Baseline subclinical sensory deficits and the development of pain and numbness in patients with multiple myeloma (MM) being treated with chemotherapy.

Abstract

9082 Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting toxicity experienced by patients with MM. Patients may develop painful and non-painful (e.g., numbness) symptoms that impair function and often persist after therapy is terminated. This study examined the predictive value of baseline subclinical sensory deficits on the development of treatment-related pain and numbness. Methods: Patients (N=56) who had two or fewer cycles of induction therapy and no obvious neuropathy were assessed for sensory deficits using quantitative sensory testing (QST). Patients reported the severity of pain and numbness (on a 0-10 scale) at least weekly via the MD Anderson Symptom Inventory during induction (up to 16 weeks); 15 of 56 patients provided data for up to 16 additional weeks of maintenance therapy. These values correlate to patient reported pain and numbness in the hands/feet. Based on data collected from healthy controls, patients were classified as being with or without a sensory deficit at baseline on each QST domain. We fit linear mixed models for pain and numbness with each sensory deficit and time, controlling for cumulative cycles, diabetes, age, and treatment agent. Data is shown as mean ± standard deviation. Results: Patients who showed baseline deficits in sharpness detection (20%) reported significantly lower levels of pain (1.2±1.9 vs 3.1±2.9, p=.004) and numbness (0.4±0.8 vs 2.4±2.6, p<.001) during induction therapy and less numbness (0.0 vs 3.5±2.8, p=.001) during maintenance therapy. Further, those who showed deficits in warmth detection (40%) reported higher levels of pain (5.2±2.8 vs 1.7±2.3, p<.001) and numbness (5.8±2.2 vs 1.6±1.8, p<.001) during maintenance therapy. Finally, those with lower skin temperature (47%) reported higher levels of pain (4.5±2.3 vs 1.7±2.9, p=.005) during maintenance therapy. Conclusions: Our results suggest that subclinical sensory deficits may be useful in determining a patient’s risk for developing CIPN prior to initiation of induction therapy. This information could be used to provide patients with more-personalized chemotherapy plans that take into account their neuropathy risk.