequent in patients with moderate-to-severe pain. Tingling, numbness, and touch hypoesthesia (p = 0.022, 0.033, 0.024, respectively) were more frequent in those with longer cancer duration and hyperesthesia (p = 0.024) was more frequent in young patients. Conclusion Age <65 years, disease duration >6 months, stage IV cancer, history of chemotherapy, and moderate-to-severe cancer pain, were identified as predictors of NCP. Some symptoms and signs of NCP were associated with these predictors. Further studies are warranted on the pathogenesis and management of NCP with respect to the symptoms and signs, and factors associated with pain severity in Korean patients.