Loprinzi, Charles L.

Individuals diagnosed with chemotherapy-induced peripheral neuropathy (CIPN) demonstrate impaired balance and carry an increased risk of falling. However, prior investigations of postural instability have only compared these individuals against healthy controls, limiting the understanding of impairments associated with CIPN. Therefore, the purpose of this study was to better isolate postural control impairments that are associated with CIPN. Twenty cancer survivors previously diagnosed with breast or colorectal cancer participated. Participants were separated into 3 groups: no prior chemotherapy exposure (CON, n = 6), and recent treatment with taxane- or oxaliplatin-based chemotherapy with no/mild symptoms of CIPN (−CIPN, n = 8) or moderate/severe symptoms of CIPN (+CIPN, n = 6). Postural control was assessed by measuring center of pressure during standing balance conditions that systematically interfered with somatosensory, visual, and/or vestibular information. The presence of CIPN sensory symptoms was associated with impaired postural control, particularly during eyes-closed balance conditions ( P < .05). Additionally, medial-lateral postural instability was more pronounced in the +CIPN group compared with the −CIPN group and CON participants ( P < .05). Greater postural instability during eyes-closed balance in individuals with CIPN is consistent with impaired peripheral sensation. Balance impairments in cancer survivors with CIPN demonstrate the unique challenges in this population and motivate the need for targeted efforts to mitigate postural control deficits that have previously been associated with fall risk.

Background: Chemotherapy-induced peripheral neuropathy (CIPN) affects 30% to 40% of patients with cancer with long-lasting disability. Scrambler therapy (ST) appeared to benefit patients in uncontrolled trials, so we performed a randomized sham-controlled Phase II trial of ST. Methods: The primary end point was “average pain” after 28 days on the Numeric Rating Scale. Each received ten 30-minute sessions of ST on the dermatomes above the painful areas, or sham treatment on the back, typically at L3-5 where the nerve roots would enter the spinal cord. Outcomes included the Brief Pain Inventory (BPI)-CIPN and the EORTC CIPN-20 scale. Patients were evaluated before treatment (day 0), day 10, and days 28, 60, and 90. Results: Data regarding pain as a primary outcome were collected for 33 of the 35 patients. There were no significant differences between the sham and the “real” ST group at day 10, 28, 60, or 90, for average pain, the BPI, or EORTC CIPN-20. Individual responses were noted during the ST treatment on the real arm, but most dissipated by day 30. There was improvement in the sensory subscale of the CIPN-20 at 2 months in the “real” group ( P = .14). All “real” patients wanted to continue treatment if available. Discussion: We observed no difference between sham and real ST CIPN treatment. Potential reasons include at least the following: ST does not work; the sham treatment had some effect; small sample size with heterogeneous patients; misplaced electrodes on an area of nonpainful but damaged nerves; or a combination of these factors.

Abstract Although recent scientific advances have improved our understanding of basic biological mechanisms underlying chemotherapy-induced peripheral neuropathy (CIPN), few interventions are available to prevent or treat CIPN. Although some biological targets from preclinical studies show promise in nonhuman animal models, few targets have been translated to successful clinical trials. To address this problem, the National Cancer Institute’s Symptom Management and Health-Related Quality of Life Steering Committee convened a meeting of experts in the CIPN and oncology symptom management fields to participate in a Clinical Trials Planning Meeting (CTPM). Investigators presented data from preclinical and translational studies for possible CIPN interventions; these were evaluated for readiness of randomized clinical trial testing by experts, and recommendations were provided. Breakout sessions were convened to discuss and develop future studies. The CTPM experts concluded that there is compelling evidence to move forward with selected pharmacological and nonpharmacological clinical trials for the prevention and treatment of CIPN. Several key feasibility issues need to be addressed, however. These include identification of optimal outcome measures to define the CIPN phenotype, establishment of parameters that guide the evaluation of clinically meaningful effects, and adoption of approaches for inclusion of translational and biomarker and/or genetic measures. The results of the CTPM provide support for conducting clinical trials that include both pharmacological and nonpharmacological approaches, alone or in combination, with biomarkers, genetics, or other measures designed to inform underlying CIPN mechanisms. Several working groups were formed to design rigorous CIPN clinical trials, the results of which are ongoing.