Physical Activity During a Course of Radiotherapy for Lung Cancer - Results of the APART-LUNG Study

Patients receiving radiotherapy for lung cancer may experience treatment-related adverse effects that reduce physical activity. Smartphone-based reminder applications may help patients maintain daily activity; however, information on changes in step counts during radiotherapy is limited. The APART-LUNG study investigated changes in physical activity between the first and fifth weeks of radiotherapy and explored potential factors associated with decreased activity.

Twenty patients were enrolled, of whom 19 were eligible for analysis. Physical activity was assessed as the weekly mean number of steps per smartphone wear-hour during weeks 1 and 5 of radiotherapy. The primary endpoint was the within-patient difference between week 5 and week 1. Associations between changes in step counts and age, sex, performance status, comorbidity, body-mass index, histology, and concurrent systemic treatment were explored.

The mean numbers of steps per wear-hour were 344.3±171.6 in week 1 and 363.5±189.9 in week 5. Median values were 318.4 (range=123.3-762.9) and 300.3 (range=108.3-704.7) steps, respectively (p=0.465). The weekly average number of steps per wear-hour decreased in nine patients, increased in nine patients, and remained almost constant (plus three steps) in one patient. No characteristic was significantly associated with a decrease in steps. The greatest difference regarding the proportion of patients with a decrease in steps was observed for concurrent systemic treatment (no vs. yes, difference=37%).

In this pilot study, step counts did not significantly decrease during radiotherapy for lung cancer. No investigated characteristic was significantly associated with decreased physical activity, although concurrent systemic treatment showed the strongest signal and should be considered in the design of future prospective trials.