Step counts did not significantly decrease during radiotherapy for lung cancer, and no investigated characteristic was significantly associated with decreased physical activity, although concurrent systemic treatment showed the strongest signal.
Key Findings
Results
Mean step counts per wear-hour did not significantly change between week 1 and week 5 of radiotherapy for lung cancer.
Mean 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) in week 1 and 300.3 (range=108.3–704.7) in week 5.
The difference was not statistically significant (p=0.465).
Physical activity was assessed as the weekly mean number of steps per smartphone wear-hour.
20 patients were enrolled and 19 were eligible for analysis.
Results
Step counts decreased in approximately half of patients, increased in approximately half, and remained nearly constant in one patient.
The weekly average number of steps per wear-hour decreased in nine patients.
Step counts increased in nine patients.
One patient showed almost no change (plus three steps).
The primary endpoint was the within-patient difference between week 5 and week 1 step counts.
Results
No patient characteristic was significantly associated with a decrease in physical activity during radiotherapy.
Factors explored included age, sex, performance status, comorbidity, body-mass index, histology, and concurrent systemic treatment.
None of these characteristics reached statistical significance in association with decreased step counts.
The greatest difference regarding the proportion of patients with a decrease in steps was observed for concurrent systemic treatment (no vs. yes, difference=37%).
Concurrent systemic treatment was identified as the strongest signal among all explored variables.
Discussion
Concurrent systemic treatment showed the strongest association with decreased physical activity and was identified as a factor to consider in future trial design.
The difference in the proportion of patients with decreased step counts between those receiving and not receiving concurrent systemic treatment was 37%.
This finding did not reach statistical significance, likely due to the small sample size of 19 patients.
The authors recommended that concurrent systemic treatment should be considered in the design of future prospective trials.
This was described as a pilot study with exploratory analyses.
Methods
The APART-LUNG study used smartphone-based step count measurement to assess physical activity during a five-week course of radiotherapy for lung cancer.
Physical activity was quantified as the weekly mean number of steps per smartphone wear-hour to account for variation in device wear time.
Assessment points were week 1 and week 5 of radiotherapy.
A smartphone-based reminder application was part of the intervention framework to help patients maintain daily activity.
The study was conducted as a pilot study with 20 enrolled patients, 19 of whom were eligible for analysis.
What This Means
This research suggests that lung cancer patients undergoing a course of radiotherapy do not experience a significant overall decline in physical activity, as measured by step counts tracked via smartphone. In the APART-LUNG pilot study, 19 patients wore smartphones that recorded their daily steps during the first and fifth weeks of treatment. On average, step counts were similar at both time points, and roughly equal numbers of patients showed increases or decreases in activity over the course of treatment.
The study also looked at whether certain patient characteristics — such as age, sex, fitness level, other health conditions, body weight, cancer type, or receiving additional drug treatments alongside radiation — were linked to drops in physical activity. None of these factors showed a statistically significant association, but patients who were also receiving systemic treatments (such as chemotherapy or immunotherapy) alongside radiotherapy were more likely to experience a decrease in step counts, with a 37% difference compared to those receiving radiation alone.
Because this was a small pilot study, it was not designed to draw definitive conclusions, but it provides preliminary evidence that radiotherapy itself may not substantially reduce physical activity in lung cancer patients. The findings suggest that future, larger studies should pay particular attention to whether patients are also receiving systemic treatments, as this may be an important factor in understanding and supporting physical activity during cancer treatment.
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Rades D, Streubel M, Doehring L, Lomidze D, But-Hadžić J, Cacicedo J, et al.. (2026). Physical Activity During a Course of Radiotherapy for Lung Cancer - Results of the APART-LUNG Study.. Anticancer research. https://doi.org/10.21873/anticanres.18359