Thalidomide sensory neurotoxicity: A prospective study in patients with multiple myeloma

Background: Peripheral neuropathy (PN), the most common complication during thalidomide (TD) treatment, remains incompletely characterized with regard to incidence, anatomic features, risk factors and optimum management Aim of tiffs study is to characterize TD-neuropathy and to assess correlations between PN and TD dose in a series of patients treated for multiple myeloma (MM). Method: We followed for up to 19 months, 25 patients (M/F -- 11/14, mean age 58 ± 10.8 yrs) without evidence of PN at baseline, with onemonthly neurological exanffnations (Neurologic Symptom Score, MRC score, Reflex score) and neurophysiological studies (NCW and SNAP amplitude of sural and ulnar nerves). Patients received a 298 ± 86 mg mean daily TD dose. Median time to PN was calculated with Kaplan-Meier method. Multiple logistic-regression analysis was used for statistics. Significance level < 0.05. Results: Eighteen patients (M/F -- 5/13, mean age 58,17 ± 10.5 yrs) developed a sensory axonal PN. Median time to PN was 8 months (95%CI 6,3-9,7 months). 95% of patients developed PN after 3 months. Twelve patients (48%) showed a SNAP reduction > 50% at PN onset. TD daily mean dose was 295 ± 85 mg, mean cumulative dose was 61.44 ± 29.5 g and mean cumulative dose/body mass index was 2.56 ± 1.2 g. Clinical characteristics and TD doses were similar to those of patients without PN. Demograplffc characteristics were not correlated with PN. Conclusion: 72% of our patients on TD for MM developed a sensory mxonal PN, which occurred in the majority of cases after 3 months. Both cumulative and daily dose of TD did not influence the occurrence of PN.