Predictors of the usefulness of duloxetine for chemotherapy-induced peripheral neuropathy

Duloxetine is an effective therapeutic agent for chemotherapy-induced peripheral neuropathy (CIPN). However, predictors of duloxetine response have not been adequately explored. Therefore, this retrospective study was performed to identify predictive factors of duloxetine response in CIPN patients to guide future strategies to improve the quality of life of patients undergoing chemotherapy. The participants were 74 cancer patients who were given duloxetine for relief of CIPN at our institute between October 2010 and January 2016. Variables were extracted from clinical records for regression analysis of factors related to relief of CIPN. We evaluated the effect of duloxetine 2 weeks after administration. Groups were categorized according to degree of improvement: poor, effective, and very effective. Multivariate ordered logistic regression analysis was performed to identify predictive factors for the usefulness of duloxetine. Threshold measures were examined using a receiver operating characteristic analysis (ROC) curve. Body height [odds ratio (OR) 0.943, 95% confidence interval (CI) 0.889-0.997; P = 0.0387], history of docetaxel use (OR 0.084, 95% Cl 0.009-0.814; P = 0.0325), and site of symptom (upper limb) (OR 3.848, 95% Cl 1.072-13.807; P = 0.0387) were significant factors related to the effect of duloxetine. ROC curve analysis of the poor effect group indicated a threshold for body height of >171.4 cm (area under the curve [AUC] = 0.61). In conclusion, body height (low), history of docetaxel use (less), and site of symptom (upper limb) were shown to be predictive factors for the usefulness of duloxetine for CIPN in patients undergoing chemotherapy.