Assessing gait, balance, and muscle strength among breast cancer survivors with chemotherapy-induced peripheral neuropathy (CIPN): study protocol for a randomized controlled clinical trial

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and understudied consequence of taxane chemotherapy for breast cancer treatment. CIPN symptoms include numbness combined with tingling sensations, persistent shooting, stabbing, or burning pain even in the absence of painful stimuli, lower extremity muscle weakness, and impaired balance. CIPN symptoms often persist for a long time after completion of chemotherapy, causing significant loss of functional abilities and increased risk of falls. Persistent CIPN caused by taxanes represents a therapeutic challenge due to the limited treatment options. Resistance exercise has shown promising results; however, the effect of exercise on CIPN remains understudied. This study aims to assess the effects of exercise on gait, balance, and lower extremity muscle strength after a 16-week home-based exercise program compared to an educational attention control condition. Methods: A sample of 312 women who completed taxane-based chemotherapy for breast cancer and have symptomatic neuropathy is recruited from a community-dwelling sample. Participants are randomized to either a 16-week Home-Based Physical Activity Intervention or an Educational Attention control group. The home-based intervention protocol consists of targeted lower extremity stretches, followed by 10 min each of gait/balance and 10 min of resistive training accessed by hyperlink or DVD. An Exercise Diary records quantitative exercise data. The gait assessment includes temporospatial parameters and lower extremity joint angles using APDM motion sensors. Participants' balance is assessed using the Sensory Organization Test (SOT) performed using a NeuroCom Balance Master. Isometric strength of hip, knee, and ankle flexor and extensor muscles is assessed using an isokinetic dynamometer, Biodex BX Advantage. In addition, we assess neuropathy symptoms using the FACT-Taxane Additional Concerns Subscale and nerve conduction velocity of the sural and peroneal nerve action potentials. Outcomes are assessed at baseline (prior to randomization) and 16 weeks. Discussion: There are currently no evidence-based interventions that address the functional declines associated with CIPN. If successful, this program is simple and easy to implement in the standard of care for individuals with CIPN. Gait and balance training have the potential to reduce physical dysfunction associated with CIPN and reduce the burden of disease in cancer survivors.