Randomized controlled pilot study of neuromuscular electrical stimulation of the quadriceps in patients with non-small cell lung cancer

Abstract

Patients with lung cancer experience muscle wasting and weakness. Therapeutic exercise may be beneficial but is not always practical. An alternative approach may be neuromuscular electrical stimulation (NMES) of the quadriceps muscles, but this has not been formally examined in patients with cancer. Thus, we have undertaken this pilot study to assess feasibility and inform the design of future studies. Sixteen patients were randomized to receive usual care (control group) or usual care plus NMES for four weeks. NMES consisted of daily stimulation to both thighs for up to 30minutes (frequency 50Hz, "on" cycle 11%-25%). Adherence was assessed by a self-report diary and a semistructured evaluation form. Quadriceps muscle strength, exercise endurance, and free-living physical activity were assessed using a Cybex NORM dynamometer, an endurance shuttle walk test, and an ActivPAL accelerometer (mean daily step count), respectively. Changes in outcome from baseline were compared between groups by mean differences and their 95% confidence intervals using independent t-test (P=0.05). Median (range) adherence to the program was 80% (69%-100%). All patients found the NMES device easy to use. Changes in outcome favored the NMES group, with mean differences of 9.4 Nm (21%) in quadriceps muscle strength, 768 steps (15%) in free-living activity, and 138 m (8%) in exercise endurance, but none of the differences were statistically significant. In conclusion, NMES warrants further study in patients with lung cancer.